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Archive for November, 2010

By Brandon M. Breen

How does one save the world’s largest flying bird? This is the question that I, and many others, will try to answer in the coming year.

Found in and around the Andes mountains of South America, the Andean condor is one of nature’s superlatives. The average person could curl up and sleep comfortably on just one of their wings. A big male, weighing up to 33 lbs, outweighs many Welsh corgis (and possibly appears in some of their nightmares). In low flight, they appear more plane than bird, and even sound the part due to engine-like vibrations that result as wind whizzes through the “fingers” of their wings.

In foraging flight, they may travel over 100 miles in search of carrion, and have been seen at altitudes greater than 15,000 feet. Flying among the snow-capped volcanos of the South American highlands, it’s quite possible the Andean condor enjoys the greatest views of any creature on earth.

The Andean condor belongs to the family of New World vultures (Cathartidae), and can be thought of as a cousin to the other six members: California condor, turkey vulture, black vulture, lesser yellow-headed vulture, greater yellow-headed vulture, and king vulture. The Andean condor is not as threatened as the California condor (which walked to the very brink of extinction, blew a kiss into the void, and then began to back slowly away), but is nevertheless listed as “Near Threatened” on the IUCN Red List of Threatened Species. Populations in the southern portion of its
range, in Chile and Argentina, appear relatively stable and strong. In the northern part of the range, in places like Venezuela, Columbia, and Ecuador, the situation is much bleaker.

In Ecuador, where I am working as a biologist for Fundacion Condor, there have been four population estimates of Andean condors in the past 20 years. Not one concluded the population was over 100 birds, and the most recent attempt, in 2008-2009, could confirm fewer than 30 individuals in the species’ stronghold in the north of the country. What is going on with the condors in northern South America?

The list of potential threats to Andean condors is daunting. They may ingest bullet fragments from human-hunted animals, and die from lead poisoning. They may feed junk to and inadvertently kill their young. (Note: Large vultures, such as condors, feed mostly on muscle and viscera and will eat small foreign objects in a search for either calcium or indigestible material that aids the expulsion of hair from the digestive tract. This behavior can be lethal on our increasingly human-dominated planet where sharp and toxic litter items are common.) Humans may shoot them as trophies or pests of livestock. Ranchers may poison them. They may strike powerlines in flight. The list goes on: habitat loss, DDT-induced reproductive failure, starvation from human-mediated changes in food supplies, human disturbance, and yet unidentified sources of toxicity. Unfortunately, and critically, the significance of each of these threats is unclear. One thing, however, is certain: Man is the cause, directly or indirectly, of every single threat.

Part of the reason Andean condors are now endangered in Ecuador is because the species is adapted to low mortality. A small increase in the death rate can cause a population crash. Consider the following. Fifteen years ago, about 12 Andean condors in Ecuador died at a single poisoned carcass. Suppose we want to replace those 12 condors. How long do you think it would take?

We will borrow two breeding condor pairs from the population to get started. Before long, each pair has laid a single egg in an inaccessible cave on an Andean cliff face. Two months later the eggs hatch, revealing two improbable creatures. Six months later the young birds jump off their cliffs and take their first terrifying flights. A year later the birds, one male and one female, gain independence from their parents. Six years later, having finally reached sexual maturity, the two birds establish a pair bond and begin their first reproduction attempt.

Unfortunately, due to inexperience, this attempt fails. One year later they try again, and successfully rear a young condor. Our two birds, and their offspring when sexually mature, have great luck in all future breeding attempts. Still, a total of approximately 25 years is needed to replace the 12 poisoned condors that were wiped out in a matter of minutes.

The Andean condor is believed by some to be a messenger between the divine and earthly worlds. It remains to be seen whether this majestic bird will continue to pay congress to the earthly world. The multidisciplinary condor research team is now working to identify threats, identify critical habitat, and begin a captive breeding program. Stay tuned.
________________________
Brandon Breen
Biólogo
Proyecto Cóndor Andino
Fundación Cóndor, Parque Cóndor

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The author, Brandon Breen, in China

By Brandon M. Breen

In early December 2006, my plane departed the Punta Arenas airport in southern Chile, and headed east over the Atlantic Ocean. I, a new Conservation Biology graduate student at the University of Minnesota, prepared to visit my field site, the Falkland Islands, for the first time. A few hours and a few hundred miles after departing Chile, I began to catch glimpses of the islands through a patchwork of clouds. I began to see winding coastlines and breaking surf, inland lakes and yellowish-brown barren land stretching out in every direction. I was heading to study a Turkey Vulture population in an unlikely location. Our plane began descending around 4pm, several hours before the vultures would fold-in their wings on the long Falkland summer days.

Before I arrived I had heard rumors of a conflict involving Falkland sheep farmers and turkey vultures. There was talk that the birds had become more predatory, and were harming farming livelihoods by preying on lambs. Some farmers were requesting permission from the government to shoot vultures, like in the old days. Turkey Vultures are generalist scavengers throughout their extensive range (from Canada down to Tierra del Fuego, and over to the Falkland Islands), and while they are known to occasionally kill weak or helpless creatures (e.g. nestling birds, a toad, baby rats), they are not believed to seriously threaten livestock. Were the farmers drinking too many hot totties on long winter nights? Or was there something unique and sinister about this little-studied population of Turkey Vultures? One thing was certain, more information was needed.

There is no better way to find out what is on farmers’ minds than to sit down with them at their kitchen table with the kettle boiling and a plate of assorted biscuits and cakes within arm’s reach. And this is what I did, from the forest at Hill Cove to the gently rolling plains of Lafonia, to understand farmers’ perspectives. 

Additionally, to find out if turkey vultures damage sheep, I went to several lambing paddocks to observe vulture-sheep interactions. As I sat on prominent hilltops and watched over ewes and lambs, it was clear the rugged grasslands of the Falklands belonged not to the humans (there is one farm resident for every 3,700 ha of pastureland), but to the hundreds of thousands of sheep and wild geese.

The farmers I visited welcomed me generously but without fanfare, as though good hospitality came as naturally as conversation about the weather. Once the tea was poured, and the small talk had ended, I began to ask farmers about turkey vultures. How do vultures behave around sheep? Have you seen a vulture attack, or kill, a sheep? What do you think about government policy on turkey vultures? I asked my questions, then grabbed a biscuit, sat back, and listened.

The conflict between farmers and turkey vultures in the Falklands is one example of the phenomenon known as human-wildlife conflict (HWC). HWCs occur when humans and wildlife compete for the same resource, such as a cassava crop or a young lamb. Farmers sometimes kill offending wildlife, and humans with wildlife sympathies become involved and oppose wildlife killings. HWCs tend to resist resolution because the stakeholders involved receive different costs and benefits from wildlife; the same wolf that provides aesthetic benefits to a backpacker also threatens the livelihood of a rancher trying to make ends meet. It is not surprising that different groups have different ideas about how to manage wildlife.

Back in the dining rooms of the Falkland countryside, farmers’ attitudes toward turkey vultures varied greatly; some loathing, others loving these often misunderstood birds. Taken as a whole, our interview results showed that much of the conflict in the Falklands can be explained by a government policy that many farmers see as illegitimate. This policy outlawed many farmers’ preferred method, which is shooting, for dealing with problem turkey vultures. The policy exposes farmers to wildlife costs but does not incorporate farmers’ views, and thus irks some farmers.

During 184 hours observing vulture-sheep interactions, I did not observe turkey vultures to attack sheep. However, on two occasions one or more turkey vultures fed on a sheep on its side and unable to get up. During interviews with farmers, only one of 41 farmers gave a first-hand account of vulture predation on a young lamb, which indicates such behavior is rare. While our observations and farmers experiences show that turkey vultures can indeed harm some live sheep, the vultures appear to cause very little damage overall. What damage they do cause appears to fall on helpless sheep. Many of these sheep in the Falklands would be expected to die with or without vulture intervention, but some percentage of these sheep would
be found and saved by farmers if vultures, and other birds, did not hasten their deaths.

What is the way forward? Should farmers be allowed to shoot vultures when the birds cause little damage? We see potential to modify existing policy to better incorporate farmers’ views without sacrificing the conservation of turkey vultures. Our results indicate that a policy that allows farmers to shoot a limited number of turkey vultures posing an immediate threat to sheep would result in few vultures killed overall, and would empower farmers. Admittedly, some innocent turkey vultures may be killed by farmers who perceive a threat when in fact none exists.

Nevertheless, we believe this option is a good one because (1) most farmers have little interest in shooting turkey vultures but would like to be able to act to protect their sheep if they see a threat, (2) enforcement of vulture protection is nearly non-existent in the sparsely populated Falkland countryside so a policy that appeals to farmers may provide greater protection for turkey vultures than strict, but unenforceable, regulations, (3) allowing limited shooting is unlikely to threaten the conservation status of turkey vultures because there are several thousand turkey vultures and fewer than one hundred farms, and (4) removing problem turkey vultures may protect farmers by removing birds who may possess specialized
learning and have potential to be repeat offenders.

We also recommend additional routes for managing the farmer-vulture conflict. On the husbandry front, farmers who remove carrion from lambing paddocks can reduce the number of scavengers that visit these paddocks, and hence the potential for vulture damage. Our results also show that about half of farmers do not recognize the benefits vultures provide by cleaning up many of the approximately 50,000 sheep that die annually in the Falklands. Without turkey vultures, it is likely these dead sheep would boost populations of more aggressive birds, such as crested and striated caracaras, with negative consequences for sheep farming. Speaking to farmers about
the benefits vultures provide can increase farmers’ tolerance and  appreciation of these ecologically important birds. Finally, policy-makers who occasionally travel the countryside to put their finger on the pulse of farmer opinion will pen more durable policies, build relationships as well as social capital, and enjoy a biscuit or two during the process.

Human-wildlife conflicts are complicated, and resolution strategies usually cannot satisfy everyone. It is important for stakeholders to see each other’s point of view, so that compromises can be reached, and everyone can be partially, if not completely, satisfied.

The content of this article comes from a manuscript in preparation by Brandon M. Breen, Kristen C. Nelson, Francesca J. Cuthbert, and Keith L. Bildstein.

________________________
Brandon Breen
Biólogo
Proyecto Cóndor Andino
Fundación Cóndor, Parque Cóndor

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