Abstract: Persistence of individual differences in animal behavior in reactions to various environmental challenges could reflect basic divergences in temperament, which might be used to predict details of adaptive response. Although studies have been carried out on fear and anxiety in various species, including laboratory, domestic and wild animals, no consistent definition of fearfulness as a basic trait of temperament has emerged. After a classification of the events that may produce a state of fear, this article describes the great variability in behavior and in physiological patterns generally associated with emotional reactivity. The difficulties of proposing fearfulness-the general capacity to react to a variety of potentially threatening situations-as a valid basic internal variable are then discussed. Although there are many studies showing covariation among the psychobiological responses to different environmental challenges, other studies find no such correlations and raise doubts about the interpretation of fearfulness as a basic personality trait. After a critical assessment of methodologies used in fear and anxiety studies, it is suggested that discrepancies among results are mainly due to the modulation of emotional responses in animals, which depend on numerous genetic and epigenetic factors. It is difficult to compare results obtained by different methods from animals reared under various conditions and with different genetic origins. The concept of fearfulness as an inner trait is best supported by two kinds of investigations. First, an experimental approach combining ethology and experimental psychology produces undeniable indicators of emotional reactivity. Second, genetic lines selected for psychobiological traits prove useful in establishing between behavioral and neuroendocrine aspects of emotional reactivity. It is suggested that fearfulness could be considered a basic feature of the temperament of each individual, one that predisposes it to respond similarly to a variety of potentially alarming challenges, but is nevertheless continually modulated during development by the interaction of genetic traits of reactivity with environmental factors, particularly in the juvenile period. Such interaction may explain much of the interindividual variability observed in adaptive responses.

Abstract: The social and spatial organization of urban fox groups prior to and during an outbreak of sarcoptic mange was compared with predictions derived from the resource dispersion hypothesis (RDH). We investigated the availability of three key resources. Neither daytime rest sites nor breeding sites appeared to be limited in availability. The availability of food deliberately supplied by local householders was examined by questionnaire surveys. The daily and weekly amount of food supplied was greatly in excess of the minimum requirements of a pair of foxes, but was consistent between territories. The availability of this food source increased markedly as a result of more people feeding the foxes. In agreement with the RDH, group size prior to the outbreak of mange increased from 2.25 animals (N=4) to 6.57 animals (N=7). Before the outbreak of mange, two territories were divided. Increased scavenge availability on smaller territories may have promoted these changes. Excluding these spatial changes, territories were very stable between years. After the outbreak of mange, group size declined as a direct result of mange-induced mortality. Surviving animals increased their ranges only after neighbouring groups had died out. Ranges did not increase in size in response to a decline in food availability. Nor were the increases in range size associated with the relinquishment of parts of the existing territory. These postmange changes are contrary to the RDH. Three factors may have promoted these changes: the elimination of interstitial space, the forced dispersal of young or future division of the territory.

Abstract: Abstract Obtaining reliable species observations is of great importance in animal ecology and wildlife conservation. An increasing number of studies use camera traps (CTs) to study wildlife communities, and an increasing effort is made to make better use and reuse of the large amounts of data that are produced. It is in these circumstances that it becomes paramount to correct for the species- and study-specific variation in imperfect detection within CTs. We reviewed the literature and used our own experience to compile a list of factors that affect CT detection of animals. We did this within a conceptual framework of six distinct scales separating out the influences of (a) animal characteristics, (b) CT specifications, (c) CT set-up protocols, and (d) environmental variables. We identified 40 factors that can potentially influence the detection of animals by CTs at these six scales. Many of these factors were related to only a few overarching parameters. Most of the animal characteristics scale with body mass and diet type, and most environmental characteristics differ with season or latitude such that remote sensing products like NDVI could be used as a proxy index to capture this variation. Factors that influence detection at the microsite and camera scales are probably the most important in determining CT detection of animals. The type of study and specific research question will determine which factors should be corrected. Corrections can be done by directly adjusting the CT metric of interest or by using covariates in a statistical framework. Our conceptual framework can be used to design better CT studies and help when analyzing CT data. Furthermore, it provides an overview of which factors should be reported in CT studies to make them repeatable, comparable, and their data reusable. This should greatly improve the possibilities for global scale analyses of (reused) CT data.