photo credit: Fernando Bórquez Bórquez
By Matthew Owens
Chilean scientists have discovered an entirely new population of Darwin’s fox, one of the most endangered mammals on the planet. The researchers call for further measures to reassess the conservation status of the species.
Darwin’s fox (Lycalopex fulvipes), endemic to the temperate forest of Southern Chile, has been classified ‘critically endangered’ by the International Union for Conservation of Nature (next stop ‘extinct in the wild’ then ‘extinct’) for the past 10 years. The elusive canid was first collected by Darwin in 1834 who described the encounter on his second Beagle voyage that surveyed the South American coast:
“In the evening we reached the island of S. Pedro [Chiloé], where we found the Beagle at anchor… A fox, of a kind said to be peculiar to the island, and very rare in it, and which is an undescribed species, was sitting on the rocks… I was able, by quietly walking up behind, to knock him on the head with my geological hammer. This fox, more curious or more scientific, but less wise, than the generality of his brethren, is now mounted in the museum of the Zoological Society.”
Today Darwin’s fox, once thought to be a subspecies of the South American Gray fox (Lycalopex griseus), is also known to inhabit areas in the Nahuelbuta National Park on the mainland of Southern Chile, as well as Chiloé as Darwin described. Until now the population was thought to total less than 600, with around 90% found on Chiloé. However, numbers have proved difficult to estimate due to the non-coterminous distribution of the population coupled with a lack of surveys. This has raised questions over the existence of new populations in under-explored regions, waiting to be discovered. As fox expert, Dr Jaime Jiménez from the University of North Texas points out, “Years ago we were similarly surprised to find this fox in Nahuelbuta, when it was only known from Chiloé Island.”
Now new sightings in protected areas close to the Valdivian coast (roughly equidistant between Nahuelbuta and Chiloé) have prompted a reassessment of population levels of the fox and hence its conservation status. Evidence for the new population comes from research recently published in the academic journal Revista Chilena de Historia Natural. In the study, led by Dr Ariel Farias from the Pontificia Universidad Católica de Chile, camera traps baited with raw chicken laced with bobcat urine were left in areas of dense old-growth forest and understory for between two weeks and two months, with the hope of immortalising a member of the Darwin’s Fox clan on film. Amongst other beasts such as pumas and guignas, Darwin’s foxes were recorded in nine traps in three separate areas (Oncol park, Alerce Costero National Park and the Valdivian Coastal Reserve). “Our findings add new localities halfway between those previously reported, suggesting a broader and more continuous distribution in the mainland and a bigger population size.”, explained Farias.
There had been suspicions of the existence of new groups of Darwin’s fox in other areas but evidence was either lacking or flimsy at best. Farias recounts that, “we were informed of unconfirmed suggestions made by other researchers about the possibility of the presence of Darwin’s fox in the area.” Indeed other scientists have been on the trail for some time. “A few months earlier we reported a dead specimen from an area nearby to that reported by Farias et al.” adds Dr. Guillermo D’Elía, Associate Professor at Universidad Austral de Chile in Valdivia.“But even when the animal was found dead in the countryside, the possibility that it represents a specimen that was keep as a pet and brought from somewhere else cannot be ruled out. Now, these camera trap records erase any doubt; we certainly know that Darwin’s fox inhabits areas intermediate to Nahuelbuta and Chiloé Island.”
Surveying the area to gather evidence for the prevalence of the fox has been hampered by several obstacles that researchers have struggled to overcome. The animals are largely nocturnal creatures, chary of humans and live in small concentrations in sometimes-impenetrable forest. According to Jiménez, matters are also exacerbated when local spotters confound Darwin’s fox with a juvenile chilla or culpeo fox.
Darwin’s fox is a critically endangered species, rarer than the blue whale or the Giant Panda. However the recent findings raise the prospect of more populations being found and yet potential threats to the survival of the fox remain ubiquitous. Much of the forest has been eroded or replaced by pine or eucalyptus plantations, the presence of humans, agriculture, livestock and the abundance of wild dogs in the region all present difficulty for the fox. For these reasons the Chilean scientists were in consensus on advising caution in making recommendations to remove the fox from the critically endangered list.
“I agree with Farias et al. in that given that the recently discovered new and apparently widely distributed continental population of Darwin’s fox, a reassessment of the species conservation status is required; however, I think that probably it [should] remain listed as an endangered species. No much is known about it, are populations stable, growing or declining?” counselled D’Elía. “As fox numbers are unknown, but small, and there are so many immediate threats to the species…I do not believe it would be wise to take this species off the critically endangered list.”, added Jiménez.
The current work was the result of a collaborative effort between academics, state and non-governmental organizations and private initiatives (Oncol Park), involving administrators, park rangers and local people. Such joined-up initiatives may be paramount in successfully surveying elusive species such as Darwin’s fox.