Data from: Home-range size of an Andean bird: assessing the role of physical condition

Because space-use patterns are a key aspect of the ecology and
distribution of species, identifying factors associated with variation in
size of territories and home ranges has been central to studies on
population ecology. Space use might vary in response to extrinsic factors
like habitat quality and to intrinsic factors like physical condition and
individual behavior (aggressiveness). However, the role of these factors
has been poorly documented in the tropics, particularly in high-elevation
bird species. We report the home-range size of a Neotropical Andean bird,
the Grey-browed Brush finch (Arremon assimilis), and evaluate the role of
physical condition in explaining variation in home-range size among
individuals. We performed spot mapping to estimate the home ranges of 14
territorial males in Bogotá, Colombia, using minimum convex polygons (MCP)
and 95% kernel density estimators (KDE). The mean home-range size
estimated for the 100% MCP was 0.522 ± 0.305 ha (range = 0.15-1.18 ha),
whereas the 95% KDE estimation was 0.504 ± 0.471 ha (range = 0.13-1.88).
We calculated the real mass index of each bird as a proxy of physical
condition to assess whether individuals in better physical condition had
larger home-ranges. Because we found no relation between our estimations
of physical condition and home-range size, we conclude that space use in
this species might depend more on ecological factors such as habitat
quality or neighbor density than on individual traits.