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151 vertebrate Preprints

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vertebrate behavioral ecology genetics natural history terrestrial ecosystem ecology description experimental evolution marine statistical laboratory molecular evolution comparative method development population ecology ecosystem theory evolutionary ecology selection analysis freshwater ecological experiment community ecology theoretical multiple molecular genetics
Please note: These are preprints and have not been peer reviewed. Data may be preliminary.
Spatiotemporal variation in the long-term fish assemblages of Buck Creek, Delaware Co...
Paul DeRolf
Mark Pyron

Paul DeRolf

and 2 more

November 13, 2020
Buck Creek is a spring-fed, cool-water tributary of the West Fork White River, Indiana. The Muncie Bureau of Water Quality sampled fishes and monitored water temperature in Buck Creek annually from 1986-2018. For this study, we utilized long-term fish data from the Bureau of Water Quality to evaluate spatial and temporal changes in the fish assemblages of Buck Creek in Delaware County, Indiana, USA. Non-metric multidimensional scaling (NMDS) was used to describe changes in the fish assemblages over space and time. Linear mixed effects models were used to evaluate the relationship between environmental factors and the fish assemblages. The spatial NMDS results were separated in distinct groups of upstream and downstream assemblages. This was characterized by a shift of headwater specialists shifting to large-river species. The temporal NMDS results were separated into distinct annual assemblages. This was characterized by a drop in pollution-tolerant species and an increase in intolerant species. Our findings indicate that the fish assemblages have improved in Buck Creek over space and time.
Combining modern tracking data and historical records improves understanding of the s...
Haitao Tian
Diana  Solovyeva

Haitao Tian

and 9 more

November 13, 2020
The Lesser White-fronted Goose (Anser erythropus), smallest of the “grey” geese, is listed as Vulnerable on the IUCN Red List and protected in all range states. There are three sub-populations, with the least studied being the East Asian sub-population, shared between Russia and China. The extreme remoteness of breeding enclaves makes them largely inaccessible to researchers. As a substitute for visitation, remotely tracking birds from wintering grounds allows exploration of their summer range. Over a period of three years, and using highly accurate GPS tracking devices, eleven individuals of A. erythropus were tracked from the key wintering site of Dongting Lake, China, to breeding, molting, and staging sites in north-eastern Russia. Data obtained from that tracking, bolstered by ground survey and literature records, were used to model the summer distribution of A. erythropus. Although earlier literature suggests the summer range is patchy, the model confirms a contiguous summer range. The most suitable habitats are located along the coasts of the Laptev Sea, primarily the Lena-Delta, in the Yana-Kolyma Lowland, and smaller lowlands of Chukotka with narrow riparian extensions upstream along major rivers such as the Lena, Indigirka and Kolyma. The probability of A. erythropus presence is related to sites with altitude less than 500 m with abundant wetlands, especially riparian habitat, and a climate with precipitation of warmest quarter around 55 mm and mean temperature of wettest quarter around 14oC. Human disturbance also affects site suitability, with a gradual decrease in species presence starting around 160 km from human settlements. Remote tracking of animal species can bridge the knowledge gap required for robust estimation of species distribution patterns in remote areas. Better knowledge of species’ distribution is important in understanding the large-scale ecological consequences of rapid global change and establishing conservation management strategies.
Population and habitat responses to the global climate change in a widespread species...
Liuyang Yang
Huabin Zhang

Liuyang Yang

and 7 more

November 12, 2020
Abstract: Global climate change is gradually changing the distribution and diversity pattern of species. In order to study the change of distribution area and distribution barycenter of Bufo gargarizans under climate change, we adopted the maximum-entropy modeling (Maxent) model and barycenter migration analysis. And four General circulation models (GCMs) under four representative concentration pathways (RCPs), 29 environment variables (including bioclimate, topography, habitat and human impact) were used to predict the current and future (2050 and 2070) distribution of B. gargarizans. The results show that the Mean temperature of Driest quarter (Bio9), Precipitation of driest month (Bio14) and population (POP) have greater influence on the distribution of B. gargarizans, it indicates that climate and anthropogenic factors have greater influence on the distribution of B. gargarizans than other environmental factors such as topography and landform. And in the next 30 to 50 years, from the perspective of the large spatial scale of the whole China, the distribution area of B. gargarizans is in the eastern part of China, the southeastern part is reduced, and the Midwest and northwest part is expanded. On the whole, the suitable habitat of B. gargarizans will be reduced in the future and will migrate to the high latitude and altitude area. In this study, B. gargarizans was used as a sentinel species to study the response of amphibians to climate change, this paper aims to reveal the mechanism of amphibian response to climate change from the current and future dispersal patterns of B. gargarizans.
Interactive effects of body mass changes and species-specific morphology on flight be...
Nina Dehnhard
Andrew Klekociuk

Nina Dehnhard

and 2 more

November 11, 2020
For procellariiform seabirds, wind and body morphology are crucial determinants of flight costs and flight speeds. During chick-rearing, parental seabirds commute frequently to provision their chicks, and their body mass changes between outbound and return legs. In Antarctica, the typical diurnal katabatic winds which blow stronger in the mornings, form al natural experiment to investigate flight behaviours in response to wind conditions. We GPS-tracked three closely related species of sympatrically breeding Antarctic fulmarine petrels which differ in wing loading and aspect ratio and investigated their flight behaviour in response to wind and changes in body mass. All three species reached higher flight speeds under stronger tailwinds, especially on return legs from foraging, when wing loading was increased since birds carried food for their chicks. Flight speeds decreased under stronger headwinds. Antarctic petrels (Thalassoica antarctica; intermediate body mass, highest wind loading and aspect ratio) responded stronger to changes in wind speed and direction than cape petrels (Daption capense; lowest body mass, wing loading and aspect ratio) or southern fulmars (Fulmarus glacialoides; highest body mass, intermediate wing loading and aspect ratio). Birds did not adjust their flight direction in relation to wind direction nor maximum distance to nest when they encountered strong headwinds on their outbound commutes. However, birds appeared to adjust the timing of commutes to those hours of the day when headwinds were weakest and they were more likely to encounter favourable tail- and crosswinds. Despite these adaptations to the predictable diurnal wind conditions, birds frequently encountered unfavourably strong headwinds, possibly as a result of weather systems disrupting the katabatics coupled with the need to feed. How the predicted decrease in Antarctic near-coastal wind speeds over the remainder of the century will affect flight costs and breeding success which ultimately drives population trajectories remains to be seen.
Trophic niche overlap between sympatric harbour seals (Phoca vitulina) and grey seals...
Yann Planque
Jérôme Spitz

Yann Planque

and 4 more

November 11, 2020
Competition between the sympatric harbour (Phoca vitulina) and grey seals (Halichoerus grypus) is thought to underlie some recent local declines of the former while the population of the latter remains stable or increases. A better understanding of the interactions between these two species is critical to elucidate current changes. This study aims at identifying and quantifying the niche overlap between harbour and grey seals at their Southern European limit range, in the baie de Somme (Eastern English Channel, France), in a context of exponential increase in the number of resident harbour seals and visiting grey seals. Isotopic niche overlap was quantified between both species using whisker δ13C and δ15N isotopic values, taking intra- and interindividual variability into account. Dietary overlap was quantified from scat contents using hierarchical clustering. A high degree of trophic niche overlap was identified between both species. The narrower isotopic niche of harbour seals was nested within that of grey seals (58.2% [CI95%: 22.7-100%] overlap). Six diet clusters were identified from scat content analysis. Two of them gathered most of harbour seals’ scats (85.5 % [80.3-90.2%]) and around half of grey seals’ ones (46.8% [35.1-58.4%]) that almost exclusively contained benthic flatfish. Consumption of this type of prey was identified here to be the root cause of trophic overlap. This highlighted the potential for competition between the two species at their Southern European limit range, linked to foraging on benthic flatfish, in coastal waters close to their haulout sites, especially during spring/summer. We suggest that (1) interspecific competition for prey could occur/increase in the future if the number of grey and harbour seals still increase and/or if flatfish supply decrease in this area, and (2) harbour seals would be disadvantaged in such a case if they do not adapt, as being specialised on flatfish at the colony scale.
Effects of human activity on the habitat utilization of Himalayan marmot (Marmota him...
Cheng Guo
Shuailing Zhou

Cheng Guo

and 4 more

November 04, 2020
Human activity is increasingly and persistently disturbing nature and wild animals. Affected wildlife adopts multiple strategies to deal with different human influences. To explore the effect of human activity on habitat utilization of the Himalayan marmot (Marmota himalayana), habitat utilization patterns of three neighboring marmot populations in habitats affected differently by human activities were recorded and compared. We found that: (1) Distance between reproductive burrows becomes shorter under the influence of human activity, and further, the more disturbance a population suffers, the more burrows were dug as temporary shelter to reduce the distance to those shelters when threatened. More burrows that are closer in the disturbed habitats improve ability to escape from threats. (2) Burrow site selection is determined by the availability of mounds in the habitat. Breeding pairs selectively build burrows on mounds to reproduce, potentially to improve surveillance and the drainage of their burrows. Human activities generally drive breeding pairs away from the road to build their reproductive burrows, likely to reduce disturbance from vehicles. However, even heavy human activity exerts no pressure on the distance of reproductive burrows from the road or the mound volume of the high disturbance population, potentially because mounds are the best burrowing site in the habitat. Marmots deal with nonlethal human disturbance by digging more burrows in the habitat to flee more effectively and building reproductive burrows on mounds to gain better vigilance and drainage efficiency.
Passive acoustic monitoring and automated analysis as an alternative to trapping for...
R Thomas
Stephen Davison

R Thomas

and 1 more

November 02, 2020
1. Bat abundance, diversity and behaviour can be monitored by capturing bats for identification and measurement in the hand, but this has several disadvantages. These include disturbance to the bats, which limits the frequency with which captures can be made at an individual capture site, and potentially alters the behaviours being studied. 2. Passive recording and automated analysis and identification of bat calls offers an alternative, non-invasive approach to monitoring bats. In this study, we examine the effectiveness of acoustic monitoring in comparison with capture-based monitoring of seasonal swarming behaviour among several species of Myotis bats in southern Britain. 3. We show that both approaches have advantages and disadvantages for different tasks, but can be viewed as complementary methods for addressing different types of research questions. 4. We applied these complementary approaches, together with observations from infra-red video monitoring, to describe seasonal, overnight and species-specific variation in swarming behaviour in a multi-species community of Myotis bats. 5. In our study of swarming behaviour, capture and examination of bats in the hand was necessary for measuring sex ratios, reproductive status, and even for confirmation of species identification for some difficult to separate taxa. Capture is also an essential aspect of tagging bats for individual identification and tracking studies. 6. Passive acoustic monitoring is a valuable non-invasive method for continuous monitoring of within-night, seasonal and between-year variation in the abundance of bat calls. These can be used as an index of variation in relative abundance within -- but not between -- bat species.
Predation release of Texas horned lizards (Phrynosoma cornutum) living in small towns
Stephen Mirkin
Mary Tucker

Stephen Mirkin

and 2 more

October 29, 2020
Texas horned lizards (Phrynosoma cornutum) have a number of ways to avoid predation, including camouflage, sharp cranial horns, flattening of the body, and the ability to squirt blood from the eyes. These characteristics and their relatively low survival rates in the wild suggests these lizards are under high predation pressure. These lizards have been declining in much of their eastern range due to increased urbanization, agriculture, and loss of prey species. However, they can be still be found in some small south Texas towns where they can reach densities that are much higher (~50 lizards/ha) than in natural areas (~4-10 lizards/ha). We hypothesized that one reason for the high densities observed in these towns may be due to reduced predation pressure. We used model Texas horned lizards to test whether predation levels were lower in two south Texas towns than on a nearby ranch. We constructed models from urethane foam, a material that is ideal for preserving marks left behind by predators. Models (n = 126) and control pieces of foam (n = 21) were left in the field for 9 days in each location in early and late summer and subsequent predation marks were categorized by predator taxa. We observed significantly more predation attempts on the models than on controls and significantly fewer attempts in town (n = 1) compared to the ranch (n = 60). On the ranch, avian predation attempts appear to be common especially when the models did not match the color of the soil. Our results suggest that human modified environments that have suitable habitat and food resources may provide a refuge for some prey species like horned lizards from predators.
DIVERSITY, ABUNDANCE AND POPULATION STRUCTURE OF MONGOOSE SPECIES (FAMILY HERPESTIDAE...
Matewos Masne
Serekebirhan Takele

Matewos Masne

and 1 more

October 26, 2020
Study of the carnivore guild is the key to understand quantitative relationship between members of the carnivore community. The aim of the study was to investigate diversity, abundance and population structure of the mongoose in Nech Sar National Park. Ecological data collection on mongoose species has been carried out from September 2017 to August 2018 in Nech Sar National Park (NSNP). Based on the habitat type and topography of NSNP, 10 transects, each of 4-5 km long were sampled to traverse the major habitat types in the park. Line transect distance sampling methodology was used to determine abundance and population status. DISTANCE (Version 6.0, Release 2) Software was used for density and abundance estimation of mongoose populations. The key to distance sampling analyses is to fit a detection function to the observed distances, and hence, the key functions hazard rate + hermite polynomial, unform + cosine polynomial and half normal + hermite polynomial models were chosen over the others on the basis of best fit. Three species of mongoose namely- Egyptian mongoose (Herpestes ichneumon,) Slender mongoose (Herpestessanguineus) and White tailed mongoose (Ichneumiaalbicauda) were identified in the study. The overall density of mongoose in the study area was 2.3048+0.16070 individuals/km2 with population estimate of 943+85.593 individuals. Based on season and habitat type, density and abundance estimates showed variation (P<0.05). However, species composition between seasons and habitats was the same. The highest species diversity (H=1.197) was recorded in bushland habitat. The population was female-baised with 1:1.171 and 1:1.59, male to female ratio during wet and dry seasons, respectively. Adult to young (subadult and juvenile) ratio was1.05:1 and 0.94: 1 during wet and dry seasons, respectively. Further researches on other ecological parameters viz. behavior, feeding habit and activity pattern are important to acquire a complete picture about mongoose ecology in the park.
Migration-tracking integrated phylogeography supports long-distance dispersal-driven...
Daisuke Aoki
Haruna Sakamoto

Daisuke Aoki

and 4 more

October 26, 2020
Aim: In theory, long-distance dispersal (LDD) outside a species’ range contributes to genetic divergence. However, previous studies have not discriminated this process from vicariant speciation in migratory bird species. We conducted an integrative phylogeographic approach to test the LDD hypothesis, which predicts that a Japanese migratory bird subspecies diverged from a population in the coastal region of the East China Sea (CRECS) via LDD over the East China Sea (ECS). Location: East Asia Taxon: Brown Shrike (Lanius cristatus) Methods: Both a haplotype network and a multi-locus gene network of its three subspecies were reconstructed to examine from which continental population the Japanese subspecies diverged. A species distribution model (SDM) for the Japanese subspecies was constructed using bioclimatic variables under the maximum entropy algorithm. It was projected to the climate of the last glacial maximum (LGM) to infer the candidate source area of colonisation. A migratory route of the Japanese subspecies, which possibly reflects a candidate past colonisation route, was tracked by light-level geolocators. Results: Molecular phylogenetic networks suggest that the Japanese subspecies diverged from a population in the CRECS. The SDM inferred that the emerged continental shelf of the ECS and the present CRECS were suitable breeding areas for the Japanese subspecies during the LGM. A major migratory route for the Japanese subspecies was inferred between the CRECS and the Japanese archipelago across the ECS. Main conclusions: Our integrative approach supported the LDD hypothesis for divergence of the Japanese subspecies of the Brown Shrike. Shrinkage and expansion of the ECS may have been responsible for successful colonisation and isolation of the new population. Vicariance was inferred for divergence of the subspecies in the northeast Asian continent from the Japanese population. Our framework provides a new phylogeographic scenario in this region, and discriminating LDD and vicariance models should improve our understanding of the phylogeographic histories of migratory species.
3D Genital Shape Complexity in Female Marine Mammals
Dara Orbach
Charlotte Brassey

Dara Orbach

and 3 more

October 23, 2020
Comparisons of 3D shapes have recently been applied to diverse anatomical structures using landmarking techniques. However discerning evolutionary patterns can be challenging for structures lacking homologous landmarks. We used alpha shape analyses to quantify vaginal shape complexity in 40 marine mammal specimens including cetaceans, pinnipeds, and sirenians. We explored phylogenetic signal and the potential roles of natural and sexual selection on vaginal shape evolution. Complexity scores were consistent with qualitative observations. Cetaceans had a broad range of alpha complexities, while pinnipeds were comparatively simple and sirenians were complex. Intraspecific variation was found. Three-dimensional surface heat maps revealed that shape complexity was driven by invaginations and protrusions of the vaginal wall. Phylogenetic signal was weak and metrics of natural selection (relative neonate size) and sexual selection (relative testes size, sexual size dimorphism, and penis morphology) did not explain vaginal complexity patterns. Additional metrics, such as penile shape complexity, may yield interesting insights into marine mammal genital coevolution. We advocate for the use of alpha shapes to discern patterns of evolution that would otherwise not be possible in 3D anatomical structures lacking homologous landmarks.
The role of DNA integrity in opportunistic longitudinal telomere studies
Malin Undin
Kristene Gedey

Malin Undin

and 3 more

October 23, 2020
Determining both individual age and population age distribution is crucial for an array of ecological studies. This is generating growing interest in molecular age markers such as telomere length. Most studies exploring the relationship between age and telomere length have been cross-sectional, but such studies face problems with large individual variation and the selective loss paradox. Thus, interest is growing rapidly for turning to longitudinal studies. In this study, the rate of telomere loss was analyzed for the extraordinarily long-lived North Island brown kiwi, Apteryx mantelli. Relative telomere length (RTL) was quantified using qPCR from blood from four separate sampling occasions across 14 years were analysed. Uniquely, the analysis of RTL was combined with high resolution analysis of genomic quality to get numerical values of DNA integrity. The analysis of RTL suggested a circa 5 % annual increase in A. mantelli telomere length. However, RTL was found to be highly correlative with DNA integrity, indicating that the perceived elongation of telomeres was a result of DNA quality differences between cohorts. Notably, the observed, positive correlation remained significant even when analyzing only samples classified as being of high DNA quality. Previous work has highlighted the potential impact of sample storage differences on RTL. However, to our knowledge, this is the first study to suggest that even small differences in DNA integrity between samples cohorts can impact the results of telomere studies. These findings are of great importance since longitudinal telomere studies of long-lived species tend to be “after the fact” utilizing already available samples for which handling and/or storage regimes might differ or be unknown. For such studies, we suggest that analysis of DNA quality with higher precision than traditional gel electrophoresis is needed to generate reliable results of telomere dynamics.
A note on investigating cooccurrence patterns and dynamics for many species, with imp...
Darryl MacKenzie
Jason Lombardi

Darryl MacKenzie

and 2 more

October 23, 2020
1. Patterns in, and the underlying dynamics of, species cooccurrence is of interest in many ecological applications. Unaccounted for, imperfect detection of the species can lead to misleading inferences about the nature and magnitude of any interaction. A range of different parameterisations have been published that could be used with the same fundamental modelling framework that accounts for imperfect detection, although each parameterisation has different advantages and disadvantages. 2. We propose a parameterisation based on log-linear modelling that does not require a species hierarchy to be defined (in terms of dominance), and enables a numerically robust approach for estimating covariate effects. 3. Conceptually the parameterisation is equivalent to using the presence of species in the current, or a previous, time period as predictor variables for the current occurrence of other species. This leads to natural, ’symmetric’, interpretations of parameter estimates. 4. The parameterisation can be applied to many species, in either a maximum-likelihood or Bayesian estimation framework. We illustrate the method using camera trapping data collected on three mesocarnivore species in South Texas.
An evolutionary habitat selection by the plateau pika (Ochotona curzoniae) in relatio...
migmar Wangdwei
Ma Hong-Mei

Migmar Wangdwei

and 12 more

October 22, 2020
Habitat selection by animals is conventionally linked with nature selection pressures. However, niche construction as a potent evolutionary agent palys a crucial role for many types of evolutionary habitat selection by species and this modifies nature selection pressures. We used data obtained from an 11-year period to observe the evolutionary habitat selection by the plateau pika (Ochotona curzoniae) in relation to the niche construction of livestock management. We hypothesized that the niche construction of local nomads affects the evolutionary habitat selection of the plateau pika, and furthermore that the plateau pika does not fit niche conservatism in the Kobresia ecosystem of the Qinghai Tibetan Plateau (QTP). In order to verify the above hypotheses, we used the distance to the nearest yak-bedding areas and dung management as the variables that most strongly explain variation in pika occupancy (probability) and detection probability based on free-ranging livestock. Both pika occupancy and detection probability decrease sharply with increasing distance to the nearest yak-bedding area, suggesting that pika population densities are highest closest to yak-bedding areas. There is a strong correlation between dung cover and occupancy of the plateau pika; the more dung drying on the ground, the more plateau pikas occupy the area. Consequently, the plateau pika is frequently detected in damaged grass. Rangeland dominated by Kobresia sedges on the QTP is modified by livestock grazing and management, especially by dung management. This is the first research suggesting that local nomads may cause expansion of the habitat of the plateau pika. In sum, the habitat of the plateau pika is expanding and there is strong evidence that it retains its biodiversity on the Qinghai-Tibetan Plateau in spite of exposure to poison as control measure. Still, the current control management of the plateau pika may result in diminished diversity of both fauna and flora species and a collapse of the food web on the QTP.
Automated Location Invariant Animal Detection In Camera Trap Images Using Publicly Av...
Andrew Shepley
Greg Falzon

Andrew Shepley

and 3 more

October 21, 2020
1. A time-consuming challenge faced by ecologists is the extraction of meaningful data from camera trap images to inform ecological management. Automated object detection solutions are increasingly, however, most are not sufficiently robust to be deployed on a large scale due to lack of location invariance across sites. This prevents optimal use of ecological data and results in significant resource expenditure to annotate and retrain object detectors. 2. In this study, we aimed to (a) assess the value of publicly available image datasets including FlickR and iNaturalist (FiN) when training deep learning models for camera trap object detection (b) develop a for training location invariant object detection models and (c) explore the use of small subsets of camera trap images for optimization training. 3. We collected and annotated 3 datasets of images of striped hyena, rhinoceros and pig, from FiN, and used transfer learning to train 3 object detection models in the task of animal detection. We compared the performance of these models to that of 3 models trained on the Wildlife Conservation Society and Camera CATalogue datasets, when tested on out of sample Snapshot Serengeti datasets. Furthermore, optimized the FiN models via infusion of small subsets of camera trap images to increase robustness for challenging detection cases. 4. In all experiments, the mean Average Precision (mAP) of the FiN models was significantly higher (82.33-88.59%) than that achieved by the models trained only on camera trap datasets (38.5-66.74%). The infusion of camera trap images into FiN training further improved mAP, with increases ranging from 1.78-32.08%. 5. Ecology researchers can use FiN images for training robust, location invariant, out-of-the-box, deep learning object detection solutions for camera trap image processing. This would allow AI technologies to be deployed on a large scale in ecological applications. Datasets and code related to this study are open source and available at: https://github.com/ashep29/infusion
Unique neurophysiologic characteristics of the longest-living rodent: the naked mole...
Meng Liang
Bingying Du

Meng Liang

and 5 more

October 16, 2020
Heterocephalus glaber or the naked mole rats(NMRs) belongs to the genus nude moles of the Bathyergidae family, which is the only kind of temperature changing mammal with true sociality in the world and shares 93% genetic homology with humans. Long-term subterranean burrowing living has led to NMRs gradually evolved a series of physiological characteristics that are significantly different from mammals living on the ground, such as vitamin D deficiency, sensory organs degeneration and extreme hypoxia tolerance. Despite the harsh living environment, NMRs are extremely long-lived. Their average lifespan is 5-7 times that of laboratorial mice of the same size, up to 30 years. These physiological characteristics of NMRs giving them a good applicable prospect when studying neurological related diseases such as pain, ischemic stroke, and Alzheimer’s disease(AD). Here, we have reviewed the studies published on the neurophysiological characteristics of NMRs to provide reference for future research.
Southern range dynamics of Canada lynx over seven decades
Robby Marrotte
Jeff Bowman

Robby Marrotte

and 1 more

October 14, 2020
The range of the Canada lynx (Lynx canadensis) has contracted substantially from its historical range prior to the 19th century. Using harvest records, we found that the southern range of the lynx in Ontario in the late 1940s collapsed and then in a short period of time increased to its largest extent in the mid-1960s where the lynx range spread south of the boreal forest for a decade. After this expansion the southern range contracted northwards beginning in the 1970s. Most recently, there has been a slight expansion between 2010-2017. We have attributed these dynamics on the southern range periphery to the fluctuation of the boreal lynx population in the core of the species’ range. In addition, connectivity to boreal lynx populations and snow depth seemed to condition whether the lynx expanded into an area. However, we did not find any evidence that would suggest that these changes were due to anthropogenic disturbances or competition. The boreal lynx population does not reach numbers as it once did, consequently we likely will not see large expansions of the southern lynx range as in the mid-1960s. Our results suggest that southern lynx range in Ontario have been driven by the magnitude of the boreal lynx population cycle, connectivity to the boreal forest and snow conditions. Therefore, it is quite unlikely that southern lynx population in the Great Lakes will ever recover, since the warming climate and forestry practices are causing a northward contraction of the boreal forest and likely with it the core lynx populations.
Secondhand homes: Woodpecker cavity location and structure influences secondary neste...
Faith Hardin
Samantha Leivers

Faith Hardin

and 5 more

October 09, 2020
1. Understanding how ecosystem engineers influence other organisms has long been a goal of ecologists. Woodpeckers select nesting sites with high food availability and will excavate and then abandon multiple cavities throughout their lifetime. These cavities are crucial to secondary cavity nesting birds (SCB) that are otherwise limited by the availability of naturally occurring cavities. 2. Our study examined the influence of food resources on the nest site location and home-range size of woodpeckers, and the subsequent influence of woodpeckers on the nesting success of SCB. 3. Using five years of avian point count data to locate golden-fronted woodpeckers (GFWO), we correlated insect availability with GFWO home range size, determined differences in insect availability between GFWO occupied and unoccupied sites, and compared nesting success for the GFWO and common SCB in south Texas. We used model averaging to fit species-specific logistic regression models to predict nest success based on cavity metrics across all species. 4. Sites occupied by GFWO had a higher biomass of insects in orders Coleoptera, Hymenoptera, and Orthoptera than unoccupied sites, and there was a negative correlation between the availability of these insect orders and home-range size. GFWO nest success increased with vegetation cover and lower levels of tree decay. SCB had higher levels of nesting success in abandoned GFWO, and in trees with lower levels of nest tree decay. 5. Our results suggest that SCB may be drawn to nest in abandoned woodpecker cavities where they have higher rates of nest success compared to natural cavities. Additionally, the prevalence for GFWO to excavate cavities in trees with lower levels of decay contradicts previous literature, and may indicate a novel temperature trade-off, with live trees requiring more energy to excavate, but providing increased protection from high breeding season temperatures in arid and semi-arid areas.
Molecular characterization of MHC class I genes in Four species of Turdidae family to...
Muhammad Usman Ghani
Shakeel Hussain

Muhammad Usman Ghani

and 4 more

October 06, 2020
In vertebrate animals, the molecules encoded by major histocompatibility complex (MHC) genes play an essential role in the adaptive immunity. MHC class I deal with intracellular pathogens (Virus) in birds. MHC class I diversity depends on the consequence of local and global environment selective pressure and gene flow. Here, we evaluated the MHC class I gene in four species of Turdidae family from a broad geographical area of northeast China. We isolated 77 MHC class I sequence, including 47 putatively functional sequences and 30 pseudo sequences from 80 individuals. Method based on analysis of cloned amplicons (n=25) for each species, we found two and seven MHC I sequence per individual indicates more than one MHC I loci identified in all sampled species. Results revealed an overall elevated genetic diversity at MHC class I, evidence of different selection patterns among the domains of PBR and non-PBR. Alleles found to be divergent with overall polymorphic sites per species ranging between 58 to 70 (out of 291 sites). Moreover, trans-species alleles were evident due to convergent evolution or recent speciation for the genus. Phylogenetic relationships among MHC I show an intermingling of alleles clustering among Turdidae family rather than between other passerines. Pronounced MHC I gene diversity is essential for existence of species. Our study signifies a valuable tool for the characterization of evolutionary relevant difference across a population of birds with high conservational concerns.
Water depth, vegetation height, and offshore distance are critical factors in nest-si...
Wanyoike Wamiti
Nathan Gichuki

Wanyoike Wamiti

and 6 more

October 05, 2020
Grey Crowned Crane Balearica regulorum is described as an icon of Africa’s wetlands and grasslands and is listed as Endangered on the IUCN Red List of Threatened species. Conservation efforts are partially hindered by lack of information on factors influencing breeding productivity, such as nest-site selection. Factors influencing nest-site selection were investigated at Lake Ol’ Bolossat, a 43.3 km2 wetland located in the central Kenya from 30 paired nests. Generalized Linear Mixed-Effects Models were used to analyse the relationship between factors influencing nest-site selection by cranes and variables that were predicted to have a compelling influence on nest-site selection besides i) food and nesting materials availability i.e. the offshore distance of the nest and water depth, and ii) nest concealment and susceptibility to predation i.e. vegetation height and grazing intensity. Results show that variables which had a significant influence on nest-site selection were: water depth (p=0.005), the offshore distance from the nest (p=0.037), and vegetation height (p=0.035). Cranes located their nests in water points above 50 cm deep, vegetation height of 60-90 cm, and preferably 100 m offshore. A minimum of 103 territorial pairs, both breeding and non-breeding cranes, were recorded. The middle section of the lake had the highest number (52), while north and south had 32 and 19 pairs respectively. The mean distance between any two pairs was 302.53±17.02 (SE) meters. This study sheds some light on the understanding of characteristics of Grey Crowned Crane’s nesting sites that will facilitate manipulation and management of breeding sites. Lake Ol’ Bolossat is consequently a critical breeding site with a substantial role in the species’ population recovery and survival. A wetland management option that aims at achieving sustainable use of lake’s resources by local communities without compromising needs of wildlife is highly commended.
Modelling koala density using incidental koala sightings in South East Queensland, Au...
Ravi Dissanayake
Emanuele Giorgi

Ravi Dissanayake

and 4 more

October 01, 2020
The koala, Phascolarctos cinereus, is an iconic Australian wildlife species, but faces rapid decline in South-East Queensland (SEQLD). For conservation planning, estimating koala populations is crucial. Systematic surveys are the most common approach to estimate koala populations, but such surveys are restricted to small geographic areas, they are costly and conducted infrequently. Public interest and participation in the collection of koala sightings is increasing in popularity, but such data is generally not used for population estimation. We used incidental sightings of koalas reported by members of the public from 1997-2013 in SEQLD to estimate the yearly spatio-temporal koala sightings density. For this, a spatio-temporal point process model was developed accounting for observed koala density, spatio-temporal detection bias and clustering. The density of koalas varied throughout the study period due to the heterogeneous nature of koala habitat in SEQLD, with density estimates ranging between 0.005 to 8.9 koalas per km2. The percentage of land areas with very low sightings densities (0-0.25 koalas per km2) remained similar throughout the study period representing in average (SD) 68.3% (0.06) of the total study area. However, land areas with more koalas per km2 showed larger annual variations, with koala mean (SD) densities of 0.25-0.5, 0.5-1, 1-2, 2-5 and > 5 koalas per km2 representing 16.8% (0.21), 13.8% (0.25), 0.7% (0.20), 0.3% (0.13), and 0.2% (0.1) of the study area in South-East Queensland, respectively.We did find that clustering of koala sightings was not prominently different between the mating and non-mating seasons of koalas. While acknowledging the limitations associated sightings data, we developed a statistical model that addressed the spatio-temporal bias associated with observed koala sightings and provided long-term relative koala density estimates for one of the largest koala populations of Australia.
Eurasian lynx. How many of them lives in Central Europe?
Klaudia Wlaźlak
Przemysław Cwynar

Klaudia Wlaźlak

and 2 more

September 28, 2020
Knowledge about the number of Eurasian lynx in Poland is important from the viewpoint of lynx protection and education of society in the field of wild animals. The occurrence of lynx in Poland is limited to the forest environment. These animals rarely leave forested areas as the territories used by humans are a relevant barrier in long-distance migrations. Habitats' fragmentation is probably the most important factor determining the stability of the lynx population. This is evidenced by the comparison of the species situation in areas with different levels of forestation. Based on the collected data, we observed that Eurasian lynx occur mostly in the Podkarpackie Voivodeship, which is a part of Carpathian Mountains, and in the primeval forests of north-eastern part of Poland. In the west part is still scarce. Our study presents estimation of the number of Eurasian lynx in Poland from 2004 to 2018 and the prediction of the trend in the population development in the next 10 years, using Holt's model as statistical analysis which is the most useful for wildlife populations. The data were collected from Central Statistical Office of Poland and supplementary data from the Polish Hunting Association in Poland. This study may be helpful for the better understanding of the species and also to protect it, because since 1995 the Eurasian lynx is an endangered species in Poland. Many institutions have been implementing conservation plans for this species, mainly attempts to reintroduce the species are used into the most suitable areas of Poland.
Processes that drive the population structuring of Jenynsia lineata (Cyprinidontiform...
Yanina Briñoccoli
Luiz Jardim de Quieroz

Yanina Briñoccoli

and 7 more

September 25, 2020
1. Species are not genetically homogeneous, as the genetic structure among populations is related to the degree of isolation amongst them, such as isolation-by-distance, isolation-by-barrier and isolation-by-environment. 2. To decipher the isolation processes that drive population structuring in Jenynsia lineata we analyzed 221 sequences of the mitochondrial cytochrome c oxidase I gene (COI), which came from 19 localities. Jenynsia lineata is a small viviparous fish that inhabits a wide range of habitats in South America. Then, we examined the influence of the three most common types of isolation to explain the genetic variation found in this species. 3. Our results revealed a marked structuration, with three groups: i) La Plata/Desaguadero Rivers (sampling sites across Argentina, Uruguay, and Southern Brazil), ii) Central Argentina, and iii) Northern Argentina. A distance-based redundancy analysis including the explanatory variables geographical distances, altitude, latitude, basin, was able to explain up to 65% of the genetic structure. A variance partitioning analysis showed that the two most important variables underlying the structuration in J. lineata were altitude (isolation-by-environment) and type of basin (isolation-by-barrier). 4. Our results show that in this species, the processes of population diversification are complex and are not limited to a single mechanism. Population-structuring may lead to population reproductive isolation and ultimately to speciation. 5. This study demonstrated that the process of diversification of populations is complex and is not limited to a single mechanism. The processes that play a prominent role in this study could explain the high rate of diversity that characterizes freshwater fish species. And these processes in turn are the basis for possible speciation events.
Effective number of white shark (Carcharodon carcharias, Linneaus) breeders is stable...
Danielle Davenport
Paul Butcher

Danielle Davenport

and 5 more

September 24, 2020
Population size is a central parameter for conservation, however monitoring abundance is often problematic for threatened marine species. Despite substantial investment in research, many marine species remain data-poor resulting in uncertain population forecasts and restricting the evaluation of past and present conservation actions. Such is the case for the white shark (Carcharodon carcharias), a highly mobile apex predator for whom population monitoring is a conservation priority following substantial declines recorded through the 20th century. Here, we estimate the effective number of breeders that successfully contribute offspring in one reproductive cycle (Nb) providing a snapshot of recent reproductive effort in an east-Australian New Zealand population of white shark. Nb was estimated over four consecutive age cohorts (2010, 2011, 2012, 2013) using two genetic estimators (linkage-disequilibrium; LD and sibship assignment; SA) based on genetic data derived from two types of genetic markers (single-nucleotide-polymorphisms; SNPs and microsatellite loci). While estimates of Nb using different marker types produced comparable estimates, microsatellite loci were the least precise. The LD and SA estimates of Nb within cohorts using SNPs were comparable, for example the 2013 age-cohort Nb(SA) was 289 (95%CI 200-461) and Nb(LD) was 208.5 (95%CI 116.4-712.7). We show that over the time period studied Nb was stable and ranged between 206.1(±45.9) and 252.0(±46.7) per year using a combined estimate of Nb(SA+LD) from SNP loci, and a simulation approach showed that in this population effective population size (Ne) per generation can be expected to be larger than Nb per reproductive cycle. This study demonstrates how breeding population size can be monitored over time to provide insight into the effectiveness of recovery and conservation measures for the white shark, where the methods described here may be applicable to other data-poor species of conservation concern.
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