Reproductive behavior drives female space use in a sedentary Neotropical frog

Longer-range movements of anuran amphibians such as mass migrations and habitat
invasion have received a lot of attention, but fine-scale spatial behavior remains largely
understudied. This gap is especially striking for species that show long-term site
fidelity and display their whole behavioral repertoire in a small area. Studying fine-
scale movement with conventional capture-mark-recapture techniques is difficult in
inconspicuous amphibians: individuals are hard to find, repeated captures might affect
their behavior and the number of data points is too low to allow a detailed interpretation
of individual space use and time budgeting. In this study, we overcame these limitations
by equipping females of the Brilliant-Thighed Poison Frog (Allobates femoralis) with a
tag allowing frequent monitoring of their location and behavior. Neotropical poison
frogs are well known for their complex behavior and diverse reproductive and parental
care strategies. Although the ecology and behavior of the polygamous leaf-litter frog
Allobates femoralis is well studied, little is known about the fine-scale space use of the
non-territorial females who do not engage in acoustic and visual displays. We tracked
17 females for 6 to 17 days using a harmonic direction finder to provide the first precise
analysis of female space use in this species. Females moved on average 1 m per hour
and the fastest movement, over 20 m per hour, was related to a subsequent mating
event. Traveled distances and activity patterns on days of courtship and mating differed
considerably from days without reproduction. Frogs moved more on days with lower
temperature and more precipitation, but mating seemed to be the main trigger for
female movement. We observed 21 courtships of 12 tagged females. For seven females,
we observed two consecutive mating events. Estimated home ranges after 14 days
varied considerably between individuals and courtship and mating associated space
use made up for ∼30% of the home range. Allobates femoralis females spent large parts
of their time in one to three small centers of use. Females did not adjust their time or
space use to the density of males in their surroundings and did not show wide-ranging
exploratory behavior. Our study demonstrates how tracking combined with detailed
behavioral observations can reveal the patterns and drivers of fine-scale spatial behavior
in sedentary species.