Diving Birds on the Precipice: New Study Raises Extinction Concerns

A recent study conducted by the Milner Centre for Evolution at the University of Bath has unveiled alarming findings about the potential vulnerability of diving birds to extinction. Penguins, puffins, and cormorants, beloved for their unique underwater antics, may be facing a heightened risk of extinction compared to their non-diving counterparts.

Diving birds have long captured our imaginations with their graceful underwater maneuvers and remarkable adaptations. However, this new research underscores the urgency of comprehending the intricate interplay between diving behavior, physical attributes, and the survival prospects of these avian marvels.

 The study, led by researchers Joshua Tyler and Jane Younger, revealed that the act of diving has evolved independently an astonishing 14 times across various bird species. Once a lineage had acquired this diving ability, subsequent evolutionary paths rarely saw a reversal of this trait. A particularly intriguing observation emerged: the evolution of body size among diving birds varied based on the specific diving techniques they employed.

Wing divers, exemplified by charismatic species like penguins and puffins, employ their wings as propellers underwater. These birds showcase larger body sizes that are superbly adapted for effective swimming. Similarly, the “foot divers,” such as cormorants, rely on foot-propelled swimming and also display larger body sizes. In contrast, “plunge divers,” including gulls and gannets, master the art of vertical dives from the air to secure their prey. For these species, adaptability to flight takes precedence over swimming prowess, leading to more constrained body size evolution.

While the study did not discern significant differences in speciation rates between diving and non-diving birds, it did uncover a concerning trend: many diving birds appear more susceptible to extinction than their non-diving counterparts. The specialization inherent in diving adaptations appears to hinder these birds’ capacity to cope with changing environments. The result could be an evolutionary cul-de-sac for these unique avian lineages.

The research methodology employed in this study holds promise for conservationists striving to anticipate which species face the gravest extinction risks from an evolutionary perspective. This predictive framework empowers conservation efforts to focus on safeguarding diving birds and other at-risk species.

Josh Tyler, lead author of the paper and a PhD student at the Milner Centre for Evolution, emphasized the study’s implications: “Our work shows that rather than being a random process, there are predictable patterns to evolution. Penguins, for example, are highly adapted for their environment. They have a torpedo body shape that helps them swim fast, but they don’t fly, and they can’t move that well on land. This means they can’t easily adapt to other environments or types of diet. In contrast, plunge divers like gulls are more generalists – they eat anything from fish to Cornish pasties – and we found they are exploding in diversity.”

Funded by the University of Bath and a scholarship from the Evolution Education Trust, this study sheds light on the delicate balance between adaptation, specialization, and the precarious road to survival for these enchanting diving birds.