22 Dec 2016

Cryptic by name, cryptic by nature

No photographs of a live Cryptic Treehunter have been made public. Above, the similar looking Alagoas Foliage-gleaner © Ciro Albano
No photographs of a live Cryptic Treehunter have been made public. Above, the similar looking Alagoas Foliage-gleaner © Ciro Albano
By Irene Lorenzo

The Cryptic Treehunter is so elusive, researchers are not even sure it still exists anymore. The name reflects its enigmatic nature, but the reasons why its habitat is vanishing are somewhat more glaring.

Juan and Dante once again ventured into the dense forests of Murici in north-eastern Brazil, hoping to see some rare birds. When the two researchers left the Centre for Ornithological Studies in São Paulo that week, they could not imagine what they were about to witness.
As the two friends discussed their sightings, a flash of cinnamon brown stopped them on their tracks. Hidden in the 20m high forest canopy, there it was. A small bird that looked like an Alagoas Foliage-gleaner Philydor novaesi – itself also on the brink of extinction.
But something was off. It was slightly larger and darker. The bill seemed longer. And the weirdest part: it screeched, loudly. The call could not belong to the whistling Foliage-gleaner. In fact, it sounded more like a Pale-browed Treehunter Cichlocolaptes leucophrus. But they were outside of this species’ range – it’s found in south-eastern Brazil, not in the north. What could they be looking at?
On that day in October 2002, Juan Mazar Barnett and Dante Buzzetti had in fact discovered a new species. Since it was so difficult to spot, researchers decided to call it Cryptic Treehunter. In Portuguese, it was named gritador-do-nordeste – the screamer of the northeast, after its unique screeching sound.
The scientific name came a few years later, after Juan Barnett had passed away. Dante dedicated the name Cichlocolaptes mazarbarnetti to his colleague, in recognition of a life devoted to ornithology.
Cryptic Treehunter Illustration © HBW
In the following years, other researchers had the same luck as Juan and Dante and recorded new sightings of the Cryptic, until 2007, when the screamer suddenly fell silent. Almost ten years have passed and the bird has not been seen again; it was last spotted at Serra do Urubu in February 2005 and at Murici in April 2007.
Since it hasn't been reported in any other sites, if the species survives, the estimated global population would be very low – under 50 individuals. As the description of the new species was confirmed, it was added to this year’s Red List.
While researchers should be cheering for the discovery of a new species, the immediate response was concern; deforestation has been running wild within the home range of this small bird. This is why like other unique species in the same area, it has gone straight into the highest threat category: Critically Endangered (Possibly Extinct).
Researchers have had difficulty locating the species as only the call can be used to confirm its presence. All we know is that the regions of Serra do Urubu and Murici are part of a highly threatened ecosystem and biodiversity hotspot known as the Atlantic Forest.
Serra do Urubu, home of the Cryptic Treehunter © Marc Egger
This forest stretches across eastern Brazil, eastern Paraguay and north-eastern Argentina. It is a neotropical, humid ecosystem that is home to about 20,000 species of plants, 260 species of mammals and 700 species of birds, many of which can’t be found anywhere else in the world.
But the Atlantic Forest is not what it used to be. This vast region used to extend beyond 150 million hectares; an endless expanse of trees, hosting an incredible amount of endemic species, teeming with life. However, in recent years, unremitting logging and deforestation have left just 11% of it still standing.
Sugarcane plantations and cattle ranching have sliced up and degraded this primeval forest. Today, the Atlantic Forest is not the continuous jungle one would imagine. The region is a mosaic of over 245,000 pieces with little original forest cover left.
Most fragments are smaller than ten hectares and few are larger than 1,000. There’s little chance for fragments to connect with each other, as they are surrounded by sugarcane plantations: hardly a welcoming ecosystem for wild animals. The remaining patches are threatened by fire, logging and firewood removal.
It does not come as a surprise that many of the inhabitants of the Atlantic Forest are in peril. In fact, over 70% of nearly 200 endemic bird species found there are of elevated conservation concern. Along the Atlantic Forest range the situation is not homogenous.
In the south-east there are still some large protected areas with more than 100,000 hectares. The most extreme situation in terms of threat and fragmentation is taking place in the north-east, where both the Cryptic Treehunter and the Alagoas Foliage-gleaner live. The forest cover is declining fast and extensive logging has been reported in the areas where these birds have been sighted.
However, SAVE Brasil (BirdLife Partner) is working hard to save this vital ecosystem. In 2004, they purchased one important forest area of 360 hectares, adjacent to a private reserve in Frei Caneca, Serra do Urubu. The combined area, part of which was being deforested as a result of charcoal exploitation, is today 1,000 hectares of well managed, protected forest.
A year later, they started conducting bird monitoring in both reserves and while there were no records of the Treehunter or Foliage-gleaner, they have been spotting other birds such as the White-collared Kite Leptodon forbesi (Critically Endangered) and Alagoas Tyrannulet Phylloscartes ceciliae (Endangered).
As the forest slowly recovers, SAVE Brasil are even recording species that haven’t been seen for years like the White-winged Cotinga Xipholena atropurpurea (Endangered).
“In the last remnants of the north-east Atlantic Forest, we might be too late to save the Alagoas Foliage-gleaner and the Cryptic Treehunter, but we still have time to try, and are working hard to save the other globally threatened birds that still survive”, said Pedro Develey, Executive Director of SAVE Brasil.
The Atlantic Forest and specific sites such as Murici and Serra do Urubu are the maximum priority for SAVE Brasil because so many species depend on this ecosystem. The presence of yet another new species should be a renewed reason for governments to take immediate action for their preservation.
For the Cryptic Treehunter, we can only aim to conserve its habitat and continue surveying the area in the hope that the species is still extant. In the meantime, we can’t help but wonder: what other species are we losing before they can even be discovered?