Impacts of Climate-Driven Changes in Spring Green-Up on Migratory Birds in Alaska
Impacts of Climate-Induced Changes in Plant Phenology on Migration, Breeding, and Redistribution of Sub Arctic- and Arctic- Nesting Avifauna
Dates
Start Date
2009
End Date
2011
Release Date
2009
Summary
Migratory birds are important for recreation and tourism, contributing to a vibrant birdwatching industry in Alaska. Every spring, hundreds of birds migrate to their summer breeding grounds in Alaska and northern Canada. Their arrival is timed with the height of the spring green-up of plants, which provide the food necessary for birds to reproduce and raise their young. However, over the last fifty years, warming temperatures in Alaska as a result of climate change have prompted an earlier transition from winter to spring. The purpose of this project was to examine whether there have been changes in the timing of spring green-up in recent years (1985-2009) and, if so, whether migratory birds are adapting their migration schedules accordingly. [...]
Summary
Migratory birds are important for recreation and tourism, contributing to a vibrant birdwatching industry in Alaska. Every spring, hundreds of birds migrate to their summer breeding grounds in Alaska and northern Canada. Their arrival is timed with the height of the spring green-up of plants, which provide the food necessary for birds to reproduce and raise their young. However, over the last fifty years, warming temperatures in Alaska as a result of climate change have prompted an earlier transition from winter to spring. The purpose of this project was to examine whether there have been changes in the timing of spring green-up in recent years (1985-2009) and, if so, whether migratory birds are adapting their migration schedules accordingly.
Researchers used historical satellite imagery and long-term records on bird migration and breeding from across Alaska to generate a series of maps and publications to answer these questions. They found that bird species ranged widely in their adaptation to earlier spring, with some doing better than others at timing their arrival with changing temperature. The researchers also used downscaled climate models to project how bird habitat will be affected by climate change through the 21st century. This information can be used by Alaska land managers to focus their conservation efforts on species or habitat areas that appear especially vulnerable.
Collaborators in this project included the University of Alaska; National Oceanic and Atmospheric Administration; U.S. Fish and Wildlife Service; National Park Service; Alaska Song Institute Fairbanks; North Slope Borough Department of Wildlife Management Barrow, Alaska; and U.S. National Forest Service.
NCCW-2009-13_Permafrost_ArcticCoast_USGS.jpg “Collapsed permafrost block of coastal tundra - Credit: USGS”
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NCCW-2009-13_White-FrontedGoose_USGS.jpg “White-fronted goose and goslings - Credit: USGS”
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Purpose
There is considerable evidence that global climate change has altered the start of spring vegetative growth or green-up and extended the growing season in plants at northern latitudes. What is not clear is whether migratory birds have adapted to these shifts in plant phenology by modifying the timing of migration and nesting. We examined whether long-term changes in phenology of spring vegetative green-up have occurred during the past 23-years in Alaska, and whether arctic and subarctic avian migrants have altered timing of migration or reproduction correspondingly. Failure to adapt to changes in plant phenology associated with climate change may put populations at risk because key northern wildlife events occur during periods of peak resource abundance. Our approach for this project was to assess historical and future changes in plant phenology relative to major climate drivers, and determine if the timing of spring green-up is synchronized across breeding areas or if the process has become fractured, potentially disrupting the timing of bird migration and breeding and putting species at risk. We used a time-series of normalized difference vegetation index (NDVI) composites developed from historical satellite imagery (1985-2009) to derive vegetation phenology metrics. These metrics were then related to long-term data records on bird migration and breeding taken across Alaska. Projections of how climate will affect habitats in the future were made by linking our mapped phenology metrics for the major habitats of Alaska with downscaled climate models. The objective was to generate publications and a series of maps of past (1985-2009) and future (2009-2099) variability in phenology across major habitats of Alaska. These maps are accompanied by a trend analysis that illustrates the effects of these trends on migratory bird behavior across biomes. Alaska land managers can use the maps and downscaled climate projections of habitat change to identify key habitats and natural resource units that may need special management actions because of projected vulnerability, rarity, or importance to wildlife. The project outputs can also be used to predict which species will be most vulnerable to climate-induced changes and to develop landscape-level plans to conserve their populations and habitats. Collaborators in this project are the University of Alaska; the National Oceanic and Atmospheric Administration; the US Fish and Wildlife Service; the National Park Service; the Alaska Bird Observatory Fairbanks; the North Slope Borough Department of Wildlife Management Barrow, Alaska; and the US National Forest Service.
Project Extension
projectStatus
Completed
Preview Image
Wetlands and low relief tundra of the Arctic Coastal Plain - Credit: USGS