What is the MAPS Program?
The Monitoring Avian Productivity and Survivorship (MAPS) Program is a continent-wide collaborative effort among public agencies, non-governmental groups, and individuals to assist the conservation of birds and their habitats through demographic monitoring. Since 1989, more than 1,200 MAPS stations spread across nearly every state and Canadian province have collected more than 2 million bird capture records. MAPS data provide insights into important questions such as:
- What factors drive avian population declines?
- Where are problems most acute, on the breeding or non-breeding grounds?
- What drives differences in population trends between particular regions or habitats?
- What is the relationship between population change and weather, climate, or habitat loss?
- What can we do to reverse declines?
Most avian monitoring programs in effect today count or estimate numbers of birds to track changes in population size. Estimates of population trend are useful but limited in their capacity to reveal underlying causes of the trends. Demographic monitoring provides inferences about the life-stages of birds that may be most important in limiting population growth.
Why is MAPS Important?
Examining key demographic parameters -- often called vital rates -- especially productivity, recruitment, and survival, can enhance the effectiveness of conservation efforts. Determining the vital rates that drive population change is important for conservation because management can then
- be directed at the life-cycle stage that actually limits the population
- be based on true indicators of habitat quality
- identify sources and sink populations
- avoid ecological traps
How Does MAPS Work?
MAPS uses a standardized, constant-effort protocol with a system of fine mesh nets to capture birds during the summer nesting season. MAPS stations are usually comprised of ten nets operated at fixed locations within a 20 hectare area. Stations are run by independent banders; state, federal or U.S. government personnel; or by IBP under contract. MAPS operators band the birds and collect information on their age, sex, body condition, and reproductive status. Captured birds are given a lightweight, numbered aluminum leg band and released unharmed. Subsequent recapture data provide information on survival, reproductive rates, and sometimes, movement patterns.
What have we learned from MAPS to date?
IBP and our collaborators have published more than 100 peer-reviewed papers and hundreds of reports on the vital rates of landbirds, and their relationships to climate, habitat, land management actions and other environmental variables. Some of the most important findings are that:
- Survival of adult and first year birds is often as or more important than productivity in driving population declines. This highlights the importance of wintering grounds and migration routes.
- Conditions on wintering grounds and migration routes affect the survival rates and can affect their reproductive output the following summer. This is known as “carry-over effect.”
- Weather, especially the amount and timing of precipitation, and the interaction of weather and habitat, greatly affect vital rates. Considerations of climate are crucial for conservation efforts.
New Directions and Developing Research
Methodological innovations are continually improving the ways in which MAPS data can be analyzed and used to make inferences about demographic parameters. IBP and collaborators at the US Geological Survey are currently developing integrated population models that allow MAPS data to be formally combined with point count data from the North American Breeding Bird Survey (BBS). These models will improve estimates of avian vital rates and population change at a variety of spatial scales and provide a robust framework for making inferences about links between vital rates, population change, and environmental conditions.
The importance of full annual-cycle conservation - protecting birds on migration and wintering sites as well as breeding areas – is increasingly recognized. Recent advances in rapid, inexpensive DNA sequencing, some of it using feathers collected at MAPS stations, have yielded great progress in linking breeding, migration, and wintering locales of particular bird populations.
Another advance has been in miniaturized GPS units, which can gather location information over the course of a year and indicate to within a few meters where a bird has been. New units weigh about a gram and can be used on birds as small as thrushes. These techniques and others can help researchers get a more complete picture of bird annual cycles, critical areas, and linkages between nesting, migrating, and wintering sites. The MAPS network can provide a spatially extensive platform for implementing such techniques.
A sister program to MAPS, MoSI, works with Latin American researchers to study Neotropical migrant and resident birds on their wintering grounds in the Neotropics to help complete the picture of migratory birds’ annual-cycle dynamics.
