A first look at geographic variation in gentoo penguin calls

Many birds use sound to attract mates and defend territories – vocal communication is central to their lives. Penguins are no exception, but we know little about how or why penguin vocalisations vary geographically between isolated populations.

Gentoo penguin calling. Credit: M Lynch.

A new study from The Auk: Ornithological Advances takes a broad look at vocalisations across the range of gentoo penguins. It concludes that while their calls do vary from place to place, we still have a lot to learn about the processes at work.

The gentoo penguin’s “ecstatic” call, consisting of repeated pairs of short syllables, is used to attract and contact mates. Maureen Lynch and her PhD advisor Dr Heather Lynch (no relation) of Stony Brook University recorded ecstatic calls at 22 gentoo penguin colonies across the Antarctic Peninsula, southern Argentina and nearby islands.

They found variation in call frequency and duration both within and between colonies, but saw no clear patterns based on latitude, region or subspecies. An algorithm based on their data was able to classify calls to correct colonies better than random, but with a high error rate.

Penguin-mounted video captures gastronomic close encounters of the gelatinous kind

SOUTHERN OCEANS – Footage from penguin-mounted mini video recorders shows four species of penguin eating jellyfish and other gelatinous animals, a food source penguins were not previously believed to eat. Scientists reported the findings this month in the Ecological Society of America's peer-reviewed journal Frontiers in Ecology and the Environment.

Video logs confirmed that penguins targeted gelatinous animals for meals  – the birds did not merely ingest them accidentally while aiming for fish or other prey. Connecting this link in the food web helps ecologists understand the ecological niche of "gelata", a group the authors have defined based on shared gelatinous physique and ocean habitat, though it includes organisms from very different branches of the tree of life.