Data from: Good guardian, bad parent: tradeoffs between territory defense and parental care in Darwin’s finches

Although defending a territory may benefit individuals by allowing them to
retain important resources, the time and energy costs associated with
territory defense may lead territory owners to neglect other
reproductively important behaviors. In this study, we assessed the
potential trade-off between territory defense and parental care in four
Darwin’s finch species on Floreana Island, Galápagos. First, using song
playback, we simulated territory intrusions to measure male aggressiveness
across multiple stages of the breeding cycle (unpaired, paired,
incubating, and chick feeding). We conducted 168 playback trials at 98
nests (37 small ground finch, 28 medium tree finch, 27 small tree finch, 6
cactus finch). To quantify parental care at each nest, we conducted
one-hour observations to record the frequency of male food deliveries and
the duration of female incubation and brooding. We conducted 113 parental
care observations at 59 nests (24 small ground finch, 18 small tree finch,
15 medium tree finch, 2 cactus finch). By breeding stage, we conducted 76
observations at 53 nests during the incubation period (mean ± SE
observations per nest = 1.43 ± 0.07, range 1–3) and 37 observations at 28
nests during the chick feeding period (1.32 ± 0.12 observations per nest,
range 1–3).