Bears foraging near human developments are often presumed to be responding to food shortage, but this explanation ignores social factors, in particular despotism in bears. We analyzed the age distribution and body condition index (BCI) of shot brown bears in relation to densities of bears and people, and whether the shot bears were killed by managers (i.e., problem bears; n = 149), in self-defense (n = 51), or were hunter-killed nonproblem bears (n = 1,896) during 1990–2010. We compared patterns between areas with (Slovenia) and without supplemental feeding (Sweden) of bears relative to 2 hypotheses. The food-search/food-competition hypothesis predicts that problem bears should have a higher BCI (e.g., exploiting easily accessible and/or nutritious human-derived foods) or lower BCI (e.g., because of food shortage) than nonproblem bears, that BCI and human density should have a positive correlation, and problem bear occurrence and seasonal mean BCI of nonproblem bears should have a negative correlation (i.e., more problem bears during years of low food availability). Food competition among bears additionally predicts an inverse relationship between BCI and bear density. The safety-search/naivety hypothesis (i.e., avoiding other bears or lack of human experience) predicts no relationship between BCI and human density, provided no dietary differences due to spatiotemporal habitat use among bears, no relationship between problem bear occurrence and seasonal mean BCI of nonproblem bears, and does not necessarily predict a difference between BCI for problem/nonproblem bears. If food competition or predation avoidance explained bear occurrence near settlements, we predicted younger problem than nonproblem bears and a negative correlation between age and human density. However, if only food search explained bear occurrence near settlements, we predicted no relation between age and problem or nonproblem bear status, or between age and human density. We found no difference in BCI or its variability between problem and nonproblem bears, no relation between BCI and human density, and no correlation between numbers of problem bears shot and seasonal mean BCI for either country. The peak of shot problem bears occurred from April to June in Slovenia and in June in Sweden (i.e., during the mating period when most intraspecific predation occurs and before fall hyperphagia). Problem bears were younger than nonproblem bears, and both problem and nonproblem bears were younger in areas of higher human density. These age differences, in combination with similarities in BCI between problem and nonproblem bears and lack of correlation between BCI and human density, suggested safety-search and naïve dispersal to be the primary mechanisms responsible for bear occurrence near settlements. Younger bears are less competitive, more vulnerable to intraspecific predation, and lack human experience, compared to adults. Body condition was inversely related to the bear density index in Sweden, whereas we found no correlation in Slovenia, suggestin...

In species distribution analyses, environmental predictors and distribution data for large spatial extents are often available in long‐lat format, such as degree raster grids. Long‐lat projections suffer from unequal cell sizes, as a degree of longitude decreases in length from approximately 110 km at the equator to 0 km at the poles. Here we investigate whether long‐lat and equal‐area projections yield similar model parameter estimates, or result in a consistent bias. We analyzed the environmental effects on the distribution of 12 ungulate species with a northern distribution, as models for these species should display the strongest effect of projectional distortion. Additionally we choose four species with entirely continental distributions to investigate the effect of incomplete cell coverage at the coast. We expected that including model weights proportional to the actual cell area should compensate for the observed bias in model coefficients, and similarly that using land coverage of a cell should decrease bias in species with coastal distribution. As anticipated, model coefficients were different between long‐lat and equal‐area projections. Having progressively smaller and a higher number of cells with increasing latitude influenced the importance of parameters in models, increased the sample size for the northernmost parts of species ranges, and reduced the subcell variability of those areas. However, this bias could be largely removed by weighting long‐lat cells by the area they cover, and marginally by correcting for land coverage. Overall we found little effect of using long‐lat rather than equal‐area projections in our analysis. The fitted relationship between environmental parameters and occurrence probability differed only very little between the two projection types. We still recommend using equal‐area projections to avoid possible bias. More importantly, our results suggest that the cell area and the proportion of a cell covered by land should be used as a weight when analyzing distribution of terrestrial species.

Studying the evolution of climatic niches through time in a phylogenetic 12 comparative framework combines species distribution modeling with phylogenies. 13 Phylogenetic comparative studies aid the understanding of the evolution of species' 14 environmental preferences by revealing the underlying evolutionary processes and causes, 15 detecting the differences among groups of species or relative to evolutionary pattern of other 16 phenotypic traits, but also act as a yardstick to gauge the adaptational potential under 17 climate change. Because several alternatives exist on how to compute and represent the 18 climatic niche, we here review and discuss the current state of the art and propose a best 19 practice to use in comparative studies. Moreover we outline the common evolutionary models 20 and available model-fitting methods and describe the procedure for ancestral niche 21 reconstruction with the intention to give a broad overview and highlight the most advanced 22 approaches for optimal niche-related comparative studies. 23 24 25Phylogenetic comparative studies use a wide range of methods to explore patterns and 26 processes linked to phylogenetic trees and species traits (Pennell and Harmon, 2013). These 27 studies uncover how a certain trait evolves among different taxa, how evolution of one trait 28 influences another, whether a trait represents adaptation to the environment etc. In this 29 review we focus exclusively on studies testing hypotheses about species' climatic niches 30 evolution through phylogeny. 31The aim of such studies is typically not only to suggest the trajectories of niche evolution, 32 but rather to test specific hypothesis about the timing of appearance, causation or 33 evolutionary processes responsible for observed patterns. Such studies aim to discover, for 34 instance, whether shifts in the climate niche occur at the same time as shifts in a particular 35 trait (such as C3/C4 photosynthesis: Edwards and Smith, 2010), whether it was a key driver 36 for developing specific life-histories (e.g. cactus life-form: Edwards and Donoghue, 2006), or 37 whether temporal and/or spatial fluctuation of climate caused species to evolve and diversify 38 (Evans et al., 2009). Furthermore, linking climate niche evolution to population demography 39 through time could reveal whether major niche shifts occur in small or large populations 40 (Jakob et al., 2010). The analyses are based on current trait values, the phylogenetic 41 relationship between species and an evolutionary model. Climate niche is treated as if it was a 42 phenotypic trait and the analysis of, say, temperature values follows the same logic as 43 evolutionary analysis of body mass. The actual reconstruction of ancestral trait values is 44 unnecessary for testing correlations between characters. Being an integral part of the 45 procedure, ancestral states along the phylogeny are implicitly inferred but not actually 46 presented. However, other hypotheses might require reconstruction of ancestral values, such as 47 tests of nic...