The study of animal behavior in the wild requires the ability to locate and observe animals with the minimum disturbance to their natural behavior. This can be challenging for animals that avoid humans, are difficult to detect, or range widely between sightings. Global Positioning System (GPS) collars provide one solution but limited battery life, and the disturbance to the animal caused by capture and collaring can make this impractical in many applications. Wild wolves Canis lupus are an example of a species that is difficult to study in the wild, yet are of considerable conservation and management importance. This manuscript presents a system for accurately locating wolves using differences in the time of arrival of howl vocalizations at multiple recorders (multilateration), synchronized via GPS. This system has been deployed in Yellowstone National Park for two years and has recorded over 1200 instances of howling behavior. As most instances of howling occur at night, or when human observers are not physically present, the system provides location information that would otherwise be unavailable to researchers. The location of a vocalizing animal can, under some circumstances, be determined to within an error of approximately 20 m and at ranges up to 7 km. V
The chick-a-dee call of chickadee species (genus Poecile) has been the focus of much research. A great deal is known about the structural complexity and the meaning of variation in notes making up calls in these species. However, little is known about the likely homologous "chick-a-dee" call of the closely related tufted titmouse, Baeolophus bicolor. Tufted titmice are a prime candidate for comparative analyses of the call, because their vocal and social systems share many characteristics with those of chickadees. To address the paucity of data on the structure of chick-a-dee calls of tufted titmice, we recorded birds in field and aviary settings. Four main note types were identified in the call: Z, A, D(h), and D notes. Several acoustic parameters of each note type were measured, and statistical analyses revealed that the note types are acoustically distinct from one another. Furthermore, note types vary in the extent of individual distinctiveness reflected in their acoustic parameters. This first step towards understanding the chick-a-dee call of tufted titmice indicates that the call is comparable in structure and complexity to the calls of chickadees.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.