BirdNote: Solving the Mystery of the Herring Gulls Red Spot

CURWOOD: Its Living on Earth. Im Steve Curwood.

[MUSIC: BIRDNOTE THEME]

CURWOOD: The way animals behave is a constant source of fascination for some observers and an interest for scientists. And as Mary McCann explains in todays BirdNote, careful observation can help solve mysteries.

[GULL CALLS]

BIRDNOTE/GULLS BEAKS

http://birdnote.org/show/little-red-spot-gulls-bill

The Little Red Spot on a Gulls Bill

[Bugling calls of Glaucous-winged Gulls]

MCCANN: 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.

Herring Gull (Photo: mongolito404; Courtesy of BirdNote)

[BUGLING CALLS OF GULLS]

MCCANN: Behind that red spot lies a considerable tale thats t-a-l-e!

MCCANN: 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]

MCCANN: Tinbergen devised experiments that varied the shape and coloration of the adults bill. It became clear that the red spot on the adult gulls bill was a crucial visual cue in a chicks demands to be fed, and thus its survival.

A mature Herring Gull looks out over the water. (Photo: Timelapsed; Courtesy of BirdNote)

[BEGGING CALLS OF YOUNG GULLS]

MCCANN: Tinbergen also made the case that the chicks 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.

MCCANN: Tinbergens 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.

An adult Herring Gull displays its iconic red spot. (Photo: roamingwab; Courtesy of BirdNote)

[BEGGING CALLS OF YOUNG GULLS]

MCCANN: Im Mary McCann.

###
Written by Bob Sundstrom
Bird audio provided by The Macaulay Library at the Cornell Lab of Ornithology, Ithaca, New York. Calls of Glaucous-winged Gulls recorded by A.A. Allen. Begging call of Glaucous-winged Gulls recorded by E.S. Booth. Herring Gulls recorded by Martha Fischer.
Producer: John Kessler
Executive Producer: Dominic Black
2014 Tune In to Nature.org October 2014 Narrator: Mary McCann

Herring Gull chicks peck at an adult in the hopes of a meal. (Photo: Tony Morris; Courtesy of BirdNote)

CURWOOD: Youll find photographs of gulls and their red spots – at our website, LOE.org.

[BEGGING CALLS OF YOUNG GULLS]