Importance/Issues

Landbirds are a conspicuous component of many ecosystems. They have high body temperatures, rapid metabolisms, and occupy high trophic levels. Because they can respond quickly to changes in resource conditions, landbirds are considered good indicators of ecosystem health. In other words, changes in landbird populations may indicate changes in the biotic or abiotic components of the environment upon which they depend. Relative to other vertebrates, landbirds are also highly detectable and can be efficiently surveyed with the use of numerous standardized methods.

Parks Monitored

All 11 Sonoran Desert Network parks.

Monitoring Objectives

Monitor density of the most common species, with the goal of detecting a 2% annual decline over a 30-year period, with an 80% probability and a Type I error rate of 10%.

Monitor relative abundance of many other species, with the goal of detecting a 3% annual decline over a 30-year period with an 80% probability and a Type I error rate of 10%.

Estimate the proportion of sites occupied for most species in most parks, with the goal of detecting a 1% annual decline over a 20-year period with an 80% probability and a Type I error rate of 10%.

Measure associated environmental features at bird-survey points, so as to relate changes in landbird population parameters to changes in the environment, such as vegetation structure and composition.

Potential Measures

Relative abundance and density of avian species by park, segregrated by riparian and upland sites.

Proportion of sites occupied by avian species per park.

Environmental features (subplots): canopy, mid-canopy, and herbaceous cover (%); horizontal vegetation density (%); topographic position, slope, and aspect.

Management Applications

Bird monitoring data can be used to ascertain the overall natural condition of SODN parks, and can provide insights into the potential consequences of stressors and current and proposed management actions.

Protocol Development Status

This protocol has completed two seasons of pilot testing and internal review. The protocol is currently in external review.

Status & Trends

Status data for 2007- 2008 are discussed in the corresponding annual SODN bird monitoring reports. Insufficient data has been collected to date for trend determination.

Project Lead

Robert Bennetts, Southern Plains Network Program Manager
Andy Hubbard, Network Program Manager