Project Description: 

Are you amazed by weird –but awesome– arachnids? 

Do you like making and analyzing videos?

Do you want to know how and why we study animal locomotion, chemical ecology AND/or sexual behavior?

In the Elias Lab we study the animal behavior and ecology in an evolutionary framework. We are currently interested in the responses and adaptations of animals to environmental challenges, particularly predation. Animals have developed strategies to compensate for such challenges to survive, perform adequately, and reproduce.

Arachnids are ideal organisms to study this because of their morphological and behavioral adaptations, and the possibility of performing extensive field and laboratory experiments. Daddy long-legs (Arachnida; order Opiliones) have features that are thought to be adaptations to deal with environmental pressures: (1) autotomy –the voluntary release of legs to escape predators–, (2) chemical defenses and communication, and (3) grouping behavior. However, the functions or the costs and benefits of these strategies are unknown. We are investigating research questions that integrate mechanisms, behavior, ecology, and physiology, including:

  • Can harvestmen compensate the loss of locomotor performance after autotomy throughout time?
  • What are the costs of losing legs in their sexual behavior? Can they compensate for those potential costs?
  • Is there a trade-off between the use of defensive strategies (releasing legs versus using chemical defenses) in these arachnids?

Our preliminary observations indicate that autotomy is frequent in one species in the Bay Area (Nelima paessleri), therefore compensation strategies are expected to occur. This novel research set up will give the opportunity to self-motivated and curious students to participate and develop field and laboratory research projects, mostly dealing with biomechanics, sexual behavior, and chemical ecology. Field work involves registering natural history data, collecting daddy long-legs in Berkeley (the Fire Trail), and bringing them to campus. In the lab, experiments will use a high-speed video camera setup to investigate their locomotion and sexual behavior (as we will stage mating trials) and analyze them using specialized software. Also, we will be doing hand-on morphological measures of living and preserved animals to understand the influence of body size on behavior. Finally, this project also offers the opportunity to do a pilot study of extraction and analysis of chemical compounds expelled by daddy long-legs as a defense mechanism.

Undergraduate's Role: 

Students will actively participate in all the stages of the research. On campus, students will get training in scoring behavior and video analysis, as well as participating in the continuous animal care tasks, experimental procedures (locomotion trials, chemical extraction or sexual behavior), measuring live and preserved specimens, and gathering and analyzing data. The project also includes field trips (in Berkeley) to study organisms in their natural environment, collecting specimens and bringing them to the lab. 

Undergraduate's Qualifications: 

Self-motivated curious students. Knowledge and skills in video visualization and editing (Adobe Premiere, Quicktime), as well as coding (R, Matlab, Mathematica) will be ideal, although not required. The research will be a good experience to learn these techniques with a real-life example. Also, behavioral research requires patience and careful skills in animal care, morphological measures, and observations. Experience in chemistry classes or labs, as well as working with invertebrates or small organisms will be useful, but not required. 

On Campus
6-9 hours
Project URL: