EU Sanitary Regulation on Livestock Disposal: Implications for the Diet of Wolves

Increased grey wolf diurnality in southern Europe under human-restricted conditions

Wolves have been the archetype of wildlife persecution by humans for centuries all over the world, and still are heavily persecuted in some regions. Facultative diurnal/nocturnal wild mammals are known to become more nocturnal when persecuted. Conversely, little is known regarding the possibility of wolves becoming more diurnal if not persecuted. We took advantage of a 9-year natural experiment of restricted human access to a restored coal mine debris dump to study the daily activity patterns of wolves under conditions of infrequent human presence. Results were compared with a paired control site with frequent human use. Circadian wolf activity was monitored using camera traps (3 years in human-restricted site; 2 years in control). Additionally, data from two GPS-GSM-collared wolves monitored in a second control site were also analyzed. In our control sites, wolves were nearly inactive during daylight hours. In contrast, in the human-restricted site wolves extended their activity toward noon, with a daily activity peak between 10:00 and 12:00, and showed some activity throughout the entire circadian 2-h interval cycle considered. Wolves clearly had higher diurnality in the human-restricted area with 78% greater incidence of capture with remote cameras during the day than in the control site. We suggest that the shift toward increased diurnality was related to the loss of fear of humans. Evidence in support of this hypothesis comes from flight initiation distance (FID) data. Wolves showed relatively short FIDs when faced with a human observer (range 70-183 m) in broad daylight at the human-restricted site, but were so afraid of humans in the control site that we were unable to conduct FID trials there. Based on these results, we suggest that wolves may increase their diurnality in those European countries with currently increasing movement of human populations from rural to urban areas and that do not conduct lethal control of wolves. This would represent a historical landmark for a species that has been persecuted for many centuries. However, such behavioral shifts could bring new human-wolf conflicts that would require new policies.

Long-term demographic dynamics of a keystone scavenger disrupted by human-induced shifts in food availability

Scavenging is a key ecological process controlling energy flow in ecosystems and providing valuable ecosystem services worldwide. As long-lived species, the demographic dynamics of vultures can be disrupted by spatiotemporal fluctuations in food availability, with dramatic impacts on their population viability and the ecosystem services provided. In Europe, the outbreak of bovine spongiform encephalopathy (BSE) in 2001 prompted a restrictive sanitary regulation banning the presence of livestock carcasses in the wild on a continental scale. In long-lived vertebrate species, the buffering hypothesis predicts that the demographic traits with the largest contribution to population growth rate should be less temporally variable. The BSE outbreak provides a unique opportunity to test for the impact of demographic buffering in a keystone scavenger suffering abrupt but transient food shortages. We studied the 42-year dynamics (1979-2020) of one of the world's largest breeding colonies of Eurasian griffon vultures (Gyps fulvus). We fitted an inverse Bayesian state-space model with density-dependent demographic rates to the time series of stage-structured abundances to investigate shifts in vital rates and population dynamics before, during, and after the implementation of a restrictive sanitary regulation. Prior to the BSE outbreak the dynamics was mainly driven by adult survival: 83% of temporal variance in abundance was explained by variability in this rate. Moreover, during this period the regulation of population size operated through density-dependent fecundity and subadult survival. However, after the onset of the European ban, a 1-month delay in average laying date, a drop in fecundity, and a reduction in the number of fledglings induced a transient increase in the impact of fledgling and subadult recruitment on dynamics. Although adult survival rate remained constantly high, as predicted by the buffering hypothesis, its relative impact on the temporal variance in abundance dropped to 71% during the sanitary regulation and to 54% after the ban was lifted. A significant increase in the relative impact of environmental stochasticity on dynamics was modeled after the BSE outbreak. These results provide empirical evidence on how abrupt environmental deterioration may induce dramatic demographic and dynamic changes in the populations of keystone scavengers, with far-reaching impacts on ecosystem functioning worldwide.

Dealing With Deadstock: A Case Study of Carnivore Conflict Mitigation From Southwestern Alberta

Livestock deaths are an unfortunate reality for livestock producers and dead livestock (i.e., deadstock) disposal options can have implications beyond the ranch itself. In Alberta, Canada, natural disposal (i.e., disposing of the carcass in a manner that allows for scavenging) has increased since the 2003 detection of bovine spongiform encephalopathy (BSE) in Canadian cattle. Prior to BSE, rendering companies removed deadstock for free. However, rendering companies started charging producers to remove deadstock to offset costs associated with new regulatory requirements enacted by the Canadian Food Inspection Agency, which has resulted in increased on-farm natural disposal of deadstock. This increase has ecological implications because deadstock are a major attractant for large carnivores. Carnivores feeding on deadstock are often near other agricultural attractants such as stored grain and feed, silage, and living livestock, which can exacerbate conflict potential and pose a risk to human safety. To help mitigate conflicts associated with deadstock, the Waterton Biosphere Reserve's (a local non-profit) Carnivores and Communities Program (CACP) supported expansion of community deadstock removal efforts beginning in 2009, including reimbursement of on-farm removal costs, bear-resistant deadstock bins, and a livestock compost facility (operational 2013–2014). Here, we present an evaluative case study describing the development, implementation, and results of the deadstock removal program, including the compost facility. We tracked the number of head of livestock removed each year, the number of participating landowners, the average cost per head, and total program costs. We also used an online survey to assess participants' perspectives of the deadstock removal program and future needs. To date, the CACP has removed >5,400 livestock carcasses, representing between 15.1 and 22.6% of available carcasses in the program area, and 67.3% of livestock owners indicated they currently use the deadstock removal program to dispose of deadstock. Average cost to compost an animal was significantly less than other removal methods ($36.89 composting vs. $79.59 non-composting, one-tailed t-test, unequal sampling variances: t = 4.08, df = 5.87, p = 0.003). We conclude by discussing both ecological and social implications for deadstock removal as a conflict mitigation measure and make suggestions for future management considerations.

Scavenging Effects of Large Canids

Many large predators are also facultative scavengers that may compete with and depredate other species at carcasses. Yet, the ecological impacts of facultative scavenging by large predators, or their "scavenging effects," still receive relatively little attention in comparison to their predation effects. To address this knowledge gap, we comprehensively examine the roles played by, and impacts of, facultative scavengers, with a focus on large canids: the African wild dog (Lycaon pictus), dhole (Cuon alpinus), dingo (Canis dingo), Ethiopian wolf (Canis simensis), gray wolf (Canis lupus), maned wolf (Chrysocyon brachyurus), and red wolf (Canis rufus). Specifically, after defining facultative scavenging as use or usurpation of a carcass that a consumer has not killed, we (1) provide a conceptual overview of the community interactions around carcasses that can be initiated by facultative scavengers, (2) review the extent of scavenging by and the evidence for scavenging effects of large canids, (3) discuss external factors that may diminish or enhance the effects of large canids as scavengers, and (4) identify aspects of this phenomenon that require additional research attention as a guide for future work.

Wolf diet and livestock selection in central Greece

Understanding the feeding habits of wolves is essential for designing and implementing fundamental management processes across the range of the species. This is even more important within human-dominated areas, such as southern Europe, and more especially Greece. In this context, we analyzed 123 scat samples, collected between 2010 and 2012, from a mixed agricultural, forested and human-dominated area, centered on the municipality of Domokos in central continental Greece. We used standard laboratory procedures for scat analysis and calculated percentages of frequency of occurrence (FO%), average volume (AV%) and biomass index (BM%) to assess diet composition, and estimated prey selectivity. Domestic prey composed the bulk of wolf diet (FO%=73.5, AV%=84.8, BM%=97.2), wild ungulates were almost absent (FO%=0.5, AV%=0.8, BM%=1.2), whereas grass consumption was high in our area (FO%=19.5, AV%=11.0). The high dependence on livestock corroborates previous studies from Greece and other countries in southern Europe. Goat (FO%=46.0, AV%=61.2, BM%=64.9) was the main prey and was strongly selected, with sheep (FO%=11.5, AV%=9.0, BM%=11.2), pig carrion and cattle ranking behind (FO%=11.5, AV%=10.1, BM%=8.7 and FO%=4.5, AV%=4.5, BM%=12.4, respectively). No differences across seasons were detected, except from pig carrion, which increased during winter. The preference for goats is probably associated with its grazing behavior. High livestock consumption generally results in increased human-wolf conflict. Thus, substantial improvement of husbandry practices and restoration of wild ungulate populations are recommended to facilitate wolf-human coexistence in Greece.

Tools for co-existence: fladry corrals efficiently repel wild wolves (Canis lupus) from experimental baiting sites

Context Mitigating wolf–livestock conflict is crucial for both wolf (Canis lupus) conservation and livestock farming. Wolf attacks at livestock gathering areas often result in surplus killing, severe economic losses and emotional distress for the farmers, and financial claims from compensation funds. They may also trigger retaliatory killing of wolves. One method for reducing attacks on gathered livestock is the fladry fence, a primary repellent based on wolf neophobia. Fladry, used mainly in North America, remains largely untested in southern Europe. Aims To test the effectiveness of fladry corrals at excluding wild wolves from experimental feeding sites and discuss their potential for protecting livestock in human-dominated landscapes. Methods We tested the repelling efficiency of fladry corrals at six stations baited with livestock remains close to the homesites of three wild-wolf packs in central-northern Greece. Using infrared cameras, we recorded approaching and feeding rates of wolves, brown bears and wild boars attracted to the baits, before and during fladry use. Key results The feeding rate of all wolf packs reduced to zero during fladry use. Effective repelling lasted from 23 to 157 days and ended with the removal of fladry. Wolf approaches also reduced by 75%. Modelling of wolf-approach levels showed fladry effect to be stronger when using a less attractive bait and weaker as pre-baiting duration or wolves’ pre-exposure time to fladry increased. Fladry also significantly reduced the overall feeding rates of wild boars, whereas repellence of brown bears was poor. Key conclusions Fladry can be a cost-effective tool to exclude wolves from small-sized corrals, for weeks or months. It may also be useful for repelling wild boar. We recommend further testing with live-prey at the regional scale with standardised protocols. Implications Fladry installation at farms should take into account livestock attractiveness and wolf habituation. Fladry efficiency and deterrence duration can be improved when it is combined with other livestock protection methods. Wolf habituation to fladry can be reduced by deploying it primarily in high-risk depredation areas. Moreover, deployment soon after an attack could prevent wolves from associating specific farms with being sources of prey.

Plant-based remedies for wolf bites and rituals against wolves in the Iberian Peninsula: Therapeutic opportunities and cultural values for the conservation of biocultural diversity

ETHNOPHARMACOLOGICAL RELEVANCE

Combined approaches to local knowledge and folk plant use improve awareness and promote effective strategies for the conservation of significant biocultural patrimony. Moreover, the information reported might be the basis for further appropriate phytochemical and pharmacological research. Therefore we provide an insight into traditional herbal remedies and practices for healing bite injuries in humans and domestic animals caused by the Iberian wolf. Wolf bites are associated with inflammatory processes and rabies is a potential complication AIMS: This paper describes and summarises the medicinal-veterinary empirical and ritual uses of the Iberian flora for wolf injuries and reviews the ethnopharmacological data of specific plants that are already published. The Iberian wolf is a critically endangered subspecies of the grey wolf. Livestock attacks attributed to wolves are increasingly frequent in the Iberian Peninsula, resulting in serious social problems. Interesting strategies for Iberian wolf conservation might be related to traditional grazing practices that are deeply linked with empirical knowledge and local practices passed on by oral tradition, which are also vulnerable now.

MATERIALS AND METHODS

Based on documentary sources from the beginning of the twentieth century to the present, we systematically searched old monographs, regional documents, technical papers, project reports, as well as the international and national databases and the available scientific literature, without restrictions regarding the language of the publications consulted.

RESULTS

A total of 39 remedies for healing wolf bite injuries in humans and domestic animals was reported, highlighting the medicinal use of 33 species of vascular plants, mostly wild herbs, belonging to 18 botanical families. The use of wood ashes was also reported. The number of use-reports found represents a very high number considering similar European studies. Leaves were the predominant plant part mentioned. Boiling plant materials in water for topical uses was the most frequent method of preparation found. Some traditional remedies combined two or more plant species in order to potentiate their effects. Moreover, some plant-based traditional practices and rituals to ward off wolves and to prevent wolf attacks were also documented. In these practices eleven other species (belonging to seven more families) were used.

CONCLUSIONS

Despite the decline of the Iberian wolf over the last few decades, wolves are still in the imaginary of rural communities that perceive this large carnivore as both a diabolic creature and a mythic and benign animal. Wolf-related cultural heritage is of great interest in terms of conservation strategies. This review emphasises the importance of local knowledge and provides useful information about several potential sources of phytochemicals and their claimed therapeutic effects, aiming at contributing to the conservation and appreciation of the Iberian biocultural heritage.