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Uncovering determinants of animal personalities using movement data

Periodic Reporting for period 1 - PERSONALMOVE (Uncovering determinants of animal personalities using movement data)

Reporting period: 2018-05-01 to 2020-04-30

The field of animal personality links consistent behavioral variation among individuals to simultaneous differences in life history strategies and fitness. The relative contribution of genetics and developmental processes, such as maternal or individual learning on personality are however poorly understood. In the PERSONALMOVE project I link animal personality to the field of movement ecology. Movement and biologging data are a new source of data for behavioral studies that allow access to behavioral long term data on long lived wildlife species that was formerly unavailable.
I am using a unique dataset of multigenerational GPS-relocations, genetic, and dietary data of European brown bears (Ursus arctos) in Sweden.
My main objectives are:
O1) to quantify which portion of personality is determined by genetics and which part by maternal learning,
O2) to what degree an animals personality is stable throughout life, and based on that
O3) whether behavioral traits measured at earlier stages in life can be used to predict behavior later in life.
This will be particularly useful to develop a predictive model of how environmental conditions, maternal behavior and relatedness determine the movement and dispersal behavior of young bears. These behaviors are directly linked with resilience to anthropogenic disturbances as well as population connectivity. In light of expanding carnivore populations across Europe, understanding which individuals are most likely to disperse through anthropogenic landscapes will be critical to successfully mitigate conflicts. To tackle these quesations I combine statistical models common in the behavioral ecology literature with individual based movement and dietary data to quantify individual differences in behavioral strategies among bears.
The high relevance of the topic for the foreseeable recolonization of parts of Europe by brown bears makes this project of utmost priority.
"In the first year of the project I published two papers highlighting the among-individual variation and within-individual consistency of bear behavior across study years.
I presented these studies at the 26th Conference of the International Bear Association in Ljubljana and the BIOMOVE conference in Potsdam, both in September 2018, and at the Phenology Symposium in Uppsala in February 2019.
I also processed and partially analysed the data needed for objective 1 of my project and I analysed the data for objective 2.
I organised a workshop for bear managers introducing the topic of individual variation in wildlife behavior and discussing their own observations from the field and the potential implications of individual variation in behavior on bear management and conservation.
I further organised a statistical workshop for PhD students participating in the ""International Research School for Applied Ecology"", I disseminated analytical techniques to Master students at the Goethe University Frankfurt, and I was invited to host a seminar and Master class on individual variation in wildlife behavior at the IBED in Amsterdam.

For objective 1 of the project I analysed dietary specialization of individual brown bears and determined a) whether there are consistent, life long differences in the degree of carnivory among bears, and b) whether these differences are learned from the mother.
For this I analysed the stable isotopic signature, an indicator for relative degree of carnivory, in over 800 bear hair sampled collected since the early 90's.
A hair sample is taken from every bear captured by the Scandinavian brown bear project in spring. Bears mold in early summer and the hair collected in spring therefore represent the dietary composition of this particular bear during the preceding summer and autumn.
Initial results show strong effects of sex differences and sex specific age effects on how much meat bears eat. We found that females are highly consistent in their degree of carnivory over their lifetime but strongly differ from each other, i.e. some females a very carnivorous from an early age on, whereas others are more vegetarian. For males, the picture is a little more difficult, young males show a similar degree of carnivory than females but as they age, males increase their meat intake. Keeping this age effect in mind, we still see differences among males, that is - some are more vegetarian, others eat more meat.
Analyses as to the maternal learning effect on dietary specialization are still ongoing.

In the second part of my project (objective 2) I am interested in how stable spatio-temporal behaviors are over the lifetime of individuals. We looked at the temporal activity and at movement propensity of female brown bears on an annual scale and on a multi-annual scale. Bears maintain stable home ranges and we expected that bears would reduce movement activity with age as they have a better knowledge of their home range and their movements become more efficient in finding food. We however found that on the population level, behavior was stable over the lifetime of individuals. Interestingly we however detected different strategies among bears - some bears were always very consistent in their behavior, whereas others are more variable. We discuss this in terms of variation in the degree of behavioral specialization. We presented these results at the 2nd Gordon Conference on Animal Movement and at the IBED seminar series in Amsterdam.

In the last part of my project I am particularly interested in the causes of individual variation in the dispersal behavior of subadult bears. For this project I am closely collaborating with Jenny Hansen, who is a PhD student at the University of South-East Norway (USN) and with the BearConnect consortium (https://bearconnect.org/). After several short visits to USN during the first half of my project, I spent my secondment period in Norway in the fall of 2019. Together we analysed the properties of home ranges when cubs are together with their mother and their settlement decisions after dispersal. We did not find evidence that female bears selected settlement home ranges which were similar in habitat to their mother's but we found that social components, such as the number of familiar females or the presence of the mother played an important role in settlement decisions of subadult female bears. These results are important for predicting the likelihood and speed of range expansion of recovering brown bear populations, such as in the Pyrenees or the Italian Alpes."
My work on studying individual behavioral variation in wildlife has attracted considerable attention in both the movement ecology and wildlife ecology research circles.
I was invited to write a review and how-to R tutorial for Movement Ecology to aid this process, which has been accepted for publication.
I submitted a follow up funding proposal to continue my work and to study the evolutionary drivers leading up to standing behavioral variation among brown bear populations world wide.
The work on Objective 1 has not been completed yet but the submission of the manuscript is planned for the fall 2020.
A mother bear with her three offspring feeding on a moose carcass