Demographic Monitoring

Since 1994,The Institute for Bird Populations (IBP) has monitored the demographics of 50+ landbird species, including a subset of USFWS-listed Bird of Conservation Concern. The results of various analyses are given in a series of reports and visualizations (link to location page). There are many justifications (PDF) for implementing demographic landbird monitoring as a conservation tool, especially in the context of land management (NABCI Monitoring Subcommittee. 2007), whereby landscape models and demographic performance measures can inform the conservation effort.

Numerous demographic parameters are calculable from constant-effort bird banding data such as that collected by MAPS. The two major "vital rate" parameters are typically presented for clusters of stations, and at regional or continental scales.

• Apparent Survival Rate - the probability of an individual bird returning the site the next year. Network-wide survival rates were estimable for 32 species (Powerpoint slide). A low survival rate may be indicative of poor quality habitat or environmental stresses causing high non-breeding season mortality.
• Reproductive Index - typically expressed as the ratio of hatch-year to after-hatch-year (#young:#adults). This index should only be used within-species to compare relative magnitude among locations.

However, species- and station-specific parameters are required to model demographics as a function of landscape variables, models that can be used to define criteria for identifying "source populations" and the landscape characteristics of source habitat.

Last edited January 12, 2010

HOME   BACK