Life in the Sagebrush: Behaviour, Ecology and Evolution of the Sagebrush Grig

Grand Teton

Supervisor: Christine Miller

Project Summary (PhD): 

The sagebrush grig, Cyphoderris strepitans, is an extraordinary but still poorly understood insect that inhabits sagebrush ecosystems of the Rocky Mountains. Males produce conspicuous acoustic signals to attract females, while females engage in an unusual form of nuptial feeding during mating, consuming the male's fleshy hind wings and haemolymph. Mating therefore provides both a remarkable reproductive interaction and a visible record of an individual's mating history. Previous research has revealed striking variation in male mating success, sexual selection on male song and wing morphology, and important costs of mating, but many fundamental questions about the ecology, behaviour and evolution of this fascinating species remain unanswered.

This PhD project will use field-based and experimental approaches to investigate how sagebrush grigs interact with their social and ecological environment, and how these interactions shape their behaviour and reproductive success. Depending on the interests of the student, research could examine the behavioural and biomechanical consequences of nuptial feeding, territoriality and space use, variation in mating strategies, or the effects of environmental conditions on signalling and reproductive behaviour. The project will combine observations of free-living insects with experiments in the field and the local laboratory in Grand Teton National Park, allowing the student to connect individual behaviour with ecological conditions and ultimately with evolutionary processes. The system also provides exciting opportunities to develop new approaches to understanding how morphology, performance, behaviour and fitness are integrated in a wild animal.

Type of work:

  • Note that this work will be conducted in the astonishingly beautiful Grand Teton National Park in Wyoming, in spring conditions at night. It will be damp, cold, and this work is only for those with previous experience working in harsh conditions. Students will be working alongside others in the field. We will stay at the University of Wyoming/ U.S. National Park field station on the shores of Jackson Lake. While the PI can contribute some funds to this project, it is expected that the student will also diligently apply for travel grants for field work. 
  • Field ecology: locating, marking and following individually identifiable grigs in natural sagebrush habitats
  • Behavioural observation: recording courtship, mating, territorial interactions, movement and nightly activity
  • Experimental field studies: manipulating social, environmental or signalling conditions and measuring behavioural responses
  • Biomechanics: examining the mechanical properties, damage and functional consequences of the male hind wings and/or sound-producing structures
  • Quantitative approaches: video analysis, acoustic analysis, morphometrics, statistical modelling

Why is this important?

Understanding animal behaviour requires connecting what individuals do with the ecological circumstances in which they live and the evolutionary consequences of their decisions. Sagebrush grigs offer an unusually powerful opportunity to do this because several aspects of their biology, including acoustic communication, sexual selection, nuptial feeding, mating costs and spatial behaviour, are tightly interconnected. For example, male song is strongly associated with mating success, while the physical consequences of mating can influence subsequent reproduction, creating the possibility of feedback between behaviour, morphology, physiology and fitness. Studying these interactions in a natural population will provide a richer understanding of how complex behavioural phenotypes evolve and how animals balance the competing demands of attracting mates, reproducing and surviving.

References

Eggert, A. K., & Sakaluk, S. K. (1994). Sexual cannibalism and its relation to male mating success in sagebrush crickets, Cyphoderris strepitans (Haglidae: Orthoptera). Animal Behaviour, 47(5), 1171-1177.

Johnson, J. C., Ivy, T. M., & Sakaluk, S. K. (1999). Female remating propensity contingent on sexual cannibalism in sagebrush crickets, Cyphoderris strepitans: a mechanism of cryptic female choice. Behavioral Ecology, 10(3), 227-233. 

Sakaluk, S. K., & Eggert, A. K. (2009). Coping with the cold: temperature and mating activity of male sagebrush crickets Cyphoderris strepitans (Orthoptera: Haglidae). Physiological Entomology, 34(3), 251-255.