Abstract
With bat populations declining in many parts of the world, detailed life history information will be critical for assessing vulnerabilities of bat populations and associated trophic effects. Myotis ciliolabrum (western small-footed bat) is a species of insectivorous bat distributed from the Great Plains to the Pacific Coast and from British Columbia to Central Mexico. The species is spottily distributed within this wider range but is locally abundant in areas containing appropriate rocky habitat. Despite M. ciliolabrum being relatively common, little information is available about its feeding ecology. Earlier studies have suggested that skull morphology can be used to determine whether insectivorous bats select for soft- or hard-bodied prey, but we hypothesized that M. ciliolabrum may feed opportunistically on a variety of insect types. To test this hypothesis, we examined the feeding habits of western small-footed bats captured during 2000–2022 at 6 national parks and 1 national conservation area across the Southwest. Visual analysis of prey remains in guano revealed that western small-footed bats within our study area consumed insects belonging to 7 orders (Lepidoptera, Coleoptera, Hymenoptera, Hemiptera, Neuroptera, Diptera, and Odonata) and 20 families. Diet varied over time and across geographic space, though we observed a general trend in which the orders Lepidoptera, Coleoptera, and Hymenoptera were consumed at the highest volumes. This varied diet indicates opportunistic feeding in which M. ciliolabrum makes use of locally abundant resources.
Dado que las poblaciones de murciélagos están disminuyendo en muchas partes del mundo, la información detallada sobre la historia de vida será fundamental para evaluar las vulnerabilidades de las poblaciones de murciélagos y los efectos tróficos asociados. Myotis ciliolabrum es una especie de murciélago insectívoro que se encuentra desde las Grandes Llanuras hasta la costa del Pacífico y desde British Columbia hasta el centro de México. La especie tiene una distribución irregular dentro de este rango, pero es abundante en áreas que contienen un hábitat rocoso apropiado. A pesar de ser relativamente común, hay poca información disponible sobre su ecología alimentaria. Estudios anteriores han sugerido que se podría usar la morfología del cráneo para determinar si murciélagos insectívoros seleccionan presas blandas o de cuerpo duro, pero planteamos la hipótesis de que M. ciliolabrum puede alimentarse de manera oportunista de una variedad de tipos de insectos. Para comprobar esta hipótesis, examinamos los hábitos alimentarios de M. ciliolabrum capturados entre 2000 y 2022 en seis parques nacionales y un área de conservación nacional en todo el suroeste. El análisis visual de los restos de presas en el guano reveló que, dentro de nuestra área de estudio, M. ciliolabrum consumió insectos pertenecientes a siete órdenes (Lepidoptera, Coleoptera, Hymenoptera, Hemiptera, Neuroptera, Diptera y Odonata) y 20 familias. La dieta varió a lo largo del tiempo y del espacio geográfico, aunque observamos una tendencia general en la que los órdenes Lepidoptera, Coleoptera e Hymenoptera se consumían en los volúmenes más altos. Esta dieta variada indica una alimentación oportunista, en la que M. ciliolabrum utiliza recursos locales abundantes.
Recommended Citation
Loehn, Ashley E.; Sparks, Dale W.; and Valdez, Ernest W.
(2024)
"Diet of Myotis ciliolabrum from six sites in the southwestern United States,"
Western North American Naturalist: Vol. 84:
No.
2, Article 5.
Available at:
https://scholarsarchive.byu.edu/wnan/vol84/iss2/5
Percent volume data for each prey type within each sampling group used for statistical analysis. Only the 4 sampling groups with sufficiently high sample sizes were included: CHACO 2000, MEVE 2007, ELMA 2000/2014. Prey volumes for ELMA 2000 and ELMA 2014 were not significantly different, so they were combined into one group for analysis.
84.2.5 Supplementary Material 2.pdf (3425 kB)
Output file for statistical analysis in R Studio 4.2.1 (2022.07.1 + 554). Statistical analysis was performed to determine whether differences existed between the mean volumes of prey types consumed in each sampling group. We determined that the assumptions for classical one-way ANOVA were not met and proceeded with a series of permutational ANOVAs followed by paired t tests to determine which groups were different.