Both climate change and global warming, have been a somewhat controversial topic, but the evidence is there that temperatures are rising, weather patterns are changing, and birds are being affected all over the world.
Climate change has accelerated to unprecedented levels due to the combustion of fossil fuels, the resulting release of carbon dioxide gas, and the heating of the globe due to a process known as the greenhouse effect.
So how exactly does climate change affect birds?
Climate change is affecting bird migration patterns and timing, shrinking the global distribution range of species and expanding the range of others. Some birds are adapting better than others, but pretty much all life on earth is likely to be affected.
Birds are highly mobile animals, which allows them to move to different areas as conditions change. Simply moving to greener pastures is not an option for many species, however, and mass extinctions are a distinct possibility if climate change is not tackled.
Now more than ever, the birds need our help. It is easy to feel despair because global problems seem too large to wrap our heads around, but the change starts with all of us, and there is a lot that we all can do!
Read along as we learn about how climate change is affecting where and how birds live. We’ll also go over a few easy tips on how you can do your part in reducing the effects of climate change on birds.
Flock of Pied Ostercatcher flying over estuary marsh at Waddensea UNESCO world heritage area
Each species of bird is specifically adapted to certain environmental conditions. The study of ecology teaches us that each species exists within environments that are shaped by various interconnected factors like climate, geology, altitude, and latitude.
These conditions determine the types of life that can call each part of our world home. Furthermore, the collection of species that live in an area interact with each other in complex ways, and birds are no exception.
Climate change can affect birds by direct physical mechanisms like covering breeding grounds in water. It can also throw entire ecosystems out of balance and affect birds indirectly. Climate change is forcing birds to adapt, move to new locations, or go extinct. Some species are more resilient and adaptable than others of course, but there is a limit to how much any bird species can change.
A pair of Adelie Penguins enjoying Antarctic sunshine
Climate change is affecting bird migration in many ways. The routes and timing of migratory birds have changed in many instances, and birds are also spending their winters and summers further north than before.
One study on 32 migratory songbirds in North America found that the average arrival date in the spring was 0.78 days earlier each year over the past 33 years. This trend correlates with the birds’ breeding grounds warming earlier each year.
Birds are not only arriving earlier, however, but they are also sticking around longer as the onset of winter is delayed.
The same climate changes that affect birds are affecting the plants and animals that they feed on. Important plant species can disappear from certain areas, or the timing of their nectar, fruit, and seed production can change.
Plants are flowering earlier as temperatures increase. This means the supply of insects is also peaking earlier. Some migratory birds time their migrations with weather systems, rather than with food availability.
Climate change has changed the way these two factors sync up, forcing some birds to undertake migrations without building up enough fat reserves to make the long journey south.
The Arctic Tern undergoes the most impressive migration each year
Most birds time their breeding to match the most favorable times of the year in terms of weather and food supply. Some birds are now adapting their breeding times in response to earlier warming in the spring.
Scientists from India analyzed 820,000 breeding observations from boreal birds, and their results show a marked advance in breeding times, as well as a contraction of the breeding period. This means birds are breeding earlier in the season, and the process is being limited to a shorter period.
Rising sea levels are another very real threat to breeding birds. Coastal birds like the gull-billed tern and sandwich tern in Florida are at increased risk of coastal erosion of breeding sites and even nest inundation by the 2030s.
This threat extends to oceanic islands too, of course, with species like laysan albatrosses and black-footed albatrosses that nest on low-elevation islands being at particular risk.
Sandwich Terns are at an increased risk of coastal erosion in Florida
Some of the worst affected bird species are probably those that inhabit high-altitude, mountainous areas. As temperatures rise, these birds are forced to rise higher up mountain slopes to remain in their preferred climatic zone. This pushes them into increasingly small areas, with both space and time running out.
No bird species have gone extinct yet as a direct result of climate change. The major historical causes of bird extinctions are overexploitation from hunting as well as habitat degradation, and loss due to urbanization, agriculture, and deforestation.
These threats continue today, but climate change is adding a new dimension to the problem, causing habitat change on a global level.
Two species of African birds will soon be extinct due to climate change according to current projections. The Ethiopian bush crow and the white-tailed swallow from Ethiopia, the ‘roof of Africa’, are projected to disappear within the next 50 years.
White-tailed Swallow (Hirundo megaensis)
All life on earth is being affected by climate change in one way or another. For some species, a warming climate brings great benefits, while for others it spells disaster. The changes happening on Earth are not felt equally in all areas and by all bird species.
The National Audubon Society has conducted an extensive study on over 600 North American bird species and found that just under two-thirds (64%) are vulnerable to extinction.
These are scary results indeed!
Certain groups of birds are predicted to be especially hard hit by climate change in North America. According to the National Audubon Society’s modeling, the most vulnerable birds include:
Close up of an Emperor Goose
Birds are adapting to climate change in many ways. These adaptations include range changes and behavioral and even physical changes. Unfortunately, not all species show the same resilience and flexibility.
Many species are moving further north where it is cooler, or in other cases, moving to higher altitudes. Simply moving to a new location is not always a good solution, however, because changes in vegetation and habitats take time.
Where birds have no choice, they must move into less than ideal areas but this puts them in competition with other species and leaves them with fewer resources and lower reproductive success.
Continue reading to learn how you can help birds in a changing climate.
Black-footed albatrosses are at risk due to them nesting on low-elevation islands
It’s easy to be overwhelmed by the scale of the environmental problems in the world today. The fact is that change starts with all citizens, and there is still a lot that we can do. Decreasing our reliance on fossil fuels is fundamental to halting climate change, but there are more direct ways that you can help birds too.
The best thing you can do for birds is to create suitable bird habitat in your own backyard or neighborhood. Plant native species that provide good nesting habitat, attract insects, and provide food sources in the form of fruits, berries, and seeds. If you have cats, keep them indoors, or at least put a bell on their collars to give our feathered friends a fair warning.
You can also get involved with local conservation initiatives in your area and educate your friends and family about the issues facing local birdlife.
Lesser Goldfinch sat amongst the flowers in the garden
Seagulls and other seabirds are not immune to the effects of climate change, but this phenomenon affects different species in different ways. Egg cannibalism is on the rise amongst glaucous-winged gulls in Puget sound, for example, while lesser black-backed gulls have benefited from increased food abundance in the North Sea.
Amazingly, studies are showing that birds are shrinking in response to climate change. Many species have shown a decrease in body size, which could be a way for the birds to stay cooler in a warming world. Their wing lengths are also increasing, which may be a way of compensating for a smaller and less muscular body.
Birds are adapting to climate change in some remarkable ways. Studies have shown that some birds are developing larger beaks, probably to assist in thermoregulation. Birds can cool their bodies using their bills because they are not insulated by feathers.
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