Douglas P. Chivers
DEPARTMENT OF BIOLOGICAL SCIENCES
UNIVERSITY OF MAINE
5751 Murray Hall
Orono, ME 04469
Phone: (207) 581-2575
Fax: (207) 581-2537
Email: CHIVERS@MAINE.MAINE.EDU
My primary research interest focuses on predator/prey interactions involving aquatic organisms. Specifically, I am interested in understanding the way in which predation, or the risk of predation, influences anti-predator defenses among prey species and the way in which predators counteract these defenses. This research includes studies of behavioral, chemical and morphological predator defenses, as well as studies of the effects of predation on changes in life history characteristics of prey. My research focuses on general concepts in behavior, ecology and evolution and combines both field and laboratory based studies. I make a special effort to incorporate a diversity of taxa into my research program.
A significant amount of my past research effort has been devoted to the study of chemical alarm signaling (Review Chivers and Smith 1998, Écoscience 5:338-352). Many organisms, including numerous fishes, release chemical signals from SPECIALIZED EPIDERMAL CLUB CELLS upon being CAPTURED BY A PREDATOR. Other members of the same species detect these signals and are 'warned' of the presence of the predator. Understanding how these signaling systems evolved has fascinated me for years. Alarm signal evolution is perplexing because often it is difficult to see any direct benefits to the senders, aside from possible benefits derived from warning kin. In a series of experiments conducted with DRS. ALICIA MATHIS, GRANT BROWN and Jan Smith, we showed that predators, including northern pike (Esox lucius), are attracted to the chemical signals released by captured fathead minnows (Pimephales promelas). Once attracted by the chemical signals, the predators interfere with each other, thereby increasing the probability that the prey will escape. It seems that the minnow benefits by releasing a chemical signal that attracts additional predators. Numerous other hypotheses for the evolution of alarm signals remain to be investigated. (See Mathis et al. 1995. Am. Nat. 145:994-1005; Chivers et al. 1996. Am. Nat. 148:649-659).
In addition to trying to understand the evolution of chemical alarm signals, I have spent a considerable amount of time trying to understand the importance of alarm signals in mediating predator/prey interactions. One of the most interesting aspects of this research indicates that prey alarm signals can 'label' a predator as dangerous to other prey animals. For example, in a series of experiments conducted with DRS. BRIAN WISENDEN and Jan Smith, we showed that predator-naïve damselfly larvae (Enallagma spp.) respond to chemical cues of a predatory pike if the pike is fed damselflies but not if the pike is fed a different diet. The damselfly alarm signal ingested by the predator 'labels' it as dangerous. Moreover, predator-naïve damselflies that detect conspecific alarm signals in the diet of the predator, learn to recognize the predator. Those individuals that detect alarm signals in the diet of the predator subsequently respond to chemical cues of the predator regardless of the predator's recent diet (See Chivers et al. 1996. Anim. Behav. 52:315-320).
Much of the research currently underway in my laboratory deals with understanding the importance of chemical alarm signals in mediating predator-prey systems. For example, work with one of my Ph.D. students MATTHEW PUTTILTZ is examining whether alarm signals mediate changes in morphology and life history of fishes, amphibians and aquatic invertebrates. We are particularly interested in determining how potential changes in morphology and life history subsequently feedback into behavioral defenses. Work with another Ph.D. student REEHAN MIRZA is examining whether trout and salmon possess chemical alarm signals, and if so, whether the signals can be used as proximate cues to condition predator-naïve fishes to recognizeunknown predators. These results may have important implications in aquaculture and fisheries management.
I have recently initiated a series of experiments with DR. JEAN-GUY GODIN of Mt. Allison University. We are examining predator/prey interaction between brook trout (Salvelinus fontinalis) and slimy sculpins (Cottus cognatus) in STREAMS IN MAINE. Throughout much of eastern North America these species are the only two fish species that occur in many streams. The brook trout/slimy sculpin system is very interesting because both species act as both predator and prey in the same system. SCULPINS are small benthic fishes that are known to enter salmonid nests and feed on developing eggs and newly hatched young. After spending weeks to months in the nest, brook trout emerge and quickly outgrow the gape of the sculpins, eventually growing large enough that they become potential predators on sculpins. In our initial experiments, we are examining the influence of sculpin predation on the early life stages of brook trout. We are attempting to assess whether trout alter their timing of hatching or emergence from the gravel in response to variation in predation risk.
Like many other members of the Animal Behavior Society, my research in behavior spans numerous other topics. For example, I have a strong interest in amphibian mate choice (e.g. Marco et al. 1998. Anim. Behav. 55:1631-1635) and conservation biology of amphibians. Some of my research related to amphibian conservation has examined the potential importance of UV-B radiation on amphibian declines and amphibian deformities (e.g. Blaustein et al. 1997. Proc. Natl. Acad. Sci. USA 94:13735-13737). In some recent research with DRS. ANDREW BLAUSTEIN (Oregon State University), JOSEPH KIESECKER (Yale University), and LEE KATS (Pepperdine University) we found that exposure to UV-B radiation may have significant effects on behavior of amphibians.
For more detailed information on my research program, please contact me by email at: CHIVERS@MAINE.MAINE.EDU