RSS 1.0Biological Sciences
The Department of Biological Sciences has an expanding research base, which, in addition to providing leading researchers of national and international standing in these areas, most importantly underpins the delivery of teaching. Research in Biological Sciences at Chester can be divided into three broad groups of expertise, namely Animal Behaviour and Conservation, Food Nutrition and Health, and Stress and Disease.
This collection is licenced under a Creative Commons licence. The collection may be reproduced for non-commerical use and without modification, providing that copyright is acknowledged.
Recent Submissions
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Dysfunctional tetraspanin 7 (TSP-7) in Caenorhabditis elegans promotes; increases in average life- & health-span, stress-induced survival and motilityCaenorhabditis elegans (C. elegans) tetraspanin-7 (TSP-7) protein is an orthologue of the Human tetraspanin CD63, which has recently been shown to be a negative regulator of autophagy. In this study a mutant strain of wild-type (WT) C. elegans (tm5761) with a 352 bp deletion in the tsp-7 gene, was studied. A polyclonal antibody was raised to a peptide sequence present only in the wild-type strain (N2). This antibody cross-reacted with the protein of the correct molecular weight (MW) in the WT lysate, but not in the tm5761, confirming the absence of a functional TSP-7 in this strain. From life-span studies, the tm5761 strain had a higher average survival age of 23.3 ± 0.6, compared to 20.1 ± 0.8 days for WT, although the absolute life-span was not statistically different. This indicates that the mutant tm5761 strain has an increased physiological health-span. Survival studies undertaken at 37 °C, showed a decrease in survival levels, with complete death of the WT occurring after 3 h of exposure, whereas the tm5761 strain was more robust (i.e. 25% survival after 3 h). Sub-lethal osmotic stress caused by increased sodium chloride (NaCl) concentrations was investigated by observing stress-related motility, such as frequency of coiling and reversing. These results showed that the tm5761 strain was more motile at higher concentrations of NaCl than the WT. These findings suggest that, like CD63, TSP-7 could be acting as a negative regulator of autophagy; therefore, the tm5761 strain likely has increased basal autophagy. This would explain its; increased, mean life- and health-span, motility under stress, and improved thermotolerance.
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Integrating human and wildlife dynamics in co‐occurrence modellingIn shared environments, where different species interact depending on overlapping resources, complex interspecific interactions emerge, with human activities impacting these dynamics and influencing wildlife abundance and distribution. In the Alps, the presence of multiple species of ungulates, such as roe deer and red deer, and a predator, the wolf, creates a web of spatial and behavioral interactions in an area where farming, hunting and tourism have persisted over time, with tourism recently experiencing a substantial growth. Accounting for these multiple interactions, we modelled the co‐occurrence probabilities of roe deer, red deer and wolves in an area of the Maritime Alps using data derived from 60 camera traps. We applied multi‐species occupancy models to investigate (i) the role of species co‐occurrences in explaining the occupancy of model species across the landscape, (ii) the role of human presence and activities on species occupancy and (iii) the potential effect of the hunting season on the species detection probabilities. Among the identified species, roe deer reported the highest frequency of recorded events and were the most widespread species. We provided important evidence of interspecific dependence, revealing that pairwise interactions among species had a greater impact than only considering individual environmental effects. We documented that the setting of cameras on trails increased the likelihood of detecting wolves but decreased the likelihood of detecting ungulates. Most importantly, the hunting season significantly reduced the likelihood of capturing roe deer, while having no effect on either red deer or wolves. Our results confirmed the relevance of including prey, predators, and human dynamics as a whole. Since the sharing of habitat makes human activities significantly important in defining predator–prey mechanisms, our insights are particularly relevant for defining solutions to optimize human‐wildlife coexistence, especially in a highly anthropogenic system such as Europe.
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SP3 protocol optimised for foodcrust protein extraction from archaeological cooking vesselsA SP3-based protocol developed for the extraction of proteins from charred organic residues (foodcrust) found on cooking vessels. This protocol is to prepare samples for MALDI-ToF MS and LC-MS/MS analysis. We recommend starting with a batch size of 2-10 samples, and including flanking negative controls (blanks) to test for any downstream contamination.
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Validating the underpinnings of water corticosterone measurement for aquatic amphibiansBACKGROUND: Good animal welfare is important ethically but also to ensure animals provide valid scientific models. Despite thousands of amphibians in research laboratories there is minimal quantitative evidence pertaining to their management and welfare. This study validated methods to non-invasively measure corticosterone, the amphibian ‘stress’ hormone, from tank water to provide a robust and reliable welfare assessment tool. METHODS: We report experiments (A) that evaluate parameters linked to the performance of our biochemical extraction methods for waterborne corticosterone and, importantly, associated sampling procedures. We evaluate appropriate sampling water type, sampling vessel, filtration methods, potential degradation of waterborne corticosterone over time and the impact of sampling procedures on animal corticosterone levels. We wanted to determine sampling parameters that yielded the least background corticosterone and had minimum negative impact on the animals. The second series of experiments (B) evaluated parameters linked to the biology of Xenopus, including the influence of circadian rhythm, sex and snout-vent length on waterborne corticosterone levels, since fundamental knowledge of a species’ biology is essential for designing robust experiments and in the interpretation of the results. RESULTS: We propose collecting corticosterone samples in deionised water in either plastic or glass containers. The filtering process does not impact the amount of corticosterone measured in the water sample. Levels of corticosterone collected in the water change over a 48-hr period so we advocate standardising time from hormone collection to storage at - 20 °C. Repeated transfer of frogs to sampling containers does not increase corticosterone, suggesting our methods are not cumulatively stressful. Corticosterone levels were not impacted by circadian phase, sex or snout-vent length. CONCLUSION: We have developed and validated robust methods to quantify waterborne corticosterone. We hope they provide a template for researchers wishing to develop methods to measure waterborne corticosterone in aquatic amphibians.
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Pain in mammals: physiology, management and assessmentPain is a sensory and emotional experience that has significant consequences on an animal’s welfare. To improve animal welfare, there is a need to prevent as well as manage pain, but we cannot manage what we cannot measure. In this chapter we highlight pains complexity, with the experience affected by multiple factors, including age, sex, personality and previous experience and remains a critical issue in veterinary care. We provide details on the physiological mechanism of pain and show how with this knowledge we can provide appropriate treatment to manage pain effectively. We acknowledge that many animals are however still experiencing pain. Even with the acceptance of animal sentience, recognizing, assessing and evaluating pain in animals is difficult. We briefly detail physiological indicators of pain such as heart rate and cortisol but acknowledge that there are difficulties in their use within veterinary clinics, for example. Behavioral indicators of pain can range from change in eating behavior to aggression. We discuss that there are many tools currently available to identify and assess pain, but that many require extensive training, are time consuming to carry out, and tend to measure the long-term impact on general biological functioning rather than pain per se. We highlight the more recent increase of the use of facial expression scales as an alternate tool that can accurately recognize and assess pain in a variety of species and can indicate what an animal is feeling at that moment in time. We also briefly touch on the use of technology such as Artificial Intelligence and Computer Vision as a novel tool to assess pain, providing a much more objective assessment. There is an urgent need for tools that can effectively and directly detect and measure pain in animals and further research in the use of computer-based modelling will be key for the future.
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A new double observer‐based census framework to improve abundance estimations in mountain ungulates and other gregarious species with a reduced effortEstimating animal abundance has a key role to play in ecology and conservation, but survey methods are always challenged by imperfect detection. Among the techniques applied to deal with this issue, Double Observer (DO) is increasing in popularity due to its cost‐effectiveness. However, the effort of using DO for surveying large territories can be significant. A DO‐based survey method that allows accurate abundance estimations with reduced effort would increase the applicability of the method. This would have positive effects on the conservation of species which are challenging to survey such as mountain ungulates. We used computer simulations based on real data and a field test to assess the reliability of the DO and of a new proposed survey procedure, the Double Observer Adjusted Survey (DOAS). DOAS is based on total block counts adjusted with some DO surveys conducted in a proportion of the total area only. Such DO surveys are then used to estimate detection probability with a mark‐recapture‐derived approach. We found that full DO is much more accurate than simple block counts for abundance estimations. DOAS is a less demanding alternative to full DO and can produce comparable abundance estimates, at the cost of a slightly lower precision. However, in the DOAS overall detectability has to be estimated within a sufficient number of sites (around a quarter of the total) to obtain a higher precision and avoid large overestimations. Practical implications. DO methods could increase the reliability of abundance estimations in mountain ungulates and other gregarious species. Full DO in particular could allow researchers to obtain unbiased estimations with high precision and its usage is therefore suggested instead of block counts in wildlife monitoring. Given the high costs of full DO, the DOAS procedure could be a viable and cost‐effective survey strategy to improve abundance estimates when resources are scarce.
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The thermal physiology of Lysathia sp. (Coleoptera: Chrysomelidae), a biocontrol agent of parrot’s feather in South Africa, supports its successThe establishment success of biocontrol agents originating from tropical regions is often limited by climate when introduced in temperate regions. However, the flea beetle, Lysathia sp. (Coleoptera: Chrysomelidae), a biocontrol agent of Myriophyllum aquaticum (Vell.) Verdc. (Haloragaceae) in South Africa, is an effective agent in regions where other biocontrol agents of tropical aquatic weeds have failed due to winter-induced mortality. The development (degree-day model) and thermal tolerance (critical thermal minimum/maximum [CTmin/max] and lower/upper lethal limits [LLT/ULT50]) of Lysathia sp. were investigated to explain this success. The model predicted that Lysathia sp. could complete 6 to 12 generations per year in the colder regions of the country. The lower threshold for development (t0) was 13.0 °C and thermal constant (K) was 222.4 days, which is considerably lower than the K values of other biocontrol agents of aquatic weeds in South Africa. This suggests that above the temperature threshold, Lysathia sp. can develop faster than those other species and complete multiple life cycles in the cooler winter months, allowing for rapid population growth and thus improving M. aquaticum control. Furthermore, the CTmin of Lysathia sp. was 2.3 ± 0.2 °C and the CTmax was 49.0 ± 0.5 °C. The LLT50 was calculated as ∼ −7.0 °C and the ULT50 as ∼ 43.0 °C. These wide tolerance ranges and survival below freezing show why Lysathia sp. has established at cool sites and suggest that it may be a suitable agent for other cold countries invaded by M. aquaticum.
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Cape vultures (Gyps coprotheres) on camera: Assessing the behaviour of a vulnerable, colonially nesting raptor with temperature and time of day at nest sites in KwaZulu-Natal, South AfricaThe Cape Vulture (Gyps coprotheres) has the smallest range of any vulture species in Africa, Europe or Asia and is substantially impacted by anthropogenic factors because of their low productivity and long maturation times. Almost year-round presence at breeding colonies makes understanding Cape Vulture breeding behaviour essential for their conservation. Camera traps, a first for this species, were used to investigate the effect of time of day and temperature on the presence and behaviours performed at nest sites. The number of vultures at a nest site was likely to be higher during the early morning and late afternoon when temperatures were lower, with significantly fewer individuals present at higher temperatures in the days before and after laying. Attendance of at least one adult at the nest was recorded for 86.9% and 99.8% of time points in the days before and after laying, respectively. Almost constant attendance during incubation may also be necessitated by predation pressure, with this study providing observation of possible predation pressure by White-necked Ravens (Corvus albicollis) at the colony. Here, we demonstrate that camera trapping is an effective method of studying Cape Vulture breeding behaviour, which improves understanding and allows more informed conservation measures to be implemented. Cape Vulture nest attendance is affected by temperature, so this species may be vulnerable to climatic changes and subsequent changes in predation pressure.
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Gone with the wind: The proximate and ultimate causes of the decline and extinction of the Bahama Nuthatch Sitta insularisNewly elevated to species rank, the Bahama Nuthatch Sitta insularis is or was a bark- and twig-gleaning insectivore only known in life from the pine forests of Grand Bahama in the Bahamas archipelago. It became increasingly difficult to find in the past 50 years, seemingly in part in response to multiple hurricanes in this century. In spring (June–April) 2018, when it was still known to be extant, we divided the island into seven sections and carried out point count transects with playback and measured habitat variables at 464 locations in pine forest across Grand Bahama. We made only six observations at six locations, all in the region of Lucayan North and each involving a single nuthatch (possibly all the same individual). Fourteen count points were within 500 m of the six locations, and tree size at these sites was greater in height and girth than at sites with no observations and indeed than at other sites within Lucayan North. Count points within 500 m of nuthatch records in 2004–2018 had larger trees and more snags than survey points over 500 m away from previous detections, while count points within 500 m of our 2018 nuthatch records tallied more snags than did those within 500 m of the 2004–2007 records. Declines in habitat quality, habitat extent, nesting substrate, and food availability (driven by logging, attritional island development, and the direct and indirect effects of hurricanes), plus speculated increases in populations of invasive predators/competitors and in major mortality events (hurricanes, increasing in force and frequency with climate change), are suspected to be the ultimate causes of the decline of the nuthatch, with Hurricanes Matthew and Dorian the proximate causes of its evident extinction in 2019.
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The Role of Antibody Expression and Their Association With Bladder Cancer Recurrence: A Single-Centre Prospective Clinical-Pilot Study in 35 PatientsBladder cancer (BC) is the 10th most common cancer in the UK, with about 10,000 new cases annually. About 75–85% of BC are non-muscle invasive (NMIBC), which is associated with high recurrence and progression rates (50–60% within 7–10 years). There are no routine biomarkers currently available for identifying BC patients at increased risk of developing recurrence. The focus of this research study was to evaluate antibody expression in BC patients and their association with cancer recurrence. Methods: 35 patients scheduled for TURBT were recruited after written informed consent. Ethical approval for the project was granted via IRAS (REC4: 14/WA/0033). Following surgical procedure, tissues were preserved in 10% buffered formalin and processed within 24 h in FFPE blocks. 7 sections (4 µm each) were cut from each block and stained for CD31, Human epidermal growth factor receptor-2 (HER-2), S100P, Cyclooxygenase-2 (COX-2), VEGFR-3 thrombomodulin and CEACAM-1 using immunohistochemistry. Clinical outcome measures (obtained via cystoscopy) were monitored for up to 6 months following surgical procedure. Results: There was significantly increased expression of CD31 (p < 0.001), HER-2 (p = 0.032), S100P (p < 0.001), COX-2 (p < 0.001), VEGFR-3 (p < 0.001) and decreased expression of thrombomodulin (p = 0.010) and CEACAM-1 (p < 0.001) in bladder tumours compared to normal bladder tissues. HER-2 expression was also significantly associated with cancer grade (p = 0.003), especially between grade 1 and grade 2 (p = 0.002) and between grade 1 and grade 3 (p = 0.004). There was also a significant association between cancer stage and HER-2 expression (p < 0.001). Although recurrence was significantly associated with cancer grade, there was no association with antibody expression. Conclusion: Findings from the present study may indicate an alternative approach in the monitoring and management of patients with BC. It is proposed that by allowing urological surgeons access to laboratory markers such as HER-2, Thrombomodulin and CD31 (biomarker profile), potentially, in the future, these biomarkers may be used in addition to, or in combination with, currently used scoring systems to predict cancer recurrence. However, verification and validation of these biomarkers are needed using larger cohorts.
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Sweet mama: Affiliative interactions are related to the reproductive success of dominant female Alpine Marmots (Marmota marmota)Sociality is a complex phenomenon, able to influence multiple traits of an individual life history. In group-living mammals, sociality is likely to play a major role in the reproductive success of individuals. Here we investigate how sociality traits are associated to reproductive success in female Alpine marmots (Marmota marmota), a highly social and cooperative breeding ground squirrel distributed in the European Alps. We used social network analysis to calculate sociality metrics and hurdle generalized linear mixed models (hurdle GLMMs) to model the relationship between sociality metrics and reproductive success of individually tagged female Alpine marmots. Our results showed that centrality of a reproductive female within her social group and the number of social partners are positively related to reproductive success, while agonistic behavior was not related with reproduction. Our results highlight the importance of affiliative interactions with other group members in cooperative breeders, suggesting that in such systems female fitness could be more related to social cohesion than to costs of agonistic behaviors to maintain dominance status.
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The ARRIVE guidelines 2.0 author checklistThe ARRIVE guidelines 2.0 - full author checklist
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Environmental toxicology: how pervasive organic environmental pollutants cause toxicity at the molecular, cellular and organism levelThis special issue in FEBS Open Bio was conceived to highlight some of the current research and future directions regarding research in the field of environmental toxicology of some organic pollutants, in relation to human health and disease. It has long been established that man has been exposed to many new (un‐natural) organic chemicals since the beginning of the Industrial Revolution, many of which are found in a vast and diverse range of products, such as agrochemicals, pharmaceuticals, plastics and electronic components, which have been instrumental in driving man's exponential advances in technology over the last 150 years. However, an unforeseen consequence of these advances is that our ecosystem has been exposed to a vast number of these organic chemicals, many of which appear to be persistent within the environment, as well as bioaccumulating in living organisms, including man.
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Validating the underpinnings of water corticosterone measurement for aquatic amphibiansRaw data for the project: Establishment of consensual husbandry protocols for laboratory Xenopus laevis using novel physiological and behavioural techniques.
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The characteristics and variation of the Golden Eagle Aquila chrysaetos home rangeSatellite tracking allows for novel investigations into golden eagle home range characteristics. Understanding home range characteristics is important for conservation and for assessing the potential impact of landscape changes from forest planting, wind farms, etc. Small sample sizes, inconsistent definitions and methods restricted several previous studies. Our study involved 69 resident tagged eagles with over one year of data across five Scottish regions. Home range size was estimated from 95% isopleth contours extracted from Utilisation Distributions. Above a small threshold, estimated range size was not affected by the number of records but at least one year of data is required, largely because of the breeding and non-breeding seasonal differences. There were no significant range size differences between birds tagged as range holders and those previously tagged as nestlings. Across four regions, with considerable intra-regional variation, planar 95% isopleths did not differ (medians, km2): Argyll 58.9, Northwest Highlands 61.7, Northeast Highlands 89.3, South of Scotland 91.9. Ranges in the isolated Outer Hebrides region were exceptionally small, at 24.0 km2. Estimated range area was usually reduced to 70–80% of the planar area when restricted to usable habitat, as estimated by the Golden Eagle Topography (GET) model. Applying measures of known unsuitable habitat (closed-canopy commercial forest and wind turbines) further reduced usable open land. Loss of otherwise suitable habitat was substantially due to commercial forest. Larger ranges had larger extents of suitable habitat (according to GET), with no apparent optimum of preferred GET habitat. Range size was not different across a year between the sexes. Breeding ranges were smaller, and females’ breeding ranges were much smaller than those of males, but larger than males’ ranges in the non-breeding season. Breeding attempt duration was probably also influential. Our study provides novel insights into golden eagle home range characteristics and can guide further research and practical applications.
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Phytochemical Analysis and In Vivo Antimalarial Activities of Ethyl Acetate Fraction of Spilanthes filicaulis on Mice Subjected to Plasmodium bergheiMalaria airs a life-threatening risk in Tropical African countries, stemming from infection by Plasmodium species. This region is richly endowed by nature with a wealth of diverse and largely unexplored plants that hold the potential for managing this protozoan parasite. The currently accessible over-the-counter drugs for disease management often present affordability challenges for the average person, exacerbated by the parasite’s increasing resistance to them. This study investigated the phytoconstituents present in the ethyl acetate fraction of Spilanthes filicaulis (EFSF) and explored the antimalarial effects of EFSF on mice infected with Plasmodium berghei.
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When enough is enough: Optimising monitoring effort for large‐scale wolf population size estimation in the Italian AlpsThe ongoing expansion of wolf (Canis lupus) populations in Europe has led to a growing demand for up‐to‐date abundance estimates. Non‐invasive genetic sampling (NGS) is now widely used to monitor wolves, as it allows individual identification and abundance estimation without physically capturing individuals. However, NGS is resource‐intensive, partly due to the elusive behaviour and wide distribution of wolves, as well as the cost of DNA analyses. Optimisation of sampling strategies is therefore a requirement for the long‐term sustainability of wolf monitoring programs. Using data from the 2020–2021 Italian Alpine wolf monitoring, we investigate how (i) reducing the number of samples genotyped, (ii) reducing the number of transects, and (iii) reducing the number of repetitions of each search transect impacted spatial capture‐recapture population size estimates. Our study revealed that a 25% reduction in the number of transects or, alternatively, a 50% reduction in the maximum number of repetitions yielded abundance estimates comparable to those obtained using the entire dataset. These modifications would result in a 2046 km reduction in total transect length and 19,628 km reduction in total distance searched. Further reducing the number of transects resulted in up to 15% lower and up to 17% less precise abundance estimates. Reducing only the number of genotyped samples led to higher (5%) and less precise (20%) abundance estimates. Randomly subsampling genotyped samples reduced the number of detections per individual, whereas subsampling search transects resulted in a less pronounced decrease in both the total number of detections and individuals detected. Our work shows how it is possible to optimise wolf monitoring by reducing search effort while maintaining the quality of abundance estimates, by adopting a modelling framework that uses a first survey dataset. We further provide general guidelines on how to optimise sampling effort when using spatial capture‐recapture in large‐scale monitoring programmes.
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Cytotoxicity by endocrine disruptors through effects on ER Ca 2+ transporters, aberrations in Ca 2+ signalling pathways and ER stressConcerns regarding man‐made organic chemicals pervading our ecosystem and having adverse and detrimental effects upon organisms, including man, have now been studied for several decades. Since the 1970s, some environmental pollutants were identified as having endocrine disrupting affects. These endocrine disrupting chemicals (EDC) were initially shown to have estrogenic or anti‐estrogenic properties and some were also shown to bind to a variety of hormone receptors. However, since the 1990s it has also been identified that many of these EDC additionally, have the ability of causing abnormal alterations in Ca2+ signalling pathways (also commonly involved in hormone signalling), leading to exaggerated elevations in cytosolic [Ca2+] levels, that is known to cause activation of a number of cell death pathways. The major emphasis of this review is to present a personal perspective of the evidence for some types of EDC, specifically alkylphenols and brominated flame retardants (BFRs), causing direct effects on Ca2+ transporters (mainly the SERCA Ca2+ ATPases), culminating in acute cytotoxicity and cell death. Evidence is also presented to indicate that this Ca2+ATPase inhibition, which leads to abnormally elevated cytosolic [Ca2+], as well as a decreased luminal ER [Ca2+], which triggers the ER stress response, are both involved in acute cytotoxicity.
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Detection of the adulteration of dairy products using immunological and DNA-based techniquesAbstract available in hard copy
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Climate drives body mass changes in a mountain ungulate: shorter winters lead to heavier Alpine ibexClimate affects seasonality and plant phenology, which can influence seasonal body mass dynamics of herbivores in temperate environments. We investigated long‐term trends of seasonal body mass changes in male Alpine ibex Capra ibex. We used SEM to test direct and indirect relationships between body mass, mass changes and environmental and climatic variables. Individually recognizable Alpine ibex were weighed repeatedly between 2000 and 2022 in Gran Paradiso National Park (Italy). Autumn mass increased substantially over these two decades, up to 15% in some age classes. Over the same time frame, both summer mass gain and winter mass loss decreased, suggesting that heavier autumn body mass was due to the cumulative effects of reduced mass loss over several winters. The environmental factor with the strongest effects on winter mass changes was the starting date of vegetation green‐up at low altitude, where ibex gather after winter to feed on new growth vegetation. Early springs led to lower winter mass loss, likely because ibex relied on stored fat for a shorter period and had greater access to forage. High population density also increased winter mass loss. Environmental conditions and resource availability, possibly also influenced by density in winter and early spring, seem therefore to directly affect the body mass dynamics of male Alpine ibex, while the effect of summer conditions appears less relevant. By affecting seasonal body mass dynamics, climate change may have consequences for life history and population dynamics of mountain herbivores, for example via earlier access of young males to reproduction.
