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European Journal of Wildlife Research
Journal Prestige (SJR): 0.733
Citation Impact (citeScore): 2
Number of Followers: 13  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1439-0574 - ISSN (Online) 1612-4642
Published by Springer-Verlag Homepage  [2467 journals]
  • Algerian and European hedgehogs cohabiting in periurban environments:
           spatial behaviour and habitat use

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      Abstract: Abstract Habitat fragmentation is one of the most important threats to biodiversity in the last decades. Numerous species are forced to adapt to human presence as urbanization keeps increasing. Some studies show the impact of habitat changes in various species; however, there is little knowledge about the effect of habitat disturbance on hedgehogs in the Iberian Peninsula. We radio tracked 31 male hedgehogs: 14 European hedgehogs and 17 Algerian hedgehogs, being 18 individuals indigenous and 13 translocated. We analysed their home ranges, spatial behaviour and habitat use in a suburban area of Valencia City, Spain, where the two species coexist. Our results show that there are phenologic variations of activity levels, which differ between species, being maximum in spring for the European hedgehog and in summer for the Algerian hedgehog. We did not detect a territorial behaviour or interspecific spatial competition. However, we could detect a clear “release effect”, with translocated individuals presenting increased home range sizes and activity levels as they explore the unknown environment. Furthermore, we found that both species showed a clear preference for the pine forest habitat, avoiding all other habitat types, especially those with high human presence. Our results also suggest that the European hedgehog has a more generalist character than the Algerian hedgehog regarding habitat use. In conclusion, this study highlights the importance of conserving a connected mosaic of green patches in urbanized environments for the conservation of hedgehog populations.
      PubDate: 2023-01-28
       
  • Correction to: Hunting for ecological indicators: are large herbivore
           skeleton measures from harvest data useful proxies for monitoring'

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      PubDate: 2023-01-27
       
  • Understanding the impact of wild boar on the European wild rabbit and
           red-legged partridge populations using a diet metabarcoding approach

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      Abstract: Abstract European wild rabbit (Oryctolagus cuniculus) and red-legged partridge (Alectoris rufa) are main small game species of conservation concern in Mediterranean ecosystems. To date, their presence in wild boar’s (Sus scrofa) diet and factors driving their consumption have been little investigated. A genetic metabarcoding approach was used on 80 wild boar faeces collected from four hunting estates devoted to small game hunting during two different seasons. Abundances of wild boar, rabbits and partridges were first estimated. Results showed DNA of seventeen chordate species. The highest frequency of occurrence (FO) corresponded to mammals and birds, with 77.6 and 22.3%, respectively. DNA of game species was detected in 39/71 (FO = 55.0%) samples, highlighting the presence of European wild rabbit in 27 (FO = 38.0%) and red-legged partridge in eight (FO = 11.3%). Dietary composition varied between seasons and estates, being rabbit the main responsible (explaining 35.26% and 39.45% of differences, respectively). Rabbit FO in the diet was positively related to the abundance of wild boar and rabbit density on the estate. It was greater in autumn and in estates where rabbits were hunted. Regarding red-legged partridge, a significant and positive relationship between its population density and its diet FO was observed, without significant differences between seasons or estates. Overall, our results suggest wild boar as an opportunistic species whose diet is largely determined by the relative availability of different food resources. Its ecological role concerning small game species in Mediterranean agroecosystems seems to be more related to consumption of carrion during the hunting season than to direct predation.
      PubDate: 2023-01-27
       
  • Against the flow: unexpected migration movements over the open sea by
           inexperienced ospreys

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      Abstract: Abstract As part of a long-term monitoring program, more than 80 Mediterranean ospreys Pandion haliaetus (both adults and juveniles) were tagged with GPS-GSM transmitters and tracked to study their spatiotemporal behaviour. Here we document the peculiar and unexpected migration movements performed by three inexperienced (juvenile/immature) individuals, who crossed the open sea “against the flow”, in the opposite direction to that foreseen for the given season. Using a combination of GPS tracking data and weather information, we found that such movements were linked to particular meteorological conditions occurring over the Mediterranean Sea during migration. Mean values of wind gust of approximately 20 km/h and moderate tailwinds seem to have mediated the onset of the movements, facilitating the flight of ospreys over water. Our findings suggest that both weather conditions (sidewinds) and the inexperience of the birds explain these long migration movements performed towards unexpected directions over the open sea. We conclude that migratory capabilities and the ability to cope with external conditions may lead inexperienced birds to perform extensive and tortuous dispersal/explotrative movements during both first autumn and spring migration.
      PubDate: 2023-01-25
       
  • Abundance and activity of carnivores in two protected areas of semi-arid
           western India with varying top predator density and human impacts

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      Abstract: Abstract Large carnivores are vulnerable to population decline due to their k-selected traits in fragmented human-dominated landscapes. In the semi-arid landscape of western India, tiger (top predator) populations went locally extinct from most of the forested ecosystems, while the mesopredators (leopards, hyenas, wolves) managed to survive in these mosaics of forest, agriculture, pasturelands, ravines, and human habitations. In this study, we used camera traps to survey two protected areas (PAs) in the semi-arid western Indian landscape—Mukundara (without tigers) and Ranthambhore (with high-density tiger population)—and compare the abundance and activity of mesopredators between sites to assess the effect of top predator presence on mesopredators. The carnivore community was more diverse in Ranthambhore (well-protected) than in the human disturbed habitats of Mukundara; however, the relative abundance of mesopredators was higher in Mukundara. Striped hyena density was estimated higher in Mukundara (40.6 ± 7.36/100 km2) than in Ranthambhore (9.3 ± 1.3/100 km2), while leopard density estimates were comparable (Mukundara, 10.9 ± 3.0/100 km2; Ranthambhore, 11.2 ± 1.6/100 km2). Temporal activities of carnivores in Mukundara indicated avoidance of human disturbance, while in Ranthambhore, it seemed primarily governed by competitive interactions between carnivores. Our findings are indicative of the mesopredator release hypothesis, where the number of mesopredators increased in the absence of top predator; however, the results are confounded by differential resource availability, human disturbance, and poaching levels between sites. The outcomes emphasised the importance of conserving habitat fragments (irrespective of charismatic species’ presence) in human-dominated landscapes to conserve carnivore populations. Conservation investments should focus on habitat protection, securing inviolate areas inside the PAs and restoring connectivity between PAs.
      PubDate: 2023-01-23
       
  • A study of the incidence of bovine tuberculosis in the wild red deer herd
           of Exmoor

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      Abstract: Abstract Bovine tuberculosis (bTB) is an infectious disease which thrives at the wildlife-livestock interface. Exmoor has the largest herd of wild red deer (Cervus elaphus) in England, and also a large number of dairy and beef farms. The population, health and well-being of the herd are managed by a combination of hunting with hounds and by stalking. This study used a serological assay to determine the incidence of bTB in the population of 106 wild red deer of Exmoor, the relationship between regional deer densities and the presence of bTB in deer, and domestic cattle. The overall number of bTB positive deer was 28.3% (30/106). Stalked deer had a slightly higher incidence of bTB (19 out of 55, 34.55%) than hunted deer (11 out of 51, 21.57%). There was no clear pattern of distribution except for one region which showed an incidence of 42.22% compared with 16.4% in the remainder of the moor. There was little difference in the incidence of bTB between male and female animals. The age of animals in the study ranged from < 1 year to over 10 years. There was no clear difference in the incidence across the age range (< 1 year– > 10 years) with the exception of a particularly high incidence in those animals aged 1 year or less. There was a significant correlation between the presence of deer with bTB and the number of farms reporting bTB positive cattle, but not between the regional population of red deer and bTB in deer or cattle.
      PubDate: 2023-01-19
       
  • Lipoarabinomannan (LAM)—a potential biomarker for the diagnosis of
           tuberculosis from the urine of infected elephants

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      Abstract: Abstract The spread of tuberculosis (TB) in Asian countries is mainly due to co-existence and close association of humans with elephants and other domestic livestock. Infected animals tend to shed the organism in the preclinical period which risks the transmission of the infection from animals to humans and vice versa. Since tuberculosis infection is chronic and lack specific clinical signs, diagnosis remains challenging. The present study focuses on the utilization of lipoarabinomannan (LAM), a glycolipid for the detection of TB infection in elephants. Usage of urine as the biological sample for the diagnosis makes it more advantageous. Seroprevalence of tuberculosis (TB) in elephants in Kerala were found to be 37.2% (n = 86) using Chembio DPP VetTB assay. Nine (10.46%) out of 86 elephants were positive for AFB and 29 (33.7%) out of 86 elephants were positive for LAM antigen. On comparison of efficiency of LF-LAM assay with that of DPP VetTB assay, LF-LAM assay had a sensitivity of 90.63%, specificity 100%, positive predictive value 100%, negative predictive value 94.7%, accuracy 95.51%, and kappa statistic value 0.924 (p value < 0.001). On comparison of LF-LAM with traditional acid fast staining method, LF-LAM assay had the sensitivity of 100%, specificity 74.03%, positive predictive value 31%, negative predictive value 100%, accuracy 76.74%, and kappa statistic value 0.374 (p value < 0.001). The presence of Mycobacterium tuberculosis was confirmed in trunk wash sample using PCR targeting gene IS6110, at 245 bp amplicon size and 25 seropositive elephants (78.2%) were confirmed positive. Custom sequencing and phylogenetic analysis revealed that the isolate obtained was Mycobacterium tuberculosis. This study in elephants prove that TB LAM Ag (LF-LAM) can be used as potent biomarker for diagnosis of tuberculosis in elephants.
      PubDate: 2023-01-16
       
  • Hunting for ecological indicators: are large herbivore skeleton measures
           from harvest data useful proxies for monitoring'

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      Abstract: Abstract Hunter-collected data and samples are used as indices of population performance, and monitoring programs often take advantage of such data as ecological indicators. Here, we establish the relationships between measures of skeleton size (lower jawbone length and hind-leg length) and autumn carcass mass of slaughtered individuals of known age and sex of the high Arctic and endemic Svalbard reindeer (Rangifer tarandus platyrhynchus). We assess these relationships using a long-term monitoring dataset derived from hunted or culled reindeer. The two skeleton measures were generally strongly correlated within age class. Both jaw length (R2 = 0.78) and hind-leg length (R2 = 0.74) represented good proxies of carcass mass. These relationships were primarily due to an age effect (i.e. due to growth) as the skeleton measures reached an asymptotic size at 4–6 years of age. Accordingly, strong positive correlations between skeleton measures and carcass mass were mainly evident at the young age classes (range r [0.45–0.84] for calves and yearlings). For the adults, these relationships weakened due to skeletal growth ceasing in mature animals causing increased variance in mass with age—potentially due to the expected substantial impacts of annual environmental fluctuations. As proxies for carcass mass, skeleton measurements should therefore be limited to young individuals. Although body mass is the ‘gold standard’ in monitoring large herbivores, our results indicate that skeleton measures collected by hunters only provide similar valuable information for young age classes, particularly calves and yearlings. In sum, jaw length and hind-leg length function as proxies identical to body mass when documenting the impacts of changing environmental conditions on important state variables for reindeer and other herbivores inhabiting highly variable environments.
      PubDate: 2023-01-13
       
  • Artificial intelligence as a potential tool for micro-histological
           analysis of herbivore diets

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      Abstract: Abstract Different non-invasive techniques have been used to determine herbivore diet composition from fecal samples, including micro-histological analysis of epidermal fragments. This method can provide reliable semi-quantitative data through the identification of plant cell structures visualized under an optical microscope. However, this method is highly time-consuming and it requires significant expertise in microscopic identification. Since micro-histological analysis is based on pattern recognition, artificial intelligence (AI) could be used to make this method more time efficient through automated identification and counting of epidermal fragments. We developed a software application based on an AI model that, appropriately trained, could identify and count epidermal fragments from photographed microscope slides. We compared the performance of this model to that of visual identification by a trained observer using in vitro mixtures of fragments from two plant species, Arbutus unedo and Rubia peregrina, with very different epidermal characteristics. Both the human observer and the AI model estimated proportions of plant fragments very close to those of the original mixtures. In addition, once trained, the AI model was over 350 times faster in identifying and counting fragments compared to a human observer. Our study highlights the potential of AI to be applied to the study of herbivore diets for labor-intensive pattern recognition tasks.
      PubDate: 2023-01-06
       
  • Characterization of Antillean manatee (Trichechus manatus manatus) habitat
           and resources availability in the Alvarado Lagoon System, Veracruz

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      Abstract: Abstract Historically, the Antillean manatee (Trichechus manatus manatus) was distributed along the coastline comprised by the five Mexican states that border the Gulf of Mexico. However, the few healthy populations that currently exist in Mexico are now limited to relatively isolated regions with very specific habitat characteristics. In the state of Veracruz, a limited number of individuals are found in the Alvarado Lagoon System (ALS), located in the coastal zone of southern central Veracruz. The aim of this study was to characterize manatee habitat in the ALS. Transects were established in the ALS and 503 points selected and sampled along these transects, producing data pertaining to salinity, depth, dissolved oxygen, total dissolved solids, surface water temperature, pH, bottom type, and conductivity. A total of 45 outings were conducted, with a total sampling effort of 332.36 h. The average physicochemical parameters found were as follows: salinity 3.33 ppm, total dissolved solids 0.51 g/l, temperature 26.29 °C, dissolved oxygen 0.51%, pH 7.55, and oxidation–reduction potential 417.04 mV. Thirteen manatees were observed, mostly (84.6%) during the cold, where the parameters of electrical conductivity, salinity, total dissolved solids, dissolved oxygen, temperature, and oxidation–reduction potential showed differences between the sampled seasons, and in the lagoons with a presence of the floating and submersible vegetation species that form part of manatees’ diet. This study shows that the ALS presents lagoons that favor the presence of the Antillean manatee, further narrowing the distribution of the species within the same ALS in the southern central zone of the state of Veracruz.
      PubDate: 2023-01-03
       
  • From species detection to population size indexing: the use of sign
           surveys for monitoring a rare and otherwise elusive small mammal

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      Abstract: Abstract Monitoring the occupancy and abundance of wildlife populations is key to evaluate their conservation status and trends. However, estimating these parameters often involves time and resource-intensive techniques, which are logistically challenging or even unfeasible for rare and elusive species that occur patchily and in small numbers. Hence, surveys based on field identification of signs (e.g. faeces, footprints) have long been considered a cost-effective alternative in wildlife monitoring, provided they produce reliable detectability and meaningful indices of population abundance. We tested the use of sign surveys for monitoring rare and otherwise elusive small mammals, focusing on the Cabrera vole (Microtus cabrerae) in Portugal. We asked how sampling intensity affects true positive detection of the species, and whether sign abundance is related to population size. We surveyed Cabrera voles’ latrines in 20 habitat patches known to be occupied, and estimated ‘true’ population size at each patch using DNA-based capture-recapture techniques. We found that a searching rate of ca. 3 min/250m2 of habitat based on adaptive guided transects was sufficient to provide true positive detection probabilities > 0.85. Sign-based abundance indices were at best moderately correlated with estimates of ‘true’ population size, and even so only for searching rates > 12 min/250m2. Our study suggests that surveys based on field identification of signs should provide a reliable option to estimate occupancy of Cabrera voles, and possibly for other rare or elusive small mammals, but cautions should be exercised when using this approach to infer population size. In case of practical constraints to the use of more accurate methods, a considerable sampling intensity is needed to reliably index Cabrera voles’ abundance from sign surveys.
      PubDate: 2022-12-23
       
  • 18 years of the European Journal of Wildlife Research: profile and
           prospects

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      Abstract: Abstract Expanding on the foundation of Zeitschrift für Jagdwissenschaft in 1955, the European Journal of Wildlife Research (EJWR) continues to publish original research and reviews on all aspects of wildlife science regardless of the geographic region. Eighteen years after publication of the first issue of EJWR, we briefly reflect on the journal’s profile and prospects. Our target audience includes researchers, wildlife biologists, forestry and game management professionals, wildlife veterinarians, and other specialists, but we also aim at providing a resource of relevant information and scientific debate for practitioners and every person interested in wildlife science. With ecosystems being at the highest level of pressure due to land use change and other effects of the global crisis, the journal is in a key position to communicate relevant research to the scientific community around the world.
      PubDate: 2022-12-22
       
  • Landscape settlement and parameters of Eurasian beaver (Castor fiber) home
           ranges in the Czech Republic

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      Abstract: Abstract Over the last few decades, the beaver has settled most of the European continent including the Czech Republic. Until recently, it was a species typically found in lowland floodplain forests. However, as the population grew, it began to spread into the agricultural landscape, where it has less favorable living conditions. In the Czech Republic, beavers were known to concentrate especially in large forest complexes; little information is so far available about their settlement of the agricultural landscape. At the same time, beaver management in the Czech Republic is applied according to zones with different levels of protection for this species; therefore, the assessment of beaver populations in different environmental conditions is essential. The article focuses on beaver population density, home range length, distribution, and dispersion in the four main types of environments, as well as on differences in food selection. Beaver population density is the highest in forest localities with small streams; the beaver finds the most suitable living conditions there. On average, the agricultural landscape is less populated. While population density in large rivers in the agricultural landscape is comparable to that in large rivers in the forest due to environmental conditions that can be similar, small streams in the agricultural landscape are inhabited 3.3 times less than small streams in forests because they are generally unsuitable environments with limited resources. The lengths of home ranges depend on the environment, the density of beavers, and especially on the availability of food resources. Likewise, the distances that beavers search for food differ, thus affecting their spatial activity.
      PubDate: 2022-12-19
       
  • An increasing human-elephant conflict' Impact of African elephant on
           cultivated cashew trees

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      Abstract: Abstract Elephants influence the structure and composition of African woodlands and, sometimes, damage cultivated trees in farms of local communities. Here, we evaluate the impact of elephant debarking on cultivated cashew trees (Anacardium occidentale) as the friction between farmers and elephant conservation is increasing. We quantified the effects of elephant debarking on tree survival, crown defoliation, and nut production by visiting elephant-damaged farms with cashew trees (n = 47 farms) along Sasawara National Forest (Tanzania). We also compared defoliation and nut production with nearby control trees (undamaged) in a paired designed. Our results reveal that elephants debarked a significant proportion of trees (36% of farms had some cashew trees damaged by elephants, with a mean of 17.3% damaged trees per farm), with a preference for medium-large tree sizes (> 20 cm of diameter at breast height). Tree mortality due to elephants was 4 trees (4.2% of the affected trees), which represents around 0.1% of the total number of trees in the affected farms. In the year of damage, elephant debarking caused no effect on defoliation whereas nut production was reduced only in trees with very high intensity of damage (> 60% of trunk circumference affected). However, a year after the damage, both defoliation and nut production were negatively affected but this effect was strongly dependent on the intensity of damage and tree diameter. These results may help reduce the social discomfort of cashew farmers and contribute to enhance human-elephant coexistence. However, further studies should analyze the future vulnerability of damaged trees to fires, pathogens or pests.
      PubDate: 2022-12-14
       
  • Lethal predator control on UK moorland is associated with high breeding
           success of curlew, a globally near-threatened wader

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      Abstract: Abstract The UK supports a quarter of Eurasian curlew Numenius arquata, so a recent halving of numbers has impacted the global population. Low breeding success is a frequently cited cause of decline. We considered breeding success in relation to predator indices and habitat measures within 18 moorland-farmland blocks across several UK regions. Each block comprised one site where gamekeepers lethally controlled predators on moors managed for red grouse Lagopus lagopus scotica (grouse moor) and another on similar habitat where predators were not controlled (non-grouse moor). More wader species occurred on grouse moors, which supported twice the density of waders as non-grouse moors. Curlew productivity was fourfold higher on grouse moors (1.05 fledglings pair-1) than non-grouse moors (0.27). Hatching and fledging success was negatively linked to a combined index of corvids and fox, which were three- to fourfold fewer on grouse moors but were unrelated to 11 habitats and two livestock grazing variables. Similar patterns were observed in three of four other wader species. These behaviour-based findings were validated by observations on actual nests and broods. Grouse moors appear to act as source populations, thereby slowing the current rapid decline. To halt declines and promote curlew recovery in the UK uplands, we recommend that predator control on grouse moors is maintained and longer term land use policies are developed to render landscapes less friendly to currently high levels of generalist predators.
      PubDate: 2022-12-14
       
  • Effect of legal regulation of supplemental feeding on space use of red
           deer in an area with chronic wasting disease

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      Abstract: Abstract Supplemental feeding of cervids during winter is a widespread management practice, but feeding may increase the risk of disease transmission. Therefore, legal regulations to limit supplemental feeding are often implemented when dealing with severe infectious diseases, such as chronic wasting disease (CWD) in cervids. However, it is currently unclear whether these regulations result in decreased spatial clustering and aggregation as intended. Supplemental feeding is expected to restrict the movement of cervids. Therefore, a ban on feeding may also result in wider space use and a risk of geographic spread of disease. The space use of 63 GPS-marked red deer (Cervus elaphus) was investigated before (n = 34) and after (n = 29) the implementation of a legal regulation aimed at limiting the supplemental feeding of cervids during winter in a CWD-affected region of Nordfjella, Norway. Snow depth was the main determinant of the space use for red deer. A moderate reduction in the number of GPS positions in spatial clusters was evident during periods of deep snow once the ban was in place. Sizes of core areas (Kernel 50%), home ranges (Kernel 95%), and dispersion (MCP 100%, number of 1 km2 pixels visited per deer) declined from January to March and with increasing snow depth. Dispersion (number of 1 km2 pixels visited per deer) did not depend on snow depth after the ban, and red deer used larger areas when snow depth was high after the ban compared to before. The ban on supplementary feeding had no effect on size of core areas or home ranges. Several potential factors can explain the overall weak effect of the ban on space use, including the use of agricultural fields by red deer, other anthropogenic feeding, and landscape topography. This study highlights that snow depth is the main factor determining space use during winter, and it remains to be determined whether the moderate reduction in spatial clustering during deep snow after the ban was sufficient to lower the risk of disease transmission.
      PubDate: 2022-12-12
       
  • Early stages of home range settlement in a newly reintroduced raptor on an
           island: Bonelli’s eagle (Aquila fasciata) on Mallorca, Spain

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      Abstract: Abstract Bonelli’s eagle (Aquila fasciata) had become extirpated in parts of their Mediterranean distribution, such as on Mallorca Island (Balearic Islands, Spain). Thanks to reintroduction programs, a new breeding population was reintroduced to the island, between 2011 and 2017. To identify movement patterns within the island, we equipped each reintroduced individual with a GPS device before release to track their movements. Home range of reintroduced eagles were calculated using a KDE — kernel density estimation approach. Although we found that home range size differed for individuals among years and sex, we found a high degree of overlap in home range in the study population. The home range of each individual remained stable in size and shape and few explorative flights outside the delineated home range were observed. In conclusion, reintroduced Bonelli’s eagles have adapted to Mallorca Island by breeding earlier than already established populations, reducing their dispersive behaviour, and accelerating establishment of home ranges.
      PubDate: 2022-12-12
       
  • The annual occurrence of mass mortality at a Common Pipistrelle swarming
           site

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      Abstract: Abstract Citizen science networks have the potential to record data that can be used to diagnose the causes of wildlife mortality events and enable action to prevent recurrence. From 2012 to 2015 and 2017 to 2019, volunteers recorded the occurrence of grounded Common Pipistrelle bats in association with seasonal swarming that takes place during late summer and early autumn at Durham Cathedral cloister, involving up to 197 recorded groundings and 64 confirmed deaths in a single year. Post-mortem examinations were also carried out on a sample of bats that died in the cloister each year from 2017 to 2019. Groundings involved juvenile bats showing a near-typical weight distribution for the time of year, and weight had no influence on the survival of bats undergoing rehabilitation. Grounding frequency generally peaked in August, but varied from year to year in parallel with variation in the timing of swarming. Variation in the daily frequency of groundings was influenced by weather conditions during the previous night and showed a strong positive association with concurrent daytime temperature. Post-mortems revealed no evidence of injury, infectious disease or chemical contamination, but disclosed a range of evidence consistent with acute heatstroke. In aggregate, the results suggest that groundings and deaths occur among juvenile bats that elect to roost within the roof of the cloister walkways during swarming visits, and then suffer heatstroke resulting from direct insolation of the roof and its surrounds during daylight.
      PubDate: 2022-12-08
       
  • Determining sex in golden eagle (Aquila chrysaetos) nestlings

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      Abstract: Abstract Incorporating sex ratios of nestlings into population viability studies increases knowledge of overall health of endangered populations. Currently, a reliable non-invasive method to identify the sex of golden eagle nestlings is not available; however, claims are commonly made based on morphology. Ten biometric measurements from 43 Scottish golden eagles aged 2–7.5 weeks were assessed to see if sex could actually be determined using this non-invasive methodology. Sex was confirmed via molecular analysis of blood samples. Discrete and principal component analyses of the different biometrics could not correctly determine individual nestling sex. Therefore, despite being more invasive, molecular sexing remains the recommended tool of choice for accurate sex identification of Scottish golden eagle nestlings younger than 7.5 weeks of age. This has important implications for golden eagle field studies where empirical morphological measurements are frequently and typically taken, but we have shown are not reliable in determining the sex of such young nestlings.
      PubDate: 2022-12-05
       
  • What can genetics tell us about the history of a human-mediated
           introduction of the golden-striped salamander south of its native
           range'

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      Abstract: Abstract The golden-striped salamander is a streamside species endemic to the northwestern corner of the Iberian Peninsula. In the first half of the twentieth century, an undisclosed number of individuals of this species were reportedly captured in Buçaco, Central Portugal, and deliberately introduced in Sintra Mountains, 170 km south of its native distribution range. The discovery of a breeding population of this salamander in Sintra during 2015 prompted this work: we used neutral genetic markers, the mitochondrial DNA cytochrome b (cytb), and seven microsatellite loci to elucidate on the relict/human-introduced nature of Sintra population, identify the potential source population, and infer the severity of founder effect. Our results support a human-mediated introduction. First, sequencing analysis of cytb showed the presence of a unique haplotype (h31) in Sintra, which was detected only in Buçaco and in two additional populations located close to Mondego river. Second, microsatellite analysis showed that Sintra is more closely related to populations in between Douro and Mondego rivers (Central Portugal), instead of its geographically closest populations (southernmost), as would be expected if Sintra was a relict population isolated in an interglacial refuge. Third, Sintra presents both reduced levels of genetic variability and effective population size when compared to native populations, particularly to those of Central Portugal. Consistent with an isolated population funded by a small number of individuals (inferred herein to be ca. 10–11 salamanders), Sintra forms a geographically coherent genetic unit that is significantly differentiated from the extant native C. lusitanica populations. Although our data provide supporting evidence for Buçaco as a likely source population, as documented in the literature, overall, we cannot unequivocally exclude other populations close to Mondego river as a potential source of the introduced individuals in Sintra.
      PubDate: 2022-12-02
       
 
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