This blog post is provided by Heather N. Abernathy and tells the #StoryBehindthePaper for the paper ‘Rain, recreation and risk: Human activity and ecological disturbance create seasonal risk landscapes for the prey of an ambush predator’, which was recently published in Journal of Animal Ecology. In their study, they show how panthers’ avoidance of human recreation and flooding create distinct schedules of risk for deer, influencing their antipredator behavior.
In the natural world, predator-prey relationships play a crucial role in shaping the evolution and ecology of species. These interactions are influenced by various factors, including fluctuations in predation risk and the responses of prey to those risks. Additionally, habitats undergo dynamic changes, leading to predictable patterns of habitat structure and resource availability. For example, an area that is seasonally flooded may not be available for some animals to use year-round.
Understanding the interplay between these dynamic landscape processes and predator-prey interactions is an ongoing area of scientific investigation. Our recent study conducted in South Florida delved into the captivating realm of predator-prey interactions between Florida panthers and white-tailed deer (Figure 1) in a seasonally flooded landscape. We sought to explore how two significant factors, seasonal flooding and human recreation, impact these interactions and create what we term “seasonal risk landscapes”.
hardwood hammock and a white-tailed deer moving through a flooded area. Copyright and
Credit: Florida Fish and Wildlife Conservation Commission
South Florida experiences distinct cycles of flooding and dry seasons. These cycles dictate human trail usage, with less human activity during the flooded season and more during the dry season (Figure 2). Humans are not allowed to hunt female deer and male hunting is very limited within South Florida due to deer population declines. Florida panthers, a protected species in the area, perceive humans as a potential threat due to historical overhunting. Consequently, panthers tend to avoid areas frequented by humans. On the other hand, white-tailed deer face substantial predation risk from panthers, considering we attributed 72% of our deer mortalities to panthers whereas hunters killed only 0.01%.
southwestern Florida, averaged across the years 2015-2017, represented by the colors yellow,
light blue, brown, and black. The dark blue color represents the annual mean daily surface water.
The bolded yellow and blue lines in each panel indicate a smoothed spline representing the
trends of human activity and surface water index values, respectively. Copyright Abernathy et al.
2023.
We hypothesized that the interplay between flooding, human recreation, and the panther-deer ecology would give rise to distinct seasonal landscapes of predation risk and corresponding antipredator responses. To gather data, we utilized camera trap surveys across southwestern Florida, capturing information about human, panther, and deer activity. We analyzed how flooding and human presence affected the detection probability, co-occurrence, and activity patterns of deer and panthers.
The findings from our study revealed fascinating and thought-provoking patterns in the interactions between predators and prey. During the flooded season, the presence of increased surface water played a crucial role in reducing spatial predation risk. Specifically, we observed a decrease in panther detections and an increase in deer detections. The co-occurrence between deer and panthers also decreased in flooded areas. Additionally, we found that human recreation had a temporal effect on predation risk, acting as a refuge during the dry season. Panthers adjusted their behavior by becoming more active at night in areas with higher human presence, while deer increased their daytime activity. These changes in activity patterns, mediated by human influence, reduced the overlap in active periods between deer and panthers, thus decreasing the likelihood of encounters between the two species in time. These intriguing findings highlight how panthers’ avoidance of human recreation and flooding create distinct schedules of risk for deer, influencing their antipredator behavior (Figure 3). They also underscore the remarkable adaptability of prey species in responding to multiple sources of risk.
responses in Florida panthers and white-tailed deer, focusing on the interactive effects of
ecological disturbance (flooding) and human activity in southwestern Florida. We observed
distinct patterns during the flooded and dry seasons, which are illustrated in the left and right
panels, respectively. The middle figure highlights the seasonality of flooding and human
recreation throughout the year. We noticed an inverse relationship, with decreased flooding
corresponding to increased human activity. Now, let’s dive into the specific findings for each
season. During the flooded season (left panel), the presence of flooding had an impact on panther
activity. The flooded areas limited suitable hunting grounds for panthers, resulting in reduced
panther activity and fewer predation opportunities (spatial-ecologically impeded). This created
spatial refuges for deer, as their natural responses reduced the spatial overlap with predators, thus enhancing their chances of avoiding predation (spatial-ecologically facilitated). In the dry season
(right panel), we observed that increased human activity had a temporal effect on panther
behavior. Panthers became less active during the day, likely to minimize encounters with humans
(temporal-human impeded). This, in turn, created temporal refuges for deer, as their antipredator
responses involved increased diurnal activity to tolerate human presence and reduce predation
risk from panthers (temporal-human facilitated).
Our study provides valuable insights into the complex interactions between ecological disturbances, human activities, and predator-prey dynamics. It emphasizes that human recreation can have indirect effects on wildlife populations, even in areas with minimal human infrastructure. By understanding how dynamic habitats shaped by ecological disturbances influence predator-prey interactions, we can gain a deeper appreciation for the delicate balance of nature. This knowledge is not only relevant to South Florida but also has broader implications for conservation efforts in areas that ecological disturbance worldwide. By studying these intricate dances between predators and prey, we can work towards a more harmonious coexistence with wildlife and strive for the preservation of our natural ecosystems.
Read the full paper
Abernathy, H. N., Crawford, D. A., Chandler, R. B., Garrison, E. P., Conner, L. M., Miller, K. V., & Cherry, M. J. (2023). Rain, recreation and risk: Human activity and ecological disturbance create seasonal risk landscapes for the prey of an ambush predator. Journal of Animal Ecology, 00, 1– 16. https://doi.org/10.1111/1365-2656.13976
Animal Ecology in Focus 