Studying animal bioacoustics and unraveling the meaning of calls doesn't come as first nature to us. We are primarily visual animals and as such perceive our world, first and foremost, in terms of what we see around us. Many other species utilize other senses much more readily. If we are to truly understand the sensory ecology of another species we really need to imagine ourselves in their world.

Hearing and recording specific vocalizations is just the beginning; we must also take note of other related behaviors to understand a call's behavioral context. Often such associations are relatively easy to understand, such as the production of an alarm call in response to seeing a predator. However, vocalizations can also occur in relation to complex social situations revealing not only the caller's behavioral state but also how other group members are affected by it. In learning to listen, we can begin to understand the day-to-day lives of each species in the Zoological Society of San Diego's collection "“ how active they are, how they interact socially, and what makes them successful reproductively.

To date, we have been using such techniques to understand the role of calls in the development of territoriality and lifelong monogamous bonds in Gabriella's crested gibbons (see blog, Singing in the Rain), early development of mother-infant bonds in African elephants (see blog, How Do You Weigh an Elephant?), and male mating vocalizations in cheetahs (see blog, Cheetah Dictionary). All of these bioacoustic studies examine a species' entire vocal repertoire, including how the animal uses its vocal tract to form the sounds. Delving into this world of sound has also revealed that many animals produce additional sounds for communication without having to use of their vocal cords. For example, the chimpanzees of Ebo forest in Cameroon (see blog, Sounds from Cameroon's Ebo Forest) use branches to beat out rhythms on tree buttresses, and lowland mountain gorillas beat on their chests to communicate in a similar manner.

Recently, we have begun studying another African species, the shoebill stork (in collaboration with Michael Mace and the Wild Animal Park's Bird Department), primarily because of its unusual approach to attracting potential mates. Both male and female shoebills have an almost prehistoric appearance with a stocky body, large gray feathers, and an enormous shoe-like hooked bill. They communicate by clapping or "clattering' their large bills together in rapid succession. Typically, shoebill pairs will duet in this manner with the male beginning his song with a bout of clattering, which is often followed by very distinctive head waving, bowing, and, finally, a soft, high-pitched moan. In turn, the female will return his call by clattering her bill and mirroring his behavior. It is thought that such duetting is a prerequisite to monogamous bonding and ultimately breeding. It is hoped that through continuous observation and recording of shoebill behavior we will be able to build upon previous work with this species undertaken by a previous Summer Fellow at CRES (see blog, Shoebill Chatter), understand more about their social dynamics, and ultimately aid breeding success. Our shoebills can be seen (and heard) bill clattering at the Mombasa Lagoon at the Wild Animal Park.

Listen to a male shoebill's clatter

Matt Anderson is a scientist in the Behavioral Biology Division/CRES.

Posted in Conservation, Default, General | Link to this post

You can follow any responses to this entry through the RSS 2.0 feed. Scroll to the end to leave a comment. Pinging is not allowed.