Southern Africa has too many elephants and lions. Is contraception the answer?

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The shepherd’s tree, from a species known as the tree of life for its nutritional qualities, stood alone for many years in a corner of a South African wildlife reserve near the Botswana border.

One morning it lay dead – uprooted and toppled by a herd of passing elephants. Wildlife rangers mourned its passing. “I loved that tree,” sighed Mike Rae, a ranger at the Madikwe reserve who often brought tourists to the tree and the birds that fluttered about it.

The fallen tree tells a larger story – about the elephants that killed the tree and an unexpected problem of abundance.

ELEPHANT

POPULATION

Decreasing

Stable

Increasing

0

1,000

KM

Madikwe

Wildlife

Reserve

The Makalali

Conservancy

is near Kruger

National Park

Note: Many smaller parks

and reserves are not

shown on this map

TRISH McALASTER / THE GLOBE AND MAIL

SOURCE: GREAT ELEPHANT CENSUS

ELEPHANT

POPULATION

Decreasing

Stable

Increasing

0

1,000

KM

Madikwe

Wildlife

Reserve

The Makalali

Conservancy

is near Kruger

National Park

Note: Many smaller parks

and reserves are not

shown on this map

TRISH McALASTER / THE GLOBE AND MAIL

SOURCE: GREAT ELEPHANT CENSUS

ALGERIA

LIBYA

EGYPT

MAURITANIA

MALI

NIGER

SUDAN

CHAD

BURKINA

FASO

NIGERIA

ETHIOPIA

CENTRAL

AFRICAN

REPUBLIC

SOUTH

SUDAN

CAMEROON

BENIN

UGANDA

KENYA

DEMOCRATIC

REPUBLIC OF

THE CONGO

ELEPHANT

POPULATION

TANZANIA

Decreasing

MALAWI

ANGOLA

ZAMBIA

Stable

Increasing

ZIMBABWE

NAMIBIA

0

1,000

BOTSWANA

Madikwe

Wildlife

Reserve

KM

MOZAMBIQUE

The Makalali

Conservancy

is near Kruger

National Park

SOUTH

AFRICA

Note: Many smaller parks

and reserves are not

shown on this map

TRISH McALASTER / THE GLOBE AND MAIL; SOURCE: GREAT ELEPHANT CENSUS

The iconic giants, beloved by tourists and photographers, have increasingly been targeted by poachers for their ivory, triggering a devastating crash in their population in many parts of Africa. Yet in other parts of the continent, their population is so fast-growing that they threaten the forests.

Another majestic animal, the lion, is trapped in the same quandary. Endangered in much of Africa and with their overall numbers sharply in decline, lions have surprisingly reached surplus levels in many public and private wildlife reserves in southern Africa, at a severe cost to other wildlife species.

So researchers are studying an innovative way to curb the growth of elephants and lions: contraception.

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When the 75,000-hectare Madikwe reserve was carved out of derelict farmland in 1991, its founding population included about 200 elephants, transplanted from Zimbabwe in what was called Operation Phoenix. Today, purely from natural growth, those 200 have rapidly transformed into about 1,200 elephants, and the number could double again in the next decade.

The herds are expanding so fast that Madikwe is now considering a plan to dart the females from helicopters to inject them with a contraceptive vaccine. It’s an idea that 27 other reserves have already begun trying, with about 850 females currently on contraception across South Africa.

Elephants can be surprisingly quiet as they pad silently along a trail to a water hole. But when they are feeding, the noise and destruction can be enormous. They sweep relentlessly through a landscape, trampling the bushes, ripping up the grass, snapping branches off trees, knocking over tree trunks, snorting, rumbling, munching and defecating. They sleep only two hours a day, giving them as many hours each day to consume up to 250 kilograms of vegetation.

For tourists, it can be a thrilling sight. But when their numbers are excessive, elephants can wreak havoc on an ecosystem, flattening entire forests in places such as northern Botswana. The death of the lonely shepherd’s tree in Madikwe is just a small example of the environmental damage that can result.

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The decline of Africa’s elephant population, which plunged from about 1.3 million in 1979 to an estimated 400,000 today as a result of poaching and other human pressures, has galvanized global attention and conservation campaigns. Poachers are killing an estimated 20,000 elephants annually. The decline has been swiftest in Tanzania, where thousands have been killed, and in West and Central Africa, where tiny populations of elephants have been completely wiped out in several countries.

Yet the publicity over the poaching crisis has obscured the reality of booming populations in much of southern Africa. There are at least 130,000 elephants in Botswana alone and some estimates suggest the number has reached 230,000, provoking a debate over whether to legalize elephant hunting to create local jobs and reduce crop damage. Zimbabwe has sparked controversy by exporting dozens of elephants to safari parks in China.

South Africa today has about 24,000 elephants – a dramatic rise from the 1920s, when fewer than 150 elephants survived in the entire country. There are about 17,000 elephants in world-famous Kruger Park today, far beyond an earlier planned limit of about 7,500.

Dozens of private reserves have been created over the past two decades, and their fast-rising elephant numbers have bumped up against the limits of their fences and their budgets. In some reserves, elephant numbers are growing by more than 15 per cent annually – twice the normal rate.

The De Beers diamond company, which runs a private reserve in South Africa, announced in July that it would relocate 200 elephants to Mozambique because of overcrowding. Its 32,000-hectare reserve can sustain only 60 elephants, but the population has soared to 270, risking “extensive damage” to the ecosystem, it said.

Until the mid-1990s, elephants were often culled in South Africa to control their numbers. The public backlash against culling has made this an impossible option today, so other approaches are being tried. Artificial waterholes have been reduced or eliminated, which helps a little. Wildlife corridors have been proposed to join reserves together, but obtaining the land can be difficult. Hundreds of surplus elephants have been translocated to other reserves or other countries – but that is a costly and complex option. And so a rising number of reserves have turned to contraception.

The experiment began in Kruger Park in the late 1990s and then shifted to a long-term program at the nearby Makalali private reserve in 2000. It is now the world’s longest-running program of elephant contraception and it has proven to be remarkably effective.

Using a dart rifle from a helicopter, cow elephants are injected with a vaccine that stimulates their immune system to produce antibodies that block fertilization. The vaccine is reinforced by annual boosters and can be reversed if necessary.

Recent scientific studies in South Africa have confirmed that the vaccine has no side effects and has been 100-per-cent effective as a contraceptive. At Makalali, it reduced the elephant growth rate from almost 9 per cent annually to a new rate of just 1 per cent to 3 per cent. It’s also cheaper than translocation, costing as little as $150 per year.

PREDICTED ELEPHANT POPULATION SIZE

AT THE MAKALALI CONSERVANCY

110

100

90

80

70

60

50

40

1998

‘00

‘02

‘04

‘06

‘08

‘10

Open circles and green line indicates the projected population size with contraception;

the closed squares and gray line represent

the projected population without contraception.

TRISH McALASTER / THE GLOBE AND MAIL

SOURCE: FREE-RANGING AFRICAN ELEPHANT

IMMUNOCONTRACEPTION REPORT

PREDICTED ELEPHANT POPULATION SIZE

AT THE MAKALALI CONSERVANCY

110

100

90

80

70

60

50

40

1998

‘00

‘02

‘04

‘06

‘08

‘10

Open circles and green line indicates the projected

population size with contraception; the closed squares and gray line represent the projected population without contraception.

TRISH McALASTER / THE GLOBE AND MAIL

SOURCE: FREE-RANGING AFRICAN ELEPHANT

IMMUNOCONTRACEPTION REPORT

PREDICTED ELEPHANT POPULATION SIZE AT THE MAKALALI CONSERVANCY

110

100

90

80

70

60

50

40

1998

‘00

‘02

‘04

‘06

‘08

‘10

Open circles and green line indicates the projected population size with

contraception; the closed squares and gray line represent the projected

population without contraception.

TRISH McALASTER / THE GLOBE AND MAIL

SOURCE: FREE-RANGING AFRICAN ELEPHANT IMMUNOCONTRACEPTION REPORT

The number of elephants in the contraception program has more than doubled over the past five years, now including provincial and national parks as well as private reserves. “It’s growing each year, and it’s been a major success,” says Audrey Delsink, executive director of the African branch of Humane Society International and field director of the elephant contraception program.

“I think we’ve really come a long way. We’ve addressed all the gaps in the knowledge that were identified in the past. There is no other alternative that’s as humane, as efficacious and as socially acceptable as this is. This ticks all the boxes.”

While the elephant puzzle seems to be solvable, an even more complex challenge is the lion – another animal whose numbers are proliferating in South African wildlife reserves, even as they decline in most other countries.

Across Africa, decimated by poaching and human expansion, the lion population has tumbled by 90 per cent over the past century, with only about 20,000 remaining. Yet in smaller reserves in South Africa, their numbers have soared.

A recent study found that a pride of four female lions in a fenced reserve can produce 64 cubs in a decade, of which 50 will survive to adulthood. In small reserves they have few competitors. “They breed like rabbits, and cub mortality is very low,” Ms. Delsink says.

Some reserves have managed to ship their excess lions to other reserves, but there aren’t enough places to take them. As a result, many reserves have been obliged to allow hunting – or simply use euthanasia to cull their lions.

LION POPULATION GROWTH RATES AND

THE NUMBER OF PERCEIVED EXCESS LIONS

IN SMALL RESERVES IN SOUTH AFRICA

(Latest available data as of 2014)

Number of lions XX

Lions in excess (XX%)

Intro

year

Reserve

8 (12.2%)

Venetia-Limpopo NR

Thornybush NR

Mun-ya-wana PNR

Pilanesberg NP

Greater Makalali PGR

Madikwe GR

Mabula GR

Welgevonden PGR

Karongwe GR

Shamwari GR

Kwandwe PGR

Addo Elephant NP

Main Camp

Kuzuko

Nyathi

Thanda PGR

Selati GR

n/a

‘91

’92

‘94

’94

‘95

’97

‘98

’99

‘00

’01

‘03

’07

‘11

’04

‘05

11 (n/a)

33 (17.9%)

45 (14.7%)

19 (14.1%)

68 (11.9%)

7 (18.7%)

15 (10.3%)

7 (16.2%)

23 (15.6%)

20 (17.4%)

9 (10.8%)

2 (n/a)

3 (n/a)

11 (8.1%)

13 (1.7%)

TRISH McALASTER / THE GLOBE AND MAIL

SOURCE:RAPID GROWTH RATES OF LION

(PANTHERA LEO) POPULATIONS IN SMALL,

FENCED RESERVES IN SOUTH AFRICA:

A MANAGEMENT DILEMMA (REPORT)

LION POPULATION GROWTH RATES AND

THE NUMBER OF PERCEIVED EXCESS LIONS

IN SMALL RESERVES IN SOUTH AFRICA

(Latest available data as of 2014)

Number of lions XX

Lions in excess (XX%)

Intro

year

Reserve

8 (12.2%)

Venetia-Limpopo NR

Thornybush NR

Mun-ya-wana PNR

Pilanesberg NP

Greater Makalali PGR

Madikwe GR

Mabula GR

Welgevonden PGR

Karongwe GR

Shamwari GR

Kwandwe PGR

Addo Elephant NP

Main Camp

Kuzuko

Nyathi

Thanda PGR

Selati GR

n/a

1991

1992

1994

1994

1995

1997

1998

1999

2000

2001

2003

2007

2011

2004

2005

11 (n/a)

33 (17.9%)

45 (14.7%)

19 (14.1%)

68 (11.9%)

7 (18.7%)

15 (10.3%)

7 (16.2%)

23 (15.6%)

20 (17.4%)

9 (10.8%)

2 (n/a)

3 (n/a)

11 (8.1%)

13 (1.7%)

TRISH McALASTER / THE GLOBE AND MAIL

SOURCE:RAPID GROWTH RATES OF LION (PANTHERA LEO)

POPULATIONS IN SMALL, FENCED RESERVES IN SOUTH AFRICA:

A MANAGEMENT DILEMMA (REPORT)

LION POPULATION GROWTH RATES AND THE NUMBER OF PERCEIVED

EXCESS LIONS IN SMALL RESERVES IN SOUTH AFRICA

(Latest available data as of 2014)

Number of lions XX

Percentage of lions in excess (XX%)

Intro

year

Reserve

8 (12.2%)

Venetia-Limpopo NR

Thornybush NR

Mun-ya-wana PNR

Pilanesberg NP

Greater Makalali PGR

Madikwe GR

Mabula GR

Welgevonden PGR

Karongwe GR

Shamwari GR

Kwandwe PGR

Addo Elephant NP

Main Camp

Kuzuko

Nyathi

Thanda PGR

Selati GR

n/a

1991

1992

1994

1994

1995

1997

1998

1999

2000

2001

2003

2007

2011

2004

2005

11 (n/a)

33 (17.9%)

45 (14.7%)

19 (14.1%)

68 (11.9%)

7 (18.7%)

15 (10.3%)

7 (16.2%)

23 (15.6%)

20 (17.4%)

9 (10.8%)

2 (n/a)

3 (n/a)

11 (8.1%)

13 (1.7%)

TRISH McALASTER / THE GLOBE AND MAIL

SOURCE:RAPID GROWTH RATES OF LION (PANTHERA LEO) POPULATIONS IN SMALL, FENCED RESERVES

IN SOUTH AFRICA: A MANAGEMENT DILEMMA (REPORT)

Under the euthanasia process, a lion – often an older male who that has been forced out of a pride – is darted with a tranquilizer. Then a ranger approaches it and shoots it in the head from close range. It’s an unpleasant sight, carefully hidden from tourists.

The Madikwe reserve began with just 11 lions in the mid-1990s, but by the end of the next decade the number had soared to about 120 and the lions were inflicting heavy damage: killing so many zebras and antelope that they were depleting the herbivores and squeezing out the smaller predators such as cheetahs and African wild dogs.

Today, after a relentless policy of relocation and euthanasia, Madikwe’s lion population is down to about 60, and its animal population is in a better balance.

Lions can’t be managed with the same kind of vaccine used on elephants, but a contraceptive implant can be used. It’s not a perfect solution. Some rangers have found that a female lion with a contraceptive implant can become large and aggressive, even attacking humans. But studies are calling for more research to find the best way to manage lions – and the consensus is that contraception is part of the answer.

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