Nuttall woodpecker
| Nuttall woodpecker | ||||||||||||
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Nuttall woodpecker ( Picoides nuttallii ) (♂) feeds nestling that is almost fully fledged. |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Picoides nuttallii | ||||||||||||
| ( Gambel , 1843) |
The Nuttallspecht ( Picoides nuttallii ) is a small great spotted woodpecker from the subfamily of the real woodpeckers, native to southwestern North America . (Picinae). It is closely related to the Palearctic small woodpecker ( Dendrocopos minor ), but is larger and looks a little darker than this. It was named after Thomas Nuttall , an important botanist and ornithologist who worked mainly in North America.
Appearance
With a body length of about 18 centimeters, the Nuttall woodpecker is only slightly larger than the native small woodpecker, but with a weight of up to 45 grams, it is almost twice as heavy. Black and white dominate the plumage. The upper side is mostly black, interspersed with relatively narrow, ladder-shaped, white stripes, which, however, are often slightly gray, so that the woodpecker looks quite dark and gloomy overall. The underside is lighter, usually very light gray or dirty white, and has clear black spots in the flank area; a black banding on the lower abdomen, rump and on the underside of the tail. The face is very dark due to the wide black eye mask and the strip of beard attached to it and the nape of the neck. The white stripes in between are narrow and often inconspicuous. Males wear a brick-red occipital cap that females lack. The forehead and crown are dashed with different intensities of white if the basic color is black. There is a small orange-yellow bulge above the upper beak, which is a little less noticeable in the female.
Possible confusion
It differs well from the somewhat smaller downy woodpecker ( P. pubescens ) by the ladder-shaped white markings of the dorsal plumage and the black markings on the belly and rump, both of which are missing in P. pubescens ; is difficult from the type Texas Specht ( P. scalaris to differentiate), the distribution area of the Nuttalspechtes overlaps slightly with the. Overall, the smaller Texas woodpecker looks lighter, the ladder-backed woodpecker is very distinctive. The yellow upper beak approach is inconspicuous in the Texas woodpecker. In the face of the Nuttal woodpecker black predominates, in the Texas woodpecker however white; In contrast to the Texas woodpecker, the black eye mask of the Nuttall woodpecker is connected to the black nape of the neck plumage.
Systematics
The Nuttall woodpecker belongs to a small group of small Nearctic woodpeckers, from which the Palearctic small woodpecker ( Dendrocopos minor ) probably also descends. Hybridization is documented with the downy woodpecker and with the Texas woodpecker . Most of these woodpeckers are assigned to the genus Picoides , earlier they formed the genus Dryobates , a generic name that is discussed again today and is occasionally used for the small woodpecker ( Dryobates minor ). No subspecies are described.
The species occasionally hybridizes with the Texas woodpecker and the downy woodpecker.
distribution and habitat
The Nuttal Woodpecker is found in all of coastal California west of the mountain and desert zones. To the north it reaches the border with Oregon , in the southern regions of which it should occasionally also breed, to the south the breeding occurrences extend to northern Baja California . An isolated population east of the Sierra Nevada exists in the Owens River valley .
The Nuttall woodpecker is a character bird of light oak forests and oak trees. In the dry southern areas of distribution, it is mainly found along rivers and in canyons . Tale oak , blue oak , black oak and coastal oak populations ( Quercus agrifolia ) are preferred. The oak forests are often mixed with various types of willow and stocks of the western Sycamore and the Oregon maple . On the Baja California it nests in groups of trees along periodic river courses. When searching for food, the woodpecker can also be seen in conifer populations, especially in those of the nut pines .
Nuttall woodpeckers inhabit the coastal forests as well as areas up to an altitude of almost 2000 meters.
hikes
This species of woodpecker remains in the breeding area or at least in large areas throughout the year. Occasionally autumn migrations to higher areas seem to occur, especially breeding sites in Canynos are often cleared in autumn.
Food and subsistence
Nuttall woodpeckers feed primarily on insects. Mainly beetles and their wood-dwelling larvae, ants, mainly those from the family of scale ants , caterpillars, termites and flies. Vegetarian food seems to play a certain role in the season; Elderberries and conifer seeds in particular are consumed in autumn and winter and can make up up to 20 percent of the total amount of food. Also, almonds are likely to be a not insignificant part of the diet occasionally. Nuttall woodpeckers were not observed when ringing , but they do exploit ringed areas of other woodpeckers, especially those of the red-breasted sap-litter ( Sphyrapicus ruber ). Natural exit points for tree sap are also used.
The Nuttall woodpecker prey on its food both by superficial hammering, by poking in cracks and crevices as well as by searching the surface of the bark. While foraging for food he is almost exclusively in the middle and upper trunk region or in the crown area; it is rarely found on the ground.
Breeding biology
The mating season begins in the southern breeding areas in January, further north in mid-February, in the mountain regions at the beginning of March. Nothing is known about the pairing itself and the duration of the partnership, but a largely monogamous breeding season connection is likely. The nest hole is almost exclusively cut by the male in an already rotten or dead tree, mainly at heights over five meters, but often significantly higher. Willow and poplar seem to be preferred because of their rather soft wood. Apparently this woodpecker creates a new nest hole every year; it is therefore an important supplier of breeding caves for other cave breeders.
The egg-laying begins in the south at the end of March, in the north not until mid-May, sometimes not until the beginning of June, whereby the June clutches are often secondary clutches. Little information is available about the clutch size; a full clutch probably consists of 4-5 (2-6) white or creamy white, unspotted, elliptical eggs with an average size of 22 × 16 millimeters.
Insufficient information is available about the incubation period, nestling and leadership times. An observation determined an incubation time of 14 days and a nestling time of 15 days. Overall, the male seems to be a little more involved in brooding and feeding the nestlings than the female.
Stock situation
The total population is roughly estimated at 100,000 to 200,000 breeding pairs. The stocks are considered stable, the species is not recorded in any endangerment category.
literature
- Factsheet Birdlife International engl.
- Peter E. Lowther: Nuttall's Woodpecker (Picoides nuttallii) . In The Birds of North America, No. 555 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA. Issue 555 - (no pagecount).
- Roger T. Peterson: Western Birds . Houghton Mifflin Co. Boston 1990: pp. 224-229.
- Hans Winkler , David A. Christie, David Nurney: Woodpeckers. A Guide to the Woodpeckers, Piculets, and Wrynecks of the World. Pica Press, Robertsbridge 1995, ISBN 0-395-72043-5 .
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Sources cited
- ^ Lowther (2000) Systematics
- ↑ Winkler et al. (1995) p. 283
- ^ Lowther (2000) Habit
- ^ Lowther (2000) Diet
- ^ Lowther (2000) Breeding
- ↑ Birdlife (2006)
Web links
- Videos, photos and sound recordings of Picoides nuttallii in the Internet Bird Collection
- Dryobates nuttallii inthe IUCN 2013 Red List of Threatened Species . Listed by: BirdLife International, 2012. Retrieved February 2, 2014.