Home Range, Territory, and Partner Replacement in the Rufous Hornero Furnarius rufus

Abstract

The way an animal uses the home range and territory often vary in time according to its breeding state and habitat complexity. Adult dispersal can follow partner replacement, however little is known about seasonal/sex variation in partner replacement in tropical passerines. Here we tested if home range and territory size of the Rufous Hornero Furnarius rufus varies between the breeding and non-breeding seasons and if this variation is consistent across three distant populations in Brazil (UFJF, UnB, and MT). In addition, we described the frequency of partner replacements in relation to sex and breeding state in two of those populations (UFJF and UnB). We observed a decrease in 33% and 38% of home range size in the non-breeding season for two sites (UFJF and MT). Territory size decreased by 50% in the non-breeding season in UnB, but this could be due to a lower sampling effort during this season. Nevertheless, the home range expansion is consistent with a higher demand for resources during the breeding season. Home range sizes, but not sizes of territories, varied across sites. We also recorded 26 partner replacements, with no sign of sex or seasonal bias. Most replaced birds disappeared, suggesting that both sexes are under similar mortality risks, a usual main driver of partner replacement. Pair bonds lasted three or more years in 25% of the studied pairs. Altogether, these results provide insights for future studies on underlying mechanisms shaping home ranging, territoriality, and partner replacement in tropical birds that defend year-round territories.