Elephant Birth Control
||21 October 2012 07:00
Chantal Rutter Dros
|Show: ||Carte Blanche|
The great elephant migrations of bygone years in search of food are a thing of the past in South Africa. Now they're trapped behind fences within artificial encampments and numbers have to be controlled so they don't eat themselves out of house and home.
Chantal Rutter Dros (Carte Blanche presenter): "Until recently culling elephants was one of the few options available to curbing elephant populations. Now, after ten years in the field, pigs' eggs are proving to be the perfect pill."
Audrey Delsink (Research Ecologist): "Primarily the vaccine is derived from what's called the PZP - it's the specific layer around the ovary of a domestic pig."
Audrey Delsink, is the resident research ecologist at the Makalali reserve near Hoedspruit. She has been working on immunocontraception for more than a decade.
Audrey: "We had a lot of critics saying it wasn't possible, that it would never work, but one by one we've demonstrated against those concerns, and we've proven them wrong."
Treatment with the PZP experimental vaccine brings about the formation of anti-bodies in the cow. The main effect of these anti-bodies is to stop sperm from binding to the egg to prevent fertilisation.
Chantal: "Where do the pigs' eggs come from?"
Audrey: "The pigs basically come from an abattoir."
So the much-maligned pig is making its mark in research in immunocontraception in free-ranging African elephants. So far 13 reserves, including Thembe National Park, have jumped on board and are jabbing their ellies from the air.
Audrey: "We have taken it to one provincial reserve and we're treating about 70 to 80 females in that population."
Over the years we've investigated various methods of elephant management - like translocation, migration corridors, contraception and the saddest of all, culling.
Chantal: "What made you look for an alternative to culling?"
Audrey: "Well, we believe that there is a place for culling and other traditional population control method. However, we were willing to investigate this as an alternative to regulate our population, but to do it in a more humane and ethical manner."
It's a technique that has been used for at least 25 years in the United States to regulate white- tailed deer and wild horse populations.
Audrey: "It's new to us in that we're using it on African elephants... or free-roaming African elephants... as a control method."
Chantal: "The difference with this vaccine is that it's non-hormonal. In fact there is currently a paper under review which suggests that there are no behavioural changes with sustained use."
Audrey: "Our paper is very exciting and we have done a number of publications, but this one specifically looks at the lack of social and behavioural consequences of the sustained use of this vaccine as a population control method."
[Web interview] Prof Henk Bertschinger (University of Pretoria): "It's a non-hormonal method, it's a reversible method, and it has very little in the way of side effects, except that the animals would keep coming on heat every 15 weeks or so."
Emeritus Professor Henk Bertschinger, once involved in reproductive research, has become a contraceptive expert.
In the mid-1990s, he was involved in trials into non-hormonal methods of contraception in the Kruger Park.
[Web interview] Prof Bertschinger: "The other method we used was a hormonal method where they put in oestrogen implants, and oestrogen is the hormone responsible for the signs of heat. So what happened in those elephants is that they were in continuous heat for at least six months."
But as can be imagined, elephants in a continuous state of sexual excitement create mammoth problems. The bulls were after the cows non-stop. The trials were stopped.
Prof Bertschinger: "They were stopped in the Kruger National Park... they never got beyond that stage."
Audrey: "And we have learnt lessons since from the severe behavioural anomalies we witnessed with the hormonal trials in Kruger and we've looked at our herds very closely to ensure that we aren't seeing such behaviours."
Chantal: "Because critics would level that at you, that there would be hormonal changes and that you are trying to mess with the natural flow of things as what happened at the Kruger Park."
Audrey: "Yes and no, because it's a non-hormonal vaccine. So what we're seeing is no hormonal induced changes, but we are seeing frequency of oestrus increasing simply because the cow is not falling pregnant. So she is coming into oestrus."
Elephant ecologist Audrey keeps a close eye on all the females and says the vaccine is 90% effective.
Hard to believe she once feared these beasts. Now they make her laugh.
Audrey: "They really do have a sense of humour. Their passion for their family is phenomenal - they are extremely loyal. But when I think of elephants, I just want to giggle 'cause they are just so comical."
Chantal: "You've got quite a close connection with them - do you feel that you've bonded with them?"
Audrey: "Certainly from my side I have. I mean, I've been here for 14 years. I know that elephants do have an incredible sense of smell... I like to think that there's some kind of relationship, but I think it's a bit presumptuous to say that."
We first met Audrey and wildlife specialist JJ van Alten tracking and darting elephants on foot 12 years ago (Carte Blanche July 2000). They were trying to curb a baby boom at Makalali, where the population of elephants had grown from 37 to 54 in just four years.
Chantal: "If you hadn't implemented this, where would your elephant population be now?"
Audrey: "Our population would well be over the hundreds... probably 120 to 130 elephants."
Chantal: "And how many have you got now?"
Audrey: "We've currently got 62 elephants, and that's with our planned pregnancy programme where we allow individuals to come through, and also with our reversals."
But it hasn't always been plain sailing - JJ, who handles all the darting for the contraception, has had some close calls.
JJ van Alten (Wildlife Specialist): "It was quite something and hair-raising as well in the beginning to do it from the ground; time consuming and very scary."
They used to have to sneak up on the elephants, vaccinate them, retrieve the dart and flee on foot.
JJ: "I'd go walking and there would be a bull elephant 20 metres from us - if the wind is right and the situation is right, I'm not even worried about him, you can push them off. A female when she comes, she's coming for business."
The cows have to be injected three times in the first year and then followed up with an annual booster. Now research into a single dose vaccine or pellet is being funded.
Audrey: "And so we're looking for a pellet which will combine those into a single shot that will last for three years."
Chantal: "It's early in the morning and we're loading the last of the darts before we take to the skies and dart these elephant. The weather is looking a little bit iffy, but everyone is confident that it's going to hold out."
JJ: "First things first - darts. We've got a marker inject dart - this is a system through trial and error we've ended up with; it's the best system for implementing this."
With the darts loaded and the team ready, it was all systems go.
Audrey: "Basically, the vaccine is delivered by means of a drop-out-dart, so the animal is injected and the dart falls out a short while after impact."
JJ: "So when this impacts the elephant, both plungers [on screen] go off... that shoots the dye out, and this plunger injects the vaccine into the elephant."
Audrey gets two satellite readings a day from collared animals, so it wasn't hard to locate them on the 23 000 hectare reserve.
JJ: "As the helicopter moved in, they bomb-shelled, so we had to slowly start ticking them off and ticking them off the list to get them done."
Audrey is able to recognise them from their characteristics. She then points the cow out to JJ and he takes over.
Audrey: "In some instances some of the little immediate family members, so mommies and babies or sisters may splinter off as you're working with that group. So our job is then to target the individuals that we need to and then re-group and continue vaccinating them."
But these courageous females stood their ground in order to protect this newborn baby.
Audrey: "The cows were a bit protective and a little bit more reluctant to split off."
Chantal: "It was very touching to see all those big elephants surrounding that tiny little baby to keep it safe when they saw the helicopter."
Audrey: "That is typical behaviour of elephants. Their role is to protect those youngsters and so that's what they do; they form a little circle and shepherd those little youngsters."
22 Elephants had their booster shots and three new recruits were done and dusted in just under 90 minutes. The price tag? R1500 per elephant, including the chopper.
JJ: "It went fantastically well. We did all the animals we needed to do and we did it in an hour and 20 minutes, which is half an hour quicker than last year's."
Chantal: "Behind me is one of the elephants who was darted yesterday. Her name is Flasher and she's a new recruit to the programme. As you can see, it's a day after, and all the elephant are very calm."
Chantal: "You're wanting to see the baby and see how it's doing?"
Audrey: "Ja. There's a brand, brand new baby that's less than a week old. And what we've done, we've allowed mothers to have their first calves because it's incredibly important that the individual has the opportunity to calve, but also for the well being of the herd."
Chantal: "The beauty of this vaccine is that it's reversible. To test this, they took five cows which had been treated for five years and removed them from the programme, and three of them calved."
Audrey: "Because this vaccine works on the animals' anti-bodies, if we stopped administering the vaccine her anti-body levels drop to normal and she can once again conceive. So it's not a permanent solution."
But the pigs' eggs vaccine is certainly proving to be one of the solutions to prevent parks from becoming over-populated, and the aim is to expand the program to larger elephant herds.
Audrey: "If it had to come down to a combination of tools, perhaps this could be used as a method to reduce the number of individuals that would have to be culled."
JJ: "It's saving elephants; you're not having to cull them. And, to me, any alternative than having to pull the trigger on the elephant to kill it is an option."
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