Climate,female traits and population features as drivers of breeding timing in Mediterranean red deer populations

Understanding the factors that lead to variation in the timing of breeding in widespread species such as red deer(Cervus elaphus)is crucial to predict possible responses of wild populations to different climate scenarios.Here,we sought to further understand the causes of inter-annual variation in the reproduction timing of female deer in Mediterranean environments.An integrative approach was used to identify the relative importance of individual,population and climate traits in the date of conception of free-ranging deer,based on a dataset of 829 hinds culled during 12 years.We found that a population trait,density,was the most important factor explaining the variation in conception dates,with greater densities causing later conception dates.Body mass was the second in importance,with heavier females conceiving earlier than lighter ones.Almost equally important was the spring real bioclimatic index,a measure of plant productivity,causing later conception dates in the least productive springs(drier and hotter).Another climatic component,the end of summer drought,showed that the sooner the autumn arrives(greater rainfalls and cooler temperatures)the earlier the conception dates.Interestingly,age class was found to be a minor factor in determining conception date.Only older females(≥10 years old)conceived significantly later,suggesting reproductive senescence.This study highlights not only the importance of population and individual traits but also the influence of climatic parameters on the deer reproductive cycle in Mediterranean environments,giving valuable insight into how reproductive phenology may respond to seasonality and global climate changes.

Early life investment in antlers and body growth reflects adult performance in roe deer population under supplementary feeding conditions

Recent research has challenged the idea that cervid antlers are such costly traits,supporting the assertion early-life antler investment is an honest signal of adult phenotypic quality.However,inferences were made based on antler measurements while growing(velvet)and thus,studies on fully-formed clean antlers are needed to avoid possible bias caused by the inter-individual variation in antler growth phenology.We studied a semi-captive population of European roe deer inhabiting a sub-Mediterranean area(Valsemana research station)and living under optimal conditions(ad libitum food supply and veterinary care).Based on repeated measurements taken from 146 individuals,we assessed whether allocation to secondary sexual traits during early life affected body mass or antler development during adulthood.Furthermore,we evaluated which body measurements better predicted future male quality.Additionally,using 488 individuals,we described age-class-specific variation in male body measurements and assessed the decline in antler size between adult and senescent stages(i.e.magnitude of senescence).Results agree with the assertion that there is no negative effect of a high investment in antler during early life on adult antler size or body mass,but we suggest the use of clean antlers as a more robust and reliable measure.The variables that better predicted body mass during adulthood were yearling body mass and body size at 6 months.Antler score between 10 and 18 months resulted in the best indicator of adult antler size.Finally,we support the idea that the magnitude of senescence in antler size is smaller in environments with higher resource availability during winter.