Expert Blames Dog Disease for Wolf Decline

摘要：Most of the gray wolf pups born in Yellowstone National Park last year have died, possibly because of a dog disease, a federal wolf expert says. 美国黄石国家公园去年出生的大部分灰狼幼仔目前都已死亡。据有关专家日前表示，之所以出现这种情况，可能是由于一种犬类疾病的影响。

Most of the gray wolf pups born in Yellowstone National Park last year have died, possibly because of a dog disease, a federal wolf expert says.

Just 22 of the 69 pups born last year are still alive, said Doug Smith, the park's wolf project leader. That's the biggest drop in pup numbers since wolves were reintroduced to the park 11 years ago. The greatest toll was seen on the park's northern range, where only eight of the 49 pups born last spring survived.

"It's cause for concern, a great deal of concern," Smith said.

During the next few weeks, he said, officials plan to catch Yellowstone wolf pups and take blood samples to see if his suspicions about the disease, parvo virus, are true. The disease can cause extreme diarrhea and dehydration and kill more vulnerable animals, like young pups.

Though vaccinations are an option — many domestic dogs receive them — Smith said it would be difficult in the park.

"It requires two vaccinations to build up an immunity, and we'd have to catch every wolf," he said. "Both those things are impractical."

If parvo virus is confirmed, there is little officials can do besides monitor the population and hope exposed wolves build a natural immunity to the disease, he said.

The state's wolf program leader also suspects parvo virus is behind the deaths. Carolyn Sim said her suspicions are based on den-site monitoring and whether pups emerge in summer with their packs.

State wildlife officials plan to collect blood from wolves — possibly even from carcasses dead 24 hours or less — as part of their disease surveillance, she said.

Terry Kreeger, supervisor of veterinary services for the Wyoming Game and Fish Department, said that while parvo virus could have a noticeable effect for years on wolf populations like Yellowstone's, he doesn't believe it will be devastating.

It could, however, have implications for how wolves are managed, Smith said. The number of wolves in Yellowstone dropped last year from 171 to 118, he said. The largest single-year drop before that was 11 from 1998-99, when parvo virus also was suspected, he said.

The gray wolf is federally protected, but Wyoming officials are seeking more control over the predators amid complaints from farmers and ranchers who say the growing wolf population poses a threat to wildlife, livestock and pets.

Montana recently took over most management duties within its borders, and Idaho signed an agreement with the Interior Department on Thursday to do the same.

美国黄石国家公园去年出生的大部分灰狼幼仔目前都已死亡。据有关专家日前表示，之所以出现这种情况，可能是由于一种犬类疾病的影响。

据美联社1月7日报道，美国黄石国家公园狼饲养计划的负责人道格·史密斯说，该公园去年出生的69只小狼仔中，目前仅有22只幸存。这是自11年前，狼这一物种被再次引入到黄石国家公园以来，幼狼数量减少最多的一次。在该公园的北部地区，这种情况显得尤为明显。这里，去年春天出生的49只小狼中，目前仅有8只存活。

史密斯表示，这种情况已经引起了有关部门的重视。在接下来的几个星期中，有关人员计划捕捉一些生活在黄石国家公园中的小狼，并提取它们的血液样本进行化验。化验结果将验证史密斯的怀疑是否正确，即幼狼数量的大规模下降是否是由犬类细小病毒（parvo virus）所引起的。有些许养犬经验的人都知道，这种疾病会引起非常严重的腹泻、脱水，甚至可导致抵抗力差的幼犬死亡。

美国怀俄明州狼类种群计划负责人卡罗林·西姆对此也有相同的猜测，她认为细小病毒正是导致黄石国家公园内幼狼大量死亡的原因。她说，该州野生动物保护官员会收集狼的血液样本，其中也包括从死亡24小时之内的狼的尸体上提取的血液样本，并以此作为疾病监控措施的一部分。

史密斯说，尽管给幼狼注射疫苗不失为一种防范措施——很多宠物犬都会接种疫苗以预防感染细小病毒；然而，在公园内实施这一措施却并非那么简单。他说，需要接种两次疫苗才能让幼狼具有免疫性，这样我们就不得不设法捕获公园里的每一只小狼，而这些都是不切实际的。史密斯还说，如果化验结果最终证明的确是由犬类细小病毒引起的幼狼大批死亡，那么除了对狼群数量进行密切监控，并希望它们能建立起来一种天然的对该疾病的免疫性之外，人们几乎什么也做不了。