Spruce tyrant
| Spruce tyrant | ||||||||||||
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Spruce tyrant ( Contopus cooperi ) on a control room |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Contopus cooperi | ||||||||||||
| ( Nuttall , 1831) |
The spruce tyrant ( Contopus cooperi ) is a medium-sized bird species from the family of the tyrants (Tyrannidae), which is native to the cold temperate coniferous forests and western mountain forests of North America. Despite his rather inconspicuous coloring, he is quite a conspicuous species with his preference for very prominent seaters and the distinctive singing. In English his piercingly loud vocal verse becomes joking but aptly with "quick, three beers!" ("Quick, three beers!", Audio sample).
description
The spruce tyrant is about as tall as a star with a body length of 18 to 20 cm , but significantly lighter at 32–37 g. The head appears large, the beak powerful and the tail short compared to that of other tyrant species. The sexes do not differ. The plumage on the upper side is overall dark gray-brown with indistinct, light-colored wing bands and light-colored hems on the umbrella feathers and inner arm wings. The underside is predominantly whitish to light gray, with the streaky gray-brown tinted flanks separating from the white throat and the middle of the chest and abdomen like an open vest. The upper beak is blackish, the lower beak, horn-colored, light with a dark tip.
The juvenile dress is similar to that of adult birds, but is more brown on the top with beige instead of whitish hems on the wing feathers.
Birds in the southwestern range are slightly larger and are therefore sometimes referred to as subspecies C. c. marjorinus separated from the nominate form . Usually the species is viewed as monotypical .
distribution
The breeding area of the spruce tyrant extends over the boreal coniferous forest zone of North America and along the Rocky Mountains and the mountains of the Pacific coast to northern Baja California .
Alaska colonizes the species south of the Brooks range , but occurs only sparsely on the west coast. In Canada, the area extends through the southern Yukon and the Northwest Territories and, excluding the Prairie Pothole region, through the southern provinces to Newfoundland . The northern limit of the distribution runs through northern Ontario and central Québec and Labrador .
In the United States, the distribution on the west coast extends through parts of Washington , Oregon and California . It is very fragmented in southern California and extends over Baja California Norte in Mexico . Large parts of Idaho and Utah , western Montana , Wyoming and Colorado as well as northern Arizona and New Mexico are settled in the Rocky Mountains . There is a small enclave in the Guadalupe Mountains in Texas . Furthermore, the southern edge of the distribution runs through the middle of the Great Lakes in Minnesota , Wisconsin and Michigan as well as through western New York and the New England states . There are scattered occurrences in the Appalachian Mountains south to North Carolina .
hikes
The spruce tyrant is a long-distance migrant whose migration routes and duration are among the longest in the Nearctic. It spends the winter half-year in Central and South America and only stays for a few months in the breeding areas when there are enough large insects for food.
The autumn migration begins with individual specimens at the end of July, reaches its peak between mid-August and mid-September and is completed by mid-October at the latest.
The main wintering areas are in Panama and in the Andes area in northwestern South America, where they extend south from northern and western Venezuela to southeastern Peru and western Bolivia . The species is most common in the Colombian Andes. Occasionally it also winters in other parts of South America such as the Guyanas , Trinidad , southern Venezuela, the Brazilian Amazon basin, and southern Peru. From southern Mexico to Guatemala and Belize as well as in the mountains of Costa Rica and Panama it is only an irregular winter visitor.
The winter quarters are cleared between the end of March and the beginning of May. The main migration period is between the end of April and the end of May. The arrival dates vary depending on the geographical location; within the first decade of June, however, the last stragglers arrive in the breeding areas.
habitat
The spruce tyrant inhabits coniferous forests of the montane level and the boreal zone . It occurs at heights between sea level and the tree line, but is most commonly found at an altitude of 920–2130 m. In Colorado and New Mexico it is still breeding bird at an altitude of over 3000 m. Within the forest areas, the species can often be found on the edge of clearings, fields and forest fire areas as well as at natural transitions to moors, swamps or river banks. Dead and isolated trees are important, which the spruce tyrant uses to sit in when looking for food.
nutrition
The spruce tyrant feeds almost exclusively on flying insects, which it prey on in fishing flights from seat guards. These are mostly dead, protruding branches from individual trees, overhangs or trees in sparse forests. Main prey form Hymenoptera such as bees , wasps or ants , but also Fly , Schuppenflügler , grasshoppers and dragonflies are part of the food spectrum.
Reproduction
The spruce tyrant presumably leads a monogamous seasonal marriage, although there have been cases in which the pair bond was broken after losing a brood. There is an annual brood.
The pairing takes place with the arrival of the females and can take up to two weeks. The main breeding season is between the end of May / beginning of June and the end of July with slight shifts depending on the geographical location, altitude and weather conditions.
The nesting place is chosen by the female and is between 1.5 and 34 m in coniferous, less often in deciduous trees. The nest is built by the female within 5 to 7 days at some distance from the trunk on more or less densely interwoven needle branches on larger branches. It is a loosely shaped, relatively flat and small bowl made of twigs and roots. Beard lichens are also often used. Sometimes the hollow is padded with grass, roots or pine needles. The nest has an average diameter of 11.8 cm, the nesting trough 7 cm in diameter.
The clutch almost always consists of three, more rarely four or even five eggs of about 22 × 16 mm in size. On a creamy white, beige or matt salmon-colored background, they wear a band of grayish to brownish spots almost in the middle, slightly towards the blunt end. They are incubated by the female for about 2 weeks before the young hatch. Both parents feed and after 15–19 days the young fly out. They are still dependent on feeding for a week and stay in the vicinity of the nesting site for around 10–15 days.
Inventory development
The species reaches its greatest population density in western North America. There are no estimates of the total stock. Since there has been a significant population decline of around 75% in the last forty years, the species was placed on the IUCN's warning list 
(= Near Threatened - potentially endangered). Presumably, habitat losses as well as changed methods in forestry and the associated poor breeding success are the cause. On the other hand, forest management tends to be beneficial for this species in many places. There may also be unknown causes of danger in the winter quarters.
literature
- Bob Altman, Rex Sallabanks: Olive-sided Flycatcher (Contopus cooperi) in A. Poole (Ed.): The Birds of North America Online , Cornell Lab of Ornithology, Ithaca 2000, doi : 10.2173 / bna.502
- DA Sibley: The Sibley Field Guide to Birds of Eastern North America , AA Knopf, New York 2003, ISBN 0-679-45120-X
Web links
- Contopus cooperi in the endangered Red List species the IUCN 2012. Posted by: BirdLife International, 2008. Accessed June 22, 2012th
- Videos, photos and sound recordings on Contopus cooperi in the Internet Bird Collection
- xeno-canto: Sound recordings - Olive-sided Flycatcher ( Contopus cooperi )