|
Abstract: Geographical distribution and movement patterns
of Cinnamon Warbling-Finch (Poospiza ornata) and Carbonated
Sierra-Finch (Phrygilus carbonarius) in Argentina.
To establish the geographic distribution of a species it is necessary
to ascertain the places where the species is likely to occur. However,
it requires verifying whether its populations are sedentary, migratory,
transient, or casual. In this study, we analyze the geographic distribution
of two endemic emberizids in Argentina, the Cinnamon Warbling-Finch
(Poospiza ornata) and the Carbonated Sierra-Finch (Phrygilus
carbonarius). To study the residence status of the populations
and movement patterns of these species we combine geographic information
about the occurrence of the species with local information about
abundance and mark-recapture studies in the central Monte desert.
Analysis at biogeographic scale showed that both species mainly
occur in arid and semi-arid environments of Argentina. The Cinnamon
Warbling-Finch shows movements that correspond to short-distance
migration. In contrast, movement patterns of the Carbonated Sierra-Finch
are not so clear because the species is always present in its central
distributional range. At local scale, in the central Monte desert,
seasonal changes in abundance were consistent with the observed
patterns in the geographic distribution and movement of both species.
Banding of birds also showed that these species are highly mobile,
at least in this region. Local results are consistent with the hypotheses
that the Cinnamon Warbling-Finch is a nomadic species in its breeding
range while the Carbonated Sierra-Finch exhibits temporal changes
in the boundary of its southern breeding range. The combined analysis
at different spatial scales allowed us to describe the movement
patterns of Cinnamon Warbling-Finch and Carbonated
Sierra-Finch. Also, it highlights the importance of having an accurate
description of the seasonal geographic distribution of birds.
|