Alternatively egret CORT levels may be higher in younger chicks to facilitate improved begging to adults and promote growth at a critical stage in the chicks’ development since CORT . We found support for the influence of hydrological variables on egret physiology, in particular egret chick body VE-822 condition increased with increasing water depth. Critical to understanding these responses is the fact that the range of water depths associated with our study did not exceed the observed foraging range and optimal depths for egrets and generally would be considered to be shallow for egret foraging. As such, the increase in chick body condition is likely driven by the fact that egrets prefer larger prey items found in deeper depths relative to those very shallow sites where large prey die rapidly. We expect that body condition would have dropped had depths increased beyond the normal foraging range of egrets. Neither water depths nor recession rates influenced ibis chick physiological condition in the current study. Although recession rates were found to influence the pre-breeding physiological condition of ibis previously, recession rates during the nestling stage may play a smaller role in chick physiological condition because water depths have largely reached optimal foraging depths for adults around breeding colonies. Thus, small variation in water depth and recession rate likely have little influence on accessibility of foraging sites or the availability of prey for ibis. However, if rainfall events occur, rapid negative recession rates that result in increased water depths may result in the loss of foraging site access and reduced prey availability. Although these conditions did not occur in the present study, they can have a substantial effect on nestlings and would be expected to decrease chick physiological condition. Similarly, water depths were largely within the foraging range and were near optimal within the proximity of breeding colonies during this study. In fact, water depths associated with ibises were less variable than those observed in egrets. Under conditions with deeper or more variable water depths, we expect that ibises may have an increased physiological response due to their dependence on high quality foraging sites. We also found that chick age was an influential variable in explaining physiological responses, including ibis body condition and HSP60, and egret FCORT. The body condition of ibis chicks declined 26% from the youngest to the oldest chicks. Although it is unclear why chick body condition declined as they aged, there was not a concomitant increase in stress biomarkers such as FCORT or HSPs. In fact, HSP60 levels actually declined by 74% across the range of ibis chick ages. One previous study found that chickens that were experimentally fed lower energy diets, resulting in lower body masses, also had lower levels of HSPs relative to those with higher energy diets and higher masses. Ibis body condition may have declined as the chicks prepared to fledge, a period where many bird species reduce their body mass/condition. It is believed that this reduction in overall mass allows birds to change from plump immobile chicks to slender and proficient flying juveniles.