DOI: 10.5061/dryad.dc30t
title: Data from: Maternal transfer of androgens in eggs is affected by food supplementation but not by predation risk

description: Mothers may affect the future success of their offspring by varying
 allocation to eggs and embryos. Allocation may be adaptive based on the
 environmental conditions perceived during early breeding. We investigated
 the effects of food supplementation and predation risk on yolk hormone
 transfer in the pied flycatcher Ficedula hypoleuca. In a food
 supplementation experiment, females were food-supplemented prior to and
 during egg-laying and androgen concentrations were measured throughout the
 laying order. Predation risk was investigated in three different studies
 combining both correlative data, where flycatchers bred in close proximity
 to two different predator species that prey upon adult flycatchers (either
 Tengmalm's owl Aegolius funereus or pygmy owl Glaucidium passerinum),
 and an experimental manipulation, where flycatchers were exposed to cues
 of a nest predator (least weasel Mustela nivalis). Females receiving food
 supplementation laid eggs with lower concentrations of androstenedione
 (A4) than females not receiving food supplements. Yolk testosterone (T)
 concentration showed the same pattern but the difference was not
 statically significant. Testosterone (but not A4) concentration increased
 within clutches, from the first to the last egg, independently of the food
 supplementation. Females breeding under high predation risk did not differ
 from control females in their yolk androgen levels (A4, T or
 progesterone). However, concentrations of A4 tended to be lower in the
 proximity of pygmy owls, which could indirectly increase offspring
 survival after fledging. Food supplementation during egg-laying seems to
 have a stronger impact on maternal transfer of androgens than predation
 risk. Food availability and predation risk could differentially affect the
 trade-offs of androgen allocation for the offspring when raised in good
 vs. dangerous environments.
description: MorosinottoEtal_JAB2016_DatasetThe data set is composed of one excel file with several data sheets. There is one sheet per experiment/study; 3 predator studies: Pygmy owl, Tengmalm's owl, weasel and "Suppl feeding" for food supplementation study. In addition there is one separate sheet with the data on progesterone concentration in the pygmy owl study in 2009, we have no data on the concentration for this hormone in previous years so it was analyzed separately. Finally, there are three sheets for the data on female condition: Female_pygmySites, Female_Tengmalm'sSites and Female_FeedingSites. The variables listed are: location (Forest patch and Nest Box in the predators files and Nest ID in the supplementary feeding experiment), year, predator (PO pygmy owl, TO Tengmalm's owl, W weasel), Treatment (there is a comment on the file itself explaining what we mean case by case, generally 0 correspond to control/unfed/low risk site and 1 correspond to treatment/fed/high risk site), Laying date, Clutch size, Yolk mass, Egg mass, Tngg (testosterone concentration), Anngg (A4 concentration), P4ngg (progesterone concentration). In addition, in the supplementary feeding file there are also the column "ExactEggOrder" (actual order in which each egg was laid) and "Laying order" (this is the variable used in the analyses, there is a comment on the file itself explaining what we mean case by case). In the female condition files mass, wing and female hematocrit are also presented.