Limpkin
Encyclopedia
The Limpkin Aramus guarauna, is a bird that looks like a large rail
but is skeletally closer to cranes
. It is the only extant species in the genus Aramus and the family
Aramidae. It is found mostly in wetlands in warm parts of the Americas
, from Florida
to northern Argentina
. It feeds on molluscs, with the diet dominated by apple snails
of the genus Pomacea
. Its name derives from its seeming limp when it walks.
family
, Aramidae, which is in turn placed within the crane
and rail
order Gruiformes
. It had been suggested that the Limpkin was close to the ibis
and spoonbill
family Threskiornithidae
, based upon shared bird lice. The Sibley-Ahlquist taxonomy of birds, based upon DNA-DNA hybridization, suggested that the Limpkin's closest relatives were the Heliornithidae
finfoots, and Sibley and Monroe even placed the species in that family in 1990. More recent studies have found little support for this relationship. More recent DNA studies have confirmed a close relationship with particularly the cranes, with the Limpkin remaining as a family close to the cranes and the two being sister taxa to the trumpeter
s.
Although the Limpkin is the only extant species in the family today, there are several fossil
s of extinct Aramidae known from across the Americas. The earliest known species in the genus Aramus, Aramus paludigrus
is dated to the middle Miocene
, while the oldest supposed members of the family, Aminornis and Loncornis, have been found in early Oligocene
deposits in Argentina, although it is not certain that these are indeed related. Another Oligocene fossil from Europe, Parvigrus pohli (family Parvigruidae), has been described as a mosaic of the features shared by the limpkins and the cranes. It shares many morphological features with the cranes and limpkins, but also was much smaller than either group, and was more rail-like in its proportions. In the paper describing the fossil Gerald Mayr suggested that it was similar to the stem species of the Grues (the cranes and limpkins), and that the limpkins evolved massively long bills as a result of the specialisation to feeding on snails. In contrast, the cranes evolved into long-legged forms to walk and probe on open grasslands.
than the females in size, but there is no difference in plumage
. Its plumage is drab—dark brown with an olive luster above. The feathers of the head, neck, wing coverts, and much of the back and underparts (except the rear) are marked with white, making the body look streaked and the head and neck light gray. It has long, dark-gray legs and a long neck. Its bill is long, heavy, and downcurved, yellowish bill with a darker tip. The bill is slightly open near but not at the end to give it a tweezers-like action in removing snails from their shells, and in many individuals the tip curves slightly to the right, like the apple snails
' shells. The white markings are slightly less conspicuous in first-year birds. Its wings are broad and rounded and its tail is short. It is often confused with the immature American White Ibis
.
This bird is easier to hear than see. Its common vocalization is a loud wild wail or scream with some rattling quality, represented as "kwEEEeeer or klAAAar." This call is most often given at night and at dawn and dusk. It has been used for jungle sound effects in Tarzan
films and for the hippogriff
in the film Harry Potter and the Prisoner of Azkaban
. Other calls include "wooden clicking", clucks, and in alarm, a "piercing bihk, bihk...".
(and formerly the Okefenokee Swamp
in southern Georgia
) and southern Mexico
through the Caribbean
and Central America
to northern Argentina
. In South America
it occurs widely east of the Andes
; west of them its range extends only to the Equator
.
It inhabits freshwater marsh
es and swamp
s, often with tall reeds
, as well as mangrove
s. In the Caribbean, it also inhabits dry brushland. In Mexico and northern Central America, it occurs at altitudes up to 1500 m (4,921.3 ft). In Florida the distribution of apple snails is the best predictor of where Limpkins can be found.
The Limpkin undertakes some localised migrations
, although the extent of these are not fully understood. In some parts in the northern part of the range females (and a few males) will leave the breeding areas at the end of summer, returning at the end of winter. Birds may also migrate between Florida and Cuba. In Brazil birds breeding in some seasonal marshes will leave during the dry season and return again with the rains.
refuges, where they do not fear people, they are active during the day. Even so, they are usually found near cover.
Because of their long toes, they can stand on floating water plants. They also swim well, both as adults or as newly hatched chicks, but they seldom do so. They fly strongly, the neck projecting forward and the legs backward, the wings beating shallowly and stiffly, with a jerky upstroke, above the horizontal most of the time.
Limpkins forage primarily in shallow water and on floating vegetation such as water hyacinth
and water lettuce
. When wading they seldom go deeper than having half the body underwater, and never are submerged up to the back. They walk slowly with a gait described as "slightly undulating" and "giving the impression of lameness or limping", "high-stepping", or "strolling", looking for food if the water is clear or probing with the bill. They do not associate with other birds in mixed-species feeding flock
s, as do some other wading birds, but may forage in small groups with others of their species.
The diet of the Limpkin is dominated by apple snails
(Ampullariidae) of the genus Pomacea. The availability of this one mollusk has a significant effect on the local distribution of the Limpkin. Freshwater mussels, including Anodonta cowperiana
, Villosa vibex
, Elliptio strigosus
, E. jayensis, and Uniomerus obesus, as well as other kinds of snails, are a secondary food sources. Less important prey items are insect
s, frog
s, lizard
s, crustacean
s and worm
s. These prey items may be important in periods of drought or flooding when birds may be pushed into less than optimal foraging areas. In one site in Florida moon snails
and mussels were the most important prey items. Two studies, both in Florida, have looked at the percentage composition of the diet of Limpkins. One, looking at stomach contents, found 70% Pomacea apple snails, 3% Campeloma
and 27% unidentified mollusc, probably Pomacea.
When a Limpkin finds an apple snail, it carries it to land or very shallow water and places it in mud, the opening facing up. It deftly removes the operculum
or "lid" and extracts the snail, seldom breaking the shell. The extraction takes 10 to 20 seconds. The orange-yellow yolk gland of female snails is usually shaken loose and not eaten. It often leaves piles of empty shells at favored spots.
, which can vary in size from just 0.15 to 4 hectare
s. In large uniform swamps nesting territories can often be clumped together, in the form of large colonies
. These are vigorously defended, with males flying to the territory edges to challenge intruders and passing Limpkins being chased out of the territory. Territorial displays between males at boundaries include ritualized charging and wing-flapping. Females may also participate in territorial defence but usually only against other females or juveniles. Territories may be maintained year-round or abandoned temporarily during the non-breeding season, usually due to lack of food.
Limpkins may be either monogamous
, with females joining a male's territory, or serially polyandrous
, with two or more females joining a male. With the monogamous pairs, banding
studies have shown that a small number of pairs will reform the following year (4 out of 18 pairs).
Nests maybe be built in a wide varaiety of places, either on the ground, in dense floating vegetation, in bushes, or at any height in trees. They are bulky structures of rushes
, sticks or other materials. Nest building is undertaken by the male initially, who will construct the nest in his territory prior to pair-bond formation. Unpaired females will visit a number of territories before settling on a male to breed with. Males may initially challenge and fight off prospective mates, and may not accept first-year females as mates. Pair-bond formation may take a few weeks. Courtship feeding is part of the bonding process, where males catch and process a snail and then feed it to the female.
The clutch consists of 3 to 8 eggs
, with 5 to 7 being typical and averaging 5.5, which measure 6 ×. The egg color is highly variable. Their background color ranges from gray-white through buff to deep olive, and they are marked with light-brown and sometimes purplish-gray blotches and speckles. The eggs are laid daily until the clutch is complete, and incubation
is usually delayed until the clutch is completed. Both parents incubate the eggs during the day, but only the female incubates at night. The shift length is variable, but the male incubates for longer during the day. The male remains territorial during incubation, and will leave the clutch to chase off intruders; if this happens the female will return quickly to the eggs. The incubation period is about 27 days, and all the eggs hatch within 24 hours of each other.
The young hatch covered with down
, capable of walking, running, and swimming. They follow their parents to a platform of aquatic vegetation where they will be brooded. They are fed by both parents; they reach adult size at 7 weeks and leave their parents at about 16 weeks.
s. There are also reports of adults with serious foot and leg injuries, suggesting that they may have been attacked by turtles while standing on floating vegetation. Their nests are apparently predated by snakes, racoon
s, crows and muskrats. Foraging adults may in times of drought be victims of kleptoparasitism
by Snail Kite
s, and the attempted theft of apple snails caught by Limpkins has also been observed in Boat-tailed Grackle
s.
Rallidae
The rails, or Rallidae, are a large cosmopolitan family of small to medium-sized birds. The family exhibits considerable diversity and the family also includes the crakes, coots, and gallinules...
but is skeletally closer to cranes
Crane (bird)
Cranes are a family, Gruidae, of large, long-legged and long-necked birds in the order Gruiformes. There are fifteen species of crane in four genera. Unlike the similar-looking but unrelated herons, cranes fly with necks outstretched, not pulled back...
. It is the only extant species in the genus Aramus and the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Aramidae. It is found mostly in wetlands in warm parts of the Americas
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
, from Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
to northern Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
. It feeds on molluscs, with the diet dominated by apple snails
Ampullariidae
Ampullariidae, common name the apple snails, is a family of large freshwater snails, aquatic gastropod mollusks with a gill and an operculum...
of the genus Pomacea
Pomacea
Pomacea is a genus of freshwater snails with gills and an operculum, aquatic gastropod mollusks in the family Ampullariidae. As Pomacea or sometimes incorrectly Ampullarius it is commonly sold as "[color] mystery snail" in aquariums in the United States.- Species :Species in the genus Pomacea...
. Its name derives from its seeming limp when it walks.
Taxonomy and systematics
The Limpkin is placed in its own monotypicMonotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, Aramidae, which is in turn placed within the crane
Crane (bird)
Cranes are a family, Gruidae, of large, long-legged and long-necked birds in the order Gruiformes. There are fifteen species of crane in four genera. Unlike the similar-looking but unrelated herons, cranes fly with necks outstretched, not pulled back...
and rail
Rallidae
The rails, or Rallidae, are a large cosmopolitan family of small to medium-sized birds. The family exhibits considerable diversity and the family also includes the crakes, coots, and gallinules...
order Gruiformes
Gruiformes
The Gruiformes are an order containing a considerable number of living and extinct bird families, with a widespread geographical diversity. Gruiform means "crane-like"....
. It had been suggested that the Limpkin was close to the ibis
Ibis
The ibises are a group of long-legged wading birds in the family Threskiornithidae....
and spoonbill
Spoonbill
Spoonbills are a group of large, long-legged wading birds in the family Threskiornithidae, which also includes the Ibises.All have large, flat, spatulate bills and feed by wading through shallow water, sweeping the partly opened bill from side to side...
family Threskiornithidae
Threskiornithidae
The family Threskiornithidae includes 34 species of large terrestrial and wading birds, falling into two subfamilies, the ibises and the spoonbills. It was formerly known as Plataleidae. The spoonbills and ibises were once thought to be related to other groups of long-legged wading birds in the...
, based upon shared bird lice. The Sibley-Ahlquist taxonomy of birds, based upon DNA-DNA hybridization, suggested that the Limpkin's closest relatives were the Heliornithidae
Heliornithidae
The Heliornithidae are a small family of tropical birds with webbed lobes on their feet like those of grebes and coots. The family overall are known as finfoots, although one species is known as a Sungrebe. The family is composed of three species in three genera.-Description:Finfoots resemble...
finfoots, and Sibley and Monroe even placed the species in that family in 1990. More recent studies have found little support for this relationship. More recent DNA studies have confirmed a close relationship with particularly the cranes, with the Limpkin remaining as a family close to the cranes and the two being sister taxa to the trumpeter
Trumpeter (bird)
The trumpeters are a family of birds restricted to the humid forests of the Amazon and Guiana Shield in South America. They are named for the trumpeting or cackling threat call of the males. The three species resemble chickens in size; they measure 45 to 52 centimetres long and weigh 1 to 1.5...
s.
Although the Limpkin is the only extant species in the family today, there are several fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s of extinct Aramidae known from across the Americas. The earliest known species in the genus Aramus, Aramus paludigrus
Aramus paludigrus
Aramus paludigrus is an extinct species of limpkin, semi-aquatic birds related to cranes , which are similar. Aramus paludigrus was found in the famous fossil site of La Venta, dating from the mid-Miocene period, in central Colombia...
is dated to the middle Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
, while the oldest supposed members of the family, Aminornis and Loncornis, have been found in early Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
deposits in Argentina, although it is not certain that these are indeed related. Another Oligocene fossil from Europe, Parvigrus pohli (family Parvigruidae), has been described as a mosaic of the features shared by the limpkins and the cranes. It shares many morphological features with the cranes and limpkins, but also was much smaller than either group, and was more rail-like in its proportions. In the paper describing the fossil Gerald Mayr suggested that it was similar to the stem species of the Grues (the cranes and limpkins), and that the limpkins evolved massively long bills as a result of the specialisation to feeding on snails. In contrast, the cranes evolved into long-legged forms to walk and probe on open grasslands.
Description
The Limpkin is a somewhat large bird, 66 cm (26 in) long, with a wingspan of about 102 cm (40 in) and a weight of about 1.1 kg (2.4 lb). The males are slightly largerSexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
than the females in size, but there is no difference in plumage
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
. Its plumage is drab—dark brown with an olive luster above. The feathers of the head, neck, wing coverts, and much of the back and underparts (except the rear) are marked with white, making the body look streaked and the head and neck light gray. It has long, dark-gray legs and a long neck. Its bill is long, heavy, and downcurved, yellowish bill with a darker tip. The bill is slightly open near but not at the end to give it a tweezers-like action in removing snails from their shells, and in many individuals the tip curves slightly to the right, like the apple snails
Ampullariidae
Ampullariidae, common name the apple snails, is a family of large freshwater snails, aquatic gastropod mollusks with a gill and an operculum...
' shells. The white markings are slightly less conspicuous in first-year birds. Its wings are broad and rounded and its tail is short. It is often confused with the immature American White Ibis
American White Ibis
The American White Ibis is a species of wading bird in the ibis family Threskiornithidae. It occurs from the mid-Atlantic and Gulf coast of the United States south through most of the New World tropics...
.
This bird is easier to hear than see. Its common vocalization is a loud wild wail or scream with some rattling quality, represented as "kwEEEeeer or klAAAar." This call is most often given at night and at dawn and dusk. It has been used for jungle sound effects in Tarzan
Tarzan
Tarzan is a fictional character, an archetypal feral child raised in the African jungles by the Mangani "great apes"; he later experiences civilization only to largely reject it and return to the wild as a heroic adventurer...
films and for the hippogriff
Hippogriff
A Hippogriff is a legendary creature, supposedly the offspring of a griffin and a mare.- Early references :...
in the film Harry Potter and the Prisoner of Azkaban
Harry Potter and the Prisoner of Azkaban (film)
Harry Potter and the Prisoner of Azkaban is a 2004 fantasy film directed by Alfonso Cuarón and based on the novel of the same name by J. K. Rowling. It is the third instalment in the Harry Potter film series, written by Steve Kloves and produced by Chris Columbus, David Heyman and Mark Radcliffe...
. Other calls include "wooden clicking", clucks, and in alarm, a "piercing bihk, bihk...".
Range and habitat
The Limpkin occurs from peninsular FloridaFlorida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
(and formerly the Okefenokee Swamp
Okefenokee Swamp
The Okefenokee Swamp is a shallow, 438,000 acre , peat-filled wetland straddling the Georgia–Florida border in the United States. A majority of the swamp is in Georgia and protected by the Okefenokee National Wildlife Refuge and the Okefenokee Wilderness. The Okefenokee Swamp is considered to be...
in southern Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
) and southern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
through the Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
and Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
to northern Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
. In South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
it occurs widely east of the Andes
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
; west of them its range extends only to the Equator
Equator
An equator is the intersection of a sphere's surface with the plane perpendicular to the sphere's axis of rotation and containing the sphere's center of mass....
.
It inhabits freshwater marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....
es and swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
s, often with tall reeds
Reed bed
Reed beds are natural habitats found in floodplains, waterlogged depressions andestuaries. Reed beds are part of a succession from young reed colonising open water or wet ground through a gradation of increasingly dry ground...
, as well as mangrove
Mangrove
Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...
s. In the Caribbean, it also inhabits dry brushland. In Mexico and northern Central America, it occurs at altitudes up to 1500 m (4,921.3 ft). In Florida the distribution of apple snails is the best predictor of where Limpkins can be found.
The Limpkin undertakes some localised migrations
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
, although the extent of these are not fully understood. In some parts in the northern part of the range females (and a few males) will leave the breeding areas at the end of summer, returning at the end of winter. Birds may also migrate between Florida and Cuba. In Brazil birds breeding in some seasonal marshes will leave during the dry season and return again with the rains.
Behavior
Limpkins are largely nocturnal and crepuscular, except that in FloridaFlorida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
refuges, where they do not fear people, they are active during the day. Even so, they are usually found near cover.
Because of their long toes, they can stand on floating water plants. They also swim well, both as adults or as newly hatched chicks, but they seldom do so. They fly strongly, the neck projecting forward and the legs backward, the wings beating shallowly and stiffly, with a jerky upstroke, above the horizontal most of the time.
Feeding
Limpkins forage primarily in shallow water and on floating vegetation such as water hyacinth
Water hyacinth
The seven species of water hyacinth comprise the genus Eichhornia. Water hyacinth are a free-floating perennial aquatic plant native to tropical and sub-tropical South America. With broad, thick, glossy, ovate leaves, water hyacinth may rise above the surface of the water as much as 1 meter in...
and water lettuce
Pistia
Pistia is a genus of aquatic plant in the arum family, Araceae. The single species it comprises, Pistia stratiotes, is often called water cabbage, water lettuce, or Nile cabbage. Its native distribution is uncertain, but probably pantropical; it was first described from the Nile near Lake Victoria...
. When wading they seldom go deeper than having half the body underwater, and never are submerged up to the back. They walk slowly with a gait described as "slightly undulating" and "giving the impression of lameness or limping", "high-stepping", or "strolling", looking for food if the water is clear or probing with the bill. They do not associate with other birds in mixed-species feeding flock
Mixed-species feeding flock
A mixed-species feeding flock, also termed a mixed-species foraging flock, mixed hunting party or informally bird wave, is a flock of usually insectivorous birds of different species, that join each other and move together while foraging...
s, as do some other wading birds, but may forage in small groups with others of their species.
The diet of the Limpkin is dominated by apple snails
Ampullariidae
Ampullariidae, common name the apple snails, is a family of large freshwater snails, aquatic gastropod mollusks with a gill and an operculum...
(Ampullariidae) of the genus Pomacea. The availability of this one mollusk has a significant effect on the local distribution of the Limpkin. Freshwater mussels, including Anodonta cowperiana
Anodonta
Anodonta is a genus of medium-sized to large freshwater mussels, aquatic bivalve molluscs in the family Unionidae.-Species:Species in this genus include:* Duck mussel, Anodonta anatina Linné, 1758* Anodonta beringiana Middendorff, 1851...
, Villosa vibex
Villosa
Villosa is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae.-Species within the genus Villosa:* Villosa amygdala* Villosa arkansasensis* Villosa choctawensis* Villosa constricta...
, Elliptio strigosus
Elliptio
Elliptio is a genus of medium-sized to large-sized freshwater mussels, aquatic bivalve mollusks in the family Unionidae, commonly known as the unionids, freshwater mussels or naiads. In contrast with many other groups of American unionidae, the Elliptio reach their greatest diversity in the...
, E. jayensis, and Uniomerus obesus, as well as other kinds of snails, are a secondary food sources. Less important prey items are insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s, lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s, crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s and worm
Worm
The term worm refers to an obsolete taxon used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, and stems from the Old English word wyrm. Currently it is used to describe many different distantly-related animals that typically have a long cylindrical...
s. These prey items may be important in periods of drought or flooding when birds may be pushed into less than optimal foraging areas. In one site in Florida moon snails
Natica
Natica is a genus of small to medium-sized predatory sea snails, marine gastropods in the family Naticidae, the moon snails. The genus is known from the Cretaceous to the Recent periods.- Species :...
and mussels were the most important prey items. Two studies, both in Florida, have looked at the percentage composition of the diet of Limpkins. One, looking at stomach contents, found 70% Pomacea apple snails, 3% Campeloma
Campeloma
Campeloma is a genus of gilled operculate freshwater snails in the family Viviparidae. They are common in unpolluted rivers in the eastern United States and southeastern Canada.-Species:Species within the genus Campeloma include:...
and 27% unidentified mollusc, probably Pomacea.
When a Limpkin finds an apple snail, it carries it to land or very shallow water and places it in mud, the opening facing up. It deftly removes the operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...
or "lid" and extracts the snail, seldom breaking the shell. The extraction takes 10 to 20 seconds. The orange-yellow yolk gland of female snails is usually shaken loose and not eaten. It often leaves piles of empty shells at favored spots.
Reproduction and breeding
Males have exclusive territoriesTerritory (animal)
In ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...
, which can vary in size from just 0.15 to 4 hectare
Hectare
The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...
s. In large uniform swamps nesting territories can often be clumped together, in the form of large colonies
Bird colony
A bird colony is a large congregation of individuals of one or more species of bird that nest or roost in close 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...
. These are vigorously defended, with males flying to the territory edges to challenge intruders and passing Limpkins being chased out of the territory. Territorial displays between males at boundaries include ritualized charging and wing-flapping. Females may also participate in territorial defence but usually only against other females or juveniles. Territories may be maintained year-round or abandoned temporarily during the non-breeding season, usually due to lack of food.
Limpkins may be either monogamous
Monogamy
Monogamy /Gr. μονός+γάμος - one+marriage/ a form of marriage in which an individual has only one spouse at any one time. In current usage monogamy often refers to having one sexual partner irrespective of marriage or reproduction...
, with females joining a male's territory, or serially polyandrous
Polyandry
Polyandry refers to a form of marriage in which a woman has two or more husbands at the same time. The form of polyandry in which a woman is married to two or more brothers is known as "fraternal polyandry", and it is believed by many anthropologists to be the most frequently encountered...
, with two or more females joining a male. With the monogamous pairs, banding
Bird ringing
Bird ringing or bird banding is a technique used in the study of wild birds, by attaching a small, individually numbered, metal or plastic tag to their legs or wings, so that various aspects of the bird's life can be studied by the ability to re-find the same individual later...
studies have shown that a small number of pairs will reform the following year (4 out of 18 pairs).
Nests maybe be built in a wide varaiety of places, either on the ground, in dense floating vegetation, in bushes, or at any height in trees. They are bulky structures of rushes
Juncaceae
Juncaceae, the rush family, are a monocotyledonous family of flowering plants. There are eight genera and about 400 species. Members of the Juncaceae are slow-growing, rhizomatous, herbaceous plants, and they may superficially resemble grasses. They often grow on infertile soils in a wide range...
, sticks or other materials. Nest building is undertaken by the male initially, who will construct the nest in his territory prior to pair-bond formation. Unpaired females will visit a number of territories before settling on a male to breed with. Males may initially challenge and fight off prospective mates, and may not accept first-year females as mates. Pair-bond formation may take a few weeks. Courtship feeding is part of the bonding process, where males catch and process a snail and then feed it to the female.
The clutch consists of 3 to 8 eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
, with 5 to 7 being typical and averaging 5.5, which measure 6 ×. The egg color is highly variable. Their background color ranges from gray-white through buff to deep olive, and they are marked with light-brown and sometimes purplish-gray blotches and speckles. The eggs are laid daily until the clutch is complete, and incubation
Avian incubation
Incubation refers to the process by which certain oviparous animals hatch their eggs, and to the development of the embryo within the egg. The most vital factor of incubation is the constant temperature required for its development over a specific period. Especially in domestic fowl, the act of...
is usually delayed until the clutch is completed. Both parents incubate the eggs during the day, but only the female incubates at night. The shift length is variable, but the male incubates for longer during the day. The male remains territorial during incubation, and will leave the clutch to chase off intruders; if this happens the female will return quickly to the eggs. The incubation period is about 27 days, and all the eggs hatch within 24 hours of each other.
The young hatch covered with down
Down feather
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding,...
, capable of walking, running, and swimming. They follow their parents to a platform of aquatic vegetation where they will be brooded. They are fed by both parents; they reach adult size at 7 weeks and leave their parents at about 16 weeks.
Ecology
Limpkins are reported to be attacked and eaten by American AlligatorAmerican Alligator
The American alligator , sometimes referred to colloquially as a gator, is a reptile endemic only to the Southeastern United States. It is one of the two living species of alligator, in the genus Alligator, within the family Alligatoridae...
s. There are also reports of adults with serious foot and leg injuries, suggesting that they may have been attacked by turtles while standing on floating vegetation. Their nests are apparently predated by snakes, racoon
Racoon
Racoon is a Dutch rock band, formed in 1997. Their first big appearance was at the 1999 Noorderslagfestival. First album Till Monkeys Fly appeared in January 2000, produced by Michael Schoots . The first single, Feel Like Flying, became a hit and got a lot of airplay on the Dutch radiostation 3FM...
s, crows and muskrats. Foraging adults may in times of drought be victims of kleptoparasitism
Kleptoparasitism
Kleptoparasitism or cleptoparasitism is a form of feeding in which one animal takes prey or other food from another that has caught, collected, or otherwise prepared the food, including stored food...
by Snail Kite
Snail Kite
The Snail Kite is a bird of prey within the family Accipitridae, which also includes the eagles, hawks, and Old World vultures. Its relative, the Slender-billed Kite, is now again placed in Helicolestes, making the genus Rostrhamus monotypic...
s, and the attempted theft of apple snails caught by Limpkins has also been observed in Boat-tailed Grackle
Boat-tailed Grackle
The Boat-tailed Grackle is a passerine bird of the family Icteridae found as a permanent resident on the coasts of the southeastern USA. It is found in coastal saltwater marshes, and, in Florida, also on inland waters. The nest is a well-concealed cup in trees or shrubs near water; three to five...
s.
External links
- Limpkin videos, photos & sounds on the Internet Bird Collection
- Limpkin Bird Sound