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.

No abstract

Hopkins’ Bioclimatic Law predicts geographical patterns in phenological timing by establishing a correspondence between latitudinal and altitudinal gradients. First proposed for key phenological events of plants, such as leaf sprouting or flowering dates, this law has rarely been used to assess the geographical equivalence of key life‐history traits of mammals. We hypothesize that (H1) parturition dates of European roe deer Capreolus capreolus are delayed and more synchronized at higher latitudes and altitudes, (H2) parturition timing varies along latitudinal and altitudinal gradients in a way that matches the Hopkins’ Bioclimatic Law and (H3) females adjust parturition timing to match the period of high energy demand with peak resource availability. We used parturition dates of 7,444 European roe deer from Switzerland to assess altitudinal variation in birth timing and synchrony from 288 to 2,366 m a.s.l. We then performed a literature survey to compare altitudinal results with those from different populations along the species’ latitudinal range of distribution. Finally, we performed spatial analysis combining our highly resolved altitudinal data on parturition dates with plant phenology data. As expected, parturition dates were delayed with increasing latitude and altitude. This delay matched the Bioclimatic Law, as the effect of 1º increase in latitude was similar to 120 m increase in altitude. However, while parturitions were more synchronized with increasing altitude, we did not detect any trend along the latitudinal gradient. Finally, plant phenology explained altitudinal variation in parturition timing better than a linear effect of altitude. Our findings clearly demonstrate the ability of a large herbivore to match parturition timing with phenological conditions across the altitudinal gradient, even at the smallest spatial scales.

1. Mediterranean oak woodlands are currently undergoing considerable anthropogenic changes that globally threaten their long-term persistence. Restoration efforts via assisted regeneration depend on species traits and type of stress.However, how different sources of stress vary across space (microsites) and time (intra-and inter-annual variation) for co-occurring oak species remains largely unknown.2. We examined spatio-temporal variation of biotic (herbivory, seed predation) and abiotic (drought) stress agents to evaluate seedling survival across different regeneration microsites, and considering two climatically contrasting years. We used two co-occurring species of contrasting ecology and leaf traits in California oak woodlands: the deciduous Quercus lobata (valley oak) and the evergreen Q. agrifolia (coast live oak).3. Most oak seedlings (98.8%) suffered from some type of stress. For both species, summer drought was the main cause of mortality, followed by rodent damage, ungulate browsing and insect damage. Rodents represented the predominant biotic stress, as all rodent-affected seedlings eventually died. Interactions among stress factors were nuanced: insect and ungulate-browsing stresses were greater during dry year, whereas rodent damage was similar in dry and average years. Intra-annually, rodent damage was the main stress agent in early spring, whereas water stress and ungulate-browsing were greater from late spring to early fall. Plant species traits were also determinant: overall, the evergreen species had greater survival probability than the deciduous one. 4. Across microsites, water stress showed higher occurrence in open grassland habitats, while rodent damage was prevalent under palatable shrubs and ungulate browsing under conspecific trees. Shrub and tree cover reduced damage attributed to water stress but increased rodent and ungulate damage, respectively. Interestingly, lower water stress but higher rodent damage was found further inside the shrub cover. 5. Synthesis and applications. Intra-and inter-annual variation are critical determinants of stress type and intensity on oak recruitment. Spatial variation (microsite K E Y W O R D S deer browsing, leaf economic spectrum, Mediterranean oak woodlands, plant facilitation, regeneration niche, rodent, ungulates, water stress | 2665 Journal of Applied Ecology LÓPEZ-SÁNCHEZ Et aL.

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Body length and weight relationships were estimated for sixteen native freshwater fish species (ten Characidae, three Loricariidae, two Heptapteridae and one Astroblepidae, mainly small-sized fish) collected in the Andean piedmont Hacha River (Caqueta´, Colombia) by electrofishing. These are the first length-weight and length-length parameters reported for the species, which are mostly endemic to the Amazonian basin. Maximum lengths in eight of the sixteen studied species are also reported. Knowledge of this biometric data and their relationships can be relevant in the management and conservation of the local fish and fisheries.

Advancing plant phenology causes an increasing trophic mismatch in an income breeder across a wide elevational range.

Fundamental understanding of the factors influencing cervid antler size, development and investment has been traditionally drawn from harvest data. However, depending on the hunting tactic, harvest data may not represent a random sample of the population leading to possible inferential biases. Cast antlers may represent an alternative, cost-effective and non-invasive method. We used 4756 red deer (Cervus elaphus L.) cast antlers collected during a 10-year period to evaluate the relationship between annual antler gross score and three key environmental components that determine habitat quality and resource availability in Mediterranean systems: (1) population traits (density and male age structure), (2) acorn yield and (3) a proxy of plant productivity [Real Bioclimatic Index(RBI)]. Population traits and acorn yield were measured before antler formation (autumn/winter) whereas RBI was calculated before (autumn/winter) and during (spring) antler formation. Population traits explained the highest amount of variance in antler score, followed by acorn yield and spring RBI, while no effect was found for autumn/winter RBI. Antler gross score was negatively related to population density but positively associated with acorn yield, spring RBI and male age structure. Interestingly, a significant interaction between population traits and acorn yield suggests a disproportional effect of population traits on antler size during non-mast years (poor acorn crops), whereas no significant population effect was observed during mast years. Similarly, we found a positive effect of spring RBI on antlers when density was medium or low and/or age structure was balanced or older. These findings have important ecological implications in environments with high inter-annual resources variability where high population densities lead to strong intraspecific competition during years of low food availability (e.g. during non-mast years or drier springs), producing large antler size variation. Finally, although cast antlers reflect changes in environmental conditions we do not recommend their use unless reliable data on age structure is available.