Cattle Egret migration in south-eastern Australia and New Zealand: an update
|Title||Cattle Egret migration in south-eastern Australia and New Zealand: an update|
|Publication Type||Journal Article|
|Year of Publication||1993|
|Authors||Maddock, M, Geering, D|
|Type of Article||paper|
The migration pattern for Cattle Egret in south-eastern Australia and New Zealand (Maddock 1990) is further clarified as a result of intensified observations of patagial-tagged birds and reporting of arrivals and departures of flocks by the observation network of Project Egret Watch in Australia and OSNZ in New Zealand since 1989. Seasonal outward migration from colonies in New South Wales after the breeding season to winter feeding ranges elsewhere in NSW, in Victoria and Tasmania, with return to the breeding colonies has been confirmed. Marked birds have been located in the same winter ranges, after having been recorded in the breeding colony for up to four consecutive years. Two cases of birds migrating to different locations in consecutive years have been recorded. The main movement is southward, but some birds migrate northward. The mean distance for southward migration is greater than for northward migration. Staging along southerly and northerly migration routes has been identified. The pattern of arrivals and departures in New Zealand identified by Heather (1978, 1982,1986) has been maintained, with tagged birds from Australia found in 1990 and 1991, but to date no marked birds have been located back in Australia after being seen in New Zealand. Birds tend to be restricted to highly localised ranges at the winter destination, using pasture on a single property or adjoining or closely related properties. Australian winter locations are generally restricted to coastal plains. Movements from the colonies take place in waves over a period of three months after the breeding period, although variation in dates from season to season has been identified. Birds tend to return to their natal colonies but some degree of colony exchange has been identified, particularly between neighbouring sites.