I am interested interspecific interactions and how they affect species survival, behavior and the conservation of biodiversity. My work uses field, experimental and comparative approaches and lies at the interface of conservation, animal behavior, ecology, and evolution. My current research projects fall into several broad categories which are briefly outlined below.

Integrating Conservation Biology and Animal Behavior

Understanding how best to manage and conserve species naturally involves understanding their behavior. We can also use animal behavior to develop solutions to conservation issues.

For example, with undergraduate students, I am developing and testing the effectiveness of strategies to monitor squirrel species using behavioral methods (e.g., acoustic playbacks).

I am also working with my graduate students to integrate an understanding of common raven behavior into management of the threatened western snowy plover.

Urban Ecology

I am addressing how urbanization influences species diversity (in particular birds) in urban areas. I am interested in examining how and why certain species persist in urban areas while others do not.

Large-scale Biodiversity Monitoring

In collaboration with the California Department of Fish and Wildlife, my graduate students and I assessed the influences of human disturbance, drought and species co-occurrences across two ecoregions in California: the Central Valley and Mojave Desert. This project utilized remote monitoring of vertebrates (e.g., camera traps and acoustic recorders) across approximately 600 sites.

Non-Invasive Survey Techniques for Small Mammals

My graduate students and I are working to develop survey techniques for small mammals (squirrels, mice, rats, voles and shrews) using camera traps and acoustic recorders.

Human Dimensions of Conservation

An understanding of the most influential species in urban ecosystems and their effects on other ecosystems is a must for conservation. My research uses human survey techniques to understand how human interact with wildlife and how their actions can impact biodiversity in urban areas and beyond.

Previous Research                                                                                                                                

My past research examined how interspecific flocking affects communication behavior in songbirds (Clucas et al. 2004), how predator-prey interactions can lead to the evolution of unique antipredator behavior in ground squirrels (Clucas et al. 2008a,b and Clucas et al. 2010) and how interactions between humans and birds in urban areas can influence both human and bird behavior (Clucas and Marzluff 2011, Clucas et al. 2011, Clucas and Marzluff 2012, Clucas et al. 2013), the economic valuation or urban birds (Clucas et al. 2015) and how urbanization influences biodiversity (Clucas and Marzluff 2015, Marzluff et al. 2016).

My dissertation work at the University of California, Davis focused on the evolution of predator-prey interactions between rattlesnakes and ground squirrels species. I investigated a unique behavior in ground squirrels - predator scent application - experimentally testing its function in the field and lab and tracing its evolutionary history with phylogenetic comparative methods and the fossil record.

I discovered that snake scent application in ground squirrels reduces rattlesnake foraging behavior and that this unique antipredator behavior likely evolved at least 30 million years ago in the common ancestor of ground squirrels and chipmunks. I also found that squirrel species that historically and currently co-occur with rattlesnakes exhibit snake scent application, but that the behavior has been lost in species that currently do not co-occur with rattlesnakes.

http://www.nytimes.com/2008/02/05/science/05obsqui.html?_r=1&ref=science&oref=slogin

https://www.pbs.org/wnet/nature/squirrel-masks-scent-with-rattlesnake-skin/13399/

For my postdoctoral research at the University of Washington and Humboldt Universität, I led an international comparative study investigating human-avian interactions in Berlin, Germany and Seattle, Washington. I found that variation in actions and attitudes of humans towards birds influenced avian diversity, abundance and behavior in these urban areas. My results and studies in other urban areas suggest birds and humans have a reciprocal relationship in urban areas: humans can create bird habitat and feeding opportunities and in turn, birds can provide a window into nature, which can improve human well-being. A full understanding combining biological and socio-economic components of these reciprocal relationships will increase our ability to conserve and restore urban ecosystems that benefit both humans and birds. Furthermore, the importance of understanding urban ecosystem processes will only increase as urban areas expand worldwide.

During my postdoc in Seattle, I also worked with undergraduate students on a project investigating whether American crows (Corvus brachyrhynchos) responded to different human facial features in urban areas (Clucas et al. 2013). We compared flight initiation distances and urgency of escape behavior to human approaches varying in eye contact and facial expression. We examined if crows distinguish between an approaching human that is directly gazing at them versus a human approaching them with an averted gaze and if crows differentiate a smiling versus scowling human approaching them. We found that crows fled sooner and more urgently when humans were directly gazing at them, however, they did not react differently to varying human facial expressions. Crows likely perceive a human directly gazing at them as a reliable threatening visual cue while they either do not perceive differences in facial expression or do not use them as a reliable cue of threat. These results possibly represent an adaptation to living in human-dominated, urban areas. This work also suggests that disturbance of birds during sensitive periods (nesting) could perhaps be lessened by humans avoiding direct eye contact with certain susceptible species.

http://www.scientificamerican.com/article.cfm?id=crows-show-off-social-skills

Prospective Graduate Students

If you are interested in joining my lab, please send me an email with the subject line “Prospective Graduate Student” and in the email describe your research interests and why you want to pursue a master’s degree in Wildlife Biology (also attach your CV and unofficial transcripts).