NEWS - Penguins and albatrosses have highly sensitive areas on their beaks to help them find food. An international team of researchers studied more than 350 modern bird species and found that seabirds have a high density of sensory receptors and nerves at the tip of their beaks that have previously been identified in specialist tactile feeders such as ducks.
This touch-sensitive area may have originated in a common ancestor and further research is needed to determine whether it has a specific function in modern birds. Further research into beaks and foraging behaviour could help conserve some birds, many of which are threatened with extinction.
Humans and other primates use their hands, but birds use their beaks to interact with the world around them. Some birds have special touch-sensitive areas at the tip of their beaks to help them find food, but this ability has not been widely studied and it is not known how the phenomenon evolved or how widespread it is.
“Many scientists assume that most birds have touch-sensitive beaks, but we haven’t investigated enough to know whether it is a general ability or whether it is restricted to certain bird families,” says Carla du Toit of the University of Cambridge.
Austrodyptornithes, which include albatrosses, petrels, penguins and many other bird species in this group, are critically endangered. Understanding how they find food using their beaks could be a valuable tool to aid conservation.
Du Toit and a team from the UK and South Africa studied 361 modern bird species based on fossil records, skeletons and birds accidentally killed by fishing lines and nets. The team focused on how the beaks are constructed and connected to nerves including blood vessels.
Albatrosses and penguins have sensory receptor organs with a high density and concentration of nerves in their beaks. Seabirds are not known to be tactile foragers. These sensitive beaks help them find food at night and underwater by detecting tiny vibrations from potential prey.
However, these sensitive areas may also be ‘leftover’ from a common ancestor in birds that had no special function, such as the beaks of ostriches and emus. Further research in living birds is needed to establish the exact purpose of these touch-sensitive areas to help determine how the ability evolved.
“This is the first time we’ve seen a touch-sensitive beak in a seabird. It’s remarkable that no-one has really studied this in detail, considering we all learn about the evolution of Darwin’s finches’ beaks at school,” du Toit said.
The findings play a role in conserving the 22 known albatross species, 15 of which are threatened with extinction and two are listed as critically endangered. Commercial fishing with fishing lines kills around 100,000 birds a year when they become entangled and drown.
“Of course, the bigger threats to birds like albatrosses are climate change, rising sea temperatures, plastic pollution and declining fish stocks. But if there’s a way to reduce the risk to seabirds, even in a small way, then it’s worth it. These are very special birds,” du Toit said.
Original research
du Toit Carla J., Bond Alexander L., Cunningham Susan J., Field Daniel J. and Portugal Steven J. (2024). Tactile bill-tip organs in seabirds suggest conservation of a deep avian symplesiomorphy. Biolgy Letters 2020240259, DOI:10.1098/rsbl.2024.0259
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