University of Calgary

Ralph Cartar

  • Associate Professor
  • Ecology & Evolutionary Biology

Research Interests

My current research, in the field of evolutionary ecology, has three themes. First, I'm interested in the ecology of resource-tracking and the mechanisms underlying the distribution of competitors across their resources. For mobile consumers (like bumble bees) competing for stationary, renewing resources (like flowers), what patterns of distribution and abundance of foragers do we expect to see, and why? Second, I am studying the relationship between physical wear and foraging in wild bumble bees, in an effort to link foraging and life history traits in these organisms. How does foraging influence the natural degradation of wings in a social insect—bumble bees—for whom wing use is essential, and what is the significance of wing wear to lifespan and lifetime foraging gain? Third, using the framework of spatial density dependence from theme one (above), I am interested in detecting ecological impacts (particularly habitat loss) on pollinator populations. How does habitat loss affect populations and the distribution of competitors across resources, and can we rationalize the scale of the impact using local perturbations?

Current Graduate Students

Kutbi, Rola PhD Bumble bee foraging ecology, demography, and life history.
Melathopoulos, Andony PD Pollination ecology of canola. (co-supervisor: Shelley Hoover)
Retzlaff, Jennifer MSc Trait-structured bumble bee communities in canola agro-ecosystems. (co-supervisor: Paul Galpern)
Robinson, Samuel PhD

Spatial and temporal elements in the pollination ecology of canola.
(co-supervisor: Shelley Hoover)

Waytes, Riley MSc Pollinator interactions and canola pollination. (co-supervisor: Shelley Hoover)

Selected Publications

  • Google Scholar link
  • Roberts, J.C. and R.V. Cartar. 2015. Shape of wing wear fails to affect load lifting in common eastern bumble bees (Bombus impatiens) with experimental wing wear. Canadian Journal of Zoology 93:531-537.
  • Johnson, S.A. & R.V. Cartar. 2014. Wing wear, but not asymmetry in wear, affects load-lifting capability in bumble bees Bombus impatiens. Canadian Journal of Zoology 92:179-184.
  • Kowal, V.A. & R.V. Cartar. 2012. Edge effects of three anthropogenic disturbances on spider communities in Alberta's boreal forest. Journal of Insect Conservation 16:613-627.
  • Foster, D.J. & R.V. Cartar. 2011. What causes wing wear in foraging bumble bees? Journal of Experimental Biology 214:1896-1901.
  • Pengelly, C.J. & R.V. Cartar. 2011. Effect of boreal forest logging on nectar production of four understory herbs. Forest Ecology and Management 261:2068-2074
  • Foster, D.J. & R.V. Cartar. 2011. Wing wear affects wing use and choice of floral density in foraging bumble bees. Behavioral Ecology 22:52-59.
  • Pengelly, C.J. & R.V. Cartar. 2010. Effects of variable retention logging in the boreal forest on the bumble bee-influenced pollination community, evaluated 8-9 years post-logging. Forest Ecology and Management 260:904-1002.
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