Bird communities will be lost to various regions around the world by 2080, while species such as blue tits are already changing colour in the past two decades, due to climate change.
Those are the findings of two separate studies on birds by British and European researchers, signalling the acceleration of the biodiversity crisis as the world changes due to human-induced global warming.
Basque and French researchers looked at the two blue tit populations in the south of France and the island of Corsica from 2005 to 2019, finding from nearly 6,000 observations that the bird's signature blue crest and yellow breast has faded.
"Our work suggests that environmental changes, and specifically climate change, could be the main reason why birds such as the blue tit are undergoing a change in their physical features, more specifically in the brightness and intensity of their colouration,” said David López-Idiáquez of the University of the Basque Country.
While colour changes may seem innocuous, the reality is more concerning as it may impact future mating patterns, the research suggested.
"In these birds, traits such as colouring function as signals to indicate to other individuals the quality of the specimen, which are decisive, for example, when it comes to breeding,” Mr López-Idiáquez said.
Increasing temperatures and less rainfall in Corsica over the study period seems to point to climate change, the researchers concluded.
The continuous monitoring of the two blue tit populations for more than 15 years "highlights the importance of long-term studies to understand the effects of climate change on the ecosystems around us”, Mr López-Idiáquez said.
According to West Cork-based online resource Ireland's Wildlife, the blue tit is this country's most common tit species, found all over the country all year around in all kinds of habitats.
More than 1,000 individuals may pass through a single garden in a year, even though it is unusual to see more than six or so at any one time, according to Ireland's Wildlife founder Calvin Jones.
Meanwhile, Durham University and Senckenberg Biodiversity and Climate Research Centre, Germany, bioscientists have modelled that bird communities will change worldwide by 2080 due to climate change.
The scientists looked at past bird distributions to climate data and applied them to two future climate scenarios — based on low and medium greenhouse gas emissions — to predict changes in species distributions.
Looking almost 9,000 bid species globally, they predicted losses to be most common in tropical and subtropical areas, and community restructuring of species was expected to occur around the world.