BirdNote; The Little Red Spot on a Gull's Bill

BirdNote®

The Little Red Spot on a Gull’s Bill

Written by Bob Sundstrom

This is BirdNote!

[Bugling calls of Glaucous-winged Gulls]

You may have noticed — on a trip to the shore or at a waterfront restaurant where gulls gather — that many gulls have a bright red spot near the tip of their otherwise yellow bills. [Bugling calls of gulls] Behind that red spot lies a considerable tale – that’s t-a-l-e!

In the mid-20th Century, Dutch scientist Niko Tinbergen studied nesting Herring Gulls. He noticed that newly hatched gull chicks were fed by their parents only after they pecked at the adults’ bills [Begging calls of young gulls]. Tinbergen devised experiments that varied the shape and coloration of the adult’s bill. It became clear that the red spot on the adult gull’s bill was a crucial visual cue in a chick’s demands to be fed, and thus its survival.

[Begging calls of young gulls]

Tinbergen also made the case that the chick’s attraction to the red spot on the bill was instinctive. This conclusion came at a time when there was furious debate among experts about whether such behavior was learned or innate.

Turns out it’s more complicated than that.* But Tinbergen’s gull research helped lay the groundwork for the science of animal behavior, and in 1973 earned him a Nobel Prize. And it all started with that little red spot.

[Bugling calls of gulls]

Learn more about Tinbergen’s research — and see a photo of that red spot — on our website, BirdNote.org. I’m Mary McCann.

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Bird sounds provided by The Macaulay Library at the Cornell Lab of Ornithology, Ithaca, New York. Calls of Glaucous-winged Gulls [3350] recorded by A.A. Allen. Begging call of Glaucous-winged Gulls [3347] recorded by E.S. Booth. Herring Gulls [133311] recorded by Martha Fischer.

BirdNote’s theme music was composed and played by Nancy Rumbel and John Kessler.

Producer: John Kessler

Executive Producer: Dominic Black

© 2015 Tune In to Nature.org October 2014/2015 Narrator: Mary McCann

ID# 100407redspotKPLU gull-04b

The research: http://tinyurl.com/yozx87

* The complication: https://www.nature.com/news/2009/090324/full/news.2009.186.html