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While wildlife and cultural preservation goals can be either complimentary orcounteractive, the goals of large carnivore conservation and traditional pastoralist lifestyles are often at odds. Livestock depredation can negatively impact the economies of livestock herders, while subsequent lethal removals contribute to local carnivore population declines. Here, we collaborated with two Sami reindeer herding communities (2010–2016) situated in Sweden’s boreal forest to evaluate the efficacy and economic feasibility of three brown bear predation mitigation measures: corralling pregnant reindeer during parturition, lethal bear management removals, and public bear-license hunting. Calving corrals increased survival for reindeer calves born to average-sized females by 7%–15%, and by 14%–30% for calves born to small females. However, the realized cost of implementing calving corrals outweighed the financial gain for both our study areas (net losses ranged between €1111 and €6210 per calf saved from bear predation per year when using the updated 2021 calf value; 1€ [Euro] = US$1.1), as well as for almost every theoretical scenario we explored (net losses €234 and €13,995 per calf saved from bear predation). The exception was the theoretical scenario where small herding communities overlapped large bear populations, which crossed the breakeven efficacy bear/reindeer ratio of 13.5 bears/100 reindeer and had a potential net gain of €36 per saved calf. Similarly, the cost of lethal management removals of bears outweighed the potential financial gain from saved calves, with net losses between €75 and €239 per calf. License hunting, where the hunters voluntarily incur the monetary costs of removing bears, is in most cases the only economically viable mitigation measure where the cost of mitigation did not outweigh the financial gain from increased reindeer survival. While the annual public license hunt was the most cost-effective mitigation measure, it may be less biologically effective, that is, bear hunting occurs in the fall and reindeer parturition the following spring which leaves time for the empty niche of harvested bears to be filled by survivors. Economically and biologically effective predation mitigation measures are key for promoting coexistence, and we suggest that potential mitigation measures should be studied in collaboration with local people. brown bear, calving corrals, economic feasibility, management removal, predation, reindeer herding

Competition between apex predators can alter the strength of top-down forcing, yet we know little about the behavioral mechanisms that drive competition in multipredator ecosystems. Interactions between predators can be synergistic (facilitative) or antagonistic (inhibitive), both of which are widespread in nature, vary in strength between species and across space and time, and affect predation patterns and predator-prey dynamics. Recent research has suggested that gray wolf (Canis lupus) kill rates decrease where they are sympatric with brown bears (Ursus arctos), however, the mechanisms behind this pattern remain unknown. We used data from two long-term research projects in Scandinavia (Europe) and Yellowstone National Park (North America) to test the role of interference and exploitation competition from bears on wolf predatory behavior, where altered wolf handling and search time of prey in the presence of bears are indicative of interference and exploitation competition, respectively. Our results suggest the mechanisms driving competition between bears and wolves were dependent on the season and study system. During spring in Scandinavia, interference competition was the primary mechanism driving decreased kill rates for wolves sympatric with bears; handling time increased, but search time did not. In summer, however, when both bear and wolf predation focused on neonate moose, the behavioral mechanism switched to exploitation competition; search time increased, but handling time did not. Alternartively, interference competition did affect wolf predation dynamics in Yellowstone during summer, where wolves prey more evenly on neonate and adult ungulates. Here, bear presence at a carcass increased the amount of time wolves spent at carcasses of all sizes and wolf handling time for small prey, but decreased handling time for the largest prey. Wolves facilitate scavenging opportunities for bears, however, bears alter wolf predatory behavior via multiple pathways and are primarily antagonistic to wolves. Our study helps to clarify the behavioral mechanisms driving competition between apex predators, illustrating how interspecific interactions can manifest into population-level predation patterns.

Reliable data and methods for assessing changes in wildlife population size over time are necessary for management and conservation. For most species, assessing abundance is an expensive and labor-intensive task that is not affordable on a frequent basis. We present a novel approach to reconstructing brown bear population dynamics in Slovenia in the period 1998-2019, based on the combination of two CMR non-invasive genetic estimates (in 2007 and 2015) and long-term mortality records, to show how the latter can help the study of population dynamics in combination with point-in-time estimates. The spring (i.e. including newborn cubs) population size estimate was 383 (CI: 336-432) bears in 1998 and 971 (CI: 825-1161) bears in 2019. In this period, the average annual population growth rate was 4.5 %. The predicted population size differed by just 7 % from the non-invasive genetic size estimate after eight years, suggesting that the method is reliable. It can predict the evolution of the population size under different management scenarios and provide information on key parameters, e.g. background mortality and the sex- and age-structure of the population. Our approach can be used for several other wildlife species, but it requires reliable mortality data over time. Za upravljanje in ohranjanje populacij prostoživečih živali so potrebni zanesljivi podatki in metode za ocenjevanje njihove številčnosti. Ugotavljanje številčnosti je pri večini vrst drago in zahtevno, zato ga ni mogoče pogosto izvajati. V članku predstavljamo nov pristop, ki smo ga pripravili na primeru rekonstrukcije populacijske dinamike rjavega medveda v Sloveniji v obdobju 1998-2019. Pristop temelji na kombinaciji dveh ocen njegove številčnosti z neinvazivnimi genetskimi metodami (v letih 2007 in 2015) in dolgoletnega niza podatkov monitoringa smrtnosti. Ocena 'pomladanske' (t.j. največje letne - po poleganju mladičev) številčnosti rjavega medveda v Sloveniji za leto 1998 znaša 383 (CI: 336-432), za leto 2019 pa 971 osebkov (CI: 825-1161). Povprečna letna stopnja rasti populacije je bila v tem obdobju 4,5 %. Modelno ocenjena številčnost populacije se je od ugotovljene z genetsko metodo po osmih letih razlikovala le za 7 %, kar nakazuje, da je pristop zanesljiv oz. so njegovi rezultati za upravljavske namene dovolj kakovostni. Pristop omogoča tudi napovedovanje prihodnje populacijske dinamike pri različnih scenarijih upravljanja in okvirno ocenjevanje ključnih populacijskih parametrov, kot so spolna in starostna sestava, relativna rodnost in naravna smrtnost populacije. Pristop je uporaben tudi za več drugih populacij in živalskih vrst, vendar so zanj potrebni zanesljivi dolgoletni podatki o smrtnosti.

XV Congreso de la Sociedad Española para la Conservación y Estudio de los Mamíferos (SECEM), Córdoba, 4-7 diciembre de 2021.

XV Congreso de la Sociedad Española para la Conservación y Estudio de los Mamíferos (SECEM), Córdoba, 4-7 diciembre de 2021.