Geographic Range
Phalaropus tricolor are found in North America during breeding season. They are located in the northwest United States and the western part of Canada. Within Canada, this species is found as far north as the Great Slave Lake, which is located in the Northwest Territories. Occasionally, Wilson's phalaropes can be found in isolated populations scattered along the entire length of the United States and Canada border that surrounds the Great Lakes.
During non breeding season, Wilson's phalaropes are found in the entire southern portion
of South America as well as the western coast extending from Lima, Peru northward
to Esmeraldas, Ecuador.
- Biogeographic Regions
- nearctic
- neotropical
Habitat
During the breeding season, Wilson's phalaropes nest in freshwater marshes. During
migration this bird species is found near ponds, in flooded fields, mud flats, along
lake shores, and in riparian habitats. Occasionally, this species can also be found
near sewage treatment plants during migration because of the sewer water. During the
winter months, Wilson phalaropes are mainly found near alkaline lakes and ponds in
South America. The elevation of this species is sea level up to 300m.
- Habitat Regions
- freshwater
- Aquatic Biomes
- lakes and ponds
- temporary pools
- Wetlands
- marsh
Physical Description
Wilson's phalaropes are shorebirds with long legs and pointed wings. This bird species has a slim neck and a long, straight bill. Male and female Wilson's phalaropes are 22cm to 24cm in length and have wingspans of 39cm to 43cm. Females tend to weigh more than males. The weight of male Wilson's phalaropes ranges from 38g to 110g, while females range from 52g to 128g. The slender build of Wilson's phalaropes helps distinguish them from other closely-related shorebirds such as Scolopacidae or more commonly known as sandpiper.
Non-breeding Wilson's phalaropes are mainly white, with black and grey feathers on
the posterior. Breeding male Wilson's phalaropes are mainly grey and black with a
light cinnamon color on the nape. Breeding females have more vibrant coloring than
breeding males. The breeding females have black feather patterns through their eyes
that flow down the nape. The throat of a breeding female is white and the nape is
stained a vibrant cinnamon color. Juvenile Wilson's phalaropes have vibrant colors
similar to the breeding female except they lack the black feather pattern through
the eyes.
- Other Physical Features
- endothermic
- bilateral symmetry
- Sexual Dimorphism
- female larger
- sexes colored or patterned differently
- female more colorful
Reproduction
Female Wilson's phalaropes are polyandrous, meaning they mate with many males. The
females attract the attention of males with aggressive motions such as whipping the
head back and forth. Occasionally, the females will get into physical altercations
with other females when trying to claim and defend her mate. Once the females has
the attention of a male, the females would then proceed in upright posture and stick
out their neck feathers in courtship.
- Mating System
- polyandrous
Male Wilson's phalaropes breed once a year. Female Wilson's phalaropes breed multiple
times a year. Breeding occurs during the months of May through August. The females
will abandon their clutch, in search of another male, while the original mate cares
for the clutch. Each one of the female's mates is responsible for a set of eggs. Clutch
size is almost always four eggs. Occasionally, a clutch will only be three, but this
is rare. Once the females lay their eggs, the male incubates them on average twenty-three
days. The young are hatched with their eyes open, fully feathered, and able to find
their own food. The young are independent after an average of one day. The young are
capable of breeding at one year old.
- Key Reproductive Features
- iteroparous
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- oviparous
Female Wilson's phalaropes choose a nesting site and lays her eggs. The female lays
her eggs on the ground and then departs to seek out another mate, leaving the male
to care for the offspring. The male will build a nest around the eggs using the surrounding
vegetation as camouflage for the nesting site. Once the incubation period ends the
young will hatch, with their eyes open and fully feathered. The young are able to
leave the nest within one day of hatching, fully able to feed independently. The male
provides protection from predators by preforming a broken wing act luring the predator
away from the young.
- Parental Investment
- precocial
- male parental care
-
pre-hatching/birth
-
provisioning
- male
-
protecting
- male
-
provisioning
-
pre-weaning/fledging
-
provisioning
- male
-
protecting
- male
-
provisioning
-
pre-independence
-
provisioning
- male
-
protecting
- male
-
provisioning
Lifespan/Longevity
The average lifespan of Wilson's phalaropes is ten years in the wild. This species
is not found in captivity. Male and female Wilson's phalaropes have the same lifespan.
This species of bird has a shorter lifespan than many other bird species. Drought
and cold weather are limiting factors for Wilson's phalaropes.
Behavior
Wilson's phalaropes are a social species. This species nests in loose colonies and during migration travels in large flocks. Wilson's phalaropes migrate from northwest United States and Canada to the southern portion of South America, which on average is 4,000 miles. During spring months, Wilson's phalaropes are located in the United States and Canada for breeding. During winter months, Wilson's phalaropes are located in South America.
Wilson's phalaropes are polyandrous. The female attracts the male with aggressive behavior and will occasionally engage in physical altercations with other females. Uniquely, male Wilson's phalarope are wholly responsible for protecting and caring for the young until hatching. The male can deter predators by acting as if he has a broken wing.
Home Range
Wilson's phalarope home range is their nesting area. The territory consist of the
size of the nest and the immediate area surrounding the nest. The average home range
is 0.5 square meters.
Scolopacidae
, commonly known as sandpiper, have a similar home range as the Wilson's phalarope.
Communication and Perception
During courtship, male and female Wilson's phalaropes make brief nasal calls to each other to keep in touch. Females will also make a deep call when communicating over long distances, however, when this species is in close range to each other they will make a soft purring call. During migration delicate gurgling is used to communicate amongst each other. Most calls are geared toward short range communication because of the gregarious life style of Wilson's phalarope.
Wilson's phalarope use smell to find their way in the skies during migration. Sense
of smell is also used to detect other Wilson's phalarope as well as predators.
- Communication Channels
- acoustic
Food Habits
Wilson's phalaropes forage for food in a unique way. This species swims around in circles creating a whirlpool. This agitates any small aquatic invertebrate and algae from the substrate of a pond or lake and brings it to the surface. This species of bird also forages in the mud surrounding the pond or lake for prey. Wilson's phalaropes will probe their bill into the mud or stand still and snatch flying insects out of the air. Wilson's phalaropes rarely pursue prey while in flight. Wilson's phalaropes eat opportunistically and their prey consist of mainly crustaceans, aquatic insects, and aquatic larvae.
Occasionally, on the migration path, Wilson's phalarope eat so much that they double
their body weight. Sometimes the extra weight prevents them from flying, which allows
researchers to easily catch them by hand.
- Primary Diet
-
carnivore
- insectivore
- eats non-insect arthropods
-
herbivore
- algivore
- Animal Foods
- insects
- aquatic crustaceans
Predation
Wilson's phalaropes have lightly colored feathers on their stomachs and the ventral
side of their wings that camouflages them from predators on the ground while in flight.
However, the feathers on the dorsal of this species are cinnamon and brown that blend
with surrounding vegetation camouflaging Wilson's phalaropes from predators while
they are on the ground. A defense mechanism commonly observed in this species is the
broken wing act. The male will mimic a broken wing to lure a predator away from his
young.
Common predators are raccoons
Procyon lotor
, skunks
Mephitis
, garter snakes
Thamnophis
, and gulls
Larus
. All of these predators prey on Wilson's phalarope eggs as well as adult Wilson's
phalaropes. However, gulls are the only predator that will not prey on the adult Wilson's
phalarope.
- Anti-predator Adaptations
- cryptic
Ecosystem Roles
Wilson's phalaropes aerate soil when searching for food by probing the soil with their
bill. Most of their food is located in the water. Wilson's phalaropes are commonly
infected with endoparasites such as
Levinseniella howensis
and ectoparasites such as bird lice. Wilson's phalaropes are considered a primary
consumer or a secondary consumer because it eats both algae and aquatic invertebrate.
- Ecosystem Impact
- soil aeration
Economic Importance for Humans: Positive
Wilson's phalaropes play a role in ecotourism. Wilson's phalaropes attract bird watchers
for many reasons. The main reason bird watchers are attracted to Wilson's phalaropes
is their unique foraging behavior. This species spins around in circles while swimming
in the water which brings their food to the surface.
- Positive Impacts
- ecotourism
Economic Importance for Humans: Negative
There are no known adverse effects of Wilson's phalarope on humans.
Conservation Status
Wilson's phalaropes are not globally threatened. They are listed on the IUCN Red List as a species of "Least Concern" due to their large geographic range. Wilson's phalarope are a protected species according to the United States Migratory Bird Act which protects Wilson's phalarope from being killed, captured, or sold. It has no special status on the Federal List as well as on the Convention on International Trade in Endangered Species of Wild Fauna and Flora list.
Threats against Wilson's phalaropes are degradation and loss of breeding habitat as
the result of drainage of wetlands. Conservation measures that are being taken are
preservation of Wilson's phalarope habitat by creating conservation sites in the breeding
territory of the United States and Canada as well as in the migratory territory of
Mexico.
Additional Links
Contributors
Casey Wood (author), Radford University, Cari Mcgregor (editor), Radford University, Zeb Pike (editor), Radford University, Karen Powers (editor), Radford University, April Tingle (editor), Radford University, Jacob Vaught (editor), Radford University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
- Nearctic
-
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- freshwater
-
mainly lives in water that is not salty.
- marsh
-
marshes are wetland areas often dominated by grasses and reeds.
- polyandrous
-
Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).
- young precocial
-
young are relatively well-developed when born
- male parental care
-
parental care is carried out by males
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- migratory
-
makes seasonal movements between breeding and wintering grounds
- colonial
-
used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.
- acoustic
-
uses sound to communicate
- cryptic
-
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
- soil aeration
-
digs and breaks up soil so air and water can get in
- ecotourism
-
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
- herbivore
-
An animal that eats mainly plants or parts of plants.
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
References
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