Yellow - billed Cuckoo
Methods
Because we are attempting to examine the entire state of Arizona, it is not
possible to survey every patch of potentially suitable Yellow-billed Cuckoo
habitat. To overcome this obstacle we reviewed historical accounts of
Yellow-billed Cuckoos within Arizona and based much of our survey site selection
upon these records. Additional sites have been selected where sufficient habitat
exists, and where it appears suitable for Yellow-billed Cuckoo occupancy. We
have equally subdivided the state, with the Arizona Game and Fish Department (AGFD)
surveying the southern half and the USGS Colorado Plateau Field Station (CPFS)
surveying the northern half for Yellow-billed Cuckoos. The USGS Tucson Sonoran
Desert field Station (SDFS) randomly selected bird locations, and intensively
measured vegetation variables in order to predict if the bird is selecting
specific vegetation types throughout Arizona. All personnel involved in this
project participate in survey techniques training. This 3-day event occurs in
June and is jointly sponsored by the
Kern River Research Center (Weldon, California),
AGFD and
CPFS.
The survey methodology used in this project has been modified from the
foundation work of
Halterman (1991)
and Laymon (1998, unpublished). We have developed a
Survey Data Form that has been standardize for all surveys in California and
Arizona.
Survey Methods:
1) the surveyor uses playback of a taped recording of the paired
yellow-billed cuckoo’s contact call ("kowlp" call, see "the bird" section of
this site for a sample of this call). Playback equipment must be capable of
projecting the "kowlp" call at least 100 meters with a minimum of distortion.
2) Surveys are conducted between the hours of 6:00 AM and noon. Surveys are
terminated if shade temperatures exceed 100 degrees
F (38 degrees C) or during steady rainfall.
3) One transect is made through the habitat for every 200 meters of habitat
width.
4) The surveyor initially approaches the beginning of the transect and
remains quiet for a 2-minute period to acclimate to the ambient noise and to
listen for spontaneously-calling cuckoos.
5) If no cuckoos are heard then the surveyor plays the "kowlp" call once,
followed by one minute of silence to listen for response. If no detection
occur, this playback-listen technique is repeated an additional four times.
The surveyor then moves 100 meters along the transect and begins the
listen-playback-listen protocol again.
6) Responses to the playback of the "kowlp" call will generally take one of
three forms. A bird may respond from a distance with a vocalization, it may
fly in quietly and vocalize closer to the observer, or it may fly in quietly
without vocalizing. The interpretation of these behaviors forms the basis for
determining breeding status.
7) In addition to documenting cuckoo detection's and behaviors, surveyors
collect information about habitat composition and structure, and also record
other bird species detected during the survey.
Utilizing the above methodology and
survey form, during 1998 a total of 77 sites were surveyed by the Arizona
Game and Fish Department (AGFD),
Colorado Plateau Field Station (CPFS)
and cooperators. AGFD,
CPFS and our cooperators
will visit at least 107 sites in 1999, including repeat visits to several of
the more productive sites from 1998. Each site will again be visited once
during the survey season (June 15-August 30). However, for validation
purposes, a subset (approximately 15%) of the sites will be surveyed an
additional 2 times, for a total of 3 surveys, with each visit separated by a
minimum of 10 days. This will allow us to test the relative effectiveness of
the single-survey protocol verses the standard 3-time survey suggested by
Halterman and Laymon (pers. com.).
Click Here for a
List of Survey Sites.
Survey techniques, data collection and analysis, and data archiving for this
project have been standardized so that everyone collects the same information
and can access each other’s data. In addition,
Data Summaries are provided
for public access within this web site. These summaries will be updated
bi-weekly throughout the 1999 Yellow-billed Cuckoo survey season.
View The
Survey Data Form used by Researchers | 
