Data on Atlapetes pallidiceps - Recently Updated Pages

Literature cited

NKKrabbe — Tue, 22 Sep 2009 06:07:10 CDT

The following references contain information on Atlapetes pallidiceps:

Agreda, A., Krabbe, N., Rodriguez, O., 1999. Pale-headed Brush-finch Atlapetes pallidiceps is not extinct. Cotinga 11, 50–54.

Collar, N.J., Gonzaga, L.P., Krabbe, N., Nieto, A.M., Naranjo, L.G., Parker, T.A., Wege, D.C., 1992. Threatened Birds of the Americas. International Council for Bird Preservation, Cambridge.

Krabbe, N. 2004. Pale-headed Brush-finch Atlapetes pallidiceps: notes on population size, habitat, vocalizations, feeding, interference competition, and conservation. Bird Conservation International 14: 77-86.

Oppel, S., Schaefer, H. M. and Schmidt, V. 2003. Description of the nest, eggs, and breeding behavior of the endangered Pale-headed Brush-Finch (Atlapetes pallidiceps) in Ecuador. Wilson Bulletin 115: 360-366.

Oppel, S., Schaefer, H. M., Schmidt, V., Schröder, B. 2004a. Habitat selection by the Pale-headed brush-finch (Atlapetes pallidiceps) in southern Ecuador: implications for conservation. Biological Conservation 118 (2004) 33–40.

Oppel, S., Schaefer, H. M., Schmidt, V., Schröder, B. 2004b. Cowbird parasitism of Pale-headed Brush-finch Atlapetes pallidiceps: implications for conservation and management. Bird Conservation International 14: 63-75.

Oppel, S., Schaefer, H. M., Schmidt, V., Schröder, B. 2004c. How much suitable habitat is left for the last known population of the Pale-headed Brush-Finch? The Condor 106: 429-434.

Paynter, R.A., 1972. Biology and evolution of the Atlapetes schistaceus species-group. Bulletin Museum of Comparative Zoology 143, 297–320.

Paynter, R.A., 1978. Biology and evolution of the avian genus Atlapetes. Bulletin Museum of Comparative Zoology 148, 323–369.

Ridgely, R. S. and Greenfield, P. J. 2001. The birds of Ecuador. 2 vols. Ithaca, New York: Cornell University Press.

Population size and cowbird control

NKKrabbe — Sun, 03 May 2009 09:22:18 CDT

The population size was monitored during the peak song period (March), except for 1999 and 2000 when it was monitored in February and May, and in April, respectively.

Cowbird parasitism on Atlapetes pallidiceps was first noted by Krabbe and coworkers in 1999 (Krabbe 2004), but it was not until the study by Oppel and coworkers in 2002 (Oppel et al. 2004b) and the continuing studies of the breeding biology of Atlapetes pallidiceps by Mery Juiña, that the extremely high rate of parasitism was documented.

As a consequence, cowbird control by shooting commenced in 2003, and has been undertaken highly successfully by Aldo Fernando Sornoza during all following breeding seasons, with the result that parasitism has been reduced to only one or two nests anually.

The natural history of the Shiny Cowbird (Molothrus bonariensis) appears to be much like that of the better-studied Brown-headed Cowbird (Molothrus ater) of North America. Females of Brown-headed Cowbirds are known to be able to lay up to 80 eggs in a breeding season. Therefore, female cowbirds are shot preferentially at Yunguilla, where the natural sex ratio is 4-5 males per female.

The Shiny Cowbird has been reported to parasitise more than 100 different species of birds, virtually any open-nest passerine species within its range.

All cowbirds collected at Yunguilla are weighed, sexed, investigated for stomach contents, and carefully prepared as study skins. See attached file below (cowbird data.xls) for details. Two morphs of females occur, one (the commonest) beginning with streaked plumage and terminating with uniform dull black plumage, one (less common) with unstreaked pale underparts.

96 cowbird stomachs from Yunguilla contained corn (65%), ticks (Ixodes) (34%), insects (18%), seeds (14%) and blackberries (Rubus sp.) (3%).

Photos by Aldo Fernando Sornoza

Photo by Niels Krabbe

Photo by Aldo Fernando Sornoza

Botflies

NKKrabbe — Sun, 03 May 2009 04:34:19 CDT

In 37 % of all nests of Pale-headed Brush-Finches the young, usually all of them, are infested with botfly larvae, sometimes heavily so. Infested young appear to grow and fledge normally, without noticeable delay.

Botfly parasitism has not stopped the Pale-headed Brush-Finch population from increasing markedly after cowbird control began.

Photo by Mery Juiña

Photo by Martin Schaefer

Background

NKKrabbe — Tue, 24 Mar 2009 18:53:55 CDT

The Pale-headed Brush-Finch (Atlapetes pallidiceps) is confined to the Río Jubones watershed in the provinces of Azuay and Loja, south-central Ecuador. It had disappeared from known sites and had been feared extinct for over 20 years, when a small population was located in the Yunguilla Valley in November 1998.
A reserve to protect it was established, and protective measures have proven highly successful. The population has more than quadrupled, from 20-25 occupied territories in 1999 to 113 territories in 2009.
Protective measures include improvement of habitat and control of the parasitic Shiny Cowbird (Molothrus bonariensis).

Home

NKKrabbe — Thu, 27 Nov 2008 10:54:28 CST

This site gives up-to-date information on the Pale-headed Brush-Finch (Atlapetes pallidiceps) and presents primary data too large for publishing in journals.

Click the navigation panel on the left.

Site created and maintained by Niels Krabbe (nkkrabbe@snm.ku.dk).

Photo by Aldo Fernando Sornoza

How to get to the reserve

NKKrabbe — Sun, 10 Aug 2008 05:46:32 CDT

Visits to the reserve must be arranged beforehand through the office of the Jocotoco Foundation in Quito (www.fjocotoco.org).
The road from Cuenca to Machala passes by Girón and later, some 5 km before Santa Isabel, by a small town called La Unión (Cataviña on maps). From La Unión follow the roads indicated on this map. Only smaller buses and cars can get there. Local taxis that can take you there, can be hired on the corner of the main road and the western turnoff into La Unión (north is up on the map). Arrange to meet the park ranger at his house or where the arrow on the map indicates that you can leave the bus next to a water tank.

Bird list of Reserve

NKKrabbe — Sun, 10 Aug 2008 05:16:51 CDT

For a list of bird species recorded at the reserve, see attachment below ('Birdlist Yunguilla Reserve updated 2008').

Maps of territories

NKKrabbe — Sun, 03 Aug 2008 20:09:05 CDT

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Natural History

NKKrabbe — Sun, 03 Aug 2008 19:49:56 CDT

The natural history of Atlapetes pallidiceps has been studied in some detail by Krabbe and coworkers (Agreda et al. 1999, Krabbe 2004) and Oppel and coworkers (Oppel et al. 2004a,b), but far the most data has been collected by Mery Juiña with various assistants and coworkers (including Harold Greeney) from 2002 until present. Her results are expected to be published in 2008, and a summary will later appear in this section.

Photo by Aldo Fernando Sornoza

Photo by Aldo Fernando Sornoza

Songs

NKKrabbe — Wed, 14 May 2008 00:52:57 CDT

The sonograms presented show all song phrase types and their variants of territorial males tape-recorded since the species' song was recorded for the first time in 1999. The x-axis is time (0-2 s), the y-axis frequency or pitch (0-12 kHz).
Each male has a limited repertoire, which it sings year after year. The repertoire consists of one to four phrase types, each with a variable number of middle and end notes. Some males sing very distinctive songs, others share some phrase types, but can usually be distinguished by minor details and/or by other parts of their repertoire. Neighboring males with a phrase type in common, tend to use it more while countersinging, than while singing alone. A young male may learn quite complicated phrases from the adult male, to a degree where songs of the two can be told apart only with difficulty.
For much of the year song is limited to a single or a few phrases given at dawn, and at the end of the dry season, song ceases altogether.
During the breeding season, the male sings most frequently just before and during nest building, again for a few days after the eggs hatch, and finally after fledging of the young, when he guides them very carefully for a few days, singing for nearly every change of perch. This latter period may be the most important for song learning. The young stays with its parents for almost a year, but mates and sings when one year old.
Once established, most males remain in the same territory all their life. The sonograms have therefore been arranged under the territories where the songs were recorded.
Because only few birds have been color-banded so far, an estimate of the turnover rate in males (40%) was made on basis of differences in song. The attachment below (Male turnover.xls) indicates which songs were considered to be given by the same individual as the previous year. For further notes on vocalizations see Krabbe (2004).

Fundación Jocotoco

NKKrabbe — Wed, 31 Oct 2007 03:54:51 CDT

The Jocotoco Foundation purchases and manages land for preservation of globally threatened species of birds in Ecuador. The Yunguilla Reserve is one of its many reserves and was established with the sole purpose of saving the Pale-headed Brush-Finch from extinction.
The executive director of the foundation is Francisco Sornoza (photo).
For more information see www.fjocotoco.org.

Photo by Niels Krabbe

Habitat and location of territories

NKKrabbe — Sun, 28 Oct 2007 08:16:38 CDT

The Pale-headed Brush-Finch inhabits steep bushy slopes with small clearings and stands of bamboo, in a transitional zone between arid and humid climates. For more details see Krabbe (2004) and Oppel et al. (2004a). All presently known territories are located in the upper Yunguilla Valley, Azuay province, at 3°13-14'S, 79°16-18'W at elevations ranging from 1630 to 1970 m.
See the attachment below (location of territories.xls) for coordinates and elevation of each territory.

Photo by Niels Krabbe

Color banding

NKKrabbe — Sun, 28 Oct 2007 05:18:48 CDT

A systematic search for nests and color banding of fledglings has been undertaken by Mery Juiña (photo) since 2003. Three days before fledging, the birds are banded with a numbered metal ring on one leg (photo) and colored plastic rings on the other leg. For details on birds banded, recoveries and color combination used see attached file below (ringing.xls).

Territory Z

NKKrabbe — Sat, 27 Oct 2007 23:36:34 CDT