Birds of a feather love together
Sheree Russouw
24 January 2005
They acted so much like lovers that at first conservationists were convinced that a pair of wattled cranes was exactly that. They were right, but with one small difference: the two are both female. Now staff at the Johannesburg Zoo are hoping they might become parents, too.
Over the past five years these rare birds, Amazona and Cherry, have formed an unlikely - yet very deep - same-sex bond.
Since their arrival at the Johannesburg Zoo in April 2004, the elegant pair has enthralled staff with their graceful courtship dances and public shows of affection.
Now the zoo plans to transform the couple into parents - with the help of an elaborate artificial insemination procedure that will get under way during the species' breeding season in winter in 2005.
Bird curator Mike Hamon says Cherry and Amazona's union, however mismatched, could prove vital to the survival of South Africa's critically endangered wattled crane species. Without
these interventions, he says, the future of the species "looks pretty bleak".
It is believed the birds formed their bond five years ago while nestled together at a bird breeding facility near Vereeniging in Gauteng. And wattled cranes, the largest of all crane species, mate for life.
Hamon says the "mistaken pair" display behaviour that is common to male and female breeding pairs. "They are doing things that a normal pair would do. Their unison calling is a sure sign that they have bonded. They have built a nest together and their activities around the nest indicate they are a pair."
While the phenomenon of same-sex relationships is rare among wattled cranes, it has been recorded in the wild and in captivity, says Kevin McCann, manager of the South African Crane Working Group, a project run by the Endangered Wildlife Trust (EWT).
"There are a pair of female wattled cranes living in the wild in the Free State who have been together for the past 10 years and
have formed a very strong pair bond", says McCann. "Every year they lay infertile eggs."
He attributes such unusual same-sex partnerships to the low numbers of wattled cranes in the wild in South Africa.
The annual crane count for 2004 revealed that there are only 240 of the birds left in their wetland habitats, mostly in KwaZulu-Natal. The biggest threat to the species is habitat loss from farming practices like damming and draining wetlands.
"There are so few birds and a lack of mate choice", McCann says. "This activity is a function of looking for a mate once a wattled crane is sexually mature. Wattled cranes are incredibly social and want to be with birds of the same species."
The zoo is home to four wattled cranes - three of them female. Hamon says the lone male, Mitch, is sexually mature but already has a mate of his own. Introducing Amazona, who lays infertile eggs every year, to Mitch could result in her being killed.
This is one of the
reasons why artificial insemination is the "definite option" for the zoo, says Hamon. "We will stimulate Mitch, then collect his semen. The semen will be frozen in liquid nitrogen. When the female is prepared, the semen will be implanted inside her."
The zoo hopes it can inseminate both Amazona and Cherry, to give the project a better chance of success. Wattled cranes only lay a clutch of two eggs and raise one chick - the second egg is only an "insurance policy" in case the first egg does not hatch or the fledgling suddenly dies.
And if Amazona and Cherry's eggs do hatch, it will mark the first time that wattled cranes have been born in captivity in South Africa.
But wattled cranes are very slow breeders, and Hamon says the zoo will have to "play the plans for artificial insemination by ear".
"In South Africa, we don't have much experience doing this procedure", Hamon says. "It's also a hard and long process to get wattled cranes to breed. It takes several
years for the birds to become sexually mature. They can breed in their 30s and are long-lived birds, but their breeding turnover is very slow."
McCann says it is difficult and costly to "sex" birds, as they have to be anaesthetised and examined internally by a vet.
"Their physical features are identical. It's not as if you can say the male is larger than the female, as is the case with other species. Most times the birds are blood sexed, and the technique is not 100 percent correct."
But for Amazona and Cherry, theirs seems a bond only death will part. Says Hamon: "It's difficult to get viable breeding pairs, so we are lucky that Amazona and Cherry have paired up. We just want to get the numbers of wattled cranes up. It doesn't matter if it is two females who will be helping us do that."
Source: City of Johannesburg website
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