Seabird Monitoring
on Santa Barbara Island
Channel Islands National Park
Cooperating organizations:
Point Reyes Bird Observatory
USGS-Biological Resources Division
Humboldt State University
| Taken from : SEABIRD MONITORING
HANDBOOK Lewis et al. 1988 Channel Islands National Park |
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| The purpose of the
Seabird Monitoring Protocol is to outline a methodology for monitoring selected
seabird species in Channel Islands National Park. The methods have been
derived from both long-standing studies of certain species and recent work
with other birds not monitored in the past. Consistent with Channel Islands
monitoring goals, the data will be used to detect changes in populations
over a period of time rather than to determine the cause of such changes.
To detect these changes, important parameters included in the seabird monitoring
program are: abundance of breeding birds, reproductive success, phenology,
and population age structure. All of these reflect important trends in population dynamics. The number of breeding birds may represent either reproductive effort or adult population size; changes in either category affect the total number of young recruited to the population. Reproductive success is measured by the number of fledged young, and is the most direct measure of the addition of young to the population. Chick survival can be affected by changes in phenology (timing of egg-laying, hatching and fledging). Age structure represents relative numbers of non-breeding juveniles and breeding-age adults in the population; changes in this parameter affect the number of breeding attempts and recruitment of young. When available, other parameters such as food use and chick growth rates are valuable to measure because they provide data for interpreting observed changes in a biologically meaningful way. Despite the benefits of a program containing the parameters outlined above, experience has shown that practical considerations often limit the number of parameters that can be effectively measured as well as the number of species monitored. For instance, the particular measurements taken for a given species may be limited by nesting habits, response to human intervention, experience of personnel, and time and monetary constraints. Similarly, of the eleven seabird species that nest in Channel Islands National Park, only six can reasonably be monitored; difficulties such as inaccessible nests, nocturnal behavior, and variable breeding sites preclude using the others. This handbook, then reflects a compromise between an ideal monitoring program and a practical one. |
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Data and reports from the Seabird Monitoring Program |
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| Seabird Monitoring Protocol Review, November, 2000 | ||||||||||||||||||||||||
| Contacts | ||||||||||||||||||||||||
