Correlates of homing performance in Oophaga histrionica

Homing is the ability to return to previously visited sites, often to the home range. Most studies have focused on the mechanisms used to home, but few have addressed the cost-benefit analysis of homing behavior, e.g., by testing for associations between homing performance and ecological factors. We aimed to study homing ability in males of the poison frog, Oophaga histrionica, by testing the general hypothesis that homing performance depends upon potential indicators of territory quality or the risk of losing it. First, we tested whether return time was related to displacement distance, body size, number of courtships during the previous month, or distance to nearest neighbors. All males homed and males that were displaced 10 meters (m) from their territories returned significantly faster than males displaced 25 or 40 m. Yet none of the ecological variables affected homing ability. In a second experiment, we tested whether males’ homing performance was affected by adding or removing ac..., The study was conducted during July-August 2006 and June 2007 at El Amargal Biological Station, near Arusí, Chocó, Colombia (5’34” N, 77’30” W, between 60–120 m.a.s.l.), which the NGO Fundación Inguedé privately owns. At the study sites, males of O. histrionica are found calling from fallen trunks and roots, more often as discrete aggregations of contiguous territories of about 30–70 males. Aggregations appear more common at the clearings of the relatively undisturbed tropical rainforest. Due to the high (around 8000 mm/yr) and almost continuous precipitation, the calling activity appears extended throughout most of the year. We conducted our experiments on territorial males (i.e., males that were calling for several days) from two breeding aggregations, separated by about 1.7 km.
To position individual frogs, we laid out a grid of about 96 x 144 m2, subdivided into squares of 8 x 8 m2, throughout the study area. To census territorial males, 1–2 people searched daily for calling individ...,