71 research outputs found

    Effectiveness of a commercial lure to attract red fox

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    In camera trap studies, attractants may be used to increase detection probabilities of wildlife, which may help to improve estimates of abundance and occupancy. Using a semi-experimental approach, we investigated if a commercial, strawberry scented lure increased detection probability and visiting time duration in red fox Vulpes vulpes, and the potential reasons for variation in these parameters. In September 2020, within the Stelvio National Park, central Italian Alps, 32 camera sites were randomly assigned to 4 different treatments: 8 to commercial lure, the target of our investigation; 8 to orange aroma, to test for the "curiosity" effect; 8 to cat kibble, to test for the "likability" effect; 8 to camera trap only, the control test. Detection probability and duration of visiting time were estimated using hurdle negative binomial regression models. Daily detection probability was significantly higher with lure (0.078), orange aroma (0.086), kibble (0.075) than with camera trap only (0.031); in the first day after treatment, the time an animal spent in front of the cameras significantly increased with orange aroma (16.61 s) and kibble (33.78 s) compared to lure (9.97 s) and camera trap only (0.38 s). Our results support the use of lures to improve detection probability and visit duration in red fox, but we could not disentangle the drivers of increased parameter estimates. When consumable costs are considered, the use of the commercial strawberry scented lure does not appear justified for both detection probability and visit duration, and cheaper alternatives may be preferable

    Reproductive payoffs of territoriality are snow-dependent in a mountain ungulate, the Alpine chamois

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    Female density and distribution are dependent on resource phenology and female availability strongly influences male mating behaviour and success. When a male adopts a ‘resource defence’ tactic, his reproductive success depends on the location and attractiveness of his territory. Environmental factors associated with territory quality are expected to influence mating success, for example, through territory features or male–male competition. In a protected population of a mountain-dwelling polygynous herbivore, the Alpine chamois Rupicapra r. rupicapra, we investigated the relationships among mating opportunities, some environmental variables (snow depth, topographic features and size of territories) and male intra-sexual competition for mating. We recorded the mating behaviour and territory size of 15 GPS-GSM radio-tagged territorial males, during five rutting seasons (early November to early December: N = 8 individuals in 2011, N = 9 in 2012, N = 8 in 2015, N = 11 in 2016, N = 7 in 2017; 80% of them were observed for more than one mating season) and related them to snow depth and topography of territories. In ruts with deep snow cover, territorial males had smaller territories and higher number of mating opportunities than in ruts with lower snow cover. Smaller territories showed the highest values of terrain roughness, in turn with little or no snow cover in the mating season, and were visited by a greater number of females, than larger territories. Number of wins was positively influenced by snow depth and negatively related to the frequency of aggressions. The frequency of male–male aggressive interactions was greater during ruts with deep snow cover and for males with territories at higher elevations; additionally, it was negatively related to interactions won. Thus, snow depth, which influences resource distribution and female movements, is confirmed as a strong determinant of male mating opportunities and mating behaviour

    The cooler the better? Indirect effect of spring-summer temperature on fecundity in a capital breeder

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    Female reproductive performance is a central component of ungulate population dynamics, and it can be influenced by individual, social, and environmental factors. Researchers have often assumed direct effects of different predictors on reproduction, yet more complex relationships should be considered when investigating temporal variations in life\u2010history traits within a broader eco\u2010evolutionary context. In this study, we explored direct effects of individual, social, and environmental predictors on female reproductive performance and investigated potential causal chains among variables. We analyzed the variation in fecundity, measured as the probability of being pregnant, in 215 adult female deer Cervus elaphus culled on the Italian Alps, with respect to age, body mass, kidney fat, jaw length, lactation status, population size, temperature and precipitation in spring\u2013summer, temperature and snow depth in winter, and the delayed effect of spring\u2013summer temperature. We used random forest and logistic regression models to select variables whose direct effects best explained variation in fecundity. Path analysis was used to test for alternative hypotheses of direct/indirect effects between pre\u2010selected weather (spring\u2013summer temperature) and individual (age, kidney fat index [KFI]) predictors. The most important direct predictors of fecundity were age, kidney fat, and the interaction between kidney fat and spring\u2013summer temperature. Path analysis supported the hypothesis that higher spring\u2013summer temperature had negative, indirect effects on the probability of being pregnant, mediated by decreasing values of KFI. Our study revealed some complex, cause\u2013effect relationships between weather stochasticity, body condition, and reproduction, possibly suggesting a conditional trade\u2010off between opportunity for reproduction and survival, and emphasizing how environmental variations and individual characteristics may interact to shape life\u2010history traits in ungulate population

    Past, present and future of chamois science

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    The chamois Rupicapra spp. is the most abundant mountain ungulate of Europe and the Near East, where it occurs as two spe- cies, the northern chamois R. rupicapra and the southern chamois R. pyrenaica. Here, we provide a state-of-the-art overview of research trends and the most challenging issues in chamois research and conservation, focusing on taxonomy and systematics, genetics, life history, ecology and behavior, physiology and disease, management and conservation. Research on Rupicapra has a longstanding history and has contributed substantially to the biological and ecological knowledge of mountain ungulates. Although the number of publications on this genus has markedly increased over the past two decades, major differences persist with respect to knowledge of species and subspecies, with research mostly focusing on the Alpine chamois R. r. rupicapra and, to a lesser extent, the Pyrenean chamois R. p. pyrenaica. In addition, a scarcity of replicate studies of populations of different subspecies and/or geographic areas limits the advancement of chamois science. Since environmental heterogeneity impacts behavioral, physiological and life history traits, understanding the underlying processes would be of great value from both an evolutionary and conservation/management standpoint, especially in the light of ongoing climatic change. Substantial contri- butions to this challenge may derive from a quantitative assessment of reproductive success, investigation of fine-scale foraging patterns, and a mechanistic understanding of disease outbreak and resilience. For improving conservation status, resolving taxonomic disputes, identifying subspecies hybridization, assessing the impact of hunting and establishing reliable methods of abundance estimation are of primary concern. Despite being one of the most well-known mountain ungulates, substantial field efforts to collect paleontological, behavioral, ecological, morphological, physiological and genetic data on different popu- lations and subspecies are still needed to ensure a successful future for chamois research and conservation

    Do Bat Gantries and Underpasses Help Bats Cross Roads Safely?

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    Major roads can reduce bat abundance and diversity over considerable distances. To mitigate against these effects and comply with environmental law, many European countries install bridges, gantries or underpasses to make roads permeable and safer to cross. However, through lack of appropriate monitoring, there is little evidence to support their effectiveness. Three underpasses and four bat gantries were investigated in northern England. Echolocation call recordings and observations were used to determine the number of bats using underpasses in preference to crossing the road above, and the height at which bats crossed. At gantries, proximity to the gantry and height of crossing bats were measured. Data were compared to those from adjacent, severed commuting routes that had no crossing structure. At one underpass 96% of bats flew through it in preference to crossing the road. This underpass was located on a pre-construction commuting route that allowed bats to pass without changing flight height or direction. At two underpasses attempts to divert bats from their original commuting routes were unsuccessful and bats crossed the road at the height of passing vehicles. Underpasses have the potential to allow bats to cross roads safely if built on pre-construction commuting routes. Bat gantries were ineffective and used by a very small proportion of bats, even up to nine years after construction. Most bats near gantries crossed roads along severed, pre-construction commuting routes at heights that put them in the path of vehicles. Crossing height was strongly correlated with verge height, suggesting that elevated verges may have some value in mitigation, but increased flight height may be at the cost of reduced permeability. Green bridges should be explored as an alternative form of mitigation. Robust monitoring is essential to assess objectively the case for mitigation and to ensure effective mitigation

    Male-biased gastrointestinal parasitism in a nearly monomorphic mountain ungulate

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    Background: Pyrenean chamois (Rupicapra pyrenaica pyrenaica) is a nearly monomorphic mountain ungulate with an unbiased sex-specific overwinter adult survival. Few differences in gastrointestinal parasitism have been reported by coprology as yet. This study aims to assess diversity, prevalence, intensity of infection and aggregation of gastrointestinal nematodes in male and female adult chamois. We expect no differences in the parasite infection rates between sexes. Findings: Gastrointestinal tracts of 28 harvested Pyrenean chamois in the Catalan Pyrenees (autumn 2012 and 2013) were necropsied and sexual differences in the diversity and structure of parasite community, prevalence, intensity of infection, and richness were investigated. We found 25 helminth species belonging to 13 different genera. Conclusions: Contrary to our expectations, male chamois showed different parasite communities, higher prevalence, intensity of infection and richness than females. Such sexual differences were clear irrespective of age of individuals. Hence, male chamois must cope with a more diverse and abundant parasite community than females, without apparent biological cost. Further research will be required to confirm this hypothesis

    Roadless and Low-Traffic Areas as Conservation Targets in Europe

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    With increasing road encroachment, habitat fragmentation by transport infrastructures has been a serious threat for European biodiversity. Areas with no roads or little traffic (“roadless and low-traffic areas”) represent relatively undisturbed natural habitats and functioning ecosystems. They provide many benefits for biodiversity and human societies (e.g., landscape connectivity, barrier against pests and invasions, ecosystem services). Roadless and low-traffic areas, with a lower level of anthropogenic disturbances, are of special relevance in Europe because of their rarity and, in the context of climate change, because of their contribution to higher resilience and buffering capacity within landscape ecosystems. An analysis of European legal instruments illustrates that, although most laws aimed at protecting targets which are inherent to fragmentation, like connectivity, ecosystem processes or integrity, roadless areas are widely neglected as a legal target. A case study in Germany underlines this finding. Although the Natura 2000 network covers a significant proportion of the country (16%), Natura 2000 sites are highly fragmented and most low-traffic areas (75%) lie unprotected outside this network. This proportion is even higher for the old Federal States (western Germany), where only 20% of the low-traffic areas are protected. We propose that the few remaining roadless and low-traffic areas in Europe should be an important focus of conservation efforts; they should be urgently inventoried, included more explicitly in the law and accounted for in transport and urban planning. Considering them as complementary conservation targets would represent a concrete step towards the strengthening and adaptation of the Natura 2000 network to climate change

    Seasonal differences of corticosterone metabolite concentrations and parasite burden in northern bald ibis (Geronticus eremita): The role of affiliative interactions

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    The reproductive season is energetically costly as revealed by elevated glucocorticoid concentrations, constrained immune functions and an increased risk of infections. Social allies and affiliative interactions may buffer physiological stress responses and thereby alleviate associated effects. In the present study, we investigated the seasonal differences of immune reactive corticosterone metabolite concentrations, endoparasite burden (nematode eggs and coccidian oocysts) and affiliative interactions in northern bald ibis (Geronticus eremita), a critically endangered bird. In total, 43 individually marked focal animals from a freeranging colony were investigated. The analyses included a description of initiated and received affiliative interactions, pair bond status as well as seasonal patterns of hormone and endoparasite levels. During the reproductive season, droppings contained parasite eggs more often and corticosterone metabolite levels were higher as compared to the period after reproduction. The excretion rate of endoparasite products was lower in paired individuals than in unpaired ones, but paired animals exhibited higher corticosterone metabolite concentrations than unpaired individuals. Furthermore, paired individuals initiated affiliative behaviour more frequently than unpaired ones. This suggests that the reproductive season influences the excretion patterns of endoparasite products and corticosterone metabolites and that affiliative interactions between pair partners may positively affect endoparasite burden during periods of elevated glucocorticoid levels. Being embedded in a pair bond may have a positive impact on individual immune system and parasite resistance

    Excretion patterns of coccidian oocysts and nematode eggs during the reproductive season in Northern Bald Ibis (Geronticus eremita)

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    Individual reproductive success largely depends on the ability to optimize behaviour, immune function and the physiological stress response. We have investigated correlations between behaviour, faecal steroid metabolites, immune parameters, parasite excretion patterns and reproductive output in a critically endangered avian species, the Northern Bald Ibis (Geronticus eremita). In particular, we related haematocrit, heterophil/lymphocyte ratio, excreted immune-reactive corticosterone metabolites and social behaviour with parasite excretion and two individual fitness parameters, namely, number of eggs laid and number of fledglings. We found that the frequency of excretion of parasites’ oocysts and eggs tended to increase with ambient temperature. Paired individuals excreted significantly more samples containing nematode eggs than unpaired ones. The excretion of nematode eggs was also significantly more frequent in females than in males. Individuals with a high proportion of droppings containing coccidian oocysts were more often preened by their partners than individuals with lower excretion rates. We observed that the more eggs an individual incubated and the fewer offspring fledged, the higher the rates of excreted samples containing coccidian oocysts. Our results confirm that social behaviour, physiology and parasite burden are linked in a complex and context-dependent manner. They also contribute background information supporting future conservation programmes dealing with this critically endangered species
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