Nicole Besler Research

PhD Research

Assessing the effects of organic pollutants (pesticides and wildfire smoke) on bat health

Pesticides of various classes have been used on our landscape for over 70 years; however, the effects of chronic exposure and alterations to ecoystem "services" provided by aerial insectivores (i.e., pest control) is not well understood. Additionally, smoke from wildfires are becoming more frequent and more toxic, making it imperative to understand the cumulative effects of these organic pollutants on the long-term persistence of insectivorous wildlife.

I'm investigating the exposure risk of bats to pesticides and wildfire smoke, and identifying the effects of exposure on aspects of health including:

Genotoxicity
Endocrine function: specifically reproductive hormones
Immune function

First fringed myotis captured in the East Kootenays!

On August 19, 2022 I captured the first fringed myotis (Myotis thysanodes) in the East Kootenays, confirming previous acoustic recordings in the region. It does not necessarily represent a range expansion, but is more likely attributed to the fact that bats are still relatively understudied!

Masters Research

Skin temperature of a female little brown bat in June displaying torpor over multiple days; however, there were some time periods where the transmitter signal cut out.

Thermoregulatory Responses in Female Little Brown Bats

Torpor is a thermoregulatory response involving a lowered metabolism and body temperature [1]. Some mammalian and bird species employ torpor to conserve energy and water [1]; however, there is a trade-off between using torpor and progressing reproduction [2]. White-nose syndrome is a fungal disease that affects the thermoregulatory responses of bats and has led to the decimation of bat populations in Eastern North America, particularly the little brown bat [3].

I investigated the intrinsic variables and weather conditions that may explain torpor use in female little brown bats in Newfoundland.

I found that weather variables best explained if torpor was used or not, while the pattern of torpor use (i.e., length and degree of change in body temperature) varied among individuals and by reproductive condition.
In June I had some females remain torpid for multiple days and one bat dropped their temperature as low as 4C!
Females of the same reproductive status, roosting in the same bat box would use torpor differently on the same day = the importance of individual traits in understanding physiology

Efforts to understand and mitigate effects from white-nose syndrome should consider thermoregulatory responses in the spring as intensive torpor use is likely important for bats in certain regions. White-nose syndrome and environmental perturbations may disrupt this, negatively affecting survival and reproductive success.

Publication: Besler and Broders 2019

1. Wang, L.C.H., and Wolowyk, M.W. 1988. Torpor in mammals and birds. Canadian Journal of Zoology 66, 133–137.

2. Racey, P.A., and Swift, S.M. 1981. Variations in gestation length in a colony of pipistrelle bats (Pipistrellus pipistrellus) from year to year. Journal of Reproduction and Fertility 61, 123–129.

3. Reeder et al. 2012. Frequent arousal from hibernation linked to severity of infection and mortality in bats with white-nose syndrome. PloS One 7 (6): e38920.

Undergraduate Research

Reef Fish Biodiversity Assessment

Fish are present in many trophic levels within reef ecosystems and have important symbiosis with coral [1,2]. However, fish species from all trophic levels face numerous threats, including climate change [3] and pollution [4].

Traditionally, visual transects and photographic surveying have been used to assess biodiversity of fish [5,6]. Remote sensing is typically done on nonmotile landscape features or organisms [7], but there is the potential that remote sensing can be used to quantify fish species and relative abundance based on reef fish patterns.

I compared visual, photographic, and remote sensing methods for obtaining biodiversity measures (density and species) of reef fish in Hawaii. ENVI software was used for analyzing the photos.

The photographic and visual census resulted in similar (i.e., not significantly different) biodiversity measures.
ENVI was able to identify some species, but for others it was not able to discern fish from surrounding coral resulting in a lower biodiversity measure for this method than the photographic and visual methods. Thus, remote sensing may only be suitable for identifying certain species, but not overall biodiversity.
Interestingly, fish density calculated from visual transects during my study (2013) were twice what they were from a study in the 1950's.

1. Steneck, R.S. 1997. Fisheries-induced biological changes to the structure and function of the Gulf of Maine ecosystem. In “Proceedings of the Gulf of Maine ecosystem dynamics scientific symposium and workshop.” p. 151-165. Hanover, NH: Regional Association for Research on the Gulf of Maine.

2. Depczynski, M., C. J. Fulton, M. J. Marnane, & D. R. Bellwood. 2007. Life history patterns shape energy allocation among fishes on coral reefs. Oecologia, 153: 111-120.

3. Harvell, C. D., C. E. Mitchell, J. R. Ward, S. Altizer, A. P. Dobson, R. S. Ostfeld, & M. D. Samuel. 2002. Climate warming and disease risks for terrestrial and marine biota. Science, 296: 2158-2162.

4. Fabricius, K.E. 2005. Effects of terrestrial runoff on the ecology of corals and coral reefs: review and synthesis. Marine Pollution Bulletin, 50:125-146.

5. Brock, V.E. 1954. A Preliminary Report on a Method of Estimating Reef Fish Populations. TheJournal of Wildlife Management, 18: 297-308.

6. Kipson, S., M. Fourt, N. Teixido, E. Cebrian, E. Casa, E. Ballesteros, M. Zabala, & J. Garrabou. 2011. Rapid biodiversity assessment and monitoring method for highly diverse benthic communities: a case study of Mediterranean coralligenous outcrops. PloS one, 6: e27103.

7. Knudby, A., E. LeDrew, & C. Newman. 2007 Progress in the use of remote sensing for coral reef biodiversity studies. Progress in Physical Geography, 31: 421-434.

Urban Coyote Diet

Coyotes have become a common urban species as human settlements increase and wolf populations dwindle [1]. This has resulted in increased conflict between coyotes and humans; however, the extent to which this species relies on anthropogenic materials and domestic animals as food sources can be misinterpreted [2].

I compared coyote diet composition among three urban parks in Calgary. I developed a reference set of mammalian hairs and then identified and quantified mammalian prey, along with other dietary items, in coyote fecal samples.

Rodents (primarily voles) and vegetation were the most frequently occurring items (each at ~87%), with rodents comprising the majority of diet composition.
Rodents comprised the majority of diet composition, while invertebrates were the lowest.
Anthropogenic items and domestic animals were found, but they were the least commonly encountered item (~7% and 2%, respectively).

Coyotes in Calgary primarily exploit non-anthropogenic resources, indicating that coyotes likely help maintain a balanced ecosystem within urban environments.

1. Gehrt, S.D. 2007. Ecology of coyotes in urban landscapes. Wildlife Damage Management Conferences-Proceedings. Paper 63.

2. Fox, C.H., and C.M. Papouchis. 2005. Coyotes in our midst: coexisting with an adaptable and resilient carnivore. Edited by K. Hirsch and G. Lamont. Sacramento: Animal Protection Institute.

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