A “callow” is a very special habitat. Callows are seasonally flooded grassland ecosystem found on low-lying river floodplains. The IWT own a callow reserve on Bullock Island. An island located within the Shannon Callows and inundated by the great river each year. Due to this seasonal flooding the callows have never been under intensive agriculture. It is for this reason that the callows are one of the last refuges of the corncrake, an endangered native species of bird that has suffered greatly from the modernisation of agriculture. The corncrake makes the long journey from Africa each summer to breed in the callows and has been recorded on Bullock Island in recent years.
In winter this reserve is under the river Shannon and in summer the island is one great swaying sea of hay. Cutting the hay is an essential part of the site’s management and must be carried out each year. A corncrake conservation scheme which the IWT is a part of promotes the late cutting of these hay meadows to allow the ground-nesting corncrake complete their breeding cycle before the disturbance of cutting.