Bridging human mobility to animal activity: when humans are away, bears will play

In the Anthropocene, findings on animal behavioral flexibility in response to anthropogenic changes are accumulating: human presence and activity affect the distribution, movement, activity rhythm, physiology, and diet of animal species. However, conclusions are limited by the lack of simultaneous quantitative data on both the animal and human side. Hence, the dynamic link between animal behavior and human activity and mobility is often poorly estimated. Based on long-term monitoring of a wild bear population in the Trentino region (10 bears monitored from 2006 to 2019; 20 bear-years) combined with human mobility data (Cumulative Outdoor activity Index, derived from the Strava Global Heatmap) and tourist count records, we investigated how spatial behavior and activity rhythms of bears change with variations in experienced human disturbance. We found that bears were mainly nocturnal and that, on an annual scale, nocturnality was associated with movement behavior, but both were independent of experienced human disturbance. Furthermore, nocturnality tended to increase in periods of more intense exploitation of outdoor areas by humans. Overall, these preliminary findings show that bears exhibit a notable behavioral flexibility to minimize their exposure to human presence. Through the application of different sources of human activity data, this work showcases that the integration of high resolution animal movement data with dynamic data on human mobility is crucial to meaningfully catch wildlife responses to anthropisation

Brown bear multi-scale response to human presence and mobility in the Italian Alps

In an increasingly human-dominated world, wildlife is constrained by human presence and activity, inducing behavioural adjustments as a consequence. Large mammals are especially sensitive to such changes, questioning the potential of their behavioural flexibility to cope with human disturbance. Using brown bears in the Italian Alps as a study case, we investigated their response to changes in human presence over different temporal scales. Combining human mobility data with bear tracking and activity data spanning from 2006 to 2019, we analysed bears’ behaviour and movement as a function of human activities. We observed that over the years bear activity and daily movement length have increased, while diurnality and range size have decreased. While tourism has grown in parallel, this was not identified as the main driver of such responses. Rather, it was mostly due to the increase in bear population, whose space is nonetheless limited by human infrastructure. At a weekly scale, we observed no difference in daily movement lengths between weekdays and weekends. This might perhaps be because of the continuous human disturbance in the area overall. Finally, at the daily scale, we found that individuals roamed in places more intensively exploited by humans at night compared to daytime, especially when ranging in heavily disturbed areas. Our results highlight how humans are indirectly, by hampering connectivity, and directly, through disturbance, shaping brown bear behaviour and movement. In view of a growing volume of outdoor human activity, we analyze the implications of such responses and present challenges for human-wildlife coexistence

Acquisition of a complex extractive technique by the immature chimpanzees of Loango National Park, Gabon

The relative importance of individual and social learning in acquiring complex technological skills in animals is debated, especially the influence of processes allowing high copying fidelity (namely, imitation and teaching). We investigated how immature wild chimpanzees, Pan troglodytes troglodytes, acquired the technique for extracting underground honey. This technique is interesting because (1) adults perform exploration, pounding and perforation in nonrandom but highly flexible action sequences to locate underground bee nests, (2) they have individual preferences for how to perforate the ground and (3) the nests are deeply buried and concealed, making success difficult to achieve. We analysed the behaviour of 16 immatures recorded by camera traps at 50 sites, and tested the influence of individual attributes (namely, age and sex) and maternal behaviour; we also tested whether mothers provided learning opportunities for their offspring. We found that, as they aged, immatures of both sexes progressively matched adults' behaviour in action sequences and observed their social models more continuously. Immature males used the most common grip type used by adults for perforating (namely, the coordinated use of hands and feet) progressively more as they aged, but no effect of maternal preferences was detected. Thus, the adult technique was probably acquired via a combination of physical maturation (i.e. increased body strength and motor coordination) and observational learning, although individual learning could not be completely ruled out. Finally, the proportion of time mothers spent inactive at bee nest sites was high when they were accompanied by young daughters and decreased as daughters aged, while the opposite pattern was found for sons. Mothers may thus stimulate learning by immatures by adjusting their behaviour according to their offspring's sex and age. Overall, we showed that immature chimpanzees acquired this complex tool use behaviour via a combination of social and nonsocial learning processes, including potential maternal stimulation

Host aggregation and local density corresponds to heterogeneity in tick-borne and rodent-borne diseases

Host-parasite-pathogen dynamics in nature have been linked to a range of extrinsic and intrinsic factors, which shape the spatio-temporal heterogeneity of environment. Here we evaluated how anthropogenic food manipulation may affect hosts local density and space-use patterns, parasite burden, and pathogen prevalence The study was carried out from February 2019 to April 2021 in Cembra Valley (Trentino, Italian Alps), in a treatment-control field experiments. Treatment sites were at ungulate feeding sites dispensing supplemental ad libitum food, where roe deer were being captured and marked with GPS collars, whereas control sites were placed at least 500 m away from the closest feeding site. In both treatment and control sites, we performed monthly live capture-mark recapture of rodents by individually marking captured individuals with Passive-Integrated Transponder (PIT) tag. Standard capture information, life-history traits and parasites’ presence were recorded, while biological samples (blood, tissue, faeces) were collected. We applied Spatially Explicit-Capture-Recapture models to spatially predict rodent density and space-use patterns, while we relied on GPS telemetry data to perform a recursion analysis with the aim of assessing roe deer revisitation patterns at treatment and control sites. Through Generalized Linear Mixed Models, we modelled how mice tick burden varied in dependence on the presence of ungulate feeding sites, rodent density and phenotypic traits (sex, status and body mass). Additionally, serological assays and molecular PCR-based methods coupled with sequencing were performed to assess the prevalence of rodent- and vector-borne pathogens at control and treatment sites. 398 yellow-necked and wood mice (Apodemus spp.), 109 bank voles (Myodes glareolus) and 12 roe deer individuals were captured at treatment sites. The availability of supplemental food shrunk rodents’ space-use, increasing mice but not voles local densities. Roe deer revisitation rate was significantly higher at treatment respect to control sites. 1790 feeding Ixodidae ticks were counted on rodents. Tick burden was significantly higher in heavier individuals, but did not depend on site. Conversely, spatial pattern of rodent- (Dobrava-Belgrade and Puumula viruses) and vector-borne (Tick-borne Encephalitis virus, Borrelia afzelii, Babesia microti, Anaplasma phagocytophylum and Hepatozoon spp.) pathogens occurrence varied among control and treatment sites. Vector-borne pathogens showed a lower prevalence at feeding sites (mean prevalence, 8.69%) than at control sites (13.89%), while the opposite was found for rodent-borne ones (1.55% and 1.16%, respectively). Our findings suggest that both woodland rodents and roe deer were attracted by supplemental food resources. We argue that the co-occurrence of incompetent (roe deer) and competent hosts (rodents) at these sites might affect infectious pathogens’ spreading. These results underline the importance of considering spatial distribution of competent and incompetent hosts, and not only overall density, to investigate zoonotic ris