Climate Change is Pushing Birds to Migrate Early – And That’s a Problem
The migratory patterns of birds are amazing. Take the blackpoll warbler, for example. This tiny bird (seen above) travels over 1,700 miles in fewer than three days. By fitting tiny electronic backpacks on the blackpoll warbler, scientists were able to track their epic migration patterns from Canada to South America, and concluded that they make the longest known oversea journey for landbirds.
Now researchers are finding that migratory birds, like the blackpoll warbler, may be in trouble. Natural migratory movements are being impacted by changing conditions, which could lead to more birds joining the list of victims of climate change.
According to a new study, migrating birds are arriving at their breeding grounds earlier than they used to thanks to the rise in global temperatures.
The British swallow | Photo Credit: thinkstock
Why It‘s A Problem When Migrating Birds Arrive Early
The University of Edinburgh scientists researched the records of 413 species across five continents, going back almost 300 years. They found that on average, birds are reaching their summer breeding grounds about one day earlier per degree of increasing global temperature.
Here’s why that’s a problem: If birds arrive at their summer breeding grounds at the wrong time, even if it’s only by a few days, they may be unable to find food and nesting places. This in turn affects the timing of laying and hatching eggs and the baby birds’ chances of survival.
The British swallow is just one of the bird species whose migration patterns over time were analyzed by researchers at the University of Edinburgh.
These birds arrive in the UK in April and May and take off for their wintering grounds in South Africa in September and October. To get to South Africa, they cover 200 miles a day, mainly during daylight, at speeds of 17 to 22 miles per hour. Their maximum flight speed is an incredible 35 mph.
Sandhill cranes | Photo Credit: thinkstock
This early migration is just what happened last year, when record numbers of migrating sandhill cranes arrived much earlier than usual in Nebraska’s Platte River valley, their stopover grounds on their migration to northern nesting grounds.
“We confirm earlier findings that on average birds have significantly advanced their spring migration time by 2 – 1 days per decade,” states the abstract of the report, and this correlates with a parallel rise in temperature.
Long-distance migrants, which are less responsive to rising temperatures, may get the worst of this shift, as other birds gain advantage by arriving at breeding grounds ahead of them.
What Can We Do?
The Guardian reports that the researchers hope their study, published in the Journal of Animal Ecology and supported by the Natural Environment Research Council, will help scientists predict more effectively how different species respond to environmental changes.
Takuji Usui of the university’s school of biological sciences said: ”Many plant and animal species are altering the timing of activities associated with the start of spring, such as flowering and breeding.
“Now we have detailed insights into how the timing of migration is changing and how this change varies across species. These insights may help us predict how well migratory birds keep up with changing conditions on their breeding grounds.”
Let’s hope that this information will be helpful in protecting these migrating birds. In the meantime, learn more about Care2 campaigns working to fight climate change.