Authenticating Peru’s Unique Unicorn

Over four decades ago, two well-known scientists, John Weske and John Terborgh were on expedition in central Peru when they rescued an unusual looking black, turkey-sized bird from the camp cook’s dinner prep table.  They suspected it to be a subspecies of an existing curassow from Bolivia called the Horned Curassow (Pauxi u. unicornis), and described it as the same in a peer-reviewed journal.

Sira Curassow (Pauxi koepckeae) in nature
Photo by Melvin Gastañaga

For many years the ‘Peruvian Horned Curassow (Pauxi unicornis koepckeae)’ was believed to be only a subspecies of the Bolivian form, until recent evidence showed otherwise.  The bird in question is a unique species endemic to Peru’s Sira mountain range, and thus was renamed the Sira Curassow (Pauxi koepckeae).

The fact the Peruvian form is separated at least 1000 km from the Bolivian species is a strong indicator that these are both distinct species.  Some of the parameters distinguishing the Sira Curassow from Bolivia’s Horned Curassow include thriving in different habitat at higher elevations, different behavioral patterns including the call, and of course different morphology.

In former posts I’ve explained my interest in Cracids – the rarest family of birds in the Americas, to which the Sira Curassow belongs.  While preparing Action Plans to prioritize and direct Cracid conservation efforts, whenever we came to status of the Peruvian Horned Curassow we just sort of sat around scratching our heads, as nobody definitively knew if it was a valid species.  I always had the hunch that it was valid, but without the proof of data, we’d just be telling a good story.

About a decade ago I put out a call for expeditions to locate the bird in nature to determine its status.  Melvin Gastañaga bravely answered the call, venturing solo into the Sira Mountains in search of ‘Peru’s unicorn’.  It was challenging work – of the several expeditions into the region the bird was not located during the first three, but Gastañaga remained tenacious, returning to find the bird in March 2005.

The work conditions were difficult, with several hours of hiking mountainous terrain just to locate the birds.  The efforts and results obtained by Melvin and her husband Ross MacLeod are nothing short of miraculous.  It goes without saying that they are the heroes in this story – the bird still would not be a species today if it wasn’t for them.  Indeed, weather conditions and other elements were less than cooperative, making the work all the more challenging.  I was honored to be a part of the new discovery, providing the morphological assessment.

Despite the exciting news, this new species is in serious trouble, with the threat of extinction looming over the Sira Curassow.  The range of the species is tiny and unfortunately the species is apparently being poached inside the reserve despite educational efforts.

100 Years – 100 Objects: Blue-billed Curassow

The Houston Museum of Natural Science was founded in 1909 - meaning that the curators of the Houston Museum of Natural Science have been collecting and preserving natural and cultural treasures for a hundred years now. For this yearlong series, our current curators have chosen one hundred exceptional objects from the Museum’s immense storehouse of specimens and artifacts—one for each year of our history. Check back here frequently to learn more about this diverse selection of behind-the-scenes curiosities—we will post the image and description of a new object every few days.

The endangered Blue-billed Curassow,
one of the 100 objects we’ve chosen to
celebrate the Museum’s centennial.

This description is from Dan, the museum’s curator of vertebrate zoology. He’s chosen a selection of objects that represent the most fascinating animals in the Museum’s collections, that we’ll be sharing here – and on hmns.org – throughout the year.

The Blue-billed Curassow (Crax alberti) is a large bird that is endemic to the mountain valleys of northern Colombia.  The tasty flesh of this turkey-sized bird, combined with destruction of the rainforests it thrives in represent the primary threats to this and other members of the Cracid family.

This species is considered Critically Endangered by the Cracid Specialist Group, as its global population certainly can not exceed 2000 individuals.  It is certainly among the rarest of vertebrates in the collection.

You can see larger and more detailed images of this rare specimen – as well as the others we’ve posted so far this year – in the photo gallery on hmns.org.