Climate change is having widespread impacts on bird populations around the world. Rising temperatures, changing precipitation patterns, more extreme weather events, habitat loss and shifting ranges of prey and predators are all contributing to declines in many bird species. But which birds are being most severely impacted by climate change? In this article, we will examine the major effects of climate change on birds and look at which species are most vulnerable based on their geographic ranges, habitat requirements, and other ecological factors.
Major climate change impacts on birds
Climate change is affecting birds in a variety of ways:
- Rising temperatures – Higher temperatures cause heat stress, alter habitat ranges, affect timing of migration and breeding, and allow disease vectors to expand their ranges.
- Changing precipitation – Alterations in rainfall patterns can reduce water availability and cause drought, affecting wetland habitats.
- Extreme weather – More frequent and severe storms, floods, and other extreme weather can directly kill birds and destroy nesting habitats.
- Habitat shifts – As climate conditions change, habitat ranges shift, forcing birds to move to try to find suitable breeding and foraging areas.
- Prey/predator disruptions – Changes in timing and availability of food sources and alterations in predator-prey dynamics affect reproductive success and survival.
- Sea level rise – Coastal habitat loss due to rising sea levels negatively impacts shorebirds, seabirds, and other coastal species.
These climate-related stressors are causing population declines in many bird species around the world. But some types of birds are more vulnerable than others.
Vulnerability factors
Certain traits and characteristics make some birds more susceptible to the impacts of climate change:
- Narrow geographic range – Birds limited to small habitats or regions have limited ability to shift their range.
- Specialized habitat needs – Birds dependent on rare or threatened habitats like rainforest, wetlands, and tundra are highly vulnerable if those habitats decline.
- Limited mobility – Birds unable to migrate long distances to find more suitable habitat are more at risk.
- Small population size – Species with small populations are more prone to extinction from climate impacts.
- Dependence on environmental cues – Birds that rely on specific environmental signals for migration, breeding, etc. may be affected by changing climate patterns.
- Narrow ecological niche – Specialist species with limited, inflexible diets are less able to adapt to disruptions than generalist species.
Birds that meet several of these criteria face amplified risk from climate change compared to more flexible, wide-ranging generalist species.
Most vulnerable bird groups
Looking at which birds possess many of these vulnerability characteristics, the groups predicted to be most severely affected by climate change include:
Seabirds
Many seabird species, like albatrosses, petrels, frigatebirds, tropicbirds, puffins, murrelets and auklets, face extreme climate vulnerability. They are constrained to nesting on small islands and remote cliffs, they have very specialized diets, they are top oceanic predators, and they may have to travel great distances between breeding and foraging grounds. Climate change is disrupting migration and feeding patterns, allowing invasive predators onto nesting islands as sea ice recedes, and drowning nesting sites with rising seas. Globally, seabird populations have already declined 70% since the mid-20th century.
Arctic birds
The Arctic is warming at over twice the global average rate, causing drastic changes across northern ecosystems. Tundra-nesting shorebirds and waterfowl, like plovers, stilts, yellowlegs, ducks and geese, are seeing warming destroy nesting habitat. As tree and shrub cover expands northward, open tundra is lost. Migratory patterns are shifting as warming alters food availability. Small sea ice-dependent species like the ivory gull are also at high risk.
Alpine species
Birds specialized for alpine habitats, like ptarmigan, dotterel, mountain plover, snow finch, and rosy finch, are highly climate-endangered. Warming is shrinking their limited mountaintop habitats, introducing new competitors from lower elevations, and disrupting finely-tuned adaptations to short breeding seasons. Range contractions have already been observed in multiple alpine bird populations.
Grassland birds
Grassland specialists, like meadowlarks, savannah sparrows, bobolinks, Eastern meadowlarks, and grasshopper sparrows, rely on large open grasslands. Climate shifts are projected to increase tree cover and expand shrubs in grassland areas. Increased drought may also degrade grassland habitat quality. With little other habitat available, grassland bird populations could collapse.
Desert and dryland species
Birds adapted to deserts and drylands, including roadrunners, sparrows, nightjars, pigeons, and owls, face worsening drought, heat stress and water scarcity from climate change. Expanding human water use in dry areas to support agriculture and development adds further pressure. Birds reliant on scarce oases and springs in deserts are especially climate-endangered.
Wetland birds
Wetland birds have experienced some of the steepest population declines, as changing weather patterns, drought, sea level rise, and human water extraction shrink wetland habitats. Egrets, herons, spoonbills, bitterns, grebes, and rails are among the wetland species facing deterioration of critical breeding and foraging sites. Shorebirds relying on sensitive coastal wetlands also face severe threats.
Forest birds
Forest birds in nearly every forest habitat, from boreal to tropical, are experiencing rising risks from climate change. Hotter droughts are increasing wildfires and insect pest outbreaks, reducing forest cover and quality. Range shifts are occurring, as species move to try to track suitable climate conditions and forests. Fragmentation limits migration options for some species. Birds dependent on very specific forest microclimates are the most vulnerable.
Island birds
Island species make up nearly 20% of known bird extinctions since 1500 AD. With sea level rise submerging small islands and warmer temperatures aiding the spread of invasive predators like rats and snakes, more island birds face extinction risk from climate change. Endemics with tiny population sizes, like the Tuamotu kingfisher and Mariana crow, are especially endangered.
Most threatened individual species
The specific bird species considered at greatest risk from climate change include:
Species | Threats |
---|---|
Black-footed albatross | Drought, habitat loss, changing ocean food webs |
Spotted owl | Habitat loss from fire and pests |
Piping plover | Sea level rise, storm surge, beach erosion |
Whooping crane | Drought, water diversion, habitat degradation |
Emperor penguin | Sea ice loss, Antarctic warming, krill declines |
Spoon-billed sandpiper | Coastal wetland loss, shifting migration patterns |
Golden-winged warbler | Loss of breeding habitat |
Tuamotu kingfisher | Sea level rise, predation on low-lying islands |
These species already under threat are projected to experience further declines from climate change impacts in coming decades if greenhouse gas emissions are not curtailed and habitat protections implemented.
Conclusion
Climate change poses serious risks for bird populations across habitats, but seabirds, Arctic birds, alpine species, island birds, and other specialized groups are expected to be most severely impacted. All possible protections must be enacted to preserve plummeting bird numbers, including reducing further climate change by transitioning global energy systems away from fossil fuels, expanding habitat conservation areas, and managing ecosystems to build resilience. With diligent effort, the most endangered bird species can be pulled back from the brink of extinction. But action is urgently needed before losing these iconic species forever.