Changes in home range of breeding and post-breeding male Pearly-eyed Thrashers in the Luquillo Mountains of Puerto Rico

Abstract

Food abundance, time of year, and stage of the reproductive cycle are important factors affecting home range size in birds. Between 23 January and 28 November 2003, we determined the home range and core area sizes for 10 radio-tagged male Pearly-eyed Thrashers (Margarops fuscatus; Mimidae) within the Luquillo Experimental Forest, northeastern Puerto Rico. We found significant differences among the breeding stages in home range and core area sizes. Egg and nestling stages showed the largest and smallest home range sizes (medians = 2.0 and 0.5 ha, respectively) and core area sizes (median = 0.14 and 0.09 ha, respectively). The reduced area used by the male during the nestling stage may be attributable to a shift in the male's wandering behavior while the female incubates to the defense and feeding of nestlings. Home range sizes were significantly larger during the post-breeding period (median = 17.9 ha, range = 0.5–178.7 ha) than during the breeding period (median = 2.1 ha, range = 1.3–7.7 ha). We suggest that the increase in home range size during post-breeding season was a response to the abundance of palm fruits (Prestoea acuminata) which decreased during the breeding season. Although we found a positive correlation between number of nests with eggs and palm fruit abundance, there was no significant correlation between breeding period home range size and ripe fruit density or core area size and ripe fruit density. Lack of correlation between the area used and fruit density may be due to the omnivorous and opportunistic diet of the thrasher.

Citation

Beltran, Jose William; Wunderle, Jr., Joseph M.; Arendt, Wayne J. 2010. Changes in home range of breeding and post-breeding male Pearly-eyed Thrashers in the Luquillo Mountains of Puerto Rico. Ornitologia Neotropical. 21: 409-423.