Saturday, 4 September 2010

Parrots of Bristol 2: The Black-Cheeked Lovebird (100th post!)

Close to the water play area in the middle of the zoo is our colony of Black-Cheeked lovebirds, Agapornis nigrigenis. Lovebirds have long been kept as pets, and several species are sufficiently well established that there are numerous colour varieties, but the Black-cheeked is not one of them. Until a ban was imposed some years ago, there was a trade in wild-caught birds, but this has now ceased, although some are caught for food or to protect crops.

The main threat to this species however is drought, which has adversely affected the wild population, and as this species has the smallest known range of any lovebird species (almost confined to Zambia and a wild population of at most 10,000 birds) the IUCN has classed it as Vulnerable.

There are nine species of Agapornis altogether, with a core group of four species all of which have white rings around the eyes (A.nigrigenis, A.personata, A.lilianae, A. fischeri).. Lovebirds are all much the same size, around 15cm (6 inches) long. The eye-ringed group plus the Peach-faced Lovebird A. roseicollis, all breed freely in captivity.
Masked Lovebird A.personata

Peach-Faced Lovebird A.roseicollis
The remainder are all much more difficult and the captive populations may not be sustainable. The problem with the easier species is that they will readily hybridise, and the hybrids may themselves be fertile. As a result, there may be few pure captive Fischer’s lovebirds (which hybridise with Peach-faced), and Black-cheeked lovebirds outside the zoo population may have a lot of genetic input from the Masked lovebird A.personata.
Madagascar Lovebird A.cana

Most lovebirds are birds of open woodland or wooded savannah, where they feed on the seeds of grasses and nest in holes in trees. Black-Cheeked and Masked are semi-colonial, and will freely nest in groups in large aviaries, so long as there are sufficient nest boxes, whereas the others are more territorial and need an aviary to themselves when breeding. All lovebirds are aggressive with other birds and cannot be kept with other species.

Lovebirds are among the few parrots which bring nesting material to their nests. This takes the form of strips of bark removed from green branches, which are either carried in the beak or tucked into the feathers of the back and tail to carry back to the nest. Lovebird breeders will provide fresh willow stems for their birds to collect their nest material. Like most parrots, lovebirds are inveterate chewers and it is vital that they have branches to exercise their fairly powerful beaks on.

The basic captive diet of lovebirds is a mixture of seeds of various sizes, plus some fruit and vegetables. They love to bathe, and in the wild would probably visit waterholes to drink and bathe at dusk. Although the commonly kept species are not especially sensitive to cold, they should have a frost-proof shelter with additional lighting during the winter in temperate countries.

Bristol has been very successful in breeding lovebirds, and has sent many to other zoos. We are currently restricting the reproduction to avoid winding up with more birds than we have room for. Actually, this is a common element in many zoo population management plans – from the point of view of keeping a genetically diverse captive population it is important that breeding be properly controlled.

With egg laying animals excess reproduction is controlled by removing eggs, but with mammals the entire situation is more problematic, especially as you cannot control the gender of the offspring. This results in what you might call the ‘spare male’ problem – in the wild many mammals have a harem structure with non-breeding males living either solitary lives or in bachelor groups until they win a chance to breed. In captivity this causes a serious burden, as you are faced with the choice of either maintaining animals you have bred that are genetically surplus for their entire lives, or euthanizing healthy animals, neither of which appeals.

The problem with what to do with spare, geriatric, or otherwise surplus stock is a major topic of debate in the zoo community, and is the hardest to explain to the general public. The major difference between private owners and conservation breeding is that the administrator of a conservation breeding programme has to think like a farmer – a good farmer wants his or her animals to be in the best of health and properly looked after, but in the end they are there to be sent to market, and there is no point in getting too sentimental.

When running a reintroduction programme there are also animal welfare issues – for example the Black-Footed ferret programme in the US uses live hamsters and prairie dogs to train potential introduced animals in hunting technique. All of these ethical issues have to be decided ona case by case basis, and the EAZA ethics committee is involved in creating guidelines for member zoos to adopt.;

(images from wikipedia)

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