Two Brazilian researchers doing some recreational bird-watching have made an amazing discovery: the first nest ever found for the critically endangered Stresemann's bristlefront (Merulaxis stresemanni). One of the world's rarest birds, the bristlefront has an estimated population of just 15 individuals, all at the 600-hectare Mata do Passarinho Reserve run by Fundação Biodiversitas in the state of Bahia.

"This is the discovery of a lifetime made all the more gratifying by the fact that not only have we found live adult birds, but we have also found strong evidence of several chicks as well," Alexandre Enout, the reserve's manager, said in a press release issued by the American Bird Conservancy, which funded the establishment of the property in 2005.

Very little is known about the Stresemann's bristlefront. The species was first seen in the 1830s, but scientists did not collect a second specimen until 1945. The third sighting was 50 years later, in 1995, when a single male was observed near the Una Biological Reserve in southern Bahia, where no further bristlefronts have been seen since. The birds were finally rediscovered further north in 2004 in the region that would later become the Mata do Passarinho Reserve , where surveys have since observed just six individual birds. Using those surveys, the organization BirdLife International estimates the total population for the species at 10 to 15 birds.

Although Mata do Passarinho Reserve is now protected, that protection is not exactly a guarantee of safety. "The reserve is a small island of good habitat," says David A. Wiedenfeld, conservation science specialist with the American Bird Conservancy, but it is surrounded by agriculture and pastures that have replaced the majority of the forests that used to exist there. He reports that there is some threat of illegal logging, with people taking trees out of the reserve, but a newly hired guard is helping to minimize that risk. The main threat, though, is the wildfires that plague the region. "The reserve and adjacent forest habitat is so small that it could all burn in a single fire," he says.

Getting back to the nest, researchers Dimas Pioli and Gustavo Malacco had come to the reserve this past October hoping to see the bristlefront. The reserve is a particularly good bird-watching destination, with 245 species known to spend at least some time in its trees. "They were birding along the trail where the bristlefront is commonly seen," Wiedenfeld says, but they found more than they hoped for when they came on the nest.

The bristlefront, like many in its genus, is a ground-nesting species which does not migrate. The researchers saw a tennis-ball sized hole in a vertical edge of earth about one meter above the surface of the forest floor and realized that it was like other Merulaxis nest. They saw a male on two different days and noticed that he was bringing food though the hole, back to the nest, including one small frog and an earthworm. Getting closer, they used a micro-camera to partially survey the inside of nest, which they estimated to about 1.8 meters deep. Although no other birds were observed, male's activity led to them to believe that there must have been at least one chick somewhere in the unseen part of the nest.

"No one is going near the nest now, and there are no plans to try to see all of the way into it," Wiedenfield says. "No one wants to disturb a nest of a species that is that rare!"

The American Bird Conservancy and Fundação Biodiversitas are hoping to buy more of the remaining forests around the reserve, which is also home to at least two other rare species, the endangered banded cotinga (Cotinga maculata) and the critically endangered yellow-breasted capuchin monkey (Cebus xanthosternos). The reserve is located in the rapidly shrinking Atlantic Forest, which has been reduced to 10 percent of its historical size from logging, conversion to livestock pasture, and agriculture. "It is urgent that we protect more of the natural Atlantic Forest in this area and reforest areas where forest has been lost," said Enout.

Pioli and Malacco have submitted a scientific paper about their finding for journal publication.

Your own chances of ever seeing the Stresemann's bristlefront are slim to none, but check out this one-minute video shot by Ciro Albano of NE Brazil Birding:

Photo: Stresemann's Bristlefront by Ciro Albano, NE Brazil Birding. Courtesy of American Bird Conservancy