ResearchPad - wolves https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Effects of scent lure on camera trap detections vary across mammalian predator and prey species]]> https://www.researchpad.co/article/elastic_article_7840 Camera traps are a unique survey tool used to monitor a wide variety of mammal species. Camera trap (CT) data can be used to estimate animal distribution, density, and behaviour. Attractants, such as scent lures, are often used in an effort to increase CT detections; however, the degree which the effects of attractants vary across species is not well understood. We investigated the effects of scent lure on mammal detections by comparing detection rates between 404 lured and 440 unlured CT stations sampled in Alberta, Canada over 120 day survey periods between February and August in 2015 and 2016. We used zero-inflated negative binomial generalized linear mixed models to test the effect of lure on detection rates for a) all mammals, b) six functional groups (all predator species, all prey, large carnivores, small carnivores, small mammals, ungulates), and c) four varied species of management interest (fisher, Pekania pennanti; gray wolf, Canis lupus; moose, Alces alces; and Richardson’s ground squirrel; Urocitellus richardsonii). Mammals were detected at 800 of the 844 CTs, with nearly equal numbers of total detections at CTs with (7110) and without (7530) lure, and variable effects of lure on groups and individual species. Scent lure significantly increased detections of predators as a group, including large and small carnivore sub-groups and fisher specifically, but not of gray wolf. There was no effect of scent lure on detections of prey species, including the small mammal and ungulate sub-groups and moose and Richardson’s ground squirrel specifically. We recommend that researchers explicitly consider the variable effects of scent lure on CT detections across species when designing, interpreting, or comparing multi-species surveys. Additional research is needed to further quantify variation in species responses to scent lures and other attractants, and to elucidate the effect of attractants on community-level inferences from camera trap surveys.

]]>
<![CDATA[On the synchronization techniques of chaotic oscillators and their FPGA-based implementation for secure image transmission]]> https://www.researchpad.co/article/5c648cedd5eed0c484c81aca

Synchronizing chaotic oscillators has been a challenge to guarantee successful applications in secure communications. That way, three synchronization techniques are applied herein to twenty two chaotic oscillators, three of them based on piecewise-linear functions and nineteen proposed by Julien C. Sprott. These chaotic oscillators are simulated to generate chaotic time series that are used to evaluate their Lyapunov exponents and Kaplan-Yorke dimension to rank their unpredictability. The oscillators with the high positive Lyapunov exponent are implemented into a field-programmable gate array (FPGA), and afterwards they are synchronized in a master-slave topology applying three techniques: the seminal work introduced by Pecora-Carroll, Hamiltonian forms and observer approach, and open-plus-closed-loop (OPCL). These techniques are compared with respect to their synchronization error and latency that is associated to the FPGA implementation. Finally, the chaotic oscillators providing the high positive Lyapunov exponent are synchronized and applied to a communication system with chaotic masking to perform a secure image transmission. Correlation analysis is performed among the original image, the chaotic channel and the recovered image for the three synchronization schemes. The experimental results show that both Hamiltonian forms and OPCL can recover the original image and its correlation with the chaotic channel is as low as 0.00002, demonstrating the advantage of synchronizing chaotic oscillators with high positive Lyapunov exponent to guarantee high security in data transmission.

]]>
<![CDATA[Does prey encounter and nutrient content affect prey selection in wolf spiders inhabiting Bt cotton fields?]]> https://www.researchpad.co/article/5c40f764d5eed0c48438603d

Wolf spiders are abundant and voracious predators at the soil-plant interface in cotton crops. Among other prey, they attack late-instar larvae of the cotton bollworm Helicoverpa spp., an economically important pest. Consequently, wolf spiders in transgenic Bt cotton could provide significant biological control of Bt-resistant Helicoverpa larvae that descend to the soil to pupate. The predator-prey interactions between wolf spiders and Helicoverpa could, however, be constrained by the presence of alternative prey and intraguild predators. This study used laboratory enclosures to analyse the effect of alternative prey on predatory selection of the wolf spider Tasmanicosa leuckartii Thorell. The prey included another wolf spider Hogna crispipes Koch (potential intraguild predator), the ground cricket Teleogryllus commodus Walker (minor pest), and Helicoverpa armigera larvae (major pest). We tested if encounter rates, prey vulnerability, and prey nutritional content influenced the likelihood that a prey was attacked. In three-way food webs, Tasmanicosa encountered and attacked Teleogryllus and Helicoverpa in similar frequencies. However, in the presence of a competing intraguild predator and potential prey (Hogna) in a four-way food web, Tasmanicosa did not always attack Teleogryllus at first encounter, but still attacked Helicoverpa at each encounter. Helicoverpa (protein-poor) and Hogna (protein-rich) were consumed by Tasmanicosa in similar proportions, suggesting that Tasmanicosa might benefit from nutrient balance as an outcome of diverse prey in this food web. As Teleogryllus (protein rich) escapes quicker than Helicoverpa and Hogna, Hogna may be an easier protein-rich option than Teleogryllus. Field surveys showed that while Teleogryllus was the most common prey, wolf spiders feed on diverse insect taxa, as well as other spiders. That Tasmanicosa readily attacked Helicoverpa larvae in the presence of alternative prey is an encouraging result that supports the potential of Tasmanicosa predation to assist in the control of Bt-resistant Helicoverpa larvae and thereby inhibit the proliferation and spread of resistance.

]]>
<![CDATA[Large carnivores under assault in Alaska]]> https://www.researchpad.co/article/5c478c41d5eed0c484bd1177

In Alaska, gray wolves (Canis lupis), brown bears (Ursus arctos), and black bears (U. americanus) are managed in most of the state in ways intended to significantly reduce their abundance in the expectation of increasing hunter harvests of ungulates. To our knowledge, Alaska is unique in the world because this management priority is both widespread and mandated by state law. Large carnivore management in Alaska is a reversion to outdated management concepts and occurs without effective monitoring programs designed to scientifically evaluate impacts on predator populations. Large carnivore management in Alaska should be based on rigorous science including the status and trends of carnivore populations.

]]>
<![CDATA[Cardiovascular risk prediction models for women in the general population: A systematic review]]> https://www.researchpad.co/article/5c3e4fccd5eed0c484d792d8

Aim

To provide a comprehensive overview of cardiovascular disease (CVD) risk prediction models for women and models that include female-specific predictors.

Methods

We performed a systematic review of CVD risk prediction models for women in the general population by updating a previous review. We searched Medline and Embase up to July 2017 and included studies in which; (a) a new model was developed, (b) an existing model was validated, or (c) a predictor was added to an existing model.

Results

A total of 285 prediction models for women have been developed, of these 160 (56%) were female-specific models, in which a separate model was developed solely in women and 125 (44%) were sex-predictor models. Out of the 160 female-specific models, 2 (1.3%) included one or more female-specific predictors (mostly reproductive risk factors). A total of 591 validations of sex-predictor or female-specific models were identified in 206 papers. Of these, 333 (56%) validations concerned nine models (five versions of Framingham, SCORE, Pooled Cohort Equations and QRISK). The median and pooled C statistics were comparable for sex-predictor and female-specific models. In 260 articles the added value of new predictors to an existing model was described, however in only 3 of these female-specific predictors (reproductive risk factors) were added.

Conclusions

There is an abundance of models for women in the general population. Female-specific and sex-predictor models have similar predictors and performance. Female-specific predictors are rarely included. Further research is needed to assess the added value of female-specific predictors to CVD models for women and provide physicians with a well-performing prediction model for women.

]]>
<![CDATA[Genomic characterization of the Braque Français type Pyrénées dog and relationship with other breeds]]> https://www.researchpad.co/article/5c117b55d5eed0c484698b51

The evaluation of genetic variability is a useful research tool for the correct management of selection and conservation strategies in dog breeds. In addition to pedigree genealogies, genomic data allow a deeper knowledge of the variability and genetic structure of populations. To date, many dog breeds, such as small regional breeds, still remain uncharacterized. Braque Français type Pyrénées (BRA) is a dog breed originating from a very old type of gun-dog used for pointing the location of game birds to hunters. Despite the ancient background, the knowledge about levels of genetic diversity, degree of inbreeding and population structure is scarce. This may raise concerns on the possibility that few inbred bloodlines may dominate the breed, and on its future health. The aim of this work was therefore to provide a high-resolution representation of the genome-wide diversity and population structure of BRA dogs, using the 170K genome-wide SNP array. Genome-wide polymorphisms in BRA were compared with those of other worldwide dog breeds. Between-dog relationships estimated from genomic data were very similar to pedigree relationships (Pearson correlation rg,a = 0.92). Results showed that BRA generally presents moderate levels of genetic diversity when compared with the major canine breeds. The estimated effective population size (recent Ne = 51) shows a similar declining pattern over generations as all other dog breeds, pointing at a common demographic history of modern canine breeds, clearly different from the demography of feral wolves. Multidimensional scaling (MDS), Bayesian clustering and Neighbor Joining tree were used to visualize and explore the genetic relationships among breeds, and revealed that BRA was highly differentiated and presented only low levels of admixture with other breeds. Brittany Spaniel, English Setter, Gordon Setter and Weimaraner dogs are the closest breeds to BRA. The exact reason for BRA being so divergent from other dog breeds, based on these results, is not yet clear. Further studies including additional ≪braccoid≫ breeds will be needed to refine the results presented here and to investigate the origin of the BRA breed. Nonetheless, the genome-wide characterization reported here provides a comprehensive insight into the genome diversity and population structure of the Braque Français, type Pyrénées breed.

]]>
<![CDATA[Responses of snow leopards, wolves and wild ungulates to livestock grazing in the Zorkul Strictly Protected Area, Tajikistan]]> https://www.researchpad.co/article/5c0ae479d5eed0c484589c89

Long recognized as a threat to wildlife, livestock grazing in protected areas has the potential to undermine conservation goals, via competition, habitat degradation, human-carnivore conflict and disruption of predator-prey relationships. In the Strictly Protected Area Zorkul in Tajikistan (Zorkul Reserve), grazing is commonplace despite official prohibition, with potentially detrimental effects on local fauna, in particular, snow leopard Panthera uncia, wolf Canis lupus, brown bear Ursus arctos, argali sheep Ovis ammon, Asiatic ibex Capra sibirica, and long-tailed marmot Marmota caudata. To understand the impacts of grazing and associated human pastoralism on the large mammal community in Zorkul Reserve we used data from camera traps to build models of ungulate and carnivore site use intensity, and we investigated carnivore summer diets using microscopic scat analysis. While sample sizes limited our inference for several species, we found that site use of the most common ungulate, argali, decreased with proximity to herder’s camps, indicating possible displacement into sub-optimal habitats. However, no such pattern was present in carnivore site use. For wolf and snow leopard, the most frequently encountered prey items were argali and marmot, while bear depended almost exclusively on marmot. While current pastoralist practices in the reserve may not be incompatible with wildlife presence, our findings suggest that pastoralism may negatively impact ungulates by displacing them from otherwise suitable habitats, with unknown fitness consequences for ungulates or the predators that depend upon them. Managing Zorkul Reserve and other actively grazed protected areas to meet potentially competing demands of local pastoralist communities and conservation will require careful consideration of such interactions to minimize the risk of cascading negative impacts on wildlife.

]]>
<![CDATA[Call and be counted! Can we reliably estimate the number of callers in the indri's (Indri indri) song?]]> https://www.researchpad.co/article/5b6dda04463d7e7491b405e0

Estimating the number of animals participating in a choral display may contribute reliable information on animal population estimates, particularly when environmental or behavioral factors restrict the possibility of visual surveys. Difficulties in providing a reliable estimate of the number of singers in a chorus are many (e.g., background noise masking, overlap). In this work, we contributed data on the vocal chorusing of the indri lemurs (Indri indri), which emit howling cries, known as songs, uttered by two to five individuals. We examined whether we could estimate the number of emitters in a chorus by screening the fundamental frequency in the spectrograms and the total duration of the songs, and the reliability of those methods when compared to the real chorus size. The spectrographic investigation appears to provide reliable information on the number of animals participating in the chorusing only when this number is limited to two or three singers. We also found that the Acoustic Complexity Index positively correlated with the real chorus size, showing that an automated analysis of the chorus may provide information about the number of singers. We can state that song duration shows a correlation with the number of emitters but also shows a remarkable variation that remains unexplained. The accuracy of the estimates can reflect the high variability in chorus size, which could be affected by group composition, season and context. In future research, a greater focus on analyzing frequency change occurring during these collective vocal displays should improve our ability to detect individuals and allow a finer tuning of the acoustic methods that may serve for monitoring chorusing mammals.

]]>
<![CDATA[Space Use and Habitat Selection by Resident and Transient Red Wolves (Canis rufus)]]> https://www.researchpad.co/article/5989da47ab0ee8fa60b8bfe9

Recovery of large carnivores remains a challenge because complex spatial dynamics that facilitate population persistence are poorly understood. In particular, recovery of the critically endangered red wolf (Canis rufus) has been challenging because of its vulnerability to extinction via human-caused mortality and hybridization with coyotes (Canis latrans). Therefore, understanding red wolf space use and habitat selection is important to assist recovery because key aspects of wolf ecology such as interspecific competition, foraging, and habitat selection are well-known to influence population dynamics and persistence. During 2009–2011, we used global positioning system (GPS) radio-telemetry to quantify space use and 3rd-order habitat selection for resident and transient red wolves on the Albemarle Peninsula of eastern North Carolina. The Albemarle Peninsula was a predominantly agricultural landscape in which red wolves maintained spatially stable home ranges that varied between 25 km2 and 190 km2. Conversely, transient red wolves did not maintain home ranges and traversed areas between 122 km2 and 681 km2. Space use by transient red wolves was not spatially stable and exhibited shifting patterns until residency was achieved by individual wolves. Habitat selection was similar between resident and transient red wolves in which agricultural habitats were selected over forested habitats. However, transients showed stronger selection for edges and roads than resident red wolves. Behaviors of transient wolves are rarely reported in studies of space use and habitat selection because of technological limitations to observed extensive space use and because they do not contribute reproductively to populations. Transients in our study comprised displaced red wolves and younger dispersers that competed for limited space and mating opportunities. Therefore, our results suggest that transiency is likely an important life-history strategy for red wolves that facilitates metapopulation dynamics through short- and long-distance movements and eventual replacement of breeding residents lost to mortality.

]]>
<![CDATA[Wolf (Canis lupus) Generation Time and Proportion of Current Breeding Females by Age]]> https://www.researchpad.co/article/5989d9feab0ee8fa60b730ae

Information is sparse about aspects of female wolf (Canis lupus) breeding in the wild, including age of first reproduction, mean age of primiparity, generation time, and proportion of each age that breeds in any given year. We studied these subjects in 86 wolves (113 captures) in the Superior National Forest (SNF), Minnesota (MN), during 1972–2013 where wolves were legally protected for most of the period, and in 159 harvested wolves from throughout MN wolf range during 2012–2014. Breeding status of SNF wolves were assessed via nipple measurements, and wolves from throughout MN wolf range, by placental scars. In the SNF, proportions of currently breeding females (those breeding in the year sampled) ranged from 19% at age 2 to 80% at age 5, and from throughout wolf range, from 33% at age 2 to 100% at age 7. Excluding pups and yearlings, only 33% to 36% of SNF females and 58% of females from throughout MN wolf range bred in any given year. Generation time for SNF wolves was 4.3 years and for MN wolf range, 4.7 years. These findings will be useful in modeling wolf population dynamics and in wolf genetic and dog-domestication studies.

]]>
<![CDATA[Dog Breed Differences in Visual Communication with Humans]]> https://www.researchpad.co/article/5989daffab0ee8fa60bc6024

Domestic dogs (Canis familiaris) have developed a close relationship with humans through the process of domestication. In human-dog interactions, eye contact is a key element of relationship initiation and maintenance. Previous studies have suggested that canine ability to produce human-directed communicative signals is influenced by domestication history, from wolves to dogs, as well as by recent breed selection for particular working purposes. To test the genetic basis for such abilities in purebred dogs, we examined gazing behavior towards humans using two types of behavioral experiments: the ‘visual contact task’ and the ‘unsolvable task’. A total of 125 dogs participated in the study. Based on the genetic relatedness among breeds subjects were classified into five breed groups: Ancient, Herding, Hunting, Retriever-Mastiff and Working). We found that it took longer time for Ancient breeds to make an eye-contact with humans, and that they gazed at humans for shorter periods of time than any other breed group in the unsolvable situation. Our findings suggest that spontaneous gaze behavior towards humans is associated with genetic similarity to wolves rather than with recent selective pressure to create particular working breeds.

]]>
<![CDATA[Compensatory selection for roads over natural linear features by wolves in northern Ontario: Implications for caribou conservation]]> https://www.researchpad.co/article/5ab1934f463d7e5f0fb18c54

Woodland caribou (Rangifer tarandus caribou) in Ontario are a threatened species that have experienced a substantial retraction of their historic range. Part of their decline has been attributed to increasing densities of anthropogenic linear features such as trails, roads, railways, and hydro lines. These features have been shown to increase the search efficiency and kill rate of wolves. However, it is unclear whether selection for anthropogenic linear features is additive or compensatory to selection for natural (water) linear features which may also be used for travel. We studied the selection of water and anthropogenic linear features by 52 resident wolves (Canis lupus x lycaon) over four years across three study areas in northern Ontario that varied in degrees of forestry activity and human disturbance. We used Euclidean distance-based resource selection functions (mixed-effects logistic regression) at the seasonal range scale with random coefficients for distance to water linear features, primary/secondary roads/railways, and hydro lines, and tertiary roads to estimate the strength of selection for each linear feature and for several habitat types, while accounting for availability of each feature. Next, we investigated the trade-off between selection for anthropogenic and water linear features. Wolves selected both anthropogenic and water linear features; selection for anthropogenic features was stronger than for water during the rendezvous season. Selection for anthropogenic linear features increased with increasing density of these features on the landscape, while selection for natural linear features declined, indicating compensatory selection of anthropogenic linear features. These results have implications for woodland caribou conservation. Prey encounter rates between wolves and caribou seem to be strongly influenced by increasing linear feature densities. This behavioral mechanism–a compensatory functional response to anthropogenic linear feature density resulting in decreased use of natural travel corridors–has negative consequences for the viability of woodland caribou.

]]>
<![CDATA[Gray Wolf Exposure to Emerging Vector-Borne Diseases in Wisconsin with Comparison to Domestic Dogs and Humans]]> https://www.researchpad.co/article/5989db0fab0ee8fa60bcb817

World-wide concern over emerging vector-borne diseases has increased in recent years for both animal and human health. In the United Sates, concern about vector-borne diseases in canines has focused on Lyme disease, anaplasmosis, ehrlichiosis, and heartworm which infect domestic and wild canids. Of these diseases, Lyme and anaplasmosis are also frequently diagnosed in humans. Gray wolves (Canis lupus) recolonized Wisconsin in the 1970s, and we evaluated their temporal and geographic patterns of exposure to these four vector-borne diseases in Wisconsin as the population expanded between 1985 and 2011. A high proportion of the Wisconsin wolves were exposed to the agents that cause Lyme (65.6%) and anaplasma (47.7%), and a smaller proportion to ehrlichiosis (5.7%) and infected with heartworm (9.2%). Wolf exposure to tick borne diseases was consistently higher in older animals. Wolf exposure was markedly higher than domestic dog (Canis familiaris) exposure for all 4 disease agents during 2001–2013. We found a cluster of wolf exposure to Borrelia burgdorferi in northwestern Wisconsin, which overlaps human and domestic dog clusters for the same pathogen. In addition, wolf exposure to Lyme disease in Wisconsin has increased, corresponding with the increasing human incidence of Lyme disease in a similar time period. Despite generally high prevalence of exposure none of these diseases appear to have slowed the growth of the Wisconsin wolf population.

]]>
<![CDATA[Play Behavior in Wolves: Using the ‘50:50’ Rule to Test for Egalitarian Play Styles]]> https://www.researchpad.co/article/5989dae2ab0ee8fa60bbc444

Social play is known as a cooperative interaction between individuals involving multiple mechanisms. However, the extent to which the equality of individuals’ play styles affects the interaction has not been studied in many species. Dyadic play between wolf puppies, as well as between puppies and adults, was studied to investigate both self-handicapping and offensive behaviors to determine the extent to which wolves engage in play styles where one individual does not dominate the play. Our results did not support the hypothesized ‘50:50’ rule, which suggests that more advantaged individuals should show higher rates of self-handicapping behaviors in order to facilitate play with others. Adult wolves performed significantly less self-handicapping behaviors than their puppy partners, and they performed significantly more offensive behaviors than their puppy partners. While the ‘50:50’ rule was not supported at any time during our study period, dyads consisting of two puppies had significantly more equal play than dyads consisting of one puppy and one adult. These results suggest that wolf puppies are more likely to play on equal terms with similarly-aged play partners, while the dominance status of the partners dictates offensive and self-handicapping behaviors between animals of different ages.

]]>
<![CDATA[Border Security Fencing and Wildlife: The End of the Transboundary Paradigm in Eurasia?]]> https://www.researchpad.co/article/5989dac5ab0ee8fa60bb2391

The ongoing refugee crisis in Europe has seen many countries rush to construct border security fencing to divert or control the flow of people. This follows a trend of border fence construction across Eurasia during the post-9/11 era. This development has gone largely unnoticed by conservation biologists during an era in which, ironically, transboundary cooperation has emerged as a conservation paradigm. These fences represent a major threat to wildlife because they can cause mortality, obstruct access to seasonally important resources, and reduce effective population size. We summarise the extent of the issue and propose concrete mitigation measures.

]]>
<![CDATA[Wolf Lethal Control and Livestock Depredations: Counter-Evidence from Respecified Models]]> https://www.researchpad.co/article/5989da3cab0ee8fa60b884be

We replicated the study conducted by Wielgus and Peebles (2014) on the effect of wolf mortality on livestock depredations in Montana, Wyoming and Idaho states in the US. Their best models were found to be misspecified due to the omission of the time index and incorrect functional form. When we respecified the models, this replication failed to confirm the magnitude, direction and often the very existence of the original results. Wielgus and Peebles (2014) reported that the increase in the number of wolves culled the previous year would increase the expected number of livestock killed this year by 4 to 6%. But our results showed that the culling of one wolf the previous year would decrease the expected number of cattle killed this year by 1.9%, and the expected number of sheep killed by 3.4%. However, for every wolf killed there is a corresponding 2.2% increase in the expected number of sheep killed in the same year. The increase in sheep depredation appears to be a short term phenomenon.

]]>
<![CDATA[Trans-Boundary Edge Effects in the Western Carpathians: The Influence of Hunting on Large Carnivore Occupancy]]> https://www.researchpad.co/article/5989da80ab0ee8fa60b9a525

The conservation and management of wolves Canis lupus in the periphery of their distribution is challenging. Edges of wolf distribution are characterized by very few and intermittent occurrences of individuals, which are modulated by multiple factors affecting the overall population such as human-caused mortality, management targets and food availability. The knowledge of population dynamics in the edges becomes crucial when hunting takes place nearby the edges, which may preclude population expansion. Here, using as example the occurrence of wolves in the Beskydy Mountains (Czech-Slovak border), which are the edge distribution of the wolf and Eurasian lynx Lynx lynx populations in the West Carpathians, we explored how food availability and hunting in the Slovakian core area affected the dynamics of wolves in the edges of this population. During 2003–2012, we monitored large carnivore occurrence by snow-tracking surveys and tested potential differences in the occurrence of these species in Beskydy Mountains and potential mechanisms behind detected patterns. Despite the proximity to the core area, with several wolf reproductions being confirmed at least in recent years, the wolf was a very rare species in Beskydy and was recorded 14 times less often than the lynx. The expected abundance of wolves in the Beskydy Mountains was inversely related to prey availability in the Slovakian core area. Wolf hunting the year before influenced the expected abundance of wolves in Beskydy area. We discuss how different life histories and legal status of both species probably account for most of the observed difference of occurrence at range margins.

]]>
<![CDATA[Investigating the Function of Play Bows in Dog and Wolf Puppies (Canis lupus familiaris, Canis lupus occidentalis)]]> https://www.researchpad.co/article/5989da85ab0ee8fa60b9c0a2

Animals utilize behavioral signals across a range of different contexts in order to communicate with others and produce probable behavioral outcomes. During play animals frequently adopt action patterns used in other contexts. Researchers have therefore hypothesized that play signals have evolved to clarify communicative intent. One highly stereotyped play signal is the canid play bow, but its function remains contested. In order to clarify how canid puppies use play bows, we used data on play bows in immature wolves (ages 2.7–7.8 months) and dogs (ages 2 to 5 months) to test hypotheses evaluated in a previous study of adult dogs. We found that young dogs used play bows similarly to adult dogs; play bows most often occurred after a brief pause in play followed by complementary highly active play states. However, while the relative number of play bows and total observation time was similar between dog and wolf puppies, wolves did not follow this behavioral pattern, as play bows were unsuccessful in eliciting further play activity by the partner. While some similarities for the function of play bows in dog and wolf puppies were documented, it appears that play bows may function differently in wolf puppies in regards to re-initiating play.

]]>
<![CDATA[Demographic and Component Allee Effects in Southern Lake Superior Gray Wolves]]> https://www.researchpad.co/article/5989da96ab0ee8fa60ba1f72

Recovering populations of carnivores suffering Allee effects risk extinction because positive population growth requires a minimum number of cooperating individuals. Conservationists seldom consider these issues in planning for carnivore recovery because of data limitations, but ignoring Allee effects could lead to overly optimistic predictions for growth and underestimates of extinction risk. We used Bayesian splines to document a demographic Allee effect in the time series of gray wolf (Canis lupus) population counts (1980–2011) in the southern Lake Superior region (SLS, Wisconsin and the upper peninsula of Michigan, USA) in each of four measures of population growth. We estimated that the population crossed the Allee threshold at roughly 20 wolves in four to five packs. Maximum per-capita population growth occurred in the mid-1990s when there were approximately 135 wolves in the SLS population. To infer mechanisms behind the demographic Allee effect, we evaluated a potential component Allee effect using an individual-based spatially explicit model for gray wolves in the SLS region. Our simulations varied the perception neighborhoods for mate-finding and the mean dispersal distances of wolves. Simulation of wolves with long-distance dispersals and reduced perception neighborhoods were most likely to go extinct or experience Allee effects. These phenomena likely restricted population growth in early years of SLS wolf population recovery.

]]>
<![CDATA[Effects of Wolf Mortality on Livestock Depredations]]> https://www.researchpad.co/article/5989da7fab0ee8fa60b99d37

Predator control and sport hunting are often used to reduce predator populations and livestock depredations, – but the efficacy of lethal control has rarely been tested. We assessed the effects of wolf mortality on reducing livestock depredations in Idaho, Montana and Wyoming from 1987–2012 using a 25 year time series. The number of livestock depredated, livestock populations, wolf population estimates, number of breeding pairs, and wolves killed were calculated for the wolf-occupied area of each state for each year. The data were then analyzed using a negative binomial generalized linear model to test for the expected negative relationship between the number of livestock depredated in the current year and the number of wolves controlled the previous year. We found that the number of livestock depredated was positively associated with the number of livestock and the number of breeding pairs. However, we also found that the number of livestock depredated the following year was positively, not negatively, associated with the number of wolves killed the previous year. The odds of livestock depredations increased 4% for sheep and 5–6% for cattle with increased wolf control - up until wolf mortality exceeded the mean intrinsic growth rate of wolves at 25%. Possible reasons for the increased livestock depredations at ≤25% mortality may be compensatory increased breeding pairs and numbers of wolves following increased mortality. After mortality exceeded 25%, the total number of breeding pairs, wolves, and livestock depredations declined. However, mortality rates exceeding 25% are unsustainable over the long term. Lethal control of individual depredating wolves may sometimes necessary to stop depredations in the near-term, but we recommend that non-lethal alternatives also be considered.

]]>