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93-536: The lake drains a catchment area of 15,500 hectares (38,000 acres). It is in a semi-arid zone of the Mehsana district with dominance of dry deciduous vegetation. The climate in the area consists of three seasons: winter , summer and monsoon . The average annual rainfall in the catchment of the lake is 600 millimetres (24 in) with a minimum of 100 millimetres (3.9 in) and maximum of 800 millimetres (31 in). The maximum and minimum temperatures recorded in

186-600: A regional accent , with urban mallards in London being much louder and more vociferous compared to rural mallards in Cornwall , serving as an adaptation to persistent levels of anthropogenic noise. When incubating a nest, or when offspring are present, females vocalise differently, making a call that sounds like a truncated version of the usual quack. This maternal vocalisation is highly attractive to their young. The repetition and frequency modulation of these quacks form

279-695: A 'late' clutch occurred in November 2011, in which a female successfully hatched and raised a clutch of eleven ducklings at the London Wetland Centre . During the breeding season, both male and female mallards can become aggressive, driving off competitors to themselves or their mate by charging at them. Males tend to fight more than females and attack each other by repeatedly pecking at their rival's chest, ripping out feathers and even skin on rare occasions. Female mallards are also known to carry out 'inciting displays', which encourage other ducks in

372-399: A behavior known as " marcescence " whereby dead leaves are not shed in the fall and remain on the tree until being blown off by the weather. This is caused by incomplete development of the abscission layer. It is mainly seen in the seedling and sapling stage, although mature trees may have marcescence of leaves on the lower branches. A number of deciduous plants remove nitrogen and carbon from

465-609: A brood of ducklings. Nesting sites are typically on the ground, hidden in vegetation where the female's speckled plumage serves as effective camouflage , but female mallards have also been known to nest in hollows in trees, boathouses, roof gardens and on balconies, sometimes resulting in hatched offspring having difficulty following their parent to water. Egg clutches number 8–13 creamy white to greenish-buff eggs free of speckles. They measure about 58 mm (2.3 in) in length and 32 mm (1.3 in) in width. The eggs are laid on alternate days, and incubation begins when

558-492: A combination of hot temperatures and reduced water levels place mallards at an increased risk of contracting botulism , as these conditions are ideal for Clostridium botulinum to propagate, with the birds also more likely to come into contact with botulinum toxin produced by the bacteria. Outbreaks of botulism among mallard populations can lead to mass die-offs. The predation-avoidance behaviour of sleeping with one eye open, allowing one brain hemisphere to remain aware while

651-529: A darker crown and eye-stripe. Mallards, like other sexually-dimorphic birds, can sometimes go though spontaneous sex reversal, often caused by damaged or nonfunctioning sex organs, such as the ovaries in mallard hens. This phenomenon can cause female mallards to exhibit male plumage, and vice versa (phenotypic feminisation or masculinisation). Both male and female mallards have distinct iridescent purple-blue speculum feathers edged with white, which are prominent in flight or at rest but temporarily shed during

744-510: A few blood vessels to prevent heat loss, and, as in the Greenland mallard, the bill is smaller than that of birds farther south, illustrating the rule. Due to the variability of the mallard's genetic code, which gives it its vast interbreeding capability, mutations in the genes that decide plumage colour are very common and have resulted in a wide variety of hybrids, such as Brewer's duck (mallard × gadwall, Mareca strepera ). The mallard

837-669: A few metres deep. They are attracted to bodies of water with aquatic vegetation. The mallard is omnivorous and very flexible in its choice of food. Its diet may vary based on several factors, including the stage of the breeding cycle, short-term variations in available food, nutrient availability, and interspecific and intraspecific competition . The majority of the mallard's diet seems to be made up of gastropods , insects (including beetles, flies, lepidopterans , dragonflies , and caddisflies ), crustaceans , other arthropods , worms, feces of other birds, many varieties of seeds and plant matter, and roots and tubers . During

930-404: A glass window. This paper was awarded an Ig Nobel Prize in 2003. Mallards are opportunistically targeted by brood parasites , occasionally having eggs laid in their nests by redheads , ruddy ducks , lesser scaup , gadwalls , northern shovellers , northern pintails , cinnamon teal , common goldeneyes , and other mallards. These eggs are generally accepted when they resemble the eggs of

1023-602: A greater rate of transpiration (and hence CO 2 uptake as this occurs when stomata are open) during the summer growth period. The deciduous characteristic has developed repeatedly among woody plants. Trees include maple , many oaks and nothofagus , elm , beech , aspen , and birch , among others, as well as a number of coniferous genera , such as larch and Metasequoia . Deciduous shrubs include honeysuckle , viburnum , and many others. Most temperate woody vines are also deciduous, including grapes , poison ivy , Virginia creeper , wisteria , etc. The characteristic

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1116-447: A mallard) to huge bald ( Haliaeetus leucocephalus ) and golden eagles ( Aquila chrysaetos ), and about a dozen species of mammalian predators, not counting several more avian and mammalian predators who threaten eggs and nestlings. Mallards are also preyed upon by other waterside apex predators , such as grey herons ( Ardea cinerea ), great blue herons ( Ardea herodias ) and black-crowned night herons ( Nycticorax nycticorax ),

1209-547: A part that is no longer needed or useful" and the "falling away after its purpose is finished". In plants, it is the result of natural processes. "Deciduous" has a similar meaning when referring to animal parts, such as deciduous antlers in deer , deciduous teeth (baby teeth) in some mammals (including humans); or decidua , the uterine lining that sheds off after birth. In botany and horticulture , deciduous plants , including trees , shrubs and herbaceous perennials, are those that lose all of their leaves for part of

1302-549: A patchwork of leafy and leafless trees. Mallard A. p. platyrhynchos Linnaeus, 1758 A. p. domesticus Linnaeus, 1758 A. p. conboschas C. L. Brehm , 1831 (disputed) [REDACTED] The mallard ( / ˈ m æ l ɑːr d , ˈ m æ l ər d / ) or wild duck ( Anas platyrhynchos ) is a dabbling duck that breeds throughout the temperate and subtropical Americas , Eurasia , and North Africa . It has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Argentina, Chile, Colombia,

1395-541: A river bank, but not always near water. It is highly gregarious outside of the breeding season and forms large flocks , which are known as "sordes". Mallards usually form pairs (in October and November in the Northern Hemisphere) until the female lays eggs at the start of the nesting season, which is around the beginning of spring. At this time she is left by the male who joins up with other males to await

1488-441: A separate subspecies, the Greenland mallard ( A.   p.   conboschas ). The mallard is a medium-sized waterfowl species that is often slightly heavier than most other dabbling ducks. It is 50–65 cm (20–26 in) long – of which the body makes up around two-thirds – has a wingspan of 81–98 cm (32–39 in), and weighs 0.7–1.6 kg (1.5–3.5 lb). Among standard measurements,

1581-432: A sequence of 2-10 quacks in a row, starting loud and with the volume gradually decreasing. Male mallards make a sound phonetically similar to that of the female, a typical quack , but it is deeper and quieter compared to that of the female. Research conducted by Middlesex University on two English mallard populations found that the vocalisations of the mallard varies depending on their environment and have something akin to

1674-529: A severe threat to indigenous waterfowl's genetic integrity. Mallards and their hybrids compete with indigenous birds for resources, including nest sites, roosting sites, and food. Availability of mallards, mallard ducklings, and fertilised mallard eggs for public sale and private ownership, either as poultry or as pets, is currently legal in the United States, except for the state of Florida , which has currently banned domestic ownership of mallards. This

1767-462: A shallow water reservoir, situated 25 km (15 mi) northwest of Ahmedabad and most popular birding place near Ahmedabad after Nal Sarovar Bird Sanctuary which is about 50 km (30 mi) from Thol Wildlife Sanctuary. Geographically Thol Wildlife Sanctuary falls in Mehsana district of North Gujarat . Kadi, a taluka headquarters of the district, is just 22 km (14 mi) away from

1860-777: A strong flavour. They were first domesticated in Southeast Asia at least 4,000 years ago, during the Neolithic Age , and were also farmed by the Romans in Europe, and the Malays in Asia . As the domestic duck and the mallard are the same species as each other, it is common for mallards to mate with domestic ducks and produce hybrid offspring that are fully fertile. Because of this, mallards have been found to be contaminated with

1953-512: A variety of waterfowl including mallards and large numbers of geese , sarus cranes and many other waders are common site at sanctuary. According to the IUCN categorization, the birds reported in the area are: greater flamingo ( Phoenicopterus roseus ) of least concern species; Dalmatian pelican ( Pelecanus crispus ), greater spotted eagle ( Clanga clanga ), sarus crane ( Antigone antigone ), and Indian skimmer ( Rynchops albicollis ) of

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2046-418: A very small and fluctuating population. Mallards sometimes arrive on its island home during migration, and can be expected to occasionally have remained and hybridised with Laysan ducks as long as these species have existed. However, these hybrids are less well adapted to the peculiar ecological conditions of Laysan Island than the local ducks, and thus have lower fitness . Laysan ducks were found throughout

2139-518: A white square on the wings in flight, and is a smaller bird. More similar to the female mallard in North America are the American black duck ( A.   rubripes ), which is notably darker-hued in both sexes than the mallard, and the mottled duck ( A.   fulvigula ), which is somewhat darker than the female mallard, and with slightly different bare-part colouration and no white edge on

2232-721: Is 50–65 cm (20–26 in) long, of which the body makes up around two-thirds the length. The wingspan is 81–98 cm (32–39 in) and the bill is 4.4 to 6.1 cm (1.7 to 2.4 in) long. It is often slightly heavier than most other dabbling ducks, weighing 0.7–1.6 kg (1.5–3.5 lb). Mallards live in wetlands , eat water plants and small animals, and are social animals preferring to congregate in groups or flocks of varying sizes. The female lays 8 to 13 creamy white to greenish-buff spotless eggs , on alternate days. Incubation takes 27 to 28 days and fledging takes 50 to 60 days. The ducklings are precocial and fully capable of swimming as soon as they hatch. The mallard

2325-606: Is a deciduous woody shrub found in Japan . Forests where a majority of the trees lose their foliage at the end of the typical growing season are called deciduous forests. These forests are found in many areas worldwide and have distinctive ecosystems, understory growth, and soil dynamics. Two distinctive types of deciduous forests are found growing around the world. Temperate deciduous forest biomes are plant communities distributed in North and South America, Asia, Southern slopes of

2418-700: Is completed (marked by the transition from bright green spring leaves to dark green summer ones) the chlorophyll level in the leaves remains stable until cool temperatures arrive in autumn. When autumn arrives and the days are shorter or when plants are drought-stressed, the chlorophyll steadily breaks down, allowing other pigments present in the leaf to become apparent and resulting in non-green colored foliage. The brightest leaf colors are produced when days grow short and nights are cool, but remain above freezing. These other pigments include carotenoids that are yellow, brown, and orange. Anthocyanin pigments produce red and purple colors, though they are not always present in

2511-676: Is considered to be a species of least concern by the International Union for Conservation of Nature (IUCN). Unlike many waterfowl, mallards are considered an invasive species in some regions. It is a very adaptable species, being able to live and even thrive in urban areas which may have supported more localised, sensitive species of waterfowl before development. The non-migratory mallard interbreeds with indigenous wild ducks of closely related species through genetic pollution by producing fertile offspring. Complete hybridisation of various species of wild duck gene pools could result in

2604-478: Is currently introgressing into the mallard populations of the Primorsky Krai , possibly due to habitat changes from global warming . The Mariana mallard was a resident allopatric population – in most respects a good species – apparently initially derived from mallard-Pacific black duck hybrids; it became extinct in the late 20th century. The Laysan duck is an insular relative of the mallard, with

2697-400: Is formed between the leaf petiole and the stem. This layer is formed in the spring during active new growth of the leaf; it consists of layers of cells that can separate from each other. The cells are sensitive to a plant hormone called auxin that is produced by the leaf and other parts of the plant. When auxin coming from the leaf is produced at a rate consistent with that from the body of

2790-420: Is more a consequence of local ducks declining than of mallards spreading; allopatric speciation and isolating behaviour have produced today's diversity of mallard-like ducks despite the fact that, in most, if not all, of these populations, hybridisation must have occurred to some extent. Mallards are causing severe "genetic pollution" to South Africa's biodiversity by breeding with endemic ducks even though

2883-635: Is not warranted a vulnerable rating. Also, the population size of the mallard is very large. Unlike many waterfowl, mallards have benefited from human alterations to the world – so much so that they are now considered an invasive species in some regions. They are a common sight in urban parks, lakes, ponds, and other human-made water features in the regions they inhabit, and are often tolerated or encouraged in human habitat due to their placid nature towards humans and their beautiful and iridescent colours. While most are not domesticated, mallards are so successful at coexisting in human regions that

Thol Lake - Misplaced Pages Continue

2976-526: Is sometimes still used this way. It was derived from the Old French malart or mallart for "wild drake" although its true derivation is unclear. It may be related to, or at least influenced by, an Old High German masculine proper name Madelhart , clues lying in the alternative English forms "maudelard" and "mawdelard". Masle (male) has also been proposed as an influence. Mallards frequently interbreed with their closest relatives in

3069-600: Is to prevent hybridisation with the native mottled duck . The mallard is considered an invasive species in Australia and New Zealand, where it competes with the Pacific black duck (known as the grey duck locally in New Zealand) which was over-hunted in the past. There, and elsewhere, mallards are spreading with increasing urbanisation and hybridising with local relatives. The eastern or Chinese spot-billed duck

3162-530: Is useful in plant identification; for instance in parts of Southern California and the American Southeast , deciduous and evergreen oak species may grow side by side. Periods of leaf fall often coincide with seasons: winter in the case of cool-climate plants or the dry-season in the case of tropical plants, however there are no deciduous species among tree-like monocotyledonous plants, e.g. palms , yuccas , and dracaenas . The hydrangea hirta

3255-712: Is widely distributed across the Northern and Southern Hemispheres; in North America its range extends from southern and central Alaska to Mexico, the Hawaiian Islands , across the Palearctic , from Iceland and southern Greenland and parts of Morocco ( North Africa ) in the west, Scandinavia and Britain to the north, and to Siberia, Japan, and South Korea. Also in the east, it ranges to south-eastern and south-western Australia and New Zealand in

3348-586: The Agreement on the Conservation of African-Eurasian Migratory Waterbirds – an agreement to protect the local waterfowl populations – applies to the mallard as well as other ducks. The hybrids of mallards and the yellow-billed duck are fertile, capable of producing hybrid offspring. If this continues, only hybrids occur and in the long term result in the extinction of various indigenous waterfowl. The mallard can crossbreed with 63 other species, posing

3441-785: The D-loop sequence suggest that mallards may have evolved in the general area of Siberia . Mallard bones rather abruptly appear in food remains of ancient humans and other deposits of fossil bones in Europe , without a good candidate for a local predecessor species . The large Ice Age palaeosubspecies that made up at least the European and West Asian populations during the Pleistocene has been named Anas platyrhynchos palaeoboschas . Mallards are differentiated in their mitochondrial DNA between North American and Eurasian populations, but

3534-584: The European herring gull ( Larus argentatus ), the wels catfish ( Silurus glanis ), and the northern pike ( Esox lucius ). Crows ( Corvus   spp. ) are also known to kill ducklings and adults on occasion. Also, mallards may be attacked by larger anseriformes such as swans ( Cygnus   spp. ) and geese during the breeding season, and are frequently driven off by these birds over territorial disputes. Mute swans ( Cygnus olor ) have been known to attack or even kill mallards if they feel that

3627-841: The Old World mallards and the New World mallard demonstrates the extent to which the genome is shared among them such that birds like the Chinese spot-billed duck are highly similar to the Old World mallard, and birds such as the Hawaiian duck are highly similar to the New World mallard. The size of the mallard varies clinally ; for example, birds from Greenland , though larger, have smaller bills, paler plumage, and stockier bodies than birds further south and are sometimes classified as

3720-503: The foliage before they are shed and store them in the form of proteins in the vacuoles of parenchyma cells in the roots and the inner bark. In the spring, these proteins are used as a nitrogen source during the growth of new leaves or flowers. Plants with deciduous foliage have advantages and disadvantages compared to plants with evergreen foliage. Since deciduous plants lose their leaves to conserve water or to better survive winter weather conditions, they must regrow new foliage during

3813-775: The genus Anas , such as the American black duck , and also with species more distantly related, such as the northern pintail , leading to various hybrids that may be fully fertile. The mallard has hybridised with more than 40 species in the wild, and an additional 20 species in captivity, though fertile hybrids typically have two Anas parents. Mallards and their domestic conspecifics are fully interfertile; many wild mallard populations in North America contain significant amounts of domestic mallard DNA. Genetic analysis has shown that certain mallards appear to be closer to their Indo-Pacific relatives, while others are related to their American relatives. Mitochondrial DNA data for

Thol Lake - Misplaced Pages Continue

3906-417: The vulnerable species; and the white-rumped vulture ( Gyps bengalensis ) and Indian vulture ( Gyps indicus ) of the critically endangered species. Some of the important fauna reported in the area surrounding the lake are: bluebull ( Boselaphus tragocamelus ), golden jackal ( Canis aureus ) and blackbuck ( Antilope cervicapra ). Deciduous In the fields of horticulture and botany ,

3999-402: The wing chord is 25.7 to 30.6 cm (10.1 to 12.0 in), the bill is 4.4 to 6.1 cm (1.7 to 2.4 in), and the tarsus is 4.1 to 4.8 cm (1.6 to 1.9 in). The breeding male mallard is unmistakable, with a glossy bottle-green head and a white collar that demarcates the head and neck from the purple-tinged brown breast, grey-brown wings, and a pale grey belly. The rear of

4092-549: The winter . According to IBA reports there are 150 species of birds in the sanctuary of which nearly 60% (90 species) are stated to be waterbirds which are mostly wintering birds. The most prominent of these species is the flamingos . At one time 5-6 thousand flamingos were reported here. Sarus cranes ( Grus antigone ), the tallest of the flying birds, nest here in large numbers. The rich bird life of Thol Wildlife Sanctuary encompasses native as well as migratory birds. Many winter visitors like great white pelicans , flamingos ,

4185-480: The Falkland Islands, and South Africa. This duck belongs to the subfamily Anatinae of the waterfowl family Anatidae . Males (drakes) have green heads, while the females (hens) have mainly brown-speckled plumage . Both sexes have an area of white-bordered black or iridescent purple or blue feathers called a speculum on their wings; males especially tend to have blue speculum feathers. The mallard

4278-402: The Greenland mallard which is larger than the mallards further south. Allen's Rule says that appendages like ears tend to be smaller in polar forms to minimise heat loss, and larger in tropical and desert equivalents to facilitate heat diffusion, and that the polar taxa are stockier overall. Examples of this rule in birds are rare as they lack external ears, but the bill of ducks is supplied with

4371-515: The Hawaiian archipelago before 400   AD, after which they suffered a rapid decline during the Polynesian colonisation. Now, their range includes only Laysan Island. It is one of the successfully translocated birds, after having become nearly extinct in the early 20th century. Mallards have often been ubiquitous in their regions among the ponds, rivers, and streams of human parks, farms, and other human-made waterways – even to

4464-844: The Himalayas, Europe and for cultivation purposes in Oceania. They have formed under climatic conditions which have great seasonable temperature variability. Growth occurs during warm summers, leaf drop in autumn, and dormancy during cold winters. These seasonally distinctive communities have diverse life forms that are impacted greatly by the seasonality of their climate, mainly temperature and precipitation rates. These varying and regionally different ecological conditions produce distinctive forest plant communities in different regions. Tropical and subtropical deciduous forest biomes have developed in response not to seasonal temperature variations but to seasonal rainfall patterns. During prolonged dry periods

4557-498: The Normal Biological Spectrum (NBS) study of the sanctuary, drought resistant vegetation in the category of Bio-geographiczone – IV consisting of thorny shrubs and trees are found, and also reported are mixed flora of aquatic and marshy plants. Thol Lake, as a bird sanctuary, an inland wetland and a protected area , is known as a very good habitat for waterfowl during the monsoon season, extending through

4650-491: The Sanctuary. Thol Wildlife Sanctuary is a man-made (made by Sayajirao Gayakvad , Ruler of Baroda) irrigation tank built in 1912 with water storage capacity of 84,000,000 m (68,000 ac·ft) and command area of 1450 ha (5.6 mi) and catchment area of 153 km (59 mi). [1] The wetland is predominated by the open water habitat , which is surrounded by cropland, fallow land and scrub land. Due to its popularity amongst

4743-526: The Southern hemisphere. It is strongly migratory in the northern parts of its breeding range, and winters farther south. For example, in North America, it winters south to the southern United States and northern Mexico , but also regularly strays into Central America and the Caribbean between September and May. A drake later named "Trevor" attracted media attention in 2018 when it turned up on

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4836-460: The annual summer moult. Upon hatching, the plumage of the duckling is yellow on the underside and face (with streaks by the eyes) and black on the back (with some yellow spots) all the way to the top and back of the head. Its legs and bill are also black. As it nears a month in age, the duckling's plumage starts becoming drab, looking more like the female, though more streaked, and its legs lose their dark grey colouring. Two months after hatching,

4929-524: The area are 43 °C (109 °F) and 8 °C (46 °F). The lake is situated near Thol village 20 kilometres (12 mi) from Kalol and 40 kilometres (25 mi) north-west of Ahmedabad , 75 kilometres (47 mi) from Mehsana in Mehsana District . The lake was initially built in 1912 as a tank by the Gaekwad regime to provide irrigation facilities to farmers. This established

5022-535: The auditory basis for species identification in offspring, a process known as acoustic conspecific identification. In addition, females hiss if the nest or offspring are threatened or interfered with. When taking off, the wings of a mallard produce a characteristic faint whistling noise. The mallard is a rare example of both Allen's Rule and Bergmann's Rule in birds. Bergmann's Rule, which states that polar forms tend to be larger than related ones from warmer climates, has numerous examples in birds, as in case of

5115-408: The beginning and the end of the summer moulting period. The adulthood age for mallards is fourteen months, and the average life expectancy is three years, but they can live to twenty. Several species of duck have brown-plumaged females that can be confused with the female mallard. The female gadwall ( Mareca strepera ) has an orange-lined bill, white belly, black and white speculum that is seen as

5208-492: The bird fraternity the area was notified as Sanctuary in November 1988 under Sec. 18 of Wildlife (Protection) Act, 1972 . The best time to visit the place is November to February. Apart from trees in the peripheral area of the lake, vegetation reported in this wetland consists of emergent and floating aquatic plants of Acacia nilotica , A. leucoploea , Zizyphus , Azadirachta indica , Ficus sp., Salvadora sp., Prosopis chilensis , and Capparis sp. According to

5301-400: The breeding season, male birds were recorded to have eaten 37.6% animal matter and 62.4% plant matter, most notably the grass Echinochloa crus-galli , and nonlaying females ate 37.0% animal matter and 63.0% plant matter, while laying females ate 71.9% animal matter and only 28.1% plant matter. Plants generally make up the larger part of a bird's diet, especially during autumn migration and in

5394-455: The centre tail feather (drake feather) is curled, but in females, the centre tail feather is straight. During the final period of maturity leading up to adulthood (6–10 months of age), the plumage of female juveniles remains the same while the plumage of male juveniles gradually changes to its characteristic colours. This change in plumage also applies to adult mallard males when they transition in and out of their non-breeding eclipse plumage at

5487-841: The clutch is almost complete. Incubation takes 27–28   days and fledging takes 50–60   days. The ducklings are precocial and fully capable of swimming as soon as they hatch. However, filial imprinting compels them to instinctively stay near the mother, not only for warmth and protection but also to learn about and remember their habitat as well as how and where to forage for food. Though adoptions are known to occur, female mallards typically do not tolerate stray ducklings near their broods, and will violently attack and drive away any unfamiliar young, sometimes going as far as to kill them. When ducklings mature into flight-capable juveniles, they learn about and remember their traditional migratory routes (unless they are born and raised in captivity). In New Zealand, where mallards are naturalised ,

5580-480: The ducks pose a threat to their offspring. Common loons ( Gavia inmer ) are similarly territorial and aggressive towards other birds in such disputes, and will frequently drive mallards away from their territory. However, in 2019, a pair of common loons in Wisconsin were observed raising a mallard duckling for several weeks, having seemingly adopted the bird after it had been abandoned by its parents. In summer,

5673-428: The earliest trees to lose their leaves in the fall. In sub-Arctic climates such as Alaska , leaves begin turning colors as early as August. However, for most temperate regions it takes place in late September through early November and in subtropical climates such as the southern US, it may be November into December. Leaf drop or abscission involves complex physiological signals and changes within plants. When leafout

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5766-436: The extinction of many indigenous waterfowl. The mallard itself is the ancestor of most domestic ducks, and its naturally evolved wild gene pool gets genetically polluted in turn by the domestic and feral populations. Over time, a continuum of hybrids ranging between almost typical examples of either species develop; the speciation process is beginning to reverse itself. This has created conservation concerns for relatives of

5859-463: The extinction of many indigenous waterfowl. This species is the main ancestor of most breeds of domestic duck , and its naturally evolved wild gene pool has been genetically polluted by the domestic and feral mallard populations. The mallard was one of the many bird species originally described in the 1758 10th   edition of Systema Naturae by Carl Linnaeus . He gave it two binomial names : Anas platyrhynchos and Anas boschas . The latter

5952-701: The fall months and the Western United States as it has more evergreen and fewer deciduous plants, combined with the West Coast and its maritime climate. ( See also : Autumn leaf color ) Most of the Southern Hemisphere lacks deciduous plants due to its milder winters and smaller landmass, most of which is nearer the equator with only far southern South America and the southern island of New Zealand producing distinct fall colors. The beginnings of leaf drop starts when an abscission layer

6045-423: The female. Lebret (1961) calls this behaviour "Attempted Rape Flight", and Stanley Cramp and K.E.L. Simmons (1977) speak of "rape-intent flights". Male mallards also occasionally chase other male ducks of a different species, and even each other, in the same way. In one documented case of "homosexual necrophilia", a male mallard copulated with another male he was chasing after the chased male died upon flying into

6138-414: The fledgling period has ended, and the duckling is now a juvenile. The duckling is able to fly 50–60 days after hatching. Its bill soon loses its dark grey colouring, and its sex can finally be distinguished visually by three factors: 1)   the bill is yellow in males, but black and orange in females; 2)   the breast feathers are reddish-brown in males, but brown in females; and 3)   in males,

6231-408: The flock to begin fighting. It is possible that this behaviour allows the female to evaluate the strength of potential partners. The drakes that end up being left out after the others have paired off with mating partners sometimes target an isolated female duck, even one of a different species, and proceed to chase and peck at her until she weakens, at which point the males take turns copulating with

6324-426: The foliage is dropped to conserve water and prevent death from drought. Leaf drop is not seasonally dependent as it is in temperate climates. It can occur any time of year and varies by region of the world. Even within a small local area there can be variations in the timing and duration of leaf drop; different sides of the same mountain and areas that have high water tables or areas along streams and rivers can produce

6417-402: The genes of the domestic duck. While the keeping of domestic breeds is more popular, pure-bred mallards are sometimes kept for eggs and meat, although they may require wing clipping to restrict flying. Mallards are one of the most common species shot in waterfowl hunting due to their large population size. The ideal location for hunting mallards is considered to be where the water level

6510-420: The host mallard, but the hen may attempt to eject them or even abandon the nest if parasitism occurs during egg laying. In addition to human hunting, mallards of all ages (but especially young ones) and in all locations must contend with a wide diversity of predators including raptors and owls , mustelids , corvids , snakes , raccoons , opossums , skunks , turtles , large fish , felids , and canids ,

6603-417: The humid maritime climate and lower overall species diversity . It is also a factor that the continental United States and southern Canada are at a lower latitude than northern Europe, so the sun during the fall months is higher and stronger. This combination of strong sun and cool temperatures leads to more intense fall colors. The Southern United States also has poor fall colors due to warm temperatures during

6696-507: The island of Niue , an atypical location for mallards. The mallard inhabits a wide range of habitats and climates, from the Arctic tundra to subtropical regions. It is found in both fresh- and salt-water wetlands, including parks, small ponds, rivers, lakes and estuaries , as well as shallow inlets and open sea within sight of the coastline. Water depths of less than 0.9 metres (3.0 ft) are preferred, with birds avoiding areas more than

6789-472: The last two including domestic cats and dogs. The most prolific natural predators of adult mallards are red foxes ( Vulpes vulpes ; which most often pick off brooding females) and the faster or larger birds of prey, (e.g. peregrine falcons , Aquila or Haliaeetus eagles). In North America, adult mallards face no fewer than 15 species of birds of prey, from northern harriers ( Circus hudsonius ) and short-eared owls ( Asio flammeus ) (both smaller than

6882-507: The leaves are shed at the same time. Plants that are intermediate may be called semi-deciduous ; they lose old foliage as new growth begins. Other plants are semi-evergreen and lose their leaves before the next growing season, retaining some during winter or dry periods. Many deciduous plants flower during the period when they are leafless, as this increases the effectiveness of pollination . The absence of leaves improves wind transmission of pollen for wind-pollinated plants and increases

6975-470: The leaves. Rather, they are produced in the foliage in late summer, when sugars are trapped in the leaves after the process of abscission begins. Parts of the world that have showy displays of bright autumn colors are limited to locations where days become short and nights are cool. The New England region of the United States and southeastern Canada tend to produce particularly good autumn colors for this reason, with Europe producing generally poorer colors due to

7068-734: The main conservation risk they pose comes from the loss of genetic diversity among a region's traditional ducks once humans and mallards colonise an area. Mallards are very adaptable, being able to live and even thrive in urban areas which may have supported more localised, sensitive species of waterfowl before development. The release of feral mallards in areas where they are not native sometimes creates problems through interbreeding with indigenous waterfowl . These non-migratory mallards interbreed with indigenous wild ducks from local populations of closely related species through genetic pollution by producing fertile offspring. Complete hybridisation of various species of wild duck gene pools could result in

7161-447: The male is black, with white-bordered dark tail feathers. The bill of the male is a yellowish-orange tipped with black, with that of the female generally darker and ranging from black to mottled orange and brown. The female mallard is predominantly mottled, with each individual feather showing sharp contrast from buff to very dark brown, a coloration shared by most female dabbling ducks, and has buff cheeks, eyebrow, throat, and neck, with

7254-494: The mallard species. Ecological changes and hunting have also led to a decline of local species; for example, the New Zealand grey duck population declined drastically due to overhunting in the mid-20th century. Hybrid offspring of Hawaiian ducks seem to be less well adapted to native habitat, and using them in re-introduction projects apparently reduces success. In summary, the problems of mallards "hybridising away" relatives

7347-549: The mallard, such as the Hawaiian duck , the New Zealand grey duck ( A.   s. superciliosa) subspecies of the Pacific black duck , the American black duck, the mottled duck , Meller's duck , the yellow-billed duck , and the Mexican duck , in the latter case even leading to a dispute as to whether these birds should be considered a species (and thus entitled to more conservation research and funding) or included in

7440-478: The moulting period, which begins in June (in the Northern Hemisphere). During the brief time before this, however, the males are still sexually potent and some of them either remain on standby to sire replacement clutches (for female mallards that have lost or abandoned their previous clutch) or forcibly mate with females that appear to be isolated or unattached regardless of their species and whether or not they have

7533-444: The nesting season has been found to be longer, eggs and clutches are larger and nest survival is generally greater compared with mallards in their native range. In cases where a nest or brood fails, some mallards may mate for a second time in an attempt to raise a second clutch, typically around early-to-mid summer. In addition, mallards may occasionally breed during the autumn in cases of unseasonably warm weather; one such instance of

7626-783: The next suitable growing season; this uses resources which evergreens do not need to expend. Evergreens suffer greater water loss during the winter and they also can experience greater predation pressure , especially when small. Deciduous trees experience much less branch and trunk breakage from glaze ice storms when leafless, and plants can reduce water loss due to the reduction in availability of liquid water during cold winter days. Losing leaves in winter may reduce damage from insects; repairing leaves and keeping them functional may be more costly than just losing and regrowing them. Removing leaves also reduces cavitation which can damage xylem vessels in plants. This then allows deciduous plants to have xylem vessels with larger diameters and therefore

7719-485: The nuclear genome displays a notable lack of genetic structure. Haplotypes typical of American mallard relatives and eastern spot-billed ducks can be found in mallards around the Bering Sea . The Aleutian Islands hold a population of mallards that appear to be evolving towards becoming a subspecies , as gene flow with other populations is very limited. Also, the paucity of morphological differences between

7812-510: The other half sleeps, was first demonstrated in mallards, although it is believed to be widespread among birds in general. Since 1998, the mallard has been rated as a species of least concern on the IUCN Red List of Endangered Species . This is because it has a large range–more than 20,000,000 km (7,700,000 mi ) and because its population is increasing, rather than declining by 30% over ten years or three generations and thus

7905-469: The plant, the cells of the abscission layer remain connected; in autumn, or when under stress, the auxin flow from the leaf decreases or stops, triggering cellular elongation within the abscission layer. The elongation of these cells breaks the connection between the different cell layers, allowing the leaf to break away from the plant. It also forms a layer that seals the break, so the plant does not lose sap. Some trees, particularly oaks and beeches, exhibit

7998-525: The point of visiting water features in human courtyards . Mallards have had a long relationship with humans. Almost all domestic duck breeds derive from the mallard, with the exception of a few Muscovy breeds, and are listed under the trinomial name A. p. domesticus . Mallards are generally monogamous while domestic ducks are mostly polygamous . Domestic ducks have no territorial behaviour and are less aggressive than mallards. Domestic ducks are mostly kept for meat; their eggs are also eaten, and have

8091-406: The speculum. In captivity, domestic ducks come in wild-type plumages, white, and other colours. Most of these colour variants are also known in domestic mallards not bred as livestock, but kept as pets, aviary birds, etc., where they are rare but increasing in availability. A noisy species, the female has the deep quack stereotypically associated with ducks. The female will often call with

8184-426: The term deciduous ( / d ɪ ˈ s ɪ dʒ u . ə s / ) means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves , usually in the autumn ; to the shedding of petals , after flowering; and to the shedding of ripe fruit . The antonym of deciduous in the botanical sense is evergreen . Generally, the term "deciduous" means "the dropping of

8277-547: The user rights of the lake water. The operation and management of the lake is under the dual control of the Forest and Irrigation departments of the Government of Gujarat. The lake has a storage capacity of 84 million cubic metres (3.0 × 10 ^  cu ft). Its water spread area is 699 hectares (1,730 acres). Lake's shore length is 5.62 kilometres (3.49 mi) and water depth is shallow. Thol Wildlife Sanctuary,

8370-702: The visibility of the flowers to insects in insect-pollinated plants. This strategy is not without risks, as the flowers can be damaged by frost or, in dry season regions, result in water stress on the plant. Spring leafout and fall leaf drop are triggered by a combination of daylight and air temperatures. The exact conditions required will vary with the species, but generally more cold-tolerant genera such as Salix will leaf-out earlier and lose their leaves later, while genera such as Fraxinus and Juglans can only grow in warm, frost-free conditions so they need at least 13 hours of daylight and air temperatures of around 70 °F (21 °C) to leaf out. They will be among

8463-487: The winter. The mallard usually feeds by dabbling for plant food or grazing; there are reports of it eating frogs , other amphibians , and fish , including carcasses . However, in 2017 a flock of mallards in Romania were observed hunting small migratory birds, including grey wagtails and black redstarts , the first documented occasion they had been seen attacking and consuming large vertebrates. It usually nests on

8556-501: The year. This process is called abscission . In some cases leaf loss coincides with winter—namely in temperate or polar climates . In other parts of the world, including tropical, subtropical, and arid regions, plants lose their leaves during the dry season or other seasons, depending on variations in rainfall . The converse of deciduous is evergreen , where foliage is shed on a different schedule from deciduous plants, therefore appearing to remain green year round because not all

8649-523: Was generally preferred until 1906 when Einar Lönnberg established that A.   platyrhynchos had priority, as it appeared on an earlier page in the text. The scientific name comes from Latin Anas , "duck" and Ancient Greek πλατυρυγχος, platyrhynchus , "broad-billed" (from πλατύς, platys , "broad" and ρυγχός, rhunkhos , "bill"). The genome of Anas platyrhynchos was sequenced in 2013. The name mallard originally referred to any wild drake, and it

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