[This story appears as an on-going series in the "Gilroy Dispatch"]
Climate change and habitat loss are threats to birds November, 2014 By Amy Yee
The National Audubon Society recently published a scientific, in-depth, seven year study on the future of North American wildlife, focusing on birds. Audubon's conclusion? Due to climate change and habitat loss, nearly half of North American bird species will be seriously threatened by the year 2080. While some of these birds may be able to survive by shifting their ranges; i.e., moving to a new location, many of them are unlikely to be able to do so and may face extinction. These severely "climate-endangered" birds include many familiar local species: for example, the bald eagle, golden eagle, brown pelican, Allen's hummingbird, and burrowing owl.
Why are birds important, and why does studying them make sense? Aside from their beauty and role in the ecosystem, birds are literally the canaries in the coal mine. Early coal miners would bring a caged canary, a bird that is very sensitive to deadly gases, into the mine. As long as the bird kept singing, the miners knew their air supply was safe. A dead canary was a sign that they should evacuate immediately. Like coal miners who may not realize they are breathing deadly gas until it is too late, it is difficult for humans to see the effects of climate change and habitat loss on a daily or weekly basis. Studying birds over the decades tells us what is going on in our environment.
Let's back up for a moment. What do birds need to survive? They need appropriate habitat; i.e., the natural environment in which a species lives, which provides food, water, and territory in which to live and breed. Birds are uniquely adapted to their surroundings, including temperature, precipitation and changing seasons, and different species have adapted over thousands of years to different types of habitat. If a bird's habitat changes so that either food, water or territory are lacking, the bird must either adapt to the change by shifting its needs, which is unlikely, or relocate, assuming there is an appropriate alternative habitat.
Climate change is largely caused by increasing levels of carbon emissions, which warm the earth's atmosphere. The earth is expected to warm by 3 to 7 degrees Fahrenheit by the end of the century. It doesn't sound like much, but it will have a profound effect on rainfall amounts, humidity, snow levels, etc., and consequently on avian life. For example, the U.S. wildfire season lasts two months longer now than it did 40 years ago. Polar ice is melting at a rapid rate, threatening not only polar bears but also birds that live and nest on the ice and eat the sea life underneath. Melting ice opens shipping lanes, raising the threat of pollution or oil spills. In our own area, we are in the midst of the driest year on record and many of our reservoirs are dry.
Due to changing environmental conditions, bird species are already on the move. Nearly 60% are spending the winters an average of 35 miles north of their historic winter ranges. In some parts of the world, the earth's warming is pushing birds to cooler, higher elevations. In New Guinea, a recent Cornell Lab of Ornithology study found that, by comparing data from a study done 50 years ago with current data, warming temperatures have caused 70% of native birds to move upslope by 400 feet or more. In some cases, birds are now living on the peaks of mountains and have nowhere else to go.
Of course, it is not climate alone that affects a species' survivability. The changing climate often changes the availability of food. The pine beetle in Yellowstone National Park, due to the warmer climate, can now start breeding earlier in the year and the breeding season lasts longer, producing more pine beetles than usual. The pine beetle kills pine trees, which produce the pine cones the Clark's Nutcracker eats. The longer breeding season of the pine beetle is causing thousands of trees to die. Without these pine cones, the Clark's Nutcracker will not have sufficient food to survive long-term.
Locally, the Allen's hummingbird is often seen here in the summer. Audubon predicts that climate change will push the bird further inland, but it is unknown if the nectar-producing plants the bird needs will be available for it. Moving to new territory may also cause it to encounter previously unknown predators. Ocean warming will push the range of the brown pelican, a common site along the Pacific coast, to new coastal areas and estuaries, but whether the fish it eats will be available is uncertain.
As a threat to birds, climate change often goes hand in hand with habitat loss. In western North Dakota the land has sprouted 8,000 hydraulic fracking wells in the past six years. More are being constructed on a daily basis. Yet Audubon predicts that this land, historically rich in bird life, will become even more important to birds in the coming years as grassland birds move north. If the land is unavailable due to industrial development, these birds may be faced with extinction.
Audubon has clearly shown that birds are trying to tell us something. We need to listen. When my grandchildren ask me what a bald eagle looks like, I don't want to have to say that I used to see them flying in the skies over Santa Clara County. I want to be able to show them one flying above the hills right here in our valley.
WERC is a licensed 501(c)(3) organization that has been providing wildlife education and rehabilitation services in the South County for 23 years.
Amy Randall Yee has lived in Santa Clara County for 35 years and has volunteered at WERC for six years. She is the President of the Board of Directors of WERC. Contact her at firstname.lastname@example.org.
W.E.R.C., the Wildlife Education and Rehabilitation Center provides the community with rehabilitation services for orphaned, injured and sick native wildlife. Through our educational programs, W.E.R.C. encourages a peaceful coexistence between civilization and our native wildlife. Federal tax ID #77-0324296