%0 Journal Article
%T Raising young with limited resources: supplementation improves body condition and advances fledging of Canada Jays
%A Alex O. Sutton
%A Amy E. M. Newman
%A D. Ryan Norris
%A Nikole E. Freeman
%J Ecology - Wiley Online Library
%D 2019
%R https://doi.org/10.1002/ecy.2909
%X Food availability early in life can play a vital role in an individual's development and success, but experimental evidence for the direct effects of food on body condition, physiology, and survival of young animals in the wild is still relatively scarce. Food©\caching Canada Jays (Perisoreus canadensis) begin breeding in the late winter and, therefore, rely on either cached food or seemingly limited quantities of fresh food to feed nestlings in the early spring. Using a 2©\yr food supplementation experiment conducted during the nestling period and 40 yr of observational data on food supplemented by the public, we examined whether food quantity during early life influenced the physiology, body condition, timing of fledging, and survival of young Canada Jays in Algonquin Provincial Park, Ontario, Canada. Experimental food supplementation of breeding pairs advanced the fledging date of young by 24% (5.5 d) compared to controls. In 1 yr of the experiment, nestlings raised on experimentally supplemented territories had lower feather corticosterone concentrations and were in higher body condition than controls. Across treatment and control nests, young that successfully fledged had lower concentrations of feather corticosterone and were in higher body condition than those that did not fledge. Based on 40 yr of observational data, nestling body condition was positively related to the degree of food supplementation by park visitors and nestlings in higher body condition were more likely to be observed in the population in the following fall. Our results demonstrate how food availability early in life can have important downstream consequences on metrics related to individual fitness, including first year survival. Resource availability can be a major constraint in wild animals because the amount of energy available to an individual is intimately linked with its survival and reproduction (Erikstad et al. 1998, Post and Forchhammer 2008). In particular, food quantity during reproduction plays a vital role in the growth and development of offspring. Across taxa, access to greater amounts of food influences offspring body size (Kager and Fietz 2009), growth rates (Woods and Armitage 2003, Vafidis et al. 2016), immune system development (De Neve et al. 2004), and oxidative stress response (Young et al. 2017). Typically, parents aim to maximize access to food during reproduction by timing breeding with pulses in resource availability (Lack 1954, Daan et al. 1989). However, when peak energy demands in reproduction are not matched with pulses of resources, reproductive
%U https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/ecy.2909