PACN Monitoring Landbird

Judge, Seth

The Pacific Island Network developed a protocol for long term monitoring of the landbirds in the network. Questions and objectives addressed by the protocol. are: 1. Determine long-term trends in species composition, distribution and density of native and non-native forest landbird species in PACN parks – HALE, HAVO, and NPSA units Tutuila and Tau. Objective 1: Determine long-term trends in species composition, distribution and density of landbird species. Species composition: the sampling objective of the PACN Landbirds Protocol is an 80% probability of detecting a 25% change in species composition (species richness) over a 25-year period, with a Type I error rate of 20%. Distribution: the sampling objective of the PACN Landbirds Protocol is an 80% probability of detecting a 25% change in species’ distribution over a 25-year period, with a Type I error rate of 20%. Density: 1) for all non-threatened native and most non-native landbird species the sampling objective of the PACN Landbirds Protocol is an 80% probability of detecting a 25% change in species’ density over a 25-year period, with a Type I error rate of 20%, 2) for birds of special interest, including threatened and endangered species, and species of concern, the sampling objective of the PACN Landbirds Protocol is an 80% probability of detecting a 50% change in species’ density over a 25-year period, with a Type I error rate of 20%. Justification: Tracking population distribution and density provides fundamental information for monitoring patterns of population change. These data from species with relatively low extinction risk can be used to describe trends from vital sign taxa that are expected to readily respond to environmental changes. For example, while it is difficult to distinguish the component effects of limiting factors on native bird distribution and numbers, the observed pattern in Hawaii has been a retreat to cooler elevations, primarily in response to uphill spread of disease and disease vectors (mosquitoes), likely a consequence of global warming. The existing long-term datasets at HALE and HAVO gives these parks a head start toward meeting this objective and continued monitoring will strengthen the results.2. Monitor changes in species composition and density of native and non-native forest landbird species relative to management activities in PACN parks – HALE, HAVO, and NPSA units Tutuila and Tau. Objective 2: Monitor the changes in species composition and density of native and non-native forest passerine species relative to management actions corresponding to forest restoration (i.e., alien plant and animal control) and reforestation. Species composition: the sampling objective of the PACN Landbirds Protocol is an 80% probability of detecting a 50% change in species composition (species richness) over a 25-year period, with a Type I error rate of 20%. Density: the sampling objective of the PACN Landbirds Protocol is an 80% probability of detecting a 50% change in species’ density over a 25-year period, with a Type I error rate of 20%. Justification: The restoration and recovery of ecosystems in the parks could have a strong positive effect on native bird species. Understanding and predicting how management actions relate to bird abundance and species composition is useful for evaluating management activities and identifying further conservation actions. Monitoring for this objective will be co-located with vegetation monitoring, although co-visitation may not be coincident. This second objective is included in the monitoring protocol specifically to address management concerns. In general, birds respond to changes in habitat and stressors; therefore, they are good indicators of management’s efficacy. Results of landbird monitoring will be provided to park biologists through the reporting process, allowing managers to make informed management decisions.

PACN Monitoring Landbird

Program

Products

Collections