Belding's Yellowthroat
The subspecies Geothlypis beldingi goldmani
The Belding Yellowthroat ( Geothlypis beldingi ) is a small passerine bird in the genus of the Common Yellowthroat ( Geothlypis ) in the family of warblers ( Parulidae ). Robert Ridgway is named after the American ornithologist Lyman Belding. The distribution area is located in Baja California Sur on the narrow peninsula of Baja California in Mexico. The IUCN lists the species since 2000 as " threatened with extinction " ( critically endangered ).
Features
Belding Yellowthroat reach a body length of 14 centimeters and weigh 13.8 to 17.7 grams. The wing length is 6 to 6.4 inches in the male, the female from 5.7 to 6 inches. They are similar in appearance to the Bahama Yellowthroat ( Geothlypis rostrata ). Adult male Belding Yellowthroat the nominate have a black face mask that is connected via the beak, attached wide, yellow forehead crown band that runs up below the ears ceilings and an olive green to brown tinted crown and neck feathers. The wings and the tail feathers are dull brown with olive feather edges. The top plumage is olive with faded olive flanks and sides of the chest, the underside plumage bright yellow, belly somewhat dull. The beak is black; the legs are flesh-colored.
In the adult female Belding Yellowthroat the black face mask and forehead crown band missing. The crown plumage is olive green with brown pigments. The reins and ear covers are grauoliv and the narrow Superciliarstreifen and broken eye ring olive yellow. The top plumage is olive; the underside pale yellow plumage, often with a whitish belly plumage. On the flanks of the plumage is olive-brown washy. Male individuals of the subspecies Geothlypis b. goldmani the off-white forehead crown band.
Resources, nutrition and reproduction
Belding Yellowthroat have a highly fragmented distribution area. They are endemic in the state of Baja California Sur in Mexico. Belding Yellowthroat inhabit freshwater marshes with one consisting of reeds, cattails or Ordinary Teichbinse vegetation and the edges of lagoons. They feed mainly on insects and other invertebrates that they ferret out in the lower vegetation. Hatched from March to May Her deep, cup-shaped nest they create from a height of 1.5 meters, among others, in the cattails or sometimes on the ordinary Teichbinse. The nest is built from plant parts of the inhabited water plants and grass blades, and padded the inside of the nest with fine animal hair and plant fibers. A clutch consists of two to four eggs ( usually three). About the Bebrütungs and nestling period, there are no studies.
Subspecies
The systematic division into two subspecies is not universally accepted. By some zoologists the Belding Yellowthroat is considered monotypic with different color variations.
There are two recognized subspecies:
- Geothlypis b. beldingi Ridgway, 1882
- Geothlypis b. goldmani Oberholser, 1917
Together with the willow Yellowthroat ( Geothlypis trichas ), the Bahama Yellowthroat ( Geothlypis rostrata ) and the gold crown Yellowthroat ( Geothlypis flavovelata ) forms the Belding Yellowthroat a super species. Some authors grazing and Belding Yellowthroat is also regarded as conspecific.
Conservation status and population numbers
From the IUCN they are conducted since 2000 as " threatened with extinction " ( critically endangered ). The main cause is habitat destruction. Under the Birds BirdLife International, there are occurrences of the nominate of about 70 birds in Punta San Pedro and 219-480 in San Jose del Cabo. Previously, the subspecies was also in the south of the state of Baja California to the north of La Paz in Baja California Sur before. The population, however, broke together because of habitat destruction. The subspecies Geothlypis b. goldmani comes with approximately 537-648 individuals from around the town of San Ignacio and about with 203-405 individual animals to Mulege and La Purisima. Other deposits are found in Comondú; the population size is unknown. Formerly they were also spread around Santiago, Miraflores and El Triunfo, there they were, however, eradicated.