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51-465: The Farallon Islands are the site of the largest seabird colony in the United States outside of Alaska and Hawaii , as well as an important sea lion rookery. This abundance of fresh meat and eggs attracted ships to replenish supplies and Russian sealers, who were the first to collect the abundant common murre eggs. When control of California passed from Mexico to the United States, it

102-449: A rookery . Many species of terns nest in colonies on the ground. Herons , egrets, storks , and other large waterfowl also nest communally in what are called heronries . Colony nesting may be an evolutionary response to a shortage of safe nesting sites and abundance or unpredictable food sources which are far away from the nest sites. Colony-nesting birds often show synchrony in their breeding, meaning that chicks all hatch at once, with

153-474: A colony, or even to an entire population of a colonial species. For example, there was once a large seabird known as the great auk , which nested in colonies in the North Atlantic . Eggs and birds were used for a variety of purposes. Beginning in the 16th century, seafarers took the birds in especially great numbers to fill ships' larders, and by the mid-19th century, the great auk was extinct. Likewise,

204-521: A comparable flavor, but they were smaller than murre eggs and more fragile (an important factor given the choppy seas between the Farallon Islands and San Francisco). Individual eggers collected from certain areas. Prior to collecting the workers would progress through a colony destroying every egg they could find, thus, returning to the site on subsequent days, they could be certain the eggs they collected were fresh. Eggers had to work quickly as

255-555: A dense congregation over a wide area; thousands of people were drawn to hunt the birds, shipping the squab to market by rail. The passenger pigeon is a famous example of a familiar bird going extinct in modern times. The use of seabird droppings as fertilizer, or guano, began with the Indigenous Peruvians , who collected it from sites along the coast of South America, such as the Chincha Islands . When, after

306-781: A different sort of group behavior than what is normally considered colonial. The habit of nesting in groups is believed to provide better survival against predators in several ways. Many colonies are situated in locations that are naturally free of predators. In other cases, the presence of many birds means there are more individuals available for defense. Also, synchronized breeding leads to such an abundance of offspring as to satiate predators . For seabirds, colonies on islands have an obvious advantage over mainland colonies when it comes to protection from terrestrial predators. Other situations can also be found where bird colonies avoid predation. A study of yellow-rumped caciques in Peru found that

357-528: A hundred nesting pairs. These structures resemble haystacks hanging from trees, and have been likened to apartment buildings or beehives. Some seabird colonies host thousands of nesting pairs of various species. Triangle Island, for example, the largest seabird colony in British Columbia , Canada, is home to auks, gulls, cormorants, shorebirds, and other birds, as well as some marine mammals. Many seabirds show remarkable site fidelity , returning to

408-550: A long lifespan and slow reproduction. The earliest unequivocal fossils of auks are from the late Eocene , some 35 Mya. The genus Miocepphus , (from the Miocene , 15 Mya) is the earliest known from good specimens. Two very fragmentary fossils are often assigned to the Alcidae, although this may not be correct: Hydrotherikornis (Late Eocene ) and Petralca (Late Oligocene ). Most extant genera are known to exist since

459-589: A single egg, and they use the nesting site year after year. Some species, such as the Uria guillemots (murres), nest in large colonies on cliff edges; others, such as the Cepphus guillemots, breed in small groups on rocky coasts; and the puffins , auklets, and some murrelets nest in burrows. All species except the Brachyramphus murrelets are colonial. Traditionally, the auks were believed to be one of

510-619: A suitable stand of trees. The red-cockaded woodpecker , an endangered species of southeastern North America, is a social species that feeds and roosts in family groups, or clans. Clans nest and roost in clusters of tree cavities and use a cooperative breeding system. Many parrot species are also extremely social. For example, the thick-billed parrot is another bird that nests and roosts communally; individuals of neighboring roosts has been observed to communicate with each other each morning to signal their readiness to form flocks for foraging. However, these complex social structures in birds are

561-503: Is a large congregation of individuals of one or more species of bird that nest or roost in proximity at a particular location. Many kinds of birds are known to congregate in groups of varying size; a congregation of nesting birds is called a breeding colony. Colonial nesting birds include seabirds such as auks and albatrosses ; wetland species such as herons ; and a few passerines such as weaverbirds , certain blackbirds , and some swallows . A group of birds congregating for rest

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612-579: Is an obvious advantage. Islands where terrestrial predators have arrived in the form of rats, cats, foxes, etc., have devastated island seabird colonies. One well-studied case of this phenomenon has been the effect on common murre colonies on islands in Alaska , where foxes were introduced for fur farming . Colony-nesting birds have been used by humans as a source of food in the form of eggs and meat, down for bedding, feathers for quill pens, and guano for fertilizer. Over-exploitation can be devastating to

663-481: Is called a communal roost . Evidence of colonial nesting has been found in non- neornithine birds ( Enantiornithes ), in sediments from the Late Cretaceous ( Maastrichtian ) of Romania . Approximately 13% of all bird species nest colonially. Nesting colonies are very common among seabirds on cliffs and islands. Nearly 95% of seabirds are colonial, leading to the usage, seabird colony , sometimes called

714-543: Is considered a colony. Sand martins (called bank swallows in North America) are seldom, if ever, observed to nest in solitude; such a dependence on social nesting would term the bird a colonial nester. A more extreme example of colonial nesting is found in the weaverbird family. The sociable weaver of southern Africa constructs massive, multi-family dwellings of twigs and dry grasses, with many entrances leading to different nesting chambers, accommodating as many as

765-561: The Synthliboramphus murrelets should be split into a distinct tribe, as they appear more closely related to the Alcini; in any case, assumption of a closer relationship between the former and the true guillemots was only weakly supported by earlier studies. Of the genera, only a few species are placed in each. This is probably a product of the rather small geographic range of the family (the most limited of any seabird family), and

816-540: The Lari suborder, which otherwise contains gulls and similar birds. Judging from genetic data, their closest living relatives appear to be the skuas , with these two lineages separating about 30 million years ago (Mya). Alternatively, auks may have split off far earlier from the rest of the Lari and undergone strong morphological, but slow genetic evolution, which would require a very high evolutionary pressure , coupled with

867-409: The least auklet , at 85 g (3 oz) and 15 cm (5.9 in), to the thick-billed murre , at 1 kg (2.2 lb) and 45 cm (18 in). Due to their short wings, auks have to flap their wings very quickly to fly. Although not to the extent of penguins, auks have largely sacrificed flight, and also mobility on land, in exchange for swimming ability; their wings are a compromise between

918-620: The short-tailed albatross of the North Pacific was heavily harvested at what seems to have been its primary colony on Torishima Island . Millions of birds were killed in less than two decades at the end of the 19th century. The species survives, though endangered. In North America, the extermination of the highly gregarious passenger pigeon has been well documented. The birds were hunted as if inexhaustible. Case in point: in 1871, in Wisconsin, an estimated 136 million pigeons nested in

969-599: The Atlantic during the Pliocene. Auks also tend to be restricted to continental-shelf waters and breed on few oceanic islands. Hydotherikornis oregonus (Described by Miller in 1931), the oldest purported alcid from the Eocene of California, is actually a petrel (as reviewed by Chandler in 1990) and is reassigned to the tubenoses (Procellariiformes). A 2003 paper, "The Earliest North American Record of Auk (Aves: Alcidae) From

1020-744: The Atlantic existed), with later movements across the Arctic Ocean. The flightless subfamily Mancallinae , which was apparently restricted to the Pacific Coast of southern North America and became extinct in the Early Pleistocene , is sometimes included in the family Alcidae under some definitions. One species, Miomancalla howardae , is the largest charadriiform of all time. The family contains 25 extant or recently extinct species that are divided into 11 genera. The extant auks (subfamily Alcinae) are broken up into two main groups -

1071-594: The Late Eocene of Central Georgia", reports a Late Eocene, wing-propelled, diving auk from the Priabonain stage of the Late Eocene. These sediments have been dated through Chandronian NALMA {North American Land Mammal Age}, at an estimate of 34.5 to 35.5 million years on the Eocene time scale for fossil-bearing sediments of the Clinchfield Formation, Gordon, Wilkinson County, Georgia. Furthermore,

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1122-613: The Late Miocene or Early Pliocene (about 5 Mya). Miocene fossils have been found in both California and Maryland , but the greater diversity of fossils and tribes in the Pacific leads most scientists to conclude they first evolved there, and in the Miocene Pacific, the first fossils of extant genera are found. Early movement between the Pacific and the Atlantic probably happened to the south (since no northern opening to

1173-513: The Spanish Conquest, the value of this fertilizer became known to the wider world, collection increased to the point where the supply nearly ran out, and other sources of guano had to be found. Seabird colonies can be predominately a single species or a mix of species: Colonial nesting can be so close that multiple nests are interwoven: Another variation is to have closely grouped separate nests: Heronries and rookeries are often in

1224-405: The adjoining West End (or Maintop Island). It surveyed the islands, obtained a school warrant , and constructed buildings, paths, and landing facilities. Egg collection was a seasonal occupation, from mid-May until July. The eggs of murres were preferred over those of other species, their eggs being the largest and most common ones available. Western gull eggs were also occasionally taken, having

1275-406: The advantages of group nesting in terms of enabling group defensive behavior, escape from predation by being surrounded by neighbors (called the selfish herd hypothesis), as well as escaping predators through sheer numbers, in reality, each of these functions evidently depends on a number of factors. Clearly, there can be safety in numbers, but there is some doubt about whether it balances out against

1326-413: The best possible design for diving and the bare minimum needed for flying. This varies by subfamily, with the Uria guillemots (including the razorbill ) and murrelets being the most efficient under the water, whereas the puffins and auklets are better adapted for flying and walking. The feeding behaviour of auks is often compared to that of penguins; both groups are wing -propelled, pursuit divers. In

1377-416: The birds, which build enclosed, pouch-like nests in colonies of up to one hundred active nests, situate themselves near wasp nests, which provide some protection from tree-dwelling predators such as monkeys. When other birds came to rob the nests, the caciques would cooperatively defend the colony by mobbing the invader. Mobbing, clearly a group effort, is well-known behavior, not limited to colonial species;

1428-507: The case of Uria guillemots, 40 m (130 ft) for the Cepphus guillemots and 30 m (98 ft) for the auklets. Auks are pelagic birds, spending the majority of their adult lives on the open sea and going ashore only for breeding, although some species, such as the common guillemot , spend a great part of the year defending their nesting spot from others. Auks are monogamous, and tend to form lifelong pairs. They typically lay

1479-494: The colony and the sandpipers nesting there were actually more vulnerable. In a study of a least tern colony in Connecticut , nocturnal avian predators in the form of black-crowned night herons and great horned owls were observed to repeatedly invade a colony, flying into the middle of the colony and meeting no resistance. For seabirds, the location of colonies on islands, which are inaccessible to terrestrial predators,

1530-463: The earliest distinct charadriiform lineages due to their characteristic morphology , but genetic analyses have demonstrated that these peculiarities are the product of strong natural selection, instead; as opposed to, for example, plovers (a much older charadriiform lineage), auks radically changed from a wading shorebird to a diving seabird lifestyle. Thus today, the auks are no longer separated in their own suborder (Alcae), but are considered part of

1581-453: The food source is one that can be locally abundant. This hypothesis would explain why the lesser kestrel , which feeds on insects, breeds in colonies, while the related common kestrel , which feeds on larger prey, does not. Colonial behaviour has its costs as well. It has been noted that parasitism by haematozoa is higher in colonial birds and it has been suggested that blood parasites might have shaped adaptations such as larger organs in

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1632-434: The immune system and life-history traits. Other costs include brood parasitism and competition for food and territory. Colony size is a factor in the ecological function of colony nesting. In a larger colony, increased competition for food can make it harder for parents to feed their chicks. The benefits and drawbacks for birds of nesting in groups seem to be highly situational. Although scientists have hypothesized about

1683-402: The implication that any predator coming along at that time would find more prey items than it could possibly eat. What exactly constitutes a colony is a matter of definition. Tufted puffins , for example, are pelagic birds that nest on the steep slopes and rocky crevices on coastal cliffs, often on islands. Each pair excavates its own burrow. A congregation of puffin burrows on a marine island

1734-465: The island were dealt a further blow by an executive order issued by President James Buchanan in 1859 which claimed the islands for the federal government in order to build a lighthouse (which had already been built in 1855). The then lighthouse superintendent of the area, Ira Rankin, did not attempt to push the Egg Company off the island and instead asserted their right to collect over that of

1785-582: The more birds participating in the mobbing, the more effective it is at driving off the predator. Therefore, it has been theorized that the larger number of individuals available for vigilance and defense makes the colony a safer place for the individual birds nesting there. More pairs of eyes and ears are available to raise the alarm and rise to the occasion. Another suggestion is that colonies act as information centers and birds that have not found good foraging sites are able to follow others, who have fared better, to find food. This makes sense for foragers because

1836-466: The murres would flush and immediately the gulls would move in to snatch the unguarded eggs. The Egg Company attracted rivals, due to the amount of money to be made from the trade. Many fishermen collected eggs on the smaller and more treacherous North Farallones (which were not claimed by the Egg Company), but others attempted to egg on the main islands. The company's claims to exclusive ownership of

1887-582: The other companies. In 1863, when a company of men, led by a David Batchelder sailed to the islands, Rankin sent a boat of armed men to remove them from the island, seizing several weapons. Batchelder returned a few weeks later and, reinforced, tried again to remove the Egg Company. Rankin again sent forces to evict him and his men from the island. Batchelder returned once more to the Farallones, on June 2, 1863. Rankin's forces again encountered them moored off North Landing, but Batchelder convinced them that he

1938-443: The periods of glacial advance and retreat that have kept the populations on the move in a narrow band of subarctic ocean. Today, as in the past, the auks are restricted to cooler northern waters. Their ability to spread further south is restricted as their prey hunting method, pursuit diving, becomes less efficient in warmer waters. The speed at which small fish (which along with krill are the auk's principal prey) can swim doubles as

1989-407: The region where auks live, their only seabird competition are cormorants (which are dive-powered by their strong feet). In areas where the two groups feed on the same prey, the auks tend to feed further offshore. Strong-swimming murres hunt faster, schooling fish, whereas auklets take slower-moving krill. Time depth recorders on auks have shown that they can dive as deep as 100 m (330 ft) in

2040-566: The same burrow, nest or site for many years, and they will defend that site from rivals with great vigour. This increases breeding success, provides a place for returning mates to reunite, and reduces the costs of prospecting for a new site. Young adults breeding for the first time usually return to their natal colony, and often nest very close to where they hatched. Individual nesting sites at seabird colonies can be widely spaced, as in an albatross colony, or densely packed like an auk colony. In most seabird colonies several different species will nest on

2091-427: The same colony, often exhibiting some niche separation. Seabirds can nest in trees (if any are available), on the ground (with or without nests), on cliffs, in burrows under the ground and in rocky crevices. Colony size is a major aspect of the social environment of colonial birds. Some birds are known to nest alone when conditions are suitable, but not sometimes. The white-winged dove of southwestern North America

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2142-931: The sediments containing this unabraded portion of a left humerus (43.7 mm long) are tropical or subtropical as evidenced by a wealth of warm-water shark teeth, palaeophied snake vertebrae, and turtles. Rhinoceros auklet Tufted puffin Horned puffin Atlantic puffin Cassin's auklet Least auklet Parakeet auklet Whiskered auklet Crested auklet Ancient murrelet Japanese murrelet Craveri's murrelet Guadalupe murrelet Scripps's murrelet Long-billed murrelet Marbled murrelet Kittlitz's murrelet Black guillemot Spectacled guillemot Pigeon guillemot Thick-billed murre Common murre Little auk † Great auk Razorbill Biodiversity of auks seems to have been markedly higher during

2193-950: The species called little auk in Europe is referred to as dovekie in North America. The word "auk" / ɔː k / is derived from Icelandic álka and Norwegian alka or alke from Old Norse ālka from Proto-Germanic * alkǭ (sea-bird, auk). The family name Alcidae comes from the genus Alca given by Carl Linnaeus in 1758 for the razorbill ( Alca torda ) from the Norwegian word alke . Auks are superficially similar to penguins , having black-and-white colours, upright posture, and some of their habits. Nevertheless, they are not closely related to penguins, but rather are believed to be an example of moderate convergent evolution . Auks are monomorphic (males and females are similar in appearance). Extant auks range in size from

2244-490: The temperature increases from 5 to 15 °C (41 to 59 °F), with no corresponding increase in speed for the bird. The southernmost auks, in California and Mexico, can survive there because of cold upwellings . The current paucity of auks in the Atlantic (six species), compared to the Pacific (19–20 species) is considered to be because of extinctions to the Atlantic auks; the fossil record shows many more species were in

2295-484: The tendency for conspicuous breeding colonies to attract predators, and some suggest that colonial breeding can actually make birds more vulnerable. At a common tern colony in Minnesota , a study of spotted sandpipers observed to nest near the tern colony showed that the sandpipers that nested nearest the colony seemed to gain some protection from mammalian predators, but avian predators were apparently attracted to

2346-780: The top of a stand of trees: Auk Auks or alcids are a group of birds of the family Alcidae in the order Charadriiformes . The alcid family includes the murres , guillemots , auklets , puffins , and murrelets . The family contains 25 extant or recently extinct species that are divided into 11 genera. Auks are found throughout the Northern Hemisphere . Apart from the extinct great auk , all auks can fly, and are excellent swimmers and divers (appearing to "fly" in water), but their walking appears clumsy. Several species have different English names in Europe and North America. The two species known as "murres" in North America are called "guillemots" in Europe, and

2397-413: The usually high-billed puffins (tribe Fraterculini) and auklets (tribe Aethiini), as opposed to the more slender-billed murres and true auks (tribe Alcini), and the murrelets and guillemots (tribes Brachyramphini and Cepphini). The tribal arrangement was originally based on analyses of morphology and ecology . mtDNA cytochrome b sequences , and allozyme studies confirm these findings except that

2448-539: Was intending to egg the North Farallones, not SEFI. Rankin's men left for San Francisco. With the government cutter gone, three rowboats with twenty-seven armed men attempted a landing on the morning of June 4. As Batchelder's men landed, they were fired upon by men from the Egg Company. Batchelder's men returned fire. The defenders had the advantage, having been able to pick their positions ahead of time, and after twenty minutes Batchelder's men retreated. One man

2499-405: Was killed on each side, and four of Batchelder's men were wounded. The aftermath of the conflict left the Egg Company in sole control of the islands. David Batchelder was convicted of murder , but he was acquitted on a technicality . The presence of the eggers on the island was tolerated for another twenty years, but they were finally evicted in 1881. Seabird colony A bird colony

2550-673: Was known to nest in large colonies when foraging areas could support such numbers. In 1978, in Tamaulipas , Mexico, researchers counted 22 breeding colonies of white-winged doves with a collective population size of more than eight million birds. But as habitat was transformed through urbanization or agriculture, the doves apparently spread out into smaller, less long-lived colonies. Today, these doves are observed to nest singlyin both urban and not urban areas. The term colony has also been applied, perhaps misleadingly, to smaller nesting groups, such as forest-dwelling species that nest socially in

2601-535: Was not long before the economic potential of the islands became apparent. In 1849 a recent immigrant to San Francisco, "Dr. Robinson", sailed to the islands to collect the eggs, and despite losing half of his cargo, was able to make enough money to found a pharmacy and to form the Pacific Egg Company (the name changed over its history and is usually referred to as the Egg Company). The Egg Company strove to assert its claim to South East Farallon (SEFI) and

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