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Blue-gray gnatcatcher

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(Redirected from Polioptila caerulea)

Blue-gray gnatcatcher
Call recorded in Minnesota
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Polioptilidae
Genus: Polioptila
Species:
P. caerulea
Binomial name
Polioptila caerulea
(Linnaeus, 1766)
Geographical distribution of
blue-gray gnatcatcher
  Breeding
  Year-round
  Nonbreeding
  Nonbreeding (scarce)
Synonyms

Motacilla caerulea Linnaeus, 1766

The blue-gray gnatcatcher (Polioptila caerulea) is a very small gnatcatcher native to North America.

Description

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It is 10–13 cm (3.9–5.1 in) in length, 6.3 in (16 cm) in wingspan,[2] and weighing only 5–7 g (0.18–0.25 oz).[3][4] Adult males are blue-gray on the upperparts with white underparts, slender dark bill, and a long black tail edged in white. Females are less blue, while juveniles are greenish-gray. Both sexes have a white eye ring.

Distribution and habitat

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The blue-gray gnatcatcher's breeding habitat includes open deciduous woods and shrublands in southern Ontario, the eastern and southwestern United States, and Mexico. Though gnatcatcher species are common and increasing in number while expanding to the northeast,[5][full citation needed] it is the only one to breed in Eastern North America. They migrate to the southern United States, Mexico, northern Central America (Belize, Guatemala, and Honduras), Cuba, the Bahamas, the Turks and Caicos Islands, and the Cayman Islands.

Diet and behaviour

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Blue-gray gnatcatchers prefer humid areas with large leaves, woodlands, and more open sandy areas with sparse trees where they mainly eat insects, insect eggs, and spiders. The males often work to build nests, help incubate and raise the young, as well as feed the children, often thought to be a mother's role. Their nests are often built far out on a tree's branch with spider silks and lichen plants holding them together.[6] They may hover over foliage while snatching prey (gleaning), or fly to catch insects in flight (hawking). The tail is often held upright while defending territory or searching for food.[7]

Sounds

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The songs (and calls) are often heard on breeding grounds, (usually away from nest) and occasionally heard other times of the year. Calls: "zkreee, zkreee, zkreee", Songs: "szpree zpree spreeeeey spree spre sprzrreeeee"

Breeding

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Both parents build a cone-like nest on a horizontal tree branch, and share feeding the young. The incubation period is 10–15 days for both sexes, where the female lays a clutch of 4–5 eggs.[8] The blue-gray gnatcatcher can raise up to two broods in a season.[9]

Blue-gray gnatcatcher nest made of lichens, hair, and spiderwebs
A juvenile blue-gray gnatcatcher in San Bruno
A juvenile blue-gray gnatcatcher in San Bruno

References

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  1. ^ BirdLife International (2016). "Polioptila caerulea". IUCN Red List of Threatened Species. 2016: e.T22711581A94302237. doi:10.2305/IUCN.UK.2016-3.RLTS.T22711581A94302237.en. Retrieved 13 November 2021.
  2. ^ "Blue-gray Gnatcatcher Identification, All About Birds, Cornell Lab of Ornithology". www.allaboutbirds.org. Retrieved 2020-09-28.
  3. ^ "Blue-gray Gnatcatcher". All About Birds. Cornell Lab of Ornithology.
  4. ^ "Blue-gray Gnatcatcher Polioptila caerulea". eNature.com. Archived from the original on 2012-04-28.
  5. ^ Greenberg, Russell (2001). Birds of North America. Sean Moore.
  6. ^ González-García, Fernando (2020). "First record of non-migratory Blue-gray Gnatcatcher (Polioptila caerulea) as a host to the Bronzed Cowbird (Molothrus aeneus) in Mexico". The Wilson Journal of Ornithology. 132 (3). doi:10.1676/20-96. S2CID 233429970.
  7. ^ "Blue-gray Gnatcatcher". NATURE WEB. Retrieved 2023-01-05.
  8. ^ "Blue-gray Gnatcatcher | State of Tennessee, Wildlife Resources Agency".
  9. ^ "Blue-gray Gnatcatcher". Audubon. 2014-11-13. Retrieved 2023-01-05.
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