BOGOTÁ — In a kind of eerie, Darwinian evolution, abandoned pets in parts of Colombia have become feral beasts and predators that are proving more fearsome than wild animals. Once again, wildlife is proving defenseless in the face of yet another man-made threat, produced in this case by former owners of an unwanted dog or cat.
Signs of their presence were recently seen in the Chingaza national park east of Bogotá, and in coffee producing areas west of the capital. We recently traveled to Chingaza to look, together with members of the Wii Foundation, for spectacled bears. In the park's buffer zone, we stumbled across the scattered, half-rotting, half-dried remains of a lowland paca. The large rodent didn't seem to have been killed by a bear, an ocelot or a puma — which in any case are now thought extinct in the park — but by a wild dog, or pack of dogs.
"Usually you don't find forest animals dead in an exposed area and their carcasses left exposed in this way," says Daniel Rodríguez, the foundation's director and a leading spectacled bear conservationist. Rodríguez notes that people usually take their hunting trophies with them; ocelots bury their dead prey to protect them; and foxes usually eat up their meal entirely.
Pacas aren't the only animal victims of such mishaps. In the department of Tolima west of Bogotá, a camera caught a pack of dogs attacking a bear cub. And in Guavio, outside the Chingaza park, peasants have woken to find their sheep killed in dog attacks. Deer are another frequent target.
Since when do dogs hunt this way? Are they not tagged as domestic animals? Isn't "wild dog" an oxymoron?
Enrique Zerda, a professor at Colombia's National University who has studied feral animals, says the problem began in the 1950s, when recreational hunting was permitted and pets accompanied their owners on outings. The dogs would sometimes remain in the mountains or were lost, and had to survive on their own. All ties to humans were broken as they no longer depended on people for food of shelter. Instead they formed packs to hunt. Genetically, it should be pointed out, they are identical to wolves.
Unfortunately, nobody has carefully studied these animals. Biologists deal with wild fauna not domestic animals, and the government considers this a minor issue. "We do not know their behavior, nor at which point they become wild or the area they occupy," says Zerda. "My investigation is into how much like wolves they become — if they follow the same behavioral patterns."
For now, Zerda is seeking answers to several questions: How much impact do feral dogs have on biodiversity? And how can this problem be controlled without a cull? Perhaps through sterilization or adoption centers?
Damage and disease
Wii's Daniel Rodríguez says the dogs are proving harmful in three specific ways. "They prey on native species and pursue ducks, migratory birds, guinea pigs and deer," he says. "They transmit illnesses like canine distemper, parvoviral pathologies and rabies to forest animals and humans. And they impact the economic well being of rural families by feeding on sheep."
An additional problem is that they compete with naturally existing predators. As data compiled by Procat Colombia revealed, feral dogs in Bogotá's eastern hills are thought to have forced wild cats and dwarf coatis to move to other sectors. This is happening elsewhere in the world: In Australia, dogs compete with foxes for small mammals; and in India and Africa, they compete with wolves for antelope and rodents.
For now there is no policy in place to manage these animals. Environmental and academic bodies are just starting to analyze the data and environmental authorities have yet to pay much attention to the situation. Some experts, nevertheless, have begun putting forth suggestions. While some are calling for a sterilization campaigns (for pets), others propose a "humane" cull given the difficulty of returning the animals to their domestic condition.
Time to pay attention
Generating policies is complicated, says Daniel Rodríguez. Animal defenders, for example, will likely denounce any attempted cull. Elsewhere in the world, however, authorities have ended up taking just that approach to tackle the problem of invasive species, which Colombia's feral pets essentially are.
On the Galápagos Islands, for example, authorities in the Galápagos National Park decided to kill off goats, which had stripped entire mountainsides of their vegetative cover, leaving tortoises without food or shade.
In Colombia, the problem is mainly in the department of Cundinamarca, the Bogotá wetlands, Chingaza, the countryside outside Medellín and the Nevados national park. Feral dogs aren't the only menace. Cats have also moved back into woodlands and are hunting native birds and lizards.
Researchers agree more data is needed but say the problem primarily comes from people abandoning pets. They say strong policies are needed before it's too late. The ministries of the environment, agriculture and health, in the meantime, would do well to look into the problem given its impact on forest wildlife, livestock and the possibility that feral dogs and cats could transmit diseases to humans.