Balwyn meeting Report, 23 August 2014
Can Hooded Plovers be captive bred?
We all know that they are struggling in their natural beach habitat. There are approximately 3000 birds in Western Australia, 2500 birds in Eastern Australia and 1200 in Tasmania. Eastern Australia includes South Australia and Victoria but the Hooded Plover is extinct in New South Wales. The populations are decreasing. There was a 12% decline in bird numbers during the period 2000-2010 and there was a 58% decline in the Hooded Plover population on Phillip Island in just seven years during the 1980s.
So can Hooded Plovers be captive bred to make a sustainable population?
Mike Honeyman, who is studying for a diploma in Ornithology at Charles Sturt University, presented to the Balwyn meeting his research into the matter. In 1993-95 the Adelaide Zoo formed a captive breeding program, sometimes augmented with wild birds. Of these initial birds one pair was successful in raising chicks to fledglings. Eventually this pair was lost to rat predation. Overall captive breeding has not been the success that had been hoped for. Bimble foot, a skin condition where birds get calloused feet due to inappropriate floor substrate, has been a significant problem.
Mike Honeyman has written a husbandry manual for keeping captive Hooded Plovers. This includes the best practice guides for the care of captive birds, data collected from institutions around the world doing similar programs, and a study of the ecology of wild birds. Enclosures must be 20m² for four birds according to DEPI guidelines. However other items such as construction of the enclosure, security from predators, ambient conditions, and the construction substrate are also considered. For Hooded Plovers it has been found that supplying an ideal breeding enclosure is not an easy thing to do. The size recommended in Mike’s manual for four birds is 7m x 7m x 2m: double the minimum size of the DEPI guidelines. Despite this Bimble foot still remains a problem.
Having the best conditions that man can make does not stop the birds from fighting each other, especially in breeding season. Other institutions around the world have reported a similar problem, with fighting plovers in the breeding season, even if the birds are in different enclosures. In New Zealand they have found that green netting between enclosures, giving a mating pair privacy and preventing the plover pairs from seeing each other, was the answer to this problem. Mike noted that a breeding program for plovers in Canada provided a wave machine.
Other items in the husbandry manual include feeding (a mixture of cat biscuits and insectivores food) and temperature in the enclosure. Bimble foot is only one of the diseases that Hooded Plovers suffer. There is also Avian Pox and Aspergillosis. Behavioural enrichment (i.e. giving the birds an interesting environment) and managing social groups especially in breeding seasons, are issues that have to be considered.
Breeding in captivity is always challenging. Due to insufficient data, there are limits on what can be done to provide the right environment, and there are behavioural issues as well. Collating and sharing data will be key in overcoming these problems. Mike, as a final note, said that captive breeding is an expensive operation; a cost which is very difficult to reduce. He left us with a question. Should captive breeding be trialled at all? With all the problems, the expense, the poor success rates to date, this is a question which we should all ponder.
Contributors: Scot Sharman and Daphne Hards