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379 vertebrate Preprints

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vertebrate behavioral ecology genetics terrestrial natural history description statistical molecular evolution laboratory theory freshwater ecological experiment community ecology sequencing theoretical molecular genetics multiple marine comparative population ecology method development none of the above ecosystem evolutionary ecology selection analysis
Please note: These are preprints and have not been peer reviewed. Data may be preliminary.
The complete mtDNA genome of Huaibei Grey donkey: genome characterization and phyloge...
Jingjing Xia
Liang Chang

Jingjing Xia

and 7 more

August 15, 2022
To investigate the conservation and phylogenetic relationship with other breeds of the local Anhui Province Huaibei Grey donkey (HGD), the complete mitochondrial DNA (mtDNA) was sequenced and de novo assembled using deep sequencing data from total genomic DNA. The final size of mtDNA was 16 670 bp (NCBI submission number: MZ911746), including 22 tRNA genes, two rRNA genes, 13 protein-coding genes (PCGs), and one non-coding control region. The PCGs region consisted of 5 559 codons. Most of the PCGs had ATG and TAA as the start and stop codons, respectively. Then we analyzed the proximal part of the D-loop region (418 bp, between 15 419 bp to 15 836 bp) from HGDs, using DNAsp v6 software. We identified 23 polymorphic nucleotide sites and found that the A, C, G, and T bases comprised 30.4%, 34.9%, 13.1%, 21.6%, respectively, of the mtDNA D-loop sequence. The haplotype and nucleotide diversity were 0.87000 and 0.02115, correspondingly. Altogether, the 60 sequences displayed 11 different haplotypes, the most frequent haplotype was H9 (23.33%), followed by H4 (21.67%). MJ network analysis indicated that all haplotypes were clearly divided into Clade Ⅰ and Ⅱ lineages, which indicates that HGD may have two maternal lineages. Phylogeographic analysis indicates that the Somali lineage could be the most probable domestication center for HGD. Our study provides an empirical basis for the characterization, conservation, and management of HGD genetic resources.
Factors affecting spatiotemporal patterns of nest site selection and abundance in dia...
Patricia Levasseur
Robert Prescott

Patricia Levasseur

and 3 more

August 12, 2022
Determining what factors influence the distribution and abundance of wildlife populations is crucial for implementing effective conservation and management actions. Yet, for species with dynamic seasonal, sex-, and age-specific spatial ecology, like the diamondback terrapin (Malaclemys terrapin; DBT), doing so can be challenging. Moreover, environmental factors that influence the distribution and abundance of DBT in their northernmost range have not been quantitatively characterized. We investigated proximity to nesting habitat as one potential driver of spatiotemporal variation in abundance in a three-step analytical approach. First, we used a scale selection Resource Selection Function (RSF) approach based on NLCD landcover data to identify the scale at which DBT are selecting for (or avoiding) landcover types to nest. Next, we used RSF to predict areas of suitable nesting habitat and created an index of nest suitability (NSI). Finally, analyzing visual count data using a generalized linear mixed model (GLMM), we investigate spatiotemporal drivers of relative abundance, with a specific focus on whether similar factors affect offshore abundance and onshore nest site selection. We found the scale of selection for developed and saltmarsh land use classes to be 500 m and 525 m and coniferous, beach and open water land use classes to be 100 m. Selection was positive for nesting areas proximal to saltmarsh and beach habitat and negative for developed, coniferous and open water. Expected relative abundance was best explained by the interaction between NSI and day of season, where expected relative abundance was greater within high NSI areas during the nesting season (2.30 individuals, CI: 1.29 – 4.10) compared to areas of low NSI (1.99 individuals, CI: 1.27 – 3.13). Our results provide evidence that inferred spatial patterns of suitable nesting habitat explain spatiotemporal patterns of terrapin movement and abundance.
A GRAIN DIET SUPPLEMENTED WITH INSECTS RATHER THAN FRUITS SUPPORTS A MORE ROBUST BODY...
OJODOMO SIMON
Shiiwua Manu

OJODOMO SIMON

and 3 more

August 12, 2022
1. Omnivores utilise dietary sources which differ in nutrients, hence dietary restrictions due to environmental change or habitat alteration should cause nutrient limitations; and thus, deterioration of body condition if omnivory is obligate. 2. We investigated how the body condition of the Village weaver Ploceus cucullatus (weavers), which forages predominantly on grains, responds to insects and fruits deprivation. 3. Forty wild-caught weavers held in aviaries were fed a combination of grains and fruits, or grains and insects ad libitum for eight weeks. We confirmed diet preference by recording the number of foragers on each diet option per minute for one hour and the amount of food left-over after 3 hours of foraging. Fortnightly, we assessed indices of body condition including body mass, pectoral muscle, and fat scores, Packed Cell Volume (PCV) and Haemoglobin Concentration (HBC). We modelled the number of foragers, food left-over and body condition as functions of diet, while accounting for time (weeks) and sex effects. 4. We confirmed grains as the preferred diet and found that males ate more fruits and insects than females. Weavers fed on grains and fruits lost body and pectoral muscle mass and accumulated less fat than those fed on grains and insects. This effect was sex-dependent: females deprived of insects lost more pectoral muscle mass than males of the same group and males but not females, deprived of fruits accumulated more fat reserve than those deprived of insects. PCV and HBC did not differ between diets but increased over the eight weeks. 5. Weavers are likely obligate rather than facultative omnivores, with insects as being a more nutritive supplement than fruits. We conclude that nutrient limitation arising from environmental change or habitat alteration can impair body condition and affect physiological response to environmental seasonality in other obligate omnivores like the weavers.
Pet cat personality linked to owner-reported predation frequency
Marion Cordonnier
Amira Perrot

Marion Cordonnier

and 4 more

August 10, 2022
The domestic cat, Felis catus, is one of the most popular and widespread domestic animals. Because domestic cats can reach high population densities and retain at least some tendency to hunt, their overall impact on wildlife can be severe. Domestic cats have highly variable predation rates depending on the availability of prey in their environment, their owners' practices, and individual cat characteristics. Among these characteristics, cat personality has recently been hypothesized to be an important factor contributing to variations in the hunting activity of cats. In this study, we used surveys of 2,508 cat owners living in France to collect information about cat personalities using the Feline Five personality model and about the frequency with which the cats bring home prey. For both birds and rodents, cats with high levels of extraversion or low levels of neuroticism had significantly higher frequencies of prey return. Owners whose cats had low levels of agreeableness or high levels dominance reported a significantly lower frequency of bird return. Personality differences therefore seem to contribute to the high variability in predation rates between domestic cats. We also found that the owner-reported prey return frequencies were significantly higher for cats spending more time outdoors, for non-pedigree cats, and for owners living in rural or suburban areas as opposed to urban areas. By contrast, we did not detect an effect of cat sex or age on their reported prey return rates.
Prior choice and data requirements of Bayesian multivariate mixed effects models fit...
Cody Deane
Lindsay Gray Carlson

Cody Deane

and 5 more

August 09, 2022
1. Recent empirical studies have quantified correlation between survival and recovery by estimating these parameters as correlated random effects with Bayesian multivariate mixed effects models fit to tag-recovery data. In these applications, increasingly negative correlation between survival and recovery indicates increasingly additive harvest mortality. The power of mixed effects models to detect non-zero correlations has rarely been evaluated and these few studies have not focused on a common data type in the form of tag recoveries. 2. We assessed the power of multivariate mixed effects models to estimate negative correlation between annual survival and recovery. Using three priors for multivariate normal distributions, we fit mixed effects models to a mallard (Anas platyrhychos) tag-recovery dataset and to simulated data with sample sizes corresponding to different levels of monitoring intensity. We also demonstrate a method of calculating effective sample size for capture-recapture data. 3) Different priors lead to different inference about additive harvest when we fit our models to the mallard data. Our power analysis of simulated data indicated most prior distribution and sample size combinations resulted in correlation estimates with substantial bias and imprecision. Many correlation estimates spanned the available parameter space (–1,1) and were biased towards zero. Only one prior combined with our most intensive monitoring scenario allowed our models to consistently recover negative correlation without bias. Underestimating the magnitude of correlation coincided with overestimating the variability of annual survival, but not annual recovery. 4) The inadequacy of prior distributions and sample size combinations typically assumed adequate for robust inference represents a concern in the application of Bayesian mixed effects models for the purpose of informing harvest management. Our analysis approach provides a means for examining prior influence and sample size on mixed-effects models fit to capture-recapture data while emphasizing transferability of results between empirical and simulation studies.
Adapting camera-trap placement based on animal movement patterns for rapid detection:...
Franklin Simo T.
Ghislain Difouo F.

Franklin Simo T.

and 5 more

August 09, 2022
Abstract Pangolin species are notoriously difficult to detect and monitor in the wild and, as a result, commonly used survey techniques fall short in gathering sufficient data to draw confident conclusions on pangolin populations, conservation status, and natural history. The white-bellied pangolin is a semi-arboreal species which is poorly detected in general mammal surveys, even with modern techniques such as camera trapping. As a result, population status information is often derived from hunting, market and trafficking data. There is therefore a crucial need to improve camera trap technology or survey methods to reliably detect this species in its natural environment. Here, we test the influence of camera-trap placement strategy to investigate a new monitoring approach comparing detectability of the white-bellied pangolin obtained from targeted ground-viewing camera-trapping and a log-viewing placement strategy adapted from local hunters’ knowledge. Our results suggest that (1) deploying camera-traps to target logs is an effective strategy for recording several forest species, including the white-bellied pangolin and (2) that camera-traps targeting logs are more efficient at detecting white-bellied pangolins than camera-traps viewing the ground. We also found that there was only a weak relationship between the white-bellied pangolin occurrence and environmental variables such as elevation and distance to rivers. Our results provide an effective new monitoring approach allowing consistent detection of the white-bellied pangolin with moderate survey effort.
Variations in body shape between two sympatric haplochromine species: Implications fo...
Philippe Munyandamutsa
Wilson Jere

Philippe Munyandamutsa

and 3 more

August 09, 2022
Patterns of intra- and interspecific variation based on environmental conditions in which populations live may reflect adaptive responses to their habitat. This is particularly relevant in a lake habitat where closely related species occur sympatrically. This study was aimed at determining consistency in morphological traits in head and body shapes in two haplochromine species (Haplochromis insidiae and Haplochromis kamiranzovu) in littoral and/ pelagic zones and to estimate the extent to which the habitats affect variations between the species. Specimens of both species were taken from littoral and pelagic zones, in the northern and southern parts of Lake Kivu. Morphometrics and landmark-characteristics were recorded and compared within and between habitats. The results showed that differences were found among the two species, among the two zones and for both. The most prominent difference was in the head; including the relative size of the jaws, head length and position of the pectoral fin insertion. Variation in head morphology is normally related to feeding. Changes in body shape can be linked to differences in environment and food availability between the two habitats which could have enabled the species to co-exist. This capacity is important in lakes like Kivu which have low habitat diversity compared to other African Great lakes like Malawi, Tanganyika and Victoria and provide some explanation in the differences in the number of haplochromine species in these lakes. The genetic basis of these phenotypic changes should be examined in future research.
Long-term, room temperature storage of DNA extract on filter paper
Katherine Izenour
Anwar Kalalah

Katherine Izenour

and 3 more

August 09, 2022
1. Stable nucleic acid storage and preservation in resource limited settings is often a barrier to widespread pathogen surveillance. 2. Dried Blood Spot (DBS) filter paper has a long history of preserving nucleic acid in whole blood, we tested extending this technology to the room temperature storage of DNA extract. 3. We found that DNA extracted from whole mammalian blood can be stored at room temperature on DBS filter paper, then washed with the buffer solution Tris-HCL, and used in downstream PCR analysis with results comparable to PCR performed on DNA extracted from whole blood dried on DBS filter paper which is the gold standard. 4. The success of this method means DNA can be stored at room temperature making sharing genomic samples easier by eliminating the need for cold chain.
Patterns of activity and thermoregulatory mechanisms in the primitive Chinese Crocodi...
Chengming Huang
Meng Meng

Chengming Huang

and 6 more

July 31, 2022
We employed camera traps to collect data on the activity patterns, across a 24 hour period, of three free ranging adult Chinese crocodile lizards (Shinisaurus crocodilurus), a primitive reptile and the only lizard species in the family Shinisauridae. Our study demonstrated that during the non-hibernation season, diurnal Chinese crocodile lizard spent 96.73% of their time immobile (rest+sleep), 2.89% moving and 0.26% basking. Individuals regularly woke up around 5:30 AM and rested between 7:30AM to 8:20 PM. Four substrates used by Chinese crocodile lizards with per branch for 47.07±33.3% the ground for 28.34±15.56%, bodies of water for 1.2±0.7% and stem .for 0.9±0.43%. Additional analyses suggest that several factors including the exploitation of a small home range, a high starvation tolerance, extended periods of immobility (sleep + rest), and inhabiting a stable environment, enable the Chinese crocodile lizard to minimize energy costs associated with travel and thermoregulation, promoting its survival over long evolutionary periods.
Using Multiple-Covariate Distance Sampling to estimate Djaffa Mountains Guereza (Colo...
Chala Adugna Kufa
Afework Bekele

Chala Qufa

and 3 more

July 30, 2022
Estimating population densities is essential for understanding primate ecology and for guiding conservation efforts. Information on population densities, however, is still scarce for many tropical forest primates. The Djaffa Mountains guereza (Colobus guereza gallarum) is an Ethiopian endemic taxon of which information on their distribution and population size are missing. To fill this gap of knowledge, we conducted line-transect surveys in forest fragments in the range of C. g. gallarum in the Ahmar Mountains, Eastern Ethiopia. Between December 2020 and September 2021, we sampled 22 transects, covering a total distance of 93.7 km. Throughout the surveys, we encountered 79 Djaffa Mountains guereza groups (clusters). There was a considerable difference in encounter rates between the forest fragments. The overall population density was 16.5 groups or clusters/km2 (95%CI = 10.2–24.5) and 83.1 individuals/km2 (95%CI = 50.7–121.1). We estimated the total population size as 15,205 (95%CI = 9288–22,163) individuals. The population density of C. g. gallarum is thus lower than C. g. guereza in other localities of Ethiopia. Given that the population of C. g. gallarum and its habitat are highly fragmented, further monitoring of the population and exploring the possibilities of reconnecting its habitat should be of conservation priority.
Spatial and temporal non-stationarity in long-term population dynamics of over-winter...
Stephen Murphy
Marta Jarzyna

Stephen Murphy

and 1 more

July 27, 2022
Understanding population change across long time scales and at fine spatiotemporal resolutions is important for confronting a broad suite of conservation challenges. However, this task is hampered by a lack of quality long-term census data for multiple species collected across large geographic regions. Here, we used century-long (1919-2018) data from the Audubon Christmas Bird Count (CBC) survey to assess population changes in over 300 avian species in North America and evaluate their temporal non-stationarity. To estimate population sizes across the entire century, we employed a Bayesian hierarchical model that accounts for species detection probabilities, variable sampling effort, and missing data. We evaluated population trends using generalized additive models (GAMs) and assessed temporal non-stationarity in the rate of population change by extracting the first derivatives from the fitted GAM functions. We then summarized the population dynamics across species, space, and time using a non-parametric clustering algorithm that categorized individual population trends into four distinct trend clusters. We found that species varied widely in their population trajectories, with over 90% of species showing a considerable degree of spatial and/or temporal non-stationarity, and many showing strong shifts in the direction and magnitude of population trends throughout the past century. Species were roughly equally distributed across the four clusters of population trajectories, though grassland, forest, and desert specialists more commonly showed declining trends. Interestingly, for many species, region-wide population trends often differed from those observed at individual sites, suggesting that conservation decisions need to be tailored to fine spatial scales. Together, our results highlight the importance of considering spatial and temporal non-stationarity when assessing long-term population changes. More generally, we demonstrate the promise of novel statistical techniques for improving the utility and extending the temporal scope of existing citizen science datasets.
Integral projection model reveals differences in individual growth performance and bo...
Alexandra Johne
Chris G. Carter

Alexandra Johne

and 6 more

July 26, 2022
Fed aquaculture is one of the fastest growing and most valuable food production industries. The efficiency with which farmed fish convert feed into biomass influences both environmental impact and economic revenue. Salmonid species, such as king salmon (Oncorhynchus tshawytscha), exhibit high levels of plasticity in vital rates such as feed intake and growth rates. Accurate estimations of individual variability in vital rates are important for production management. The use of mean trait values to evaluate feeding and growth performance can mask individual-level differences that potentially contribute to inefficiencies. Here, we apply an integral projection model (IPM) to investigate individual variation in growth performance of 1625 individually tagged king salmon fed one of three distinct rations and tracked over 276 days. To capture the observed sigmoidal growth, we compared a non-linear mixed-effects (logistic) model to a linear regression model used within the IPM framework. Ration significantly influenced several aspects of growth. Mean final body mass and mean growth rate increased with ration, however, variance in body mass and feed intake also increased significantly over time. Trends in body mass mean and variance were captured by both logistic and linear models, suggesting the linear model to be suitable for use in the IPM. Higher rations resulted in a decreasing proportion of individuals reaching the cohort’s mean size or larger by the end of the experiment. This suggests that, in our trial, feeding to satiation did not produce the desired effects of efficient and uniform growth in juvenile king salmon. While monitoring individuals through time is challenging in commercial aquaculture settings, recent technological advances combined with an IPM approach could provide new scope for tracking growth performance in experimental and farmed populations. The IPM framework also allows the exploration of other size-dependent processes affecting vital rate functions, such as competition and mortality.
Feather characteristics for eye protection in an insectivorous passerine: the Iberian...
Frédéric  Labouyrie

Frédéric Labouyrie

July 21, 2022
In the French Mediterranean plain, the northern extreme of its native range, the Iberian grey shrike, Lanius meridionalis, predominantly feeds on arthropods. Its type of loral plumage plays a key role in protecting its eyes while transporting large prey. The aims is to understand the role played by feathers in protecting the animal from various types of defensive prey. We combine an inspection of large insect prey types found on larders with a review of bird specimens found in museum collections to examine the morphometric characteristics of rictal feathers and culmen. In addition, precision photographs are used to observe the posture of the plumage in natura. We could identify four categories of protective feathers: clustered bristles, semi-bristles, semi-plumes distributed in the loral area, and semi-plumes above the eyes. Our results suggest that the Iberian grey shrike has a complex structure of loral feathers, specific to its foraging activity and prey types. In France, local species have longer beaks than their Spanish counterparts which suggests a more insect-based diet.
Notes of hypopigmentation in mantled howler monkeys Alouatta palliata (Gray 1849): Fi...
Cristian Barros-Diaz
Silvia Vela Pinela

Cristian Barros-Diaz

and 6 more

July 20, 2022
The existence of hypopigmentation such as leucism is the result of inbreeding in isolated populations of wildlife and it is associated with environmental stressors. This anomaly may reduce survival rates. Leucism has been record in wildlife, but overall, it is considered very rare. There have been few records of mantled howler monkeys with leucism in Mexico and Costa Rica, but whole-body leucism in howler monkeys from South America was unknown. In this article, we report for the first-time documented cases of whole-body leucism in young individuals of mantled howler monkeys Alouatta palliata in an isolated remanent of tropical dry forest in southwestern Ecuador known as Cerro Blanco Protective Forest. In total, we found two individuals: a juvenile female and a juvenile male in October 2021. We also include a short report about the observation of two seedlings of Dichapetalum (Dichapetalaceae) showing albinism. The report of howler monkeys with whole-body leucism may be caused by the interaction of two processes: inbreeding because of isolated populations and air pollution with sulphur. Thus, immediate management strategies must be considered to significantly increase connectivity with other populations of howler monkeys and reduce air pollution in Guayaquil. Our findings also reveal that hypopigmentation is becoming more frequent in howler monkey´s population along its distributional range. Therefore, we encourage the community to consider a regional management strategy.
Two aspects of longevity are associated with the rate of loss of telomeres in birds
F. Stephen Dobson
Quentin Schull

F. Stephen Dobson

and 2 more

July 20, 2022
Telomeres, the terminal repetitive DNA sequences at the ends of linear chromosomes, have strong associations with longevity in some major taxa. Longevity has been linked to rate of decline in telomere length in birds and mammals, and absolute telomere length seems to be associated with body mass in mammals. Using a phylogenetic comparative method and 30 species of birds, we examined longevity (reflected by maximum lifespan), absolute telomere length, the rate of change in telomere length (TROC), and body mass (often strongly associated with longevity) to ascertain their degree of association. We divided lifespan into two life-history components, one reflected by body size (measured as body mass), and a component that was statistically independent of body mass. While both lifespan and body mass were strongly associated with a family tree of the species (viz., the phylogeny of the species), telomere measures were not. Telomere length was not significantly associated with longevity or body mass, or our measure of mass-independent lifespan. TROC, however, was strongly associated with mass-independent lifespan, but to a lesser degree with body mass. Our results supported an association of TROC and longevity, in particular longevity that was independent of body size and part of the pace-of-life syndrome of life histories.
Climate-related range shifts in Arctic-breeding shorebirds
Christine Anderson
Lenore Fahrig

Christine Anderson

and 5 more

July 16, 2022
Aim: To test whether the occupancy of shorebirds has changed in the eastern Canadian Arctic, and whether these changes could indicate that shorebird distributions are shifting in response to long-term climate change Location: Foxe Basin and Rasmussen Lowlands, Nunavut, Canada Methods: We used a unique set of observations, made 25 years apart, using general linear models to test if there was a relationship between changes in shorebird species’ occupancy and their Species Temperature Index, a simple version of a species climate envelope. Results: Changes in occupancy and density varied widely across species, with some increasing and some decreasing. This is despite that overall population trends are known to be negative for all of these species, based on surveys during migration. The changes in occupancy that we observed were positively related to the Species Temperature Index, such that the warmer-breeding species appear to be moving into these regions, while colder-breeding species appear to be shifting out of the regions, likely northwards. Main Conclusions: Our results suggest that we should be concerned about declining breeding habitat availability for bird species whose current breeding ranges are centred on higher and colder latitudes.
First record of White Eared Kob Kobus kob leucotis in Omo National Park, Ethiopia
Tsyon Asfaw
Mihert Ewenetu

Tsyon Asfaw

and 5 more

July 15, 2022
A document by Tsyon Asfaw, written on Authorea.
Shyer fish are superior swimmers in Siberian sturgeon (Acipenser baerii)
Lingli Xiang
Xiangyuan Mi

Lingli Xiang

and 11 more

July 13, 2022
Differences in individual personality are common amongst animals, which can play an ecological and evolutionary role given links to fitness. Personality affects animal life processes and outputs (e.g., behavior, life history, growth, survival, reproduction), and has become a common theme in animal behavioral ecology research. In the present study, we used Siberian Sturgeon to explore how personality traits of boldness and shyness are related to swimming performance, post exercise recovery and phenotypic morphology. Firstly, our results indicated that the Siberian sturgeon juveniles of shyness were better swimmers, validating evolutionary biology trade-off theory. The critical swimming speed (Ucrit) of the shy groups was higher than that of the bold groups. Secondly, the shy groups were more resilient after exercise fatigue. The swimming fatigue recovery ability, the glucose and lactic acid concentration recovery ability of shy groups were greater than that of bold groups. Thirdly, the shy groups were more streamlined. Compared with bold groups, shy groups had smaller caudate stalk lengths, caudate stalk heights, superior caudal lobes, and inferior caudal lobes. These research results further enrich the theoretical viewpoints of fish behavior biology, more importantly, which provided a good example for studying the relationship between sturgeon’s “personality” and swimming performance.
Three Genome-scale Approaches Support that Lungfish is the Closest Living Relative of...
Yunfeng Shan

Yunfeng Shan

July 12, 2022
The origin of tetrapod has been one of intense debating open questions for decades between coelacanth(Latimeria chalumnae) and lungfish (Protopterus annectens). For resolving this incongruence in phylogenies, a genome-wide data mining approach is used to retrieve 43 shared genes of seven taxa from GenBank and further 1001 orthologous genes of ten taxa from the Ensembl and NCBI. We used the maximum gene-support tree approach and the majority-rule branch approach to analyze 43 nuclear genes encoding amino acid residues and compared these results to those inferred with the concatenation approach. Our results successfully provide strong evidence in favor of the lungfish-tetrapod hypothesis, but rejecting the coelacanth-tetrapod hypothesis based on significantly fewer gene supports and lower taxon jackknife probabilities for the coelacanth-tetrapod clade than the lungfish-tetrapod one with the maximum gene-support tree approach and the jackknife method for taxon subsampling. When more and more genomic data become available in recent years, sequence data of 1001 shared genes was mined. We used the maximum gene-support approach with this larger dataset successfully to infer that lungfish is the closest relative of land vertebrates with a significant difference at p < 0.01 (Chi-Square test) in gene support values between a maximum gene-support tree and the second most gene support tree with ML methods. The second most support to the maximum (SM ratio), a relative value, is a better support index than a single absolute value of support to show the insight of the phylogenetic support. Our results also show increasing the number of shared genes is much more effective than increasing the number of taxa.
Dietary and temporal partitioning facilitate sympatric coexistence of carnivore assem...
Zhong Hua
Fengjiao Li

Zhong Hua

and 3 more

July 11, 2022
Carnivore communities are extremely important for maintaining the structure/function of ecosystems. Exploring the carnivore coexistence can provide the data needed for the development of effective conservation strategies for endangered species. We aimed to (1) reveal the dietary composition of a carnivore community that inhabits the Everest region by analyzing molecular diets, (2) assess activity patterns by analyzing camera-trapping records. Dietary analysis revealed 22 food MOTUs of 7 orders and 2 classes. Snow leopard and wolf mainly preyed on ungulate mammals (%PR = 61%, 50%), while lynx and red fox mainly consumed small mammals (%PR = 62%, 76%). Higher dietary overlap (Pianka’s index = 0.95 ~ 0.97) was observed between similar-sized predators (snow leopard versus wolf, lynx versus fox); and there was no dietary difference between them (P > 0.05). Lower dietary overlap (Pianka’s index = 0.53 ~ 0.67) was observed between predators with large body size difference (snow leopard versus lynx, snow leopard versus red fox, wolf versus fox); and dietary difference was significant (P < 0.01), indicating the existence of dietary partitioning. In activity pattern analysis, predators exhibited higher temporal overlap with the more frequently consumed prey species, indicating that predator activity can be regulated by prey availability. Snow leopard and wolf had the higher activity overlap (Δ = 0.87) suggesting the lack of temporal partitioning. Red fox had the lower coefficients of overlap with snow leopard and wolf (Δ = 0.60, Δ = 0.59), suggesting that fox temporally avoid snow leopard and wolf slightly. We revealed the coexistence mechanisms of a carnivore community in the Everest region, by confirming that sympatric coexistence was facilitated by both dietary and temporal partitioning. These results will help to increase understanding of carnivore communities, and provide the scientific foundation for the conservation of threatened species in the Mount Everest region.
Can diet niche partitioning enhance sexual dimorphism?
Joshua Bauld
Jason Newton

Joshua Bauld

and 5 more

July 05, 2022
Abstract 1. Classic evolutionary theory suggests that sexual dimorphism evolves primarily via sexual and fecundity selection. However, theory and evidence is beginning to accumulate suggesting that resource competition can drive the evolution of sexual dimorphism, via ecological character displacement between sexes. A key prediction of this hypothesis is that the extent of ecological divergence between sexes will be associated with the extent of sexual dimorphism. 2. As the stable isotope ratios of animal tissues provide a quantitative measure of various aspects of ecology, we carried out a meta-analysis examining associations between the extent of isotopic divergence between sexes and the extent of body size dimorphism. Our models demonstrate that large amounts of between-study variation in isotopic (ecological) divergence between sexes is due to systematic heterogeneity, which may be associated with the traits of study subjects. We then completed meta-regressions to examine whether the extent of isotopic divergence between sexes is associated with the extent of sexual size dimorphism. 3. We found a modest but significantly positive association between size dimorphism and sex differences in trophic level. Furthermore, the strength of this positive association varied between ecological contexts, increasing in species whose diets provide the greatest scope for trophic variation and in those for which body size is of greater relevance to feeding. 4. Our results therefore provide further evidence that ecologically mediated selection, unrelated to reproduction, can contribute to the evolution of sexual dimorphism.
Molecular Histology as a Novel Proxy for Ancient DNA and Protein Sequence Preservatio...
Landon Anderson

Landon A. Anderson

July 05, 2022
Researcher ability to accurately screen fossil and sub-fossil specimens for preservation of DNA and protein sequences remains limited. Thermal exposure and geologic age are usable proxies for sequence preservation on a broad scale but are of limited use for specimens of similar depositional environments and/or ages. Cell and tissue molecular histology is thus proposed as a proxy for determining sequence preservation potential of ancient specimens with improved accuracy. Molecular histology as a proxy is hypothesized to elucidate why fossil/sub-fossils of some depositional environments and or geologic ages preserve sequences while others do not and to facilitate selection of ancient specimens for use in molecular studies.
AUTOMATED MAMMAL LOCALIZATION AND IDENTIFICATION IN CAMERA TRAP IMAGES FOR THE NORTHE...
Brannon Barr
Harold Underwood

Brannon Barr

and 3 more

July 04, 2022
1. Camera traps are popular for monitoring animal populations and communities, primarily because they eliminate physical handling of animals. However, image acquisition typically outpaces information extraction. Most deep-learning based animal classifiers do not localize animals, limiting their applicability. Existing networks that localize animals have relatively high training data and hardware requirements. 2. To reduce the hardware and training data requirements, we extended the the Machine Learning for Wildlife Image Classification network (MLWIC2) to a Faster R-CNN. MLWIC2 is currently the most accurate wildlife classification network, and also the shallowest at 18 layers. We compared our model’s performance at object localization, species identification, and deployment speed to the performance of a generically pre-trained 50-layer Faster R-CNN to determine a) relative importance of task similarity in pre-training vs. backbone depth, b) whether additionally finetuning the backbones during training is advantageous c) whether the Faster R-CNN architecture benefits from incorporating the feature pyramid network (FPN) and cascading pyramid network (CPN) modules, and d) how backbone depth and the additional modules affect deployment speeds. 3. We found that the deeper network provides a slight advantage for classification accuracy, while the shallower network with higher task similarity produces a slight advantage for object localization. The additional modules provided dramatic gains for the 18 layer backbone for both classification and localization. On a NVIDIA 1080-ti gpu, the 18-layer backbone trains ~ 30% faster than the 50-layer backbone. In deployment the 18-layer backbone is 2.5x faster than the 50-layer backbone, and 9.4x faster than Megadetector. These results show that backbone network task similarity, paired with the FPN and CPN modules, can substitute for depth, which improves deployment speeds. Our model is suitable for modest hardware and for integration into more complex pipelines. These are important steps towards the automation of data acquisition from camera trap images.
The diversity of resident Passerine bird in the East Yunnan-Guizhou Plateau is closel...
Haibo Zhang
Lingbin Yan

Haibo Zhang

and 6 more

July 04, 2022
East Yunnan-Guizhou Plateau is rich in biodiversity in China. Complex geographical and climatic conditions, and rich bird resources made this area an ideal system for studying the spatial distribution mechanism and influencing factors of birds, which were still unknown. Bird community data from 37 sites in this region were collected, including 505 bird species and 164 species of resident passerine bird analyzed. The taxonomic diversity, phylogenetic diversity, functional diversity, and community structure index were calculated. Redundancy analysis (RDA), ordinary least square (OLS), and structural equation model (SEM), were used to explore the relationship between bird diversity index and 12 environmental factors used to describe the habitat conditions of birds. Results indicated that the vascular plant species richness, habitat area, and vertical altitude difference were the three most critical factors affecting bird diversity. The phylogenetic structure of bird community was dispersed in west and clustered in east, and significantly related to latitude, habitat area, and vertical altitude difference. The functional structure was dispersed in all sites, and significantly related to mean annual precipitation and longitude. This suggest that the distribution pattern of bird diversity was caused by the comprehensive action of various habitat factors which were mainly related to food availability and habitat heterogeneity. Considering the protection of birds in this area, it is necessary to continuously promote the construction of nature reserve system proposed by the Chinese government, and pay attention to the protection of urban green space such as campus and urban parks, to maintain the area and integrity of bird habitat, while only a high plant species and area is not enough, improving the habitat heterogeneity is of great significance.
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