General Protocol: Forest Bird Recordings

Learning bird vocalizations

Before you conduct your first visit, you should be confident of your ability to identify the songs, calls, and other sounds of the species you have chosen to study. Your kit includes a CD, enabling you to learn the vocalizations of the birds you are likely to encounter. The species on the CD are catagorized by region and habitat type. The number by the species represents the track number on the CD. This will enable you to easily find your chosen species when playing the CD in the field. The 2001 BFL CD has only a single one-minute track for each species. It contains songs, calls, and/or sounds of each individual species all combined into this 1-minute track. The tracks are not separated out by song and call as on the past BFL CD.

Playback use and responses

• During the Playback Period, do not play the CD for more than the prescribed time (two one-minute segments for playback or five minutes for the mobbing call). The protocol must be standardized, and it is important not to stress territorial birds.

• Please make sure you are playing the vocalizations of the correct species at the appropriate time.

• Record on your Field Form whether you see and/or hear a study species and if you used recorded playback (see form for exact questions).

Forest birds can have varying responses to recordings of their vocalizations. In addition, be aware that another bird that is not a study species may respond to playbacks of the one you are surveying—look closely at any birds that appear. Note that responses can be immediate or somewhat delayed, so try to be alert during the entire period.

Some forest dwellers will fly in silently and behave cautiously when their vocalization is played, so be sure to watch and listen carefully. The birds may respond vocally from a hidden perch. They may be quite vocal, either singing or calling, and appear rather irritated. Realize that the recordings may be perceived as a threat to a territorial male. Some birds, such as thrushes, have an interesting behavior of sometimes “whispering” their song, apparently to make it seem as though they are farther away. They may investigate the source of the vocalization by making a quick, close pass, progressively moving closer, or perhaps flying in directly. Following playbacks, many birds will move around a study point, investigate the speaker from numerous angles, and stay in the area for a while. Many of the study species’ behaviors in reaction to conspecific playback have not been well documented.

In particular, we need your help to discover if our study species’ behaviors in response to the mobbing sequences on the CD are a better indicator of breeding success than simply searching for nests and fledglings. We hope to standardize the effort time while getting the best idea of the breeding status of each individual species by observing and recording behavior. By eliciting a response to the mobbing, we hope you will observe behaviors that you might not regularly see if you only played the species’ own vocalizations or sounds. The birds might appear agitated in response to the mobbing calls, but we feel that this five-minute mobbing sequence will be less invasive than searching the forest for nests.