The latest findings, published in the journal Current Biology, point to some decline in species with unique traits and their replacement by more widespread generalist species.
“We do find strong evidence to support the hypothesis that the largest and smallest species are likely to be most at risk of extinction,” Dr Hughes stated in a press release.
Scientists warn that local climate change may cause the birds to look similar due to their morphology.
“As species go extinct you expect the traits that they represent to also be lost. But what we found was that with morphological diversity, the traits were lost at a much, much, much greater rate than just species loss could predict,” Dr Hughes stated.
“This is really important because that can lead to a major loss of ecological strategies and functions,” she added.
Scientists warn that most ecoregions globally will lose a variety of physiological preferences seen in birds at a cost greater than just species loss, “most threatened in East Asia.” and in the highlands and foothills of the Himalayas.
Citing the example of the scarcity of vultures in the Himalayan region, the researchers said that these critically endangered raptors, as large scavengers, “fill distinct areas” in their ecosystems.
Vultures, with their distinct body preferences, represent important providers to their ecosystem by scavenging decomposing carcasses “which could otherwise increase the direct transmission of infectious diseases, and increase populations of opportunistic scavengers like dogs and rats that spread rabies and bubonic plague,” scientists stated.
“Therefore, it is likely that the considerable loss of morphological diversity in the Himalayan ecoregions is partly driven by the loss of vultures—the most imperilled group of birds,” they wrote within the examination.
“The dry and moist forests of South Vietnam and Cambodia are also vulnerable,” Dr Hughes stated.
The researchers hope that the new findings will help people understand the ways in which biodiversity loss will change the world.