Ultrasonic vocalizations of Humboldt’s flying squirrel (Glaucomys oregonensis)

Authors

Travis A. Farwell, Department of Wildlife, Cal Poly Humboldt, 1 Harpst Street, Arcata, CA 95521Follow
Corinne A. Diggins, Science Applications, U.S. Fish and Wildlife Service, Albuquerque, NM 87110Follow
Barbara Clucas, Department of Wildlife, Cal Poly Humboldt, 1 Harpst Street, Arcata, CA 95521Follow

Abstract

North American flying squirrels (Glaucomys spp.) are known to produce sonic and ultrasonic vocalizations. However, the recent designation in 2017 of a cryptic third species of Glaucomys, Humboldt’s flying squirrel (G. oregonensis), requires the classification of the vocal repertoire of this newly described species. We recorded Humboldt’s flying squirrels at 22 field sites in California and Oregon between 2018 and 2021. We recorded 3391 calls of 7 call types produced by wild Humboldt’s flying squirrels: arc trills, trills, chirps, arc chirps, 3-toned chirps, upsweeps, and downsweeps. Humboldt’s flying squirrels emit calls with fundamental frequencies between 7.2 and 56.6 kHz. Except for the 3-toned chirp, these call types are also produced by northern (G. sabrinus) and southern flying squirrels (G. volans), demonstrating overlap in vocal repertoires of all 3 species. Also, like northern and southern flying squirrels, Humboldt’s flying squirrels produced multiple call types within a call bout and displayed evidence of frequency alteration (i.e., modification of a squirrel’s call when it calls simultaneously with another squirrel). Future research on quantifying inter- and intraspecific variation in vocal repertoires of all 3 species of North American flying squirrels, as well as work on behaviors associated with specific call types, is needed to fully understand the evolutionary history, species variation, and function of North American flying squirrel vocal communication.


Se sabe que las ardillas voladoras norteamericanas (Glaucomys spp.) producen vocalizaciones sonicas y ultrasonicas. Sin embargo, la reciente designacion en 2017 de una tercera especie criptica de Glaucomys, la ardilla voladora de Humboldt (G. oregonensis), requiere la clasificacion del repertorio vocal de esta especie recientemente descrita. Registramos ardillas voladoras de Humboldt en 22 sitios de campo en California y Oregon entre 2018 y 2021. Grabamos 3391 llamadas de siete tipos producidas por ardillas voladoras de Humboldt: trinos, trinos de arco, chirridos, chirridos de arco, chirridos de tres tonos, barridos ascendentes y descendentes. Las ardillas voladoras de Humboldt emiten llamadas con frecuencias basicas entre 7.2 y 56.6 kHz. Las ardillas voladoras del norte (G. sabrinus) y del sur (G. volans) Tambien producen estos tipos de llamada, con la excepcion del chirrido de tres tonos, lo que demuestra una superposicion en los repertorios vocales de las tres especies. Tambien, de manera similar con las ardillas voladoras del norte y del sur, las ardillas voladoras de Humboldt produjeron multiples tipos de llamadas dentro de un mismo episodio y mostraron evidencia de alteracion de la frecuencia (es decir, modificacion de la llamada de una ardilla cuando llamaba simultaneamente con otra ardilla). Proyectos futuros que cuantifiquen la variacion inter e intraespecifica en los repertorios vocales de las tres especies de ardillas voladoras norteamericanas y analicen los comportamientos asociados con los tipos de llamadas especificos, podrian ayudar a comprender completamente la historia evolutiva, la variacion y la funcion de la comunicacion vocal en la ardilla voladora norteamericana.

Recommended Citation

Farwell, Travis A.; Diggins, Corinne A.; and Clucas, Barbara (2024) "Ultrasonic vocalizations of Humboldt’s flying squirrel (Glaucomys oregonensis)," Western North American Naturalist: Vol. 84: No. 1, Article 5.
Available at: https://scholarsarchive.byu.edu/wnan/vol84/iss1/5