Date of Award

2010

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

First Advisor

Christopher Sheil

Second Advisor

Carl Anthony (Committee Member)

Third Advisor

Jeff Johansen (Committee Member)

Abstract

Understanding roosting behavior and habitat use of bats is an important component when unraveling life histories and their ecology. Ohio remains under-represented in published information of bats compared to surrounding states. This large scale survey in 2002–2003 and Myotis septentrionalis radio telemetry study in 2005 is one of the few conducted within the state and is the first in Ohio’s North-Central region. It is also the first study conducted where net sites were chosen randomly and spatially distributed to adequately survey bat populations within Cuyahoga Valley National Park and Cleveland Metroparks. This survey documented seven species (n = 668), with the most abundant species being Eptesicus fuscus (n = 250) and Myotis septentrionalis (n = 210), which was unexpected. Whereas habitat preference is known for many bat species, there was an unexpected and significant stratum preference depending on sex for Eptesicus fuscus, Myotis septentrionalis and M. lucifugus, which has not been previously published. Male E. fuscus preferred either Upland Near Stream or Upland habitats, whereas females strongly preferred Floodplain (p < 0.0001). Myotis septentrionalis demonstrated a significant preference for stratum type between sexes, as females preferred Upland, whereas males preferred Upland Near Stream habitats (p = 0.01). Lastly, M. lucifugus females preferred Floodplain, whereas males preferred Upland (p = 0.001). There was a temporal trend for increased capture rates throughout the summer, as more Lasiurus borealis were captured in August (n = 33) than May–July combined (n = 27). The skewed sex ratio of more males than females in L. borealis and the temporal increase in number of captures is an indicator that there is an influx of male L. borealis into the population.

A total of eight lactating female Myotis septentrionalis were radio tracked to 21 roost trees. Myotis septentrionalis primarily roosted in dead trees (snags), as 19 of the 21 trees (90%) were dead, and bats were located most often roosting under exfoliating bark (17 of the 21 roost trees, 81%), which is unusual for this species as they are most often documented roosting in tree hollows. One individual was located behind a large vine of Toxicodendron radicans (Poison Ivy) on a dead Robinia pseudoacacia (Black Locust), and is the first documentation of M. septentrionalis roosting behind a vine. The majority of roosts were located within the genus Quercus (Oaks), with 15 of the 21 (71%) of all roost trees from this genus. Other roost tree species included: Fraxinus americana (White Ash, n = 1); Juglans nigra (Black Walnut, n = 1); Carya sp. (Hickory, n =1); Acer saccharum (Sugar Maple, n = 2); and Robinia pseudoacacia (Black Locust, n = 2).

These results provide valuable information on Ohio bats and indicate that there is still a considerable amount of work that remains to be conducted on bats, habitat use, and preference to ensure understanding of their complete life histories, allowing conservation efforts to be more effective. This study demonstrated that even though a species can have a stratum preference, there is a preference between sexes within some species and when considering conservation efforts both male and female bats need to be treated separately. The conservation of widespread and abundant species, such as Myotis septentrionalis, is critical for protection of entire ecosystems.

Comments

83 p.

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