Lead-poisoned eagle recovering quickly
Thursday, Dec 06, 2012 06:00 am
A lead-poisoned golden eagle found near Exshaw early last month is well on its way to a full recovery and may be released back into the wild in the coming weeks.
The male eagle, discovered by Fish and Wildlife officer Dave Dixon west of Exshaw on Nov. 9 and taken to the Alberta Institute for Wildlife Conservation (AIWC), was “thin, hypothermic and dangerously anemic,” according to Dianne Wittner, a wildlife biologist and director of wildlife care and operations at the Madden, Alta.-based AIWC.
When the eagle arrived at the centre, Wittner said, he weighed 3.4 kilograms and his prognosis was grim, as he had one of the highest levels of lead poisoning for an eagle that Wittner had treated at the centre.
“He was deathly ill and the biggest threat to him right off the bat, the first threat we had to address, was anemia,” Wittner said Monday (Dec. 3). “If we looked at something else and didn’t focus on that, he probably would have died of anemia.”
Lead poisoning, which in raptors can cause organ failure, paralysis and blindness, along with numerous other symptoms, is difficult to treat, as it requires a constantly evolving treatment plan that changes from day-to-day and throughout the day. How an eagle responds to a previous treatment dictates how staff at the centre follow through with the next treatment.
“You choose your medications, food and fluids depending on how he responded to the last treatment,” she said.
Drug treatments occur three times a day, along with regular checks of temperature, blood tests, hydration levels and weight. And a treatment plan for a raptor with lead poisoning is never the same twice.
“There’s a whole list of meds, but what meds you give them and when is entirely dependent on their profile. You can’t treat any two eagles the same and if you do, you’re probably going to kill one or the other.”
The drugs used to treat lead poisoning, however, are expensive and have a short shelf life,
but Wittner said the centre keeps them stocked, as it’s a matter of when a lead-poisoned raptor comes through the door, not if. One year, for example, Wittner and her staff treated five birds with lead poisoning over a two-and-a-half month period and this year, she’s treated two.
Raptors, including golden eagles, are highly susceptible to lead poisoning, Wittner said. Eagles are opportunists and will feed on prey and carrion, which can lead raptors – including the golden eagle in Wittner’s care – to ingest shards of lead bullets from carcasses and gut piles left behind by hunters.
“Usually the worst of it is over the winter-time when they are more susceptible to hypothermia and, of course, when hunting season is over. Usually within two months of hunting season being over, we’re done,” she said.
But Wittner was to quick to point out she doesn’t see this issue as one of careless hunters, but more so the use of lead bullets and a general lack of understanding of what lead can do to Canada’s most majestic birds.
“This has nothing to do with carelessness,” she said. “This has everything to do with lack of awareness.”
Poaching, however, is a different issue, altogether, she said.
Lead shot for waterfowl hunting has been banned in Canada since 1999, after researchers found that ammunition used in shotguns was the primary cause for lead poisoning among ducks and other water birds, according to Environment Canada. Prior to the lead shot ban, an estimated 250,000 water birds were poisoned annually.
Lead bullets, however, remain legal across Canada and, in many regions, such as Alberta, ground squirrels and coyotes are shot as a way to manage the numbers and those carcasses, which are often left to rot, are scavenged by other animals, including eagles.
Hawks, for example, only need to feed on ground squirrels shot with lead bullets for 23 days to ingest enough lead to kill them, according to Environment Canada.
“We kill about 36,000 coyotes in Alberta a year,” said Wittner, “and I suspect the majority of them are just shot and left, so if you’re an eagle and you see this dead body, what’s the first thing you go for? That red bloody wound.”
In a move to protect the critically endangered and iconic California condor, which as a scavenger is also prone to lead poisoning, California Fish and Game Commission in 2008 banned the use of lead ammunition in condor habitat.
A study looking at lead poisoning in the iconic condors, published earlier this year in the Proceedings of the National Academy of Sciences of the United States of America showed that even with the ban, lead ammunition continues to be the primary source of lead poisoning among condors, a bird that can cover hundreds of kilometres a day, as it only requires one exposure to lead for these birds to be poisoned. Poaching remains an issue in California as it does in Alberta.
Alberta Environment and Sustainable Resource Development spokesperson Carrie Sancartier, said Tuesday that while the Province is not considering a ban on lead bullets at this time, SRD is tracking the issue and studies documenting lead poisoning among raptors.
“As with anything like this that would potentially impact our wildlife, we are following the research being conducted around this issue to determine how pervasive it is and what the impacts are,” Sancartier said.
After responding well to Wittner’s care and feasting on feral rabbits from Canmore that were euthanized recently as part of the trapping program, the eagle now weighs a “robust” 4.4 kg.
“It’s so horrifying when (eagles) come in. They’re powerful birds and they’re helpless. They’re standing or lying down with their heads drooping and they’re unresponsive. It’s tough to look at, and when they come back, ‘wow!’
“He’s down there right now eating a rabbit. One of your Canmore rabbits, actually,” Wittner said during an interview with the Outlook. “It’s such a fantastic use of those rabbits. They are helping to save an animal’s life, something like an eagle. I think the Canmore people who have donated these rabbits to us are doing a fantastic thing. If (the rabbits) are going to die, let’s not make their death go to waste.”
With the eagle showing such positive signs in his recovery and the recent onset of warm weather, Wittner said the bird is ready to go outside for some exercise.
“Now that we have this nice window of weather we’ll get him outside and see how mobile is and if he is flying really well, we’ll want to get him out while the weather is good,” she said.
Wittner plans to consult leading golden eagle expert Peter Sherrington to get a better sense of where to release the bird, which may occur as far south as the U.S. border.
“Baldies (bald eagles) you can let go any time of the year, but I want to hear about goldens, about the best place to release him when he’s ready and if Peter suggests we keep him until March or April, we’ll do that,” she said.
If that happens, Wittner said staff at the centre would have to ensure he has shelter from the wind and weather and plenty of food to eat so he is able to keep himself warm.
Despite his awful early prognosis, the golden eagle’s recovery is providing Wittner and her staff with a needed victory.
“You need those good pieces to help counterbalance the bad ones,” she said, adding 40 per cent of all animals that come to the centre do not survive.
“Those victories – especially when they are pretty substantial, say you have one that is teetering on the brink for a while and they turn the corner and you say ‘OK, I think they’re going to make it’ – that’s when it’s great, especially with a golden eagle, because they are so impressive.”
Unlike their cousins, bald eagles, Wittner said golden eagles, classified as sensitive in Alberta, are surprisingly easy to work with.
“It’s such a pleasure to work with golden eagles. With a golden, usually you can go in and administer meds, listen to the heart and all of that without anybody holding them. I’ve even changed bandages on a golden without anybody holding it. With a baldy, look out!”