Ontogeny – how the behavior develops during an individual's lifetime

Before young bats can successfully hunt insects they must be able to produce high frequency calls and process the information contained in the echoes. They must also have mature respiratory organs that are capable of producing the calls. The vocal and auditory systems must develop and operate together for the bat to be able to echolocate. The vocal repertoire of an infant bat differs greatly from that of an adult [8]. It is common for young bats to practice flying a couple times in the home roost. The young bats vocalizations during these trial flights may be attempts at early obstacle avoidance by echolocation [8]. In a study conducted by Moss et al., it was found that bats as young as 4 days old emitted echolocation sounds during stimulated trial flight events. Once the bats were between 14-17 days of age, they began to modify the features of their echolocation sounds in a way similar to that of adult echolocation.

In captive bred bats, Buchler [2] found that flight and echolocation expertise occurred later than predicted by wild-caught bats, but rapidly together as expected. During the first few nights of flight, the young bats were already making echolocation chirps and testing out echolocation while landing. Differences between the young and adults disappeared within just two days of flight, indicating its rapid development. Some species of bats are able to fly out of the roost 14-18 days of age and begin to forage on their own.

There isn't much information out right now, but in a 2009 study, it was proven that complex vocalization can be learned through imitation for some bats [7].

fig4Figure 3: A picture of a little brown bat (Myotis lucifugus). This species is commonly used in research pertaining to the ontogeny of echolocation (Aaron Havens et al 2006).