150-555: The Greater Yellowstone Ecosystem (GYE) is one of the last remaining large, nearly intact ecosystems in the northern temperate zone of the Earth . It is located within the northern Rocky Mountains , in areas of northwestern Wyoming , southwestern Montana , and eastern Idaho , and is about 22 million acres (89,000 km). Yellowstone National Park and the Yellowstone Caldera 'hotspot' are within it. The area
300-409: A cell wall . Newly dead animals may be covered by an exoskeleton . Fragmentation processes, which break through these protective layers, accelerate the rate of microbial decomposition. Animals fragment detritus as they hunt for food, as does passage through the gut. Freeze-thaw cycles and cycles of wetting and drying also fragment dead material. The chemical alteration of the dead organic matter
450-495: A food chain . Real systems are much more complex than this—organisms will generally feed on more than one form of food, and may feed at more than one trophic level. Carnivores may capture some prey that is part of a plant-based trophic system and others that are part of a detritus-based trophic system (a bird that feeds both on herbivorous grasshoppers and earthworms, which consume detritus). Real systems, with all these complexities, form food webs rather than food chains which present
600-655: A gull 's call. The calls of young birds tend to be more harsh and shrill than those of adults. The bald eagle's natural range covers most of North America, including most of Canada, all of the continental United States , and northern Mexico. It is the only sea eagle endemic to North America. Occupying varied habitats from the bayous of Louisiana to the Sonoran Desert and the eastern deciduous forests of Quebec and New England , northern birds are migratory , while southern birds are resident, remaining on their breeding territory all year. At minimum population, in
750-619: A habitat . Ecosystem ecology is the "study of the interactions between organisms and their environment as an integrated system". The size of ecosystems can range up to ten orders of magnitude , from the surface layers of rocks to the surface of the planet. The Hubbard Brook Ecosystem Study started in 1963 to study the White Mountains in New Hampshire . It was the first successful attempt to study an entire watershed as an ecosystem. The study used stream chemistry as
900-877: A bald eagle flies close by, waterbirds will often fly away en masse, though they may seemingly ignore a perched eagle in other cases. when the birds fly away from a colony, this exposes their unprotected eggs and nestlings to scavengers such as gulls . While they usually target small to medium-sized seabirds, larger seabirds such as great black-backed gulls ( Larus marinus ) and northern gannets ( Morus bassanus ) and brown pelicans ( Pelecanus occidentalis ) of all ages can successfully be taken by bald eagles. Similarly, large waterbirds are occasionally killed. Geese such as wintering emperor geese ( Chen canagica ) and snow geese ( C. caerulescens ), which gather in large groups, sometimes becoming regular prey. Smaller Ross's geese ( Anser rossii ) are also taken, as well as large-sized Canada geese ( Branta canadensis ). Predation on
1050-546: A bald eagle was observed carrying 6.8 kg (15 lb) mule deer ( Odocoileus hemionus ) fawn. Additionally, Virginia opossums ( Didelphis virginiana ) can be preyed upon. Still, predation events are rare due to their nocturnal habits. Together with the golden eagle, bald eagles are occasionally accused of preying on livestock, especially sheep ( Ovis aries ). There are a handful of proven cases of lamb predation, some specimens weighing up to 11 kg (24 lb), by bald eagles. Still, they are much less likely to attack
1200-466: A body length of 70–102 cm (28–40 in). Typical wingspan is between 1.8 and 2.3 m (5 ft 11 in and 7 ft 7 in) and mass is normally between 3 and 6.3 kg (6.6 and 13.9 lb). Females are about 25% larger than males, averaging as much as 5.6 kg (12 lb), and against the males' average weight of 4.1 kg (9.0 lb). The size of the bird varies by location and generally corresponds with Bergmann's rule :
1350-609: A central role over a wide range, for example, in the slow development of soil from bare rock and the faster recovery of a community from disturbance . Disturbance also plays an important role in ecological processes. F. Stuart Chapin and coauthors define disturbance as "a relatively discrete event in time that removes plant biomass". This can range from herbivore outbreaks, treefalls, fires, hurricanes, floods, glacial advances , to volcanic eruptions . Such disturbances can cause large changes in plant, animal and microbe populations, as well as soil organic matter content. Disturbance
1500-432: A cliff or other terrain. Migration generally takes place during the daytime, usually between the local hours of 8:00 a.m. and 6:00 p.m., when thermals are produced by the sun. The bald eagle is an opportunistic carnivore with the capacity to consume a great variety of prey. Fish often comprise most of the eagle's diet throughout their range. In 20 food habit studies across the species' range, fish comprised 56% of
1650-507: A critical role in global nutrient cycling and ecosystem function. Phosphorus enters ecosystems through weathering . As ecosystems age this supply diminishes, making phosphorus-limitation more common in older landscapes (especially in the tropics). Calcium and sulfur are also produced by weathering, but acid deposition is an important source of sulfur in many ecosystems. Although magnesium and manganese are produced by weathering, exchanges between soil organic matter and living cells account for
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#17327653349311800-517: A faster recovery. More severe and more frequent disturbance result in longer recovery times. From one year to another, ecosystems experience variation in their biotic and abiotic environments. A drought , a colder than usual winter, and a pest outbreak all are short-term variability in environmental conditions. Animal populations vary from year to year, building up during resource-rich periods and crashing as they overshoot their food supply. Longer-term changes also shape ecosystem processes. For example,
1950-454: A form that can be readily used by plants and microbes. Ecosystems provide a variety of goods and services upon which people depend, and may be part of. Ecosystem goods include the "tangible, material products" of ecosystem processes such as water, food, fuel, construction material, and medicinal plants . Ecosystem services , on the other hand, are generally "improvements in the condition or location of things of value". These include things like
2100-427: A function-based typology has been proposed to leverage the strengths of these different approaches into a unified system. Human activities are important in almost all ecosystems. Although humans exist and operate within ecosystems, their cumulative effects are large enough to influence external factors like climate. Ecosystems provide a variety of goods and services upon which people depend. Ecosystem goods include
2250-698: A general level, for example, tropical forests , temperate grasslands , and arctic tundra . There can be any degree of subcategories among ecosystem types that comprise a biome, e.g., needle-leafed boreal forests or wet tropical forests. Although ecosystems are most commonly categorized by their structure and geography, there are also other ways to categorize and classify ecosystems such as by their level of human impact (see anthropogenic biome ), or by their integration with social processes or technological processes or their novelty (e.g. novel ecosystem ). Each of these taxonomies of ecosystems tends to emphasize different structural or functional properties. None of these
2400-404: A good long-term data set on the species, but they understand its ecology well enough to project declining future conservation status . A more immediate and serious threat to whitebark pines is an introduced fungal rust disease, White Pine Blister Rust ( Cronartium ribicola ), which is causing heavy mortality in the species. Occasional resistant individuals occur, but in the short to medium term,
2550-430: A healthy lamb than a golden eagle. Both species prefer native, wild prey and are unlikely to cause any extensive detriment to human livelihoods. There is one case of a bald eagle killing and feeding on an adult, pregnant ewe (then joined in eating the kill by at least 3 other eagles), which, weighing on average over 60 kg (130 lb), is much larger than any other known prey taken by this species. Supplemental prey
2700-531: A lack of human disturbance, spend their time in various upland, terrestrial habitats sometimes quite far away from waterways. In the northern half of North America (especially the interior portion), this terrestrial inhabitance by bald eagles tends to be especially prevalent because unfrozen water may not be accessible. Upland wintering habitats often consist of open habitats with concentrations of medium-sized mammals, such as prairies , meadows or tundra , or open forests with regular carrion access. The bald eagle
2850-455: A larger beak , straighter edged wings which are held flat (not slightly raised) and with a stiffer wing beat and feathers which do not completely cover the legs. When seen well, the golden eagle is distinctive in plumage with a more solid warm brown color than an immature bald eagle, with a reddish-golden patch to its nape and (in immature birds) a highly contrasting set of white squares on the wing. The bald eagle has sometimes been considered
3000-806: A lot of food. On Protection Island , Washington , they commonly feed on harbor seal ( Phoca vitulina ) afterbirths, still-borns and sickly seal pups. Similarly, bald eagles in Alaska readily prey on sea otter ( Enhydra lutris ) pups. Small to medium-sized terrestrial mammalian carnivores can be taken infrequently. Mustelid including American martens ( Martes pennanti ), American minks ( Neogale vison ), and larger fisher cats ( Pekania pennanti ) are known to be hunted. Foxes are also taken, including Island foxes ( Urocyon littoralis ), Arctic foxes ( Vulpes lagopus ), and grey foxes ( Urocyon cinereoargenteus ). Although fox farmers claimed that bald eagle heavily prey on young and adult free-range Arctic fox,
3150-672: A means of monitoring ecosystem properties, and developed a detailed biogeochemical model of the ecosystem. Long-term research at the site led to the discovery of acid rain in North America in 1972. Researchers documented the depletion of soil cations (especially calcium) over the next several decades. Ecosystems can be studied through a variety of approaches—theoretical studies, studies monitoring specific ecosystems over long periods of time, those that look at differences between ecosystems to elucidate how they work and direct manipulative experimentation. Studies can be carried out at
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#17327653349313300-528: A more important role in moving nutrients around. This can be especially important as the soil thaws in the spring, creating a pulse of nutrients that become available. Decomposition rates are low under very wet or very dry conditions. Decomposition rates are highest in wet, moist conditions with adequate levels of oxygen. Wet soils tend to become deficient in oxygen (this is especially true in wetlands ), which slows microbial growth. In dry soils, decomposition slows as well, but bacteria continue to grow (albeit at
3450-406: A number of common, non random properties in the topology of their network. The carbon and nutrients in dead organic matter are broken down by a group of processes known as decomposition. This releases nutrients that can then be re-used for plant and microbial production and returns carbon dioxide to the atmosphere (or water) where it can be used for photosynthesis. In the absence of decomposition,
3600-491: A population may be considered long-term by some, one of the important lessons of Greater Yellowstone management is that even half a century is not long enough to give a full idea of how a species may vary in its occupation of a wild ecosystem. The Yellowstone hot springs are important for their diversity of thermophilic bacteria. These bacteria have been useful in studies of the evolution of photosynthesis and as sources of thermostable enzymes for molecular biology . Although
3750-400: A preference for bodies of water with a circumference greater than 11 km (7 mi), and lakes with an area greater than 10 km (4 sq mi) are optimal for breeding bald eagles. The bald eagle typically requires old-growth and mature stands of coniferous or hardwood trees for perching, roosting, and nesting. Tree species reportedly is less important to the eagle pair than
3900-421: A process known as denitrification . Mycorrhizal fungi which are symbiotic with plant roots, use carbohydrates supplied by the plants and in return transfer phosphorus and nitrogen compounds back to the plant roots. This is an important pathway of organic nitrogen transfer from dead organic matter to plants. This mechanism may contribute to more than 70 Tg of annually assimilated plant nitrogen, thereby playing
4050-493: A record from 1876 in Wyoming County, New York of an enormous adult bald eagle that was shot and reportedly scaled 8.2 kg (18 lb). Among standard linear measurements, the wing chord is 51.5–69 cm (20.3–27.2 in), the tail is 23–37 cm (9.1–14.6 in) long, and the tarsus is 8 to 11 cm (3.1 to 4.3 in). The culmen reportedly ranges from 3 to 7.5 cm (1.2 to 3.0 in), while
4200-406: A severe population decline is expected. Estimates of the decline of quaking aspen ( Populus tremuloides ) on the park's northern range since 1872 range from 50% to 95%. The decline has been linked to multiple stressors, such as defoliation by the forest tent caterpillar ( Malacosoma disstria ), aspen bark beetles ( Trypophloeus populi and Procryphalus mucronatus ), wood-boring beetles such as
4350-588: A significant area of petrified trees; the northeast corner was defined by the watershed of Pebble Creek; the eastern boundary included the headwaters of the Lamar River and part of the watershed of the Yellowstone River. In 1932, President Hoover issued an executive order that added more than 7,000 acres (2,800 ha) between the north boundary and the Yellowstone River, west of Gardiner. These lands provided winter range for elk and other ungulates. By
4500-696: A significant portion of ecosystem fluxes. Potassium is primarily cycled between living cells and soil organic matter. Biodiversity plays an important role in ecosystem functioning. Ecosystem processes are driven by the species in an ecosystem, the nature of the individual species, and the relative abundance of organisms among these species. Ecosystem processes are the net effect of the actions of individual organisms as they interact with their environment. Ecological theory suggests that in order to coexist, species must have some level of limiting similarity —they must be different from one another in some fundamental way, otherwise, one species would competitively exclude
4650-408: A single bald eagle successfully displaced two consecutive golden eagles from a kill. Though bald eagles face few natural threats, an unusual attacker comes in the form of the common loon ( G. immer ), which is also taken by eagles as prey. While common loons normally avoid conflict, they are highly territorial and will attack predators and competitors by stabbing at them with their knife-like bill; as
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4800-408: A slower rate) even after soils become too dry to support plant growth. Ecosystems are dynamic entities. They are subject to periodic disturbances and are always in the process of recovering from past disturbances. When a perturbation occurs, an ecosystem responds by moving away from its initial state. The tendency of an ecosystem to remain close to its equilibrium state, despite that disturbance,
4950-464: A small effect on ecosystem function. Ecologically distinct species, on the other hand, have a much larger effect. Similarly, dominant species have a large effect on ecosystem function, while rare species tend to have a small effect. Keystone species tend to have an effect on ecosystem function that is disproportionate to their abundance in an ecosystem. An ecosystem engineer is any organism that creates, significantly modifies, maintains or destroys
5100-526: A system to absorb disturbance and reorganize while undergoing change so as to retain essentially the same function, structure, identity, and feedbacks is termed its ecological resilience . Ecosystems can be studied through a variety of approaches—theoretical studies, studies monitoring specific ecosystems over long periods of time, those that look at differences between ecosystems to elucidate how they work and direct manipulative experimentation. Biomes are general classes or categories of ecosystems. However, there
5250-522: A variety of scales, ranging from whole-ecosystem studies to studying microcosms or mesocosms (simplified representations of ecosystems). American ecologist Stephen R. Carpenter has argued that microcosm experiments can be "irrelevant and diversionary" if they are not carried out in conjunction with field studies done at the ecosystem scale. In such cases, microcosm experiments may fail to accurately predict ecosystem-level dynamics. Biomes are general classes or categories of ecosystems. However, there
5400-598: Is a bird of prey found in North America . A sea eagle , it has two known subspecies and forms a species pair with the white-tailed eagle ( Haliaeetus albicilla ), which occupies the same niche as the bald eagle in the Palearctic . Its range includes most of Canada and Alaska , all of the contiguous United States , and northern Mexico . It is found near large bodies of open water with an abundant food supply and old-growth trees for nesting. The bald eagle
5550-412: Is a flagship site among conservation groups that promote ecosystem management . The Greater Yellowstone Ecosystem (GYE) is one of the world's foremost natural laboratories in landscape ecology and Holocene geology , and is a world-renowned recreational destination. It is also home to the diverse native plants and animals of Yellowstone . Yellowstone National Park boundaries were drawn in 1872 with
5700-449: Is a powerful flier, and soars on thermal convection currents. It reaches speeds of 56–70 km/h (35–43 mph) when gliding and flapping, and about 48 km/h (30 mph) while carrying fish. Its dive speed is between 120–160 km/h (75–99 mph), though it seldom dives vertically. Regarding their flying abilities, despite being morphologically less well adapted to faster flight than golden eagles (especially during dives),
5850-493: Is able to carry it away successfully. They obtain much of their food as carrion or via a practice known as kleptoparasitism , by which they steal prey away from other predators. Due to their dietary habits, bald eagles are frequently viewed in a negative light by humans. Thanks to their superior foraging ability and experience, adults are generally more likely to hunt live prey than immature eagles, which often obtain their food from scavenging. They are not very selective about
6000-458: Is an international synthesis by over 1000 of the world's leading biological scientists that analyzes the state of the Earth's ecosystems and provides summaries and guidelines for decision-makers. The report identified four major categories of ecosystem services: provisioning, regulating, cultural and supporting services. It concludes that human activity is having a significant and escalating impact on
6150-455: Is an opportunistic feeder which subsists mainly on fish , which it swoops down upon and snatches from the water with its talons. It builds the largest nest of any North American bird and the largest tree nests ever recorded for any animal species, up to 4 m (13 ft) deep, 2.5 m (8.2 ft) wide, and 1 metric ton (1.1 short tons) in weight. Sexual maturity is attained at the age of four to five years. Bald eagles are not bald ;
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6300-442: Is consumed by animals while still alive and enters the plant-based trophic system. After plants and animals die, the organic matter contained in them enters the detritus-based trophic system. Ecosystem respiration is the sum of respiration by all living organisms (plants, animals, and decomposers) in the ecosystem. Net ecosystem production is the difference between gross primary production (GPP) and ecosystem respiration. In
6450-423: Is controlled by internal factors. Therefore, internal factors not only control ecosystem processes but are also controlled by them. Ecosystems are dynamic entities—they are subject to periodic disturbances and are always in the process of recovering from some past disturbance. The tendency of an ecosystem to remain close to its equilibrium state, despite that disturbance, is termed its resistance . The capacity of
6600-569: Is followed by succession, a "directional change in ecosystem structure and functioning resulting from biotically driven changes in resource supply." The frequency and severity of disturbance determine the way it affects ecosystem function. A major disturbance like a volcanic eruption or glacial advance and retreat leave behind soils that lack plants, animals or organic matter. Ecosystems that experience such disturbances undergo primary succession . A less severe disturbance like forest fires, hurricanes or cultivation result in secondary succession and
6750-554: Is governed by three sets of factors—the physical environment (temperature, moisture, and soil properties), the quantity and quality of the dead material available to decomposers, and the nature of the microbial community itself. Temperature controls the rate of microbial respiration; the higher the temperature, the faster the microbial decomposition occurs. Temperature also affects soil moisture, which affects decomposition. Freeze-thaw cycles also affect decomposition—freezing temperatures kill soil microorganisms, which allows leaching to play
6900-605: Is habitual mainly in Alaska) and fish-processing plants. In Southeast Alaska , fish comprise approximately 66% of the year-round diet of bald eagles and 78% of the prey brought to the nest by the parents. Eagles living in the Columbia River Estuary in Oregon were found to rely on fish for 90% of their dietary intake. At least 100 species of fish have been recorded in the bald eagle's diet. From observation in
7050-409: Is held immobile by the front toes. The beak is large and hooked, with a yellow cere . The adult bald eagle is unmistakable in its native range. The closely related African fish eagle ( Haliaeetus vocifer ) (from far outside the bald eagle's range) also has a brown body (albeit of somewhat more rufous hue), white head and tail, but differs from the bald eagle in having a white chest and black tip to
7200-778: Is home to a variety of birds, including iconic species like Bald Eagles , Golden Eagles and Peregrine Falcons . Osprey populations around Yellowstone Lake , have experienced declines, linked to the decrease in Cutthroat Trout. Several bird species act as keystone species within the GYE. For example, the Clark's Nutcracker plays a crucial role in the dispersal of the all-important Whitebark Pine seeds. Ecological management has been most often advanced through concerns over individual species rather than over broader ecological principles. Though 20 or 30 or even 50 years of information on
7350-409: Is merely 455 g (1.003 lb) lighter in mean body mass and exceeds the bald eagle in mean wing chord length by around 3 cm (1.2 in). Additionally, the bald eagle's close cousins, the relatively longer-winged but shorter-tailed white-tailed eagle and the overall larger Steller's sea eagle ( Haliaeetus pelagicus ), may, rarely, wander to coastal Alaska from Asia. The bald eagle has
7500-418: Is moderately long and slightly wedge-shaped. Males and females are identical in plumage coloration, but sexual dimorphism is evident in the species, in that females are 25% larger than males. The beak, feet and irises are bright yellow. The legs are feather-free, and the toes are short and powerful with large talons. The highly developed talon of the hind toe is used to pierce the vital areas of prey while it
7650-405: Is no clear distinction between biomes and ecosystems. Biomes are always defined at a very general level. Ecosystems can be described at levels that range from very general (in which case the names are sometimes the same as those of biomes) to very specific, such as "wet coastal needle-leafed forests". Biomes vary due to global variations in climate . Biomes are often defined by their structure: at
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#17327653349317800-516: Is no clear distinction between biomes and ecosystems. Ecosystem classifications are specific kinds of ecological classifications that consider all four elements of the definition of ecosystems : a biotic component, an abiotic complex, the interactions between and within them, and the physical space they occupy. Biotic factors of the ecosystem are living things; such as plants, animals, and bacteria, while abiotic are non-living components; such as water, soil and atmosphere. Plants allow energy to enter
7950-504: Is now generally thought that golden eagles eat more carrion than was previously assumed). However, the two species are roughly equal in size, aggressiveness and physical strength and so competitions can go either way. Neither species is known to be dominant, and the outcome depends on the size and disposition of the individual eagles involved. Wintering bald and golden eagles in Utah both sometimes won conflicts, though in one recorded instance
8100-531: Is primarily achieved through bacterial and fungal action. Fungal hyphae produce enzymes that can break through the tough outer structures surrounding dead plant material. They also produce enzymes that break down lignin , which allows them access to both cell contents and the nitrogen in the lignin. Fungi can transfer carbon and nitrogen through their hyphal networks and thus, unlike bacteria, are not dependent solely on locally available resources. Decomposition rates vary among ecosystems. The rate of decomposition
8250-685: Is readily taken given the opportunity. In some areas, reptiles may become regular prey, especially in warm areas such as Florida where reptile diversity is high. Turtles are perhaps the most regularly hunted type of reptile. In coastal New Jersey , 14 of 20 studied eagle nests included remains of turtles. The main species found were common musk turtles ( Sternotherus odoratus ), diamondback terrapin ( Malaclemys terrapin ) and juvenile common snapping turtles ( Chelydra serpentina ). In these New Jersey nests, mainly subadult and small adults were taken, ranging in carapace length from 9.2 to 17.1 cm (3.6 to 6.7 in). Similarly, many turtles were recorded in
8400-413: Is relatively easy for the much larger eagles to catch and fly with. American herring gull ( Larus smithsonianus ) are the favored avian prey species for eagles living around Lake Superior . Black ducks ( Anas rubripes ), common eiders ( Somateria mollissima ), and double-crested cormorants ( Phalacrocorax auritus ) are also frequently taken in coastal Maine and velvet scoter ( Melanitta fusca )
8550-485: Is termed its resistance . The capacity of a system to absorb disturbance and reorganize while undergoing change so as to retain essentially the same function, structure, identity, and feedbacks is termed its ecological resilience . Resilience thinking also includes humanity as an integral part of the biosphere where we are dependent on ecosystem services for our survival and must build and maintain their natural capacities to withstand shocks and disturbances. Time plays
8700-422: Is the "best" classification. Ecosystem classifications are specific kinds of ecological classifications that consider all four elements of the definition of ecosystems : a biotic component, an abiotic complex, the interactions between and within them, and the physical space they occupy. Different approaches to ecological classifications have been developed in terrestrial, freshwater and marine disciplines, and
8850-598: The Greater Yellowstone area average 27 m (89 ft) high. Trees or forest used for nesting should have a canopy cover of no more than 60%, and no less than 20%, and be in close proximity to water. Most nests have been found within 200 m (660 ft) of open water. The greatest distance from open water recorded for a bald eagle nest was over 3 km (1.9 mi), in Florida. Bald eagle nests are often very large in order to compensate for size of
9000-624: The United States House of Representatives Subcommittees on Public Lands and National Parks and Recreation held a joint subcommittee hearing on Greater Yellowstone, resulting in a 1986 report by the Congressional Research Service outlining shortcomings in inter-agency coordination and concluding that the area's essential values were at risk. Federally managed areas within the GYE include: Ten distinct National Wilderness Areas have been established within
9150-939: The Willamette River in Portland , Oregon or John Heinz National Wildlife Refuge at Tinicum in Philadelphia , Pennsylvania, which are surrounded by a great quantity of human activity. Even more contrary to the usual sensitivity to disturbance, a family of bald eagles moved to the Harlem neighborhood in New York City in 2010. While wintering, bald eagles tend to be less habitat and disturbance sensitive. They will commonly congregate at spots with plentiful perches and waters with plentiful prey and (in northern climes) partially unfrozen waters. Alternately, non-breeding or wintering bald eagles, particularly in areas with
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#17327653349319300-528: The brown bullhead ( Ameiurus nebulosus ) and any species in the genus Ictalurus as well as mullet , trout , needlefish , and eels . Chain pickerels ( Esox niger ) and white suckers ( Catostomus commersonii ) are frequently taken in interior Maine . Wintering eagles on the Platte River in Nebraska preyed mainly on American gizzard shads and common carp. Bald eagles are also known to eat
9450-468: The poplar borer ( Saperda calcarata ) and the bronze poplar borer ( Agrilus liragus ), fungal disturbances such as those by the Cytospora canker ( Valsa sordida ), and Climate change related stressors. Anecdotal information on grizzly bear abundance dates to the mid-19th century, and administrators have made informal population estimates for more than 70 years. From these sources, ecologists know
9600-555: The resource inputs are generally controlled by external processes like climate and parent material, the availability of these resources within the ecosystem is controlled by internal factors like decomposition, root competition or shading. Other factors like disturbance, succession or the types of species present are also internal factors. Primary production is the production of organic matter from inorganic carbon sources. This mainly occurs through photosynthesis . The energy incorporated through this process supports life on earth, while
9750-520: The salmon spawning in the area. Similar congregations of wintering bald eagles at open lakes and rivers, wherein fish are readily available for hunting or scavenging, are observed in the northern United States. It has occurred as a vagrant twice in Ireland; a juvenile was shot illegally in Fermanagh on January 11, 1973 (misidentified at first as a white-tailed eagle ), and an exhausted juvenile
9900-435: The "tangible, material products" of ecosystem processes such as water, food, fuel, construction material, and medicinal plants . They also include less tangible items like tourism and recreation, and genes from wild plants and animals that can be used to improve domestic species. Ecosystem services , on the other hand, are generally "improvements in the condition or location of things of value". These include things like
10050-698: The 1950s, it was largely restricted to Alaska , the Aleutian Islands , northern and eastern Canada, and Florida. From 1966 to 2015 bald eagle numbers increased substantially throughout its winter and breeding ranges, and as of 2018 the species nests in every continental state and province in the United States and Canada. The majority of bald eagles in Canada are found along the British Columbia coast while large populations are found in
10200-499: The 1970s, the grizzly bear 's ( Ursus arctos ) range in and near the park became the first informal minimum boundary of a theoretical "Greater Yellowstone Ecosystem" that included at least 4,000,000 acres (16,000 km). Since then, definitions of the greater ecosystem's size have steadily grown larger. A 1994 study listed the size as 19,000,000 acres (76,890 km), while a 1994 speech by a Greater Yellowstone Coalition leader enlarged that to 20,000,000 acres (80,000 km). In 1985
10350-473: The Chinook salmon's large size (12 to 18 kg (26 to 40 lb) average adult size) probably being taken only as carrion and a single carcass can attract several eagles. Also important in the estuaries and shallow coastlines of southern Alaska are Pacific herring ( Clupea pallasii ), Pacific sand lance ( Ammodytes hexapterus ) and eulachon ( Thaleichthys pacificus ). In Oregon's Columbia River Estuary,
10500-721: The Columbia River, 58% of the fish were caught alive by the eagle, 24% were scavenged as carcasses and 18% were pirated away from other animals. In the Pacific Northwest , spawning trout and salmon provide most of the bald eagles' diet from late summer throughout fall. Though bald eagles occasionally catch live salmon, they usually scavenge spawned salmon carcass. Southeast Alaskan eagles largely prey on pink salmon ( Oncorhynchus gorbuscha ), coho salmon ( O. kisutch ) and, more locally, sockeye salmon ( O. nerka ), with Chinook salmon ( O. tshawytscha ). Due to
10650-673: The English name is from an older usage meaning "having white on the face or head" rather than "hairless", referring to the white head feathers contrasting with the darker body. The genus name is Neo-Latin : Haliaeetus (from the Ancient Greek : ἁλιάετος , romanized : haliaetos , lit. 'sea eagle'), and the specific name, leucocephalus , is Latinized ( Ancient Greek : λευκός , romanized : leukos , lit. 'white') and ( κεφαλή , kephalḗ , 'head'). The bald eagle
10800-592: The GYE's National Forests since 1966, mandating a higher level of habitat protection than the USFS otherwise uses. The GYE also encompasses some privately held and state lands surrounding those managed by the U.S. Government. The Trust for Public Land has protected 67,000 acres (27,000 ha) over about 40 projects in the Greater Yellowstone Ecosystem. The GYE is home to some of North America's most iconic wildlife. The ecosystem supports
10950-481: The absence of disturbance, net ecosystem production is equivalent to the net carbon accumulation in the ecosystem. Energy can also be released from an ecosystem through disturbances such as wildfire or transferred to other ecosystems (e.g., from a forest to a stream to a lake) by erosion . In aquatic systems , the proportion of plant biomass that gets consumed by herbivores is much higher than in terrestrial systems. In trophic systems, photosynthetic organisms are
11100-402: The amount of energy available to the ecosystem. Parent material determines the nature of the soil in an ecosystem, and influences the supply of mineral nutrients. Topography also controls ecosystem processes by affecting things like microclimate , soil development and the movement of water through a system. For example, ecosystems can be quite different if situated in a small depression on
11250-504: The amount of light available, the amount of leaf area a plant has to capture light (shading by other plants is a major limitation of photosynthesis), the rate at which carbon dioxide can be supplied to the chloroplasts to support photosynthesis, the availability of water, and the availability of suitable temperatures for carrying out photosynthesis. Energy and carbon enter ecosystems through photosynthesis, are incorporated into living tissue, transferred to other organisms that feed on
11400-454: The bald eagle is considered surprisingly maneuverable in flight. Bald eagles have also been recorded catching up to and then swooping under geese in flight, turning over and thrusting their talons into the other bird's breast. It is partially migratory, depending on location. If its territory has access to open water, it remains there year-round, but if the body of water freezes during the winter, making it impossible to obtain food, it migrates to
11550-405: The bill. The plumage of the immature is a dark brown overlaid with messy white streaking until the fifth (rarely fourth, very rarely third) year, when it reaches sexual maturity. Immature bald eagles are distinguishable from the golden eagle ( Aquila chrysaetos ), the only other very large, non-vulturine raptorial bird in North America, in that the former has a larger, more protruding head with
11700-572: The biodiversity of the world ecosystems, reducing both their resilience and biocapacity . The report refers to natural systems as humanity's "life-support system", providing essential ecosystem services. The assessment measures 24 ecosystem services and concludes that only four have shown improvement over the last 50 years, 15 are in serious decline, and five are in a precarious condition. Bald eagle Falco pygargus Daudin, 1800 (nec Linnaeus) Falco ossifragus Shaw, 1809 (nec Linnaeus) The bald eagle ( Haliaeetus leucocephalus )
11850-523: The birds. The largest recorded nest was found in Florida in 1963, and was measured at nearly 10 feet wide and 20 feet deep. In Florida, nesting habitats often consist of Mangrove swamps, the shorelines of lakes and rivers, pinelands , seasonally flooded flatwoods , hardwood swamps , and open prairies and pastureland with scattered tall trees. Favored nesting trees in Florida are slash pines ( Pinus elliottii ), longleaf pines ( P. palustris ), loblolly pines ( P. taeda ) and cypress trees , but for
12000-709: The breeding season around Lake Britton in California, fish measuring 34 to 38 cm (13 to 15 in) were taken 71.8% of the time by parent eagles while fish measuring 23 to 27.5 cm (9.1 to 10.8 in) were chosen only 25% of the time. At nests around Lake Superior , the remains of fish (mostly suckers ) were found to average 35.4 cm (13.9 in) in total length. In the Columbia River estuary, most preyed on by eagles were estimated to measure less than 30 cm (12 in), but larger fish between 30 and 60 cm (12 and 24 in) or even exceeding 60 cm (24 in) in length also taken especially during
12150-408: The carbon makes up much of the organic matter in living and dead biomass, soil carbon and fossil fuels . It also drives the carbon cycle , which influences global climate via the greenhouse effect . Through the process of photosynthesis, plants capture energy from light and use it to combine carbon dioxide and water to produce carbohydrates and oxygen . The photosynthesis carried out by all
12300-432: The combustion of fossil fuels, ammonia gas which evaporates from agricultural fields which have had fertilizers applied to them, and dust. Anthropogenic nitrogen inputs account for about 80% of all nitrogen fluxes in ecosystems. When plant tissues are shed or are eaten, the nitrogen in those tissues becomes available to animals and microbes. Microbial decomposition releases nitrogen compounds from dead organic matter in
12450-418: The concept to draw attention to the importance of transfers of materials between organisms and their environment. He later refined the term, describing it as "The whole system, ... including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment". Tansley regarded ecosystems not simply as natural units, but as "mental isolates". Tansley later defined
12600-602: The condition or origin, whether provided by humans, other animals, auto accidents or natural causes, of a carcass's presence, but will avoid eating carrion where disturbances from humans are a regular occurrence. They will scavenge carcasses up to the size of whales, though carcasses of ungulates and large fish are seemingly preferred. Congregated wintering waterfowl are frequently exploited for carcasses to scavenge by immature eagles in harsh winter weather. Bald eagles also may sometimes feed on material scavenged or stolen from campsites and picnics, as well as garbage dumps (dump usage
12750-1926: The consumption of the dead victims. Nine species of other accipitrids and owls are known to have been preyed upon by bald eagles. Owl prey species have ranged in size from western screech-owls ( Megascops kennicotti ) to snowy owls ( Bubo scandiacus ). Larger diurnal raptors known to have fallen victim to bald eagles have included red-tailed hawks ( Buteo jamaicensis ), peregrine falcons ( Falco peregrinus ), northern goshawks ( Accipiter gentilis ), ospreys ( Pandion haliaetus ) and black ( Coragyps atratus ) and turkey vultures ( Cathartes aura ). Mammalian preys are generally less frequently taken than fish or avian prey. However, in some regions, such as landlocked areas of North America, wintering bald eagles may become habitual predators of medium-sized mammals that occur in colonies or local concentrations, such as prairie dogs ( Cynomys sp.) and jackrabbits ( Lepus sp.). Bald eagles in Seedskadee National Wildlife Refuge often hunt in pair to catch cottontails, jackrabbits and prairie dogs. They can attack and prey on rabbits and hares of nearly any size, from marsh rabbits ( Sylvilagus palustris ) to black and white-tailed jackrabbits ( Lepus californicus & L. townsendii ), and Arctic hares ( Lepus arcticus ). In San Luis Valley , white-tailed jackrabbits can be important prey. Additionally, rodents such as montane voles ( Microtus montanus ), brown rats ( Rattus norvegicus ), and various squirrels are taken as supplementary prey. Larger rodents such as muskrats ( Ondatra zibethicus ), young or small adult nutrias ( Myocastor coypus ) and groundhogs ( Marmota monax ) are also preyed upon. Even American porcupines ( Erethizon dorsatum ) are reportedly attacked and killed. Where available, seal colonies can provide
12900-403: The dead organic matter would accumulate in an ecosystem, and nutrients and atmospheric carbon dioxide would be depleted. Decomposition processes can be separated into three categories— leaching , fragmentation and chemical alteration of dead material. As water moves through dead organic matter, it dissolves and carries with it the water-soluble components. These are then taken up by organisms in
13050-1439: The diet in the Chesapeake Bay . In Texas , softshell turtles are the most frequently taken prey, and a large number of Barbour's map turtles are taken in Torreya State Park . Other reptilian and amphibian prey includes southern alligator lizards ( Elgaria multicarinata ), snakes such as garter snakes and rattlesnakes , and Greater siren ( Siren lacertina ). Invertebrates are occasionally taken. In Alaska , eagles feed on sea urchins ( Strongylocentrotus sp.), chitons, mussels, and crabs. Other various mollusks such as land snails , abalones , bivalves , periwinkles , blue mussels , squids , and starfishes are taken as well. When competing for food, eagles will usually dominate other fish-eaters and scavengers, aggressively displacing mammals such as coyotes ( Canis latrans ) and foxes, and birds such as corvids , gulls , vultures and other raptors . Occasionally, coyotes, bobcats ( Lynx rufus ) and domestic dogs ( Canis familiaris ) can displace eagles from carrion, usually less confident immature birds, as has been recorded in Maine. Bald eagles are less active, bold predators than golden eagles and get relatively more of their food as carrion and from kleptoparasitism (although it
13200-528: The diet of nesting eagles, birds 28%, mammals 14% and other prey 2%. More than 400 species are known to be included in the bald eagle's prey spectrum, far more than its ecological equivalent in the Old World, the white-tailed eagle , is known to take. Despite its considerably lower population, the bald eagle may come in second amongst all North American accipitrids, slightly behind only the red-tailed hawk , in number of prey species recorded. To hunt fish,
13350-447: The eagle swoops down over the water and snatches the fish out of the water with its talons . They eat by holding the fish in one claw and tearing the flesh with the other. Eagles have structures on their toes called spicules that allow them to grasp fish. Osprey also have this adaptation. Bird prey may occasionally be attacked in flight, with prey up to the size of Canada geese attacked and killed in mid-air. It has been estimated that
13500-545: The eagle's diet is variable, depending on the quantity and availability of fish near the water's surface. Waterbirds can seasonally comprise from 7% to 80% of the prey selection for eagles in certain localities. Overall, birds are the most diverse group in the bald eagle's prey spectrum, with 200 prey species recorded. Bird species most preferred as prey by eagles tend to be medium-sized, such as western grebes ( Aechmophorus occidentalis ), mallards ( Anas platyrhynchos ), and American coots ( Fulica americana ) as such prey
13650-823: The eastern Appalachian Mountains without apparent conflict. Bald eagles are frequently mobbed by smaller raptors, due to their infrequent but unpredictable tendency to hunt other birds of prey. Many bald eagles are habitual kleptoparasites, especially in winters when fish are harder to come by. They have been recorded stealing fish from other predators such as ospreys , herons and even otters . They have also been recorded opportunistically pirating birds from peregrine falcons ( Falco peregrinus ), prairie dogs from ferruginous hawks ( Buteo regalis ) and even jackrabbits from golden eagles . When they approach scavengers such as dogs, gulls or vultures at carrion sites, they often attack them in an attempt to force them to disgorge their food. Healthy adult bald eagles are not preyed upon in
13800-655: The ecosystem or to gradual disruption of biotic processes and degradation of abiotic conditions of the ecosystem. Once the original ecosystem has lost its defining features, it is considered "collapsed ". Ecosystem restoration can contribute to achieving the Sustainable Development Goals . An ecosystem (or ecological system) consists of all the organisms and the abiotic pools (or physical environment) with which they interact. The biotic and abiotic components are linked together through nutrient cycles and energy flows. "Ecosystem processes" are
13950-829: The ecosystem. Although the Greater Yellowstone population is relatively close to recovery goals, the plan's definition of recovery is controversial. Thus, even though the population may be stable or possibly increasing in the short term, in the longer term, continued habitat loss , climate change, and increasing human activities may well reverse the trend. Yellowstone cutthroat trout ( Oncorhynchus clarki bouvieri ) have suffered considerable declines since European settlement, but recently began flourishing in some areas. Especially in Yellowstone Lake itself, long-term records indicate an almost remarkable restoration of robust populations from only three decades ago when
14100-695: The effects on prey species, the gray wolf's presence also affected the park's grizzly bear population. The bears, emerging from hibernation, chose to scavenge off wolf kills to gain needed energy and fatten up after fasting for months. Dozens of other species have been documented scavenging from wolf kills. Ecosystem An ecosystem (or ecological system ) is a system that environments and their organisms form through their interaction. The biotic and abiotic components are linked together through nutrient cycles and energy flows. Ecosystems are controlled by external and internal factors . External factors such as climate , parent material which forms
14250-519: The fish (possibly due to overfishing) and otters (cause unknown) have had steep population declines, causing concern for seabird conservation. Because of this more extensive predation, some biologist has expressed concern that murres are heading for a "conservation collision" due to heavy eagle predation. Eagles have been confirmed to attack nocturnally active, burrow-nesting seabird species such as storm petrels and shearwaters by digging out their burrows and feeding on all animals they find inside. If
14400-421: The flow of energy through a lake was the primary driver of the ecosystem. Hutchinson's students, brothers Howard T. Odum and Eugene P. Odum , further developed a "systems approach" to the study of ecosystems. This allowed them to study the flow of energy and material through ecological systems. Ecosystems are controlled by both external and internal factors. External factors, also called state factors, control
14550-709: The following fish species: rainbow trout ( Oncorhynchus mykiss ), white catfish ( Ameiurus catus ), rock greenling ( Hexagrammos lagocephalus ), Pacific cod ( Gadus macrocephalus ), Atka mackerel ( Pleurogrammus monopterygius ), largemouth bass ( Micropterus salmoides ), northern pike ( Esox lucius ), striped bass ( Morone saxatilis ), dogfish shark ( Squalidae.sp ) and Blue walleye ( Sander vitreus ). Fish taken by bald eagles varies in size, but bald eagles take larger fish than other piscivorous birds in North America, typically range from 20 to 75 cm (7.9 to 29.5 in) and prefer 36 cm (14 in) fish. When experimenters offered fish of different sizes in
14700-546: The forests of Alberta , Saskatchewan, Manitoba and Ontario . Bald eagles also congregate in certain locations in winter. From November until February, one to two thousand birds winter in Squamish, British Columbia , about halfway between Vancouver and Whistler . In March 2024, bald eagles were found nesting in Toronto for the first time. The birds primarily gather along the Squamish and Cheakamus Rivers, attracted by
14850-458: The forests of eastern North America still show legacies of cultivation which ceased in 1850 when large areas were reverted to forests. Another example is the methane production in eastern Siberian lakes that is controlled by organic matter which accumulated during the Pleistocene . Ecosystems continually exchange energy and carbon with the wider environment . Mineral nutrients, on
15000-705: The golden eagle, with the bald species estimated to number at least 150,000 individuals, about twice as many golden eagles there are estimated to live in North America. Due to this, bald eagles often outnumber golden eagles at attractive food sources. Despite the potential for contention between these animals, in New Jersey during winter, a golden eagle and numerous bald eagles were observed to hunt snow geese alongside each other without conflict. Similarly, both eagle species have been recorded, via video-monitoring, to feed on gut piles and carcasses of white-tailed deer ( Odocoileus virginianus ) in remote forest clearings in
15150-727: The gripping power (pounds by square inch) of the bald eagle is ten times greater than that of a human. Bald eagles can fly with fish at least equal to their own weight, but if the fish is too heavy to lift, the eagle may be dragged into the water. Bald eagles are able to swim, in some cases dragging its catch ashore with its talons, but some eagles drown or succumb to hypothermia . Many sources claim that bald eagles, like all large eagles, cannot normally take flight carrying prey more than half of their own weight unless aided by favorable wind conditions. On numerous occasions, when large prey such as large fish including mature salmon or geese are attacked, eagles have been seen to make contact and then drag
15300-407: The ground. In a more typical tree standing on dry ground, nests may be located from 16 to 38 m (52 to 125 ft) in height. In Chesapeake Bay , nesting trees averaged 82 cm (32 in) in diameter and 28 m (92 ft) in total height, while in Florida, the average nesting tree stands 23 m (75 ft) high and is 23 cm (9.1 in) in diameter. Trees used for nesting in
15450-481: The intent to include all the known geothermal basins in the region . As landscape ecology considerations were not incorporated into original boundary, revisions were suggested to conform more closely to natural topographic features, such as the ridgeline of the Absaroka Range along the east boundary. In 1929, President Hoover signed the first bill changing the park's boundaries: The northwest corner now included
15600-558: The kills secondarily. Once North Pacific salmon die off after spawning, usually local bald eagles eat salmon carcasses almost exclusively. Eagles in Washington need to consume 489 g (1.078 lb) of fish each day for survival, with adults generally consuming more than juveniles and thus reducing potential energy deficiency and increasing survival during winter. Behind fish, the next most significant prey base for bald eagles are other waterbirds . The contribution of such birds to
15750-691: The landscape, versus one present on an adjacent steep hillside. Other external factors that play an important role in ecosystem functioning include time and potential biota , the organisms that are present in a region and could potentially occupy a particular site. Ecosystems in similar environments that are located in different parts of the world can end up doing things very differently simply because they have different pools of species present. The introduction of non-native species can cause substantial shifts in ecosystem function. Unlike external factors, internal factors in ecosystems not only control ecosystem processes but are also controlled by them. While
15900-599: The largest free-roaming herds of American bison (Bison bison) on public land, a species central to the region's ecological balance. Grizzly bears (Ursus arctos horribilis) and gray wolves (Canis lupus) are apex predators that play crucial roles in regulating prey populations. Elk (Cervus canadensis) are abundant and form a key component of the ecosystem, providing sustenance for predators. Other significant ungulate species include moose (Alces alces), pronghorn (Antilocapra americana), bighorn sheep (Ovis canadensis), and mountain goats (Oreamnos americanus). The GYE
16050-899: The largest subspecies ( Branta canadensis maxima ) has been reported. Other large waterbird prey include common loons ( Gavia immer ) of all ages. Large wading birds can also fall prey to bald eagles. For the great blue herons ( Ardea herodias ), bald eagles are their only serious enemies of all ages. Slightly larger Sandhill cranes ( Grus canadensis ) can be taken as well. While adult whooping cranes ( Grus americana ) are too large and formidable, their chicks can fall prey to bald eagles. They even occasionally prey on adult tundra swans ( Cygnus columbianus ). Young trumpeter swans ( Cygnus buccinator ) are also taken, and an unsuccessful attack on an adult swan has been photographed. Bald eagles have been occasionally recorded as killing other raptors . In some cases, these may be attacks of competition or kleptoparasitism on rival species but end with
16200-485: The largest true raptor ( accipitrid ) in North America. The only larger species of raptor-like bird is the California condor ( Gymnogyps californianus ), a New World vulture which today is not generally considered a taxonomic ally of true accipitrids. However, the golden eagle, averaging 4.18 kg (9.2 lb) and 63 cm (25 in) in wing chord length in its American race ( Aquila chrysaetos canadensis ),
16350-423: The living and dead plant matter, and eventually released through respiration. The carbon and energy incorporated into plant tissues (net primary production) is either consumed by animals while the plant is alive, or it remains uneaten when the plant tissue dies and becomes detritus . In terrestrial ecosystems , the vast majority of the net primary production ends up being broken down by decomposers . The remainder
16500-471: The maintenance of hydrological cycles , cleaning air and water, the maintenance of oxygen in the atmosphere, crop pollination and even things like beauty, inspiration and opportunities for research. Many ecosystems become degraded through human impacts, such as soil loss , air and water pollution , habitat fragmentation , water diversion , fire suppression , and introduced species and invasive species . These threats can lead to abrupt transformation of
16650-408: The maintenance of hydrological cycles, cleaning air and water, the maintenance of oxygen in the atmosphere, crop pollination and even things like beauty, inspiration and opportunities for research. While material from the ecosystem had traditionally been recognized as being the basis for things of economic value, ecosystem services tend to be taken for granted. The Millennium Ecosystem Assessment
16800-517: The measurement from the gape to the tip of the bill is 7–9 cm (2.8–3.5 in). The bill size is unusually variable: Alaskan eagles can have up to twice the bill length of birds from the southern United States ( Georgia , Louisiana , Florida), with means including both sexes of 6.83 cm (2.69 in) and 4.12 cm (1.62 in) in culmen length, respectively, from these two areas. The call consists of weak staccato, chirping whistles, kleek kik ik ik ik , somewhat similar in cadence to
16950-556: The most significant prey species were largescale suckers ( Catostomus macrocheilus ) (17.3% of the prey selected there), American shad ( Alosa sapidissima ; 13%) and common carp ( Cyprinus carpio ; 10.8%). Eagles living in the Chesapeake Bay in Maryland were found to subsist largely on American gizzard shad ( Dorosoma cepedianum ), threadfin shad ( Dorosoma petenense ) and white bass ( Morone chrysops ). Floridian eagles have been reported to prey on catfish , most prevalently
17100-479: The name derives from an older meaning of the word, "white headed". The adult is mainly brown with a white head and tail. The sexes are identical in plumage , but females are about 25 percent larger than males. The yellow beak is large and hooked. The plumage of the immature is brown. The bald eagle is the national symbol of the United States of America and appears on its seal . In the late 20th century it
17250-599: The nesting trees used by eagles, followed by hemlocks ( Tsuga ) at 20%. Increasingly, eagles nest in human-made reservoirs stocked with fish. The bald eagle is usually quite sensitive to human activity while nesting, and is found most commonly in areas with minimal human disturbance. It chooses sites more than 1.2 km (0.75 mi) from low-density human disturbance and more than 1.8 km (1.1 mi) from medium- to high-density human disturbance. However, bald eagles will occasionally nest in large estuaries or secluded groves within major cities, such as Hardtack Island on
17400-567: The non-breeding seasons. They can take fish up to at least twice their own weight, such as large mature salmons , carps , or even muskellunge ( Esox masquinongy ), by dragging its catch with talons and pull toward ashore. Much larger marine fish such as Pacific halibut ( Hippoglossus stenolepis ) and lemon sharks ( Negaprion brevirostris ) have been recorded among bald eagle prey though probably are only taken as young, as small, newly mature fish, or as carrion. Benthic fishes such as catfish are usually consumed after they die and float to
17550-580: The numbers of this fish were depleted because of excessive harvest. Its current recovery, though a significant management achievement, does not begin to restore the species' historical abundance. Also, they declined because of invasive lake trout. An aggressive lake trout removal program has caused the cutthroats to rebound. Early accounts of pronghorn ( Antilocapra americana ) in Greater Yellowstone described herds of hundreds seen ranging through most major river valleys . These populations were decimated by 1900, and declines continued among remaining herds. On
17700-449: The other comes behind it in order to ambush it. While hunting waterfowl, bald eagles repeatedly fly at a target and cause it to dive repeatedly, hoping to exhaust the victim so it can be caught (white-tailed eagles have been recorded hunting waterfowl in the same way). When hunting concentrated prey, a successful catch often results in the hunting eagle being pursued by other eagles and needing to find an isolated perch for consumption if it
17850-537: The other hand, are mostly cycled back and forth between plants, animals, microbes and the soil. Most nitrogen enters ecosystems through biological nitrogen fixation , is deposited through precipitation, dust, gases or is applied as fertilizer . Most terrestrial ecosystems are nitrogen-limited in the short term making nitrogen cycling an important control on ecosystem production. Over the long term, phosphorus availability can also be critical. Macronutrients which are required by all plants in large quantities include
18000-509: The other. Despite this, the cumulative effect of additional species in an ecosystem is not linear: additional species may enhance nitrogen retention, for example. However, beyond some level of species richness, additional species may have little additive effect unless they differ substantially from species already present. This is the case for example for exotic species . The addition (or loss) of species that are ecologically similar to those already present in an ecosystem tends to only have
18150-403: The overall structure of an ecosystem and the way things work within it, but are not themselves influenced by the ecosystem. On broad geographic scales, climate is the factor that "most strongly determines ecosystem processes and structure". Climate determines the biome in which the ecosystem is embedded. Rainfall patterns and seasonal temperatures influence photosynthesis and thereby determine
18300-615: The park's northern range, pronghorn declined from 500 to 700 in the 1930s to about 122 in 1968. By 1992 the herd had increased to 536. The park is a commonly cited example of apex predators affecting an ecosystem through a trophic cascade . After the reintroduction of the gray wolf in 1995, researchers noticed drastic changes occurring. Elk , the primary prey of the gray wolf, became less abundant and changed their behavior, freeing riparian zones from constant grazing. The respite allowed willows and aspens to grow, creating habitat for beaver , moose , and scores of other species. In addition to
18450-405: The plants in an ecosystem is called the gross primary production (GPP). About half of the gross GPP is respired by plants in order to provide the energy that supports their growth and maintenance. The remainder, that portion of GPP that is not used up by respiration, is known as the net primary production (NPP). Total photosynthesis is limited by a range of environmental factors. These include
18600-678: The predation events are sporadic. In one instance, two bald Eagles fed upon a red fox ( Vulpes vulpes ) that had tried to cross a frozen Delaware Lake . Other medium-sized carnivorans such as striped skunks ( Mephitis mephitis ), American hog-nosed skunks ( Conepatus leuconotus ), and common raccoons ( Procyon lotor ) are taken, as well as domestic cats ( Felis catus ) and dogs ( canis familiaris ). Other wild mammalian prey include fawns of deer such as white-tailed deer ( Odocoileus virginianus ) and Sitka deer ( Odocoileus hemionus sitkensis ), which weigh around 3 kg (6.6 lb) can be taken alive by bald eagles. In one instance,
18750-527: The prey in a strenuously labored, low flight over the water to a bank, where they then finish off and dismember the prey. When food is abundant, an eagle can gorge itself by storing up to 1 kg (2.2 lb) of food in a pouch in the throat called a crop. Gorging allows the bird to fast for several days if food becomes unavailable. Occasionally, bald eagles may hunt cooperatively when confronting prey, especially relatively large prey such as jackrabbits or herons, with one bird distracting potential prey, while
18900-585: The primary nutrients (which are most limiting as they are used in largest amounts): Nitrogen, phosphorus, potassium. Secondary major nutrients (less often limiting) include: Calcium, magnesium, sulfur. Micronutrients required by all plants in small quantities include boron, chloride, copper, iron, manganese, molybdenum, zinc. Finally, there are also beneficial nutrients which may be required by certain plants or by plants under specific environmental conditions: aluminum, cobalt, iodine, nickel, selenium, silicon, sodium, vanadium. Until modern times, nitrogen fixation
19050-413: The primary producers. The organisms that consume their tissues are called primary consumers or secondary producers — herbivores . Organisms which feed on microbes ( bacteria and fungi ) are termed microbivores . Animals that feed on primary consumers— carnivores —are secondary consumers. Each of these constitutes a trophic level. The sequence of consumption—from plant to herbivore, to carnivore—forms
19200-403: The range of the bald eagle has increased following conservation efforts, these interactions have been observed on several occasions, including a fatality of a bald eagle in Maine that is presumed to have come about as a result of it attacking a nest, then having a fatal puncture wound inflicted by one or both loon parents. The bald eagle is thought to be much more numerous in North America than
19350-545: The same ecological niche in their respective ranges. The pair diverged from other sea eagles at the beginning of the Early Miocene (c. 10 Ma BP ) at the latest, but possibly as early as the Early/Middle Oligocene , 28 Ma BP, if the most ancient fossil record is correctly assigned to this genus . The plumage of an adult bald eagle is evenly dark brown with a white head and tail. The tail
19500-494: The smell of sulfur is common and there are some sulfur fixing cyanobacteria , it has been found that hydrogen is being used as an energy source by extremophile microbes . Among native plants of the GYE, whitebark pine ( Pinus albicaulis ) is a species of special interest, in large part because of its seasonal importance to grizzly bears, but also because its distribution could be dramatically reduced by relatively minor global warming . In this case, researchers do not have
19650-409: The soil and topography , control the overall structure of an ecosystem but are not themselves influenced by the ecosystem. Internal factors are controlled, for example, by decomposition , root competition, shading, disturbance, succession, and the types of species present. While the resource inputs are generally controlled by external processes, the availability of these resources within the ecosystem
19800-611: The soil, react with mineral soil, or are transported beyond the confines of the ecosystem (and are considered lost to it). Newly shed leaves and newly dead animals have high concentrations of water-soluble components and include sugars , amino acids and mineral nutrients. Leaching is more important in wet environments and less important in dry ones. Fragmentation processes break organic material into smaller pieces, exposing new surfaces for colonization by microbes. Freshly shed leaf litter may be inaccessible due to an outer layer of cuticle or bark , and cell contents are protected by
19950-511: The soil, where plants, fungi, and bacteria compete for it. Some soil bacteria use organic nitrogen-containing compounds as a source of carbon, and release ammonium ions into the soil. This process is known as nitrogen mineralization . Others convert ammonium to nitrite and nitrate ions, a process known as nitrification . Nitric oxide and nitrous oxide are also produced during nitrification. Under nitrogen-rich and oxygen-poor conditions, nitrates and nitrites are converted to nitrogen gas ,
20100-409: The south or to the coast. A number of populations are subject to post-breeding dispersal, mainly in juveniles; Florida eagles, for example, will disperse northwards in the summer. The bald eagle selects migration routes which take advantage of thermals , updrafts , and food resources. During migration, it may ascend in a thermal and then glide down, or may ascend in updrafts created by the wind against
20250-448: The southern coastal areas where mangroves are usually used. In Wyoming , groves of mature cottonwoods or tall pines found along streams and rivers are typical bald eagle nesting habitats. Wyoming eagles may inhabit habitat types ranging from large, old-growth stands of ponderosa pines ( Pinus ponderosa ) to narrow strips of riparian trees surrounded by rangeland. In Southeast Alaska , Sitka spruce ( Picea sitchensis ) provided 78% of
20400-483: The spatial extent of ecosystems using the term " ecotope ". G. Evelyn Hutchinson , a limnologist who was a contemporary of Tansley's, combined Charles Elton 's ideas about trophic ecology with those of Russian geochemist Vladimir Vernadsky . As a result, he suggested that mineral nutrient availability in a lake limited algal production . This would, in turn, limit the abundance of animals that feed on algae. Raymond Lindeman took these ideas further to suggest that
20550-575: The species increases in size further away from the equator and the tropics. For example, eagles from South Carolina average 3.27 kg (7.2 lb) in mass and 1.88 m (6 ft 2 in) in wingspan, smaller than their northern counterparts. One field guide in Florida listed similarly small sizes for bald eagles there, at about 4.13 kg (9.1 lb). Of intermediate size, 117 migrant bald eagles in Glacier National Park were found to average 4.22 kg (9.3 lb) but this
20700-485: The species was common in Greater Yellowstone when Europeans arrived and that the population was not isolated before the 1930s, but is now. Researchers do not know if bears were more or less common than now. A 1959-1970 bear study suggested a grizzly bear population size of about 176, later revised to about 229. Later estimates have ranged as low as 136 and as high as 540; the most recent is a minimum estimate of 236, but biologists think there may be as many as 1,000 bears in
20850-473: The surface, though while temporarily swimming in the open may be more vulnerable to predation than most fish since their eyes focus downwards. Bald eagles also regularly exploit water turbines which produce battered, stunned or dead fish easily consumed. Predators who leave behind scraps of dead fish that they kill, such as brown bears ( Ursus arctos ), gray wolves ( Canis lupus ) and red foxes ( Vulpes vulpes ), may be habitually followed in order to scavenge
21000-454: The system through photosynthesis , building up plant tissue. Animals play an important role in the movement of matter and energy through the system, by feeding on plants and on one another. They also influence the quantity of plant and microbial biomass present. By breaking down dead organic matter , decomposers release carbon back to the atmosphere and facilitate nutrient cycling by converting nutrients stored in dead biomass back to
21150-421: The transfers of energy and materials from one pool to another. Ecosystem processes are known to "take place at a wide range of scales". Therefore, the correct scale of study depends on the question asked. The term "ecosystem" was first used in 1935 in a publication by British ecologist Arthur Tansley . The term was coined by Arthur Roy Clapham , who came up with the word at Tansley's request. Tansley devised
21300-436: The tree's height, composition and location. Perhaps of paramount importance for this species is an abundance of comparatively large trees surrounding the body of water. Selected trees must have good visibility, be over 20 m (66 ft) tall, an open structure, and proximity to prey. If nesting trees are in standing water such as in a mangrove swamp, the nest can be located fairly low, at as low as 6 m (20 ft) above
21450-526: The wild and are thus considered apex predators . Bald eagles are sexually mature at four or five years of age. When they are old enough to breed, they often return to the area where they were born. Bald eagles have high mate fidelity and generally mate for life . However, if one pair member dies or disappears, the survivor will choose a new mate. A pair that has repeatedly failed in breeding attempts may split and look for new mates. Bald eagle courtship involves elaborate, spectacular calls and flight displays by
21600-411: The wings. A survey of adult weights in Alaska showed that females there weighed on average 5.35 kg (11.8 lb), respectively, and males weighed 4.23 kg (9.3 lb) against immatures which averaged 5.09 kg (11.2 lb) and 4.05 kg (8.9 lb) in the two sexes. An Alaskan adult female eagle that was considered outsized weighed some 7.4 kg (16 lb). R.S. Palmer listed
21750-542: Was captured near Castleisland , County Kerry on November 15, 1987. There is also a record of it from Llyn Coron, Anglesey, in the United Kingdom, from October 17, 1978; the provenance of this individual eagle has remained in dispute. The bald eagle occurs during its breeding season in virtually any kind of American wetland habitat such as seacoasts , rivers, large lakes or marshes or other large bodies of open water with an abundance of fish. Studies have shown
21900-651: Was dominant prey in San Miguel Island . Due to easy accessibility and lack of formidable nest defense against eagles by such species, bald eagles are capable of preying on such seabirds at all ages, from eggs to mature adults, and they can effectively cull large portions of a colony. Along some portions of the North Pacific coastline, bald eagles which had historically preyed mainly kelp -dwelling fish and supplementally sea otter ( Enhydra lutris ) pups are now preying mainly on seabird colonies since both
22050-542: Was mostly (possibly post-dispersal) juvenile eagles, with 6 adults here averaging 4.3 kg (9.5 lb). Wintering eagles in Arizona (winter weights are usually the highest of the year since, like many raptors, they spend the highest percentage of time foraging during winter) were found to average 4.74 kg (10.4 lb). The largest eagles are from Alaska , where large females may weigh more than 7 kg (15 lb) and span 2.44 m (8 ft 0 in) across
22200-416: Was on the brink of extirpation in the contiguous United States. Populations have since recovered, and the species' status was upgraded from " endangered " to " threatened " in 1995 and removed from the list altogether in 2007. The bald eagle is placed in the genus Haliaeetus ( sea eagles ), and gets both its common and specific scientific names from the distinctive appearance of the adult's head. Bald in
22350-482: Was one of the many species originally described by Carl Linnaeus in his 18th-century work Systema Naturae , under the name Falco leucocephalus . There are two recognized subspecies of bald eagle: The bald eagle forms a species pair with the white-tailed eagle of Eurasia . This species pair consists of a white-headed and a tan-headed species of roughly equal size; the white-tailed eagle also has overall somewhat paler brown body plumage. The two species fill
22500-679: Was the major source of nitrogen for ecosystems. Nitrogen-fixing bacteria either live symbiotically with plants or live freely in the soil. The energetic cost is high for plants that support nitrogen-fixing symbionts—as much as 25% of gross primary production when measured in controlled conditions. Many members of the legume plant family support nitrogen-fixing symbionts. Some cyanobacteria are also capable of nitrogen fixation. These are phototrophs , which carry out photosynthesis. Like other nitrogen-fixing bacteria, they can either be free-living or have symbiotic relationships with plants. Other sources of nitrogen include acid deposition produced through
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