Title:

Differences in the Nestling Diets of Sympatric Redstarts Phoenicurus phoenicurus and Black Redstarts P. ochruros: Species-Specific Preferences or Responses to Food Supply?

Subtitle:

Skład pokarmu sympatrycznie występujących kopciuszka i pleszki w okresie lęgowym —preferencje gatunkowe czy odpowiedź na warunki środowiska? ; Sources of diet segregation in coexisting redstarts

Creator:

Sedláček, Ondřej ; Fuchs, Roman ; Exnerová, Alice

Contributor:

Museum and Institute of Zoology, Polish Academy of Sciences

Publisher:

Natura Optima Dux Foundation ; Museum and Institute of Zoology, Polish Academy of Sciences

Place of publishing:

Warsaw

Date issued/created:

2007

Description:

pg(s) 99–106

Type of object:

Journal/Article

Subject and Keywords:

diet selection ; interspecific competition ; local sympatry ; urban environment ; seasonal variation ; Redundancy Analysis ; variance partitioning ; pleszka zwyczajna ; kopciuszek zwyczajny

Abstract:

We have investigated whether differences in nestling diet found between locally sympatric Redstarts and Black Redstarts are caused by species-specific preferences or by a different food supply in their territories. The diet of nestlings in a mosaic-like urban environment was studied using the neck-collar method. We found no significant difference in the length of Redstart and Black Redstart prey items. However, the two species did bring to their nestlings invertebrates of different taxa. We used the variance partitioning method based on multivariate Redundancy Analysis to test the influence of habitat, timing of breeding, and the species of redstart itself on nestling-diet composition. Most of the variance in the nestling diet (all the canonical axes explained 70.6% of the variance) could be attributed to habitat variables (34%) and the timing of breeding (8.9%), but only 8.1% to the species of redstart. We suggest that the diet of the two redstart species is influenced largely by current prey availability and, consequently, that interspecific competition is avoided primarily by territory exclusion rather than by food-niche separation. We consider the variance partitioning method to be a powerful tool for identifying the effects of various explanatory variables that could influence food composition in birds.

Relation:

Acta Ornithologica

Volume:

42

Issue:

1

Start page:

99

End page:

106

Resource type:

Text

Detailed Resource Type:

Journal

Format:

text/xml

Resource Identifier:

10.3161/068.042.0104

Source:

MiIZ PAN, call no. P.257 ; MiIZ PAN, call no. P.4568 ; click here to follow the link

Language:

eng

Language of abstract:

pol ; eng

Rights:

Rights Reserved - Free Access

Terms of use:

Copyright-protected material. May be used within the limits of statutory user freedoms

Digitizing institution:

Museum and Institute of Zoology of the Polish Academy of Sciences

Original in:

Library of the Museum and Institute of Zoology of the Polish Academy of Sciences

Access:

Open