Search

Abstract Background Identifying the behavioral state for wild animals that can’t be directly observed is of growing interest to the ecological community. Advances in telemetry technology and statistical methodologies allow researchers to use space-use and movement metrics to infer the underlying, latent, behavioral state of an animal without direct observations. For example, researchers studying ungulate ecology have started using these methods to quantify behaviors related to mating strategies. However, little work has been done to determine if assumed behaviors inferred from movement and space-use patterns correspond to actual behaviors of individuals. Methods Using a dataset with male and female white-tailed deer location data, we evaluated the ability of these two methods to correctly identify male-female interaction events (MFIEs). We identified MFIEs using the proximity of their locations in space as indicators of when mating could have occurred. We then tested the ability of utilization distributions (UDs) and hidden Markov models (HMMs) rendered with single sex location data to identify these events. Results For white-tailed deer, male and female space-use and movement behavior did not vary consistently when with a potential mate. There was no evidence that a probability contour threshold based on UD volume applied to an individual’s UD could be used to identify MFIEs. Additionally, HMMs were unable to identify MFIEs, as single MFIEs were often split across multiple states and the primary state of each MFIE was not consistent across events. Conclusions Caution is warranted when interpreting behavioral insights rendered from statistical models applied to location data, particularly when there is no form of validation data. For these models to detect latent behaviors, the individual needs to exhibit a consistently different type of space-use and movement when engaged in the behavior. Unvalidated assumptions about that relationship may lead to incorrect inference about mating strategies or other behaviors.

Background: Identifying the behavioral state for wild animals that can't be directly observed is of growing interest to the ecological community. Advances in telemetry technology and statistical methodologies allow researchers to use space-use and movement metrics to infer the underlying, latent, behavioral state of an animal without direct observations. For example, researchers studying ungulate ecology have started using these methods to quantify behaviors related to mating strategies. However, little work has been done to determine if assumed behaviors inferred from movement and space-use patterns correspond to actual behaviors of individuals. Methods: Using a dataset with male and female white-tailed deer location data, we evaluated the ability of these two methods to correctly identify male-female interaction events (MFIEs). We identified MFIEs using the proximity of their locations in space as indicators of when mating could have occurred. We then tested the ability of utilization distributions (UDs) and hidden Markov models (HMMs) rendered with single sex location data to identify these events. Results: For white-tailed deer, male and female space-use and movement behavior did not vary consistently when with a potential mate. There was no evidence that a probability contour threshold based on UD volume applied to an individual's UD could be used to identify MFIEs. Additionally, HMMs were unable to identify MFIEs, as single MFIEs were often split across multiple states and the primary state of each MFIE was not consistent across events. Conclusions: Caution is warranted when interpreting behavioral insights rendered from statistical models applied to location data, particularly when there is no form of validation data. For these models to detect latent behaviors, the individual needs to exhibit a consistently different type of space-use and movement when engaged in the behavior. Unvalidated assumptions about that relationship may lead to incorrect inference about mating strategies or other behaviors. [ABSTRACT FROM AUTHOR]

In species where defense of females or resources attractive to females is not an option, males search for mates. How males locate mates is not well understood. Male white-tailed deer ( Odocoileus virginianus) are assumed to search widely for females in estrus; but the rut (2-4 weeks) and estrus (1-2 days) are short and males would benefit by having a strategy to locate mates. Because females typically have small home-range sizes and exhibit site fidelity, we predicted males would spend time in small focal areas containing females during rut. We fitted 102 males with GPS collars across 5 breeding seasons in South Texas. During rut, movement rates increased but most males used a small portion (26-34%) of their home ranges. Most males had ≥ 2 small focal areas (18-33 ha) which were revisited every 20-28 h. Because estrus is ∼24 h, males may revisit focal areas to assess female receptiveness. During peak rut, 1 year olds had the lowest movement rates and rates were similar in 2- and ≥ 3-year-old males. However, most 2 year-old males exhibited Levy walks, an efficient search strategy when resources are rare. One-year-old males may not have exerted high effort, whereas most 2 year olds used a different strategy because of competition or lack of experience. Our results provide the first fine-scale description of ungulate mate-searching behavior and how spatial memory may be important for acquiring mating opportunities in species that rove for mates. [ABSTRACT FROM AUTHOR]