Birds are at risk of starvation due to climate change. A new study by researchers at the Max Planck Institute of Animal Behavior and Cornell University has made a disturbing discovery, based on a set of data collected over 30 years.
According to research, birds always breed earlier and this is not good news. The study also highlighted the heavy consequences on the bird's fitness but may also provide clues to an as-yet-unsolved mystery: aerial insectivorous birds, such as swallows, swifts and flycatchers are declining faster than other groups across much of North America and of Europe.
In fact, due to the anticipation of the arrival of spring, they cannot find the insects they eat and whose activity is determined by the weathe. The study has discovered the serious consequences for these animals that unknowingly reproduce earlier to "synchronize" with the early beginning of spring.
If the climate changes, animals try to keep up but don't always succeed and when they do this can be harmful. For example, chicks that hatch earlier face an increased risk of bad weather, food shortages, and early mortality.
Birds threatened by climate change
Surviving on a warming planet may be a matter of timing, but simply moving and changing life cycle stages to match the pace of climate change has hidden dangers for some animals, including birds.
In recent years, studies have raised concerns about whether or not species may adapt to climate change. The new study found that early mating and consequently premature birth can expose animals to a greater risk of exposure to adverse weather events that tend to occur more frequently at the beginning of the year.
The researchers studied a population of tree swallows in Ithaca, New York, which was the focus of a lengthy 30-year experiment. Studies of this length are rare in the field of ornithology. This allowed them to analyze a series of long-term data on the reproduction of the tree swallow, the daily abundance of insects and weather conditions.
Researchers, who have examined decades of data on the weather, food availability of swallows, argue that the time of reproduction and when food is available is becoming decoupled for some animals. Experts said: "Simply anticipating dates to keep pace with climate change is not without risk.
Risky conditions at the start of the year can expose animals to unwanted consequences when they have to adjust to the unusually warm spring weather. findings raise the possibility that animals that rely on food resources that can change rapidly due to the weather may be at particular risk from climate change."