Age-dependent relationships between multiple sexual pigments and condition in males and females

The reliability of sexual signaling may change across age classes due to shifts in resource allocation patterns. Two contrasting hypotheses exist regarding how the condition dependence of ornaments may shift with age, and both have received empirical support. On one hand, ornaments may more reliably reflect condition and quality in older individuals, because younger individuals of high quality invest in survival over signaling effort. On the other hand, the condition dependence of ornaments may decline with age, if older individuals in poor condition terminally invest in ornaments, or if resource constraints decline with age. Further, the expression and condition dependence of different ornaments may shift with age in unique ways, such that multifaceted sexual displays maintain reliable signaling across age classes. In yellow warblers (Setophaga petechia) of both sexes, we assessed how relationships between carotenoid-and phaeomelanin-based sexual pigmentation, prenesting body reserves, and condition at molt (reflected by growth bars and feather quality) vary across age classes. Melanin coverage correlated with condition at molt across age classes in males and showed high repeatability in both sexes. In contrast, carotenoid saturation increased longitudinally with age in males and correlated with condition at molt in different age classes in the 2 sexes. Specifically, carotenoid saturation correlated positively with condition at molt in younger, but not older males, whereas in females, the situation was reversed, with a positive correlation present only in older females. Results suggest that age-dependent signaling may promote maintenance of multifaceted sexual displays and that agedependent signaling dynamics depend on sex. © The Author 2013. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved

Data from: Elevating perceived predation risk modifies the relationship between parental effort and song complexity in the song sparrow (Melospiza melodia)

Adult-directed predation risk elevates costs of parental care, and may modify relationships between sexually selected ornaments and parental effort by accentuating the tradeoff between survival and parental investment. We assessed multiple hypotheses regarding the relationship between maternal effort, paternal effort, and the sexually selected trait of male song complexity in the song sparrow Melospiza melodia. Further, we explored whether experimentally elevating perceived adult-directed predation risk near nests affected these relationships. We quantified two dimensions of song complexity: song repertoire size and residual syllable number (the relative number of syllables for a given song repertoire size). Under elevated perceived predation risk, but not in the absence of the predator stimuli, females mated to males with higher residual syllable number displayed higher nestling provisioning rates and performed a greater proportion of nestling provisioning trips. In other words, elevating perceived predation risk induced a pattern of maternal investment consistent with differential allocation. In contrast, under elevated perceived predation risk, only, females performed a lesser proportion of provisioning trips when mated to males with large song repertoire sizes. Further, consistent with the good parent hypothesis, males with large song repertoire sizes displayed lower latencies to return to the nest, independent of the predator stimuli. Results suggest that residual syllable number may reflect some aspect of male genetic quality, such that females are more willing to maintain maternal effort while facing heightened predation risk. On the other hand, females may gain paternal benefits when mated to males with large song repertoires. Our study supports the hypothesis that increased costs of parental care associated with predation risk may induce relationships between sexually selected traits and parental behavior, which may increase the strength of sexual selection. Additionally, results suggest that different aspects of song complexity may fulfill non-equivalent signaling roles

Data for-Personality and plasticity in neophobia levels vary with anthropogenic disturbance but not toxic metal exposure in urban great tits

This file contains data from a novel object test performed on incubating female great tits in Antwerp, Belgium, in 2018, to test for effects of toxic metal pollution and anthropogenic disturbance levels on neophobia and other behavioral traits. Incubating females were presented with up to two different novel objects which were placed on the top of the nest box. We recorded the latency of females to return to the nest ("On 1" in the file) in the presence of a novel object, after being flushed from the nest. To account for differences in sensitivity to disturbance at the nest, the return latency of all females was also recorded during a baseline trial, in which females were flushed from the nest, but no novel object was placed on top of the box. The file contains information on trial type (O = object, B = baseline), female ID, study site, nest box ID, distance from the metal pollution source, distance from public paths/roads, and whether or not the box was in a publicly accessible area for all trials. Nest date, recording time, the order of trials and female age (ASY=after second year, SY=second year) are also included. The column "On 1" contains return latencies, and was our primary response variable. Female novel environment exploration scores and hissing (nest defense) scores are also included, as are fledgling numbers. This data was used to assess relationships between neophobia, other behavioral traits, and fitness

Avian Energetics in a Warming Arctic

The Arctic is warming nearly four times as rapidly as other regions of the planet, challenging the capacity of organisms to cope with shifting resources and maintain thermal balance. Tracking responses of free-living animals in dynamic environments can be challenging, but is increasingly enabled by advanced biologging approaches. We used data gathered from miniaturized bird-borne devices to demonstrate increases in energy expenditure with declining sea ice conditions and warming sea surface temperatures in a dove-sized seabird, the little auk (also named dovekie; Alle alle). This keystone species feeds on sea ice-associated copepods and inhabits large breeding colonies in the High Arctic