TY - JOUR
T1 - Hawaiian hoary bat responses to habitat, season, and non-native insectivore suppression
AU - Moseley, Rachel D.
AU - Shiels, Aaron B.
AU - Aue, Asa
AU - Haines, William P.
AU - Aslan, Clare E.
AU - Liang, Christina T.
N1 - Funding Information:
Mention of a company or commercial product does not mean endorsement by the United States Government. We thank B. Colby, H. Coad, M. Donofrio, J. Felt, K. Jacobs, C. King, J. Latsha, I. Leinbach, L. Perry, M. Sample, D. Sedgwick, J. Smith, A. Wagner, T. Warner, and T. Winthers‐Barcelona for their rigorous maintenance of invasive insectivore suppression and monitoring, and N. Narahari, J. A. Raine, and J. D. Dzurisin for essential logistical support and assistance. We also thank C. P. Shea for valuable statistical analysis guidance. Bat monitoring equipment was provided by USDA's National Wildlife Research Center. This work was funded by the United States Department of Defense's Strategic Environmental Research and Development Program (grant number RC‐2432).
Publisher Copyright:
© 2022 The Wildlife Society. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
PY - 2022
Y1 - 2022
N2 - Habitat loss and non-native species are 2 of the most important factors that influence native species persistence and behaviors globally. The insectivorous Hawaiian hoary bat (Lasiurus semotus) is the only extant terrestrial mammal native to the Hawaiian Islands. Non-native invasive insectivore species, which are potential competitors of bats for prey, may influence hoary bat behavior. The goal of this study was to determine how small-scale suppression of invasive insectivores (rodents, ants, and yellowjacket wasps [Vespula pensylvanica]) influenced bat activity in grasslands and woodlands. We measured bat activity as a function of the number of distinct minutes in a night containing bat echolocations (bat call minutes) at 20 experimental plots (each 2.25 ha) in a dryland ecosystem on Hawaiʻi Island, November 2016–January 2018. We included 3 predictor variables: vegetation type (woodland, grassland), season (bat reproductive cycle periods: lactation, mating, pre-pregnancy, and pregnancy), and insectivore treatment type (ant suppressed, yellowjacket wasp suppressed, rodent suppressed, combined ant+wasp+rodent suppressed, and no treatment). Bat activity was associated with all 3 predictors using a negative binomial generalized linear model. Bat call minutes and feeding buzzes were twice as high in woodlands than in the grasslands (2.4 and 2.3 times as high, respectively). Bat activity was slightly lower (0.47 bat call min/night fewer) in plots receiving the combined ant + wasp + rodent treatment compared to all other treatment plots. Feeding buzzes did not differ significantly among treatments. Mean activity was lowest during lactation (mid-Jun–Aug). Although woodlands appear particularly important for the Hawaiian hoary bat, small-scale bat activity and foraging do not appear to be strongly affected by resource competition with the invasive insectivores in this study.
AB - Habitat loss and non-native species are 2 of the most important factors that influence native species persistence and behaviors globally. The insectivorous Hawaiian hoary bat (Lasiurus semotus) is the only extant terrestrial mammal native to the Hawaiian Islands. Non-native invasive insectivore species, which are potential competitors of bats for prey, may influence hoary bat behavior. The goal of this study was to determine how small-scale suppression of invasive insectivores (rodents, ants, and yellowjacket wasps [Vespula pensylvanica]) influenced bat activity in grasslands and woodlands. We measured bat activity as a function of the number of distinct minutes in a night containing bat echolocations (bat call minutes) at 20 experimental plots (each 2.25 ha) in a dryland ecosystem on Hawaiʻi Island, November 2016–January 2018. We included 3 predictor variables: vegetation type (woodland, grassland), season (bat reproductive cycle periods: lactation, mating, pre-pregnancy, and pregnancy), and insectivore treatment type (ant suppressed, yellowjacket wasp suppressed, rodent suppressed, combined ant+wasp+rodent suppressed, and no treatment). Bat activity was associated with all 3 predictors using a negative binomial generalized linear model. Bat call minutes and feeding buzzes were twice as high in woodlands than in the grasslands (2.4 and 2.3 times as high, respectively). Bat activity was slightly lower (0.47 bat call min/night fewer) in plots receiving the combined ant + wasp + rodent treatment compared to all other treatment plots. Feeding buzzes did not differ significantly among treatments. Mean activity was lowest during lactation (mid-Jun–Aug). Although woodlands appear particularly important for the Hawaiian hoary bat, small-scale bat activity and foraging do not appear to be strongly affected by resource competition with the invasive insectivores in this study.
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U2 - 10.1002/jwmg.22164
DO - 10.1002/jwmg.22164
M3 - Article
AN - SCOPUS:85122396219
SN - 0022-541X
JO - Journal of Wildlife Management
JF - Journal of Wildlife Management
ER -