Even the wildest parts of the Amazon untouched by humanity are being impacted by climate change, according to new research.
Hotter, drier conditions over the past four decades are decreasing the body size of the rainforest's birds while increasing their wingspans, a study published in the journal Science Advances said Friday.
The changes are thought to be a response to nutritional and physiological challenges, especially during the June to November dry season.
"The biggest takeaway for me is that this is happening far from direct human disturbance, such as deforestation, in the heart of the world's biggest rainforest," Vitek Jirinec, an ecologist at the Integral Ecology Research Center and the paper's lead author told AFP.
"That is something to ponder on the last day of COP26," he added.
Jirinec and colleagues analyzed data collected on more than 15,000 birds that were caught, measured, weighed, and tagged over the course of 40 years of field work. They found that nearly all the birds had become lighter since the 1980s.
Most species lost an average of two percent of body weight every decade, meaning a bird species that would have weighed 30 grams in the 1980s would now average 27.6 grams. The data was not tied to a specific site but rather collected from a large range of the rainforest, meaning the phenomenon is ubiquitous, the AFP report explains.
In all, the scientists investigated 77 species whose habitats ranged from the cool, dark forest floor to the sunlit and warmer midstory -- the forest's middle layer of vegetation.
Avian species around the world are now facing increasing threat from not just climate change but also massive alterations to their natural habitat. Earlier this year, researchers said that birds of prey were declining globally due to habitat loss and exposure to toxic substances.
A new analysis of data from the International Union for the Conservation of Nature and BirdLife International found that 30% of 557 raptor species worldwide are considered near threatened, vulnerable or endangered or critically endangered. Eighteen species are critically endangered, including the Philippine eagle, the hooded vulture and the Annobon scops owl, the researchers found.
Other species are in danger of becoming locally extinct in specific regions, meaning they may no longer play critical roles as top predators in those ecosystems, a report in the Associated Press explained.
According to another AFP report, deforestation of the Amazon rainforest hit a new record in October. An area more than half the size of the city of Rio de Janeiro -- 877 square kilometers (339 square miles) -- of Amazon's lush rainforest was cleared, the largest ever recorded for October since Brazil's National Institute for Space Research (INPE) started documenting deforestation in 2016.
The October figure was a five percent increase from the corresponding period last year. Attributed mostly to illegal mining and farming activity, deforestation of the Amazon surged in 2020, and is on track to reach similar highs in 2021, with 7,880 square kilometers of forest cleared and two months yet to go.
(With inputs from AP and AFP)