During 2017 a census was carried out of heron and cormorant colonies in the Veneto and Trentino-Alto Adige. 145 colonies were monitored, with a total of between 6299-6818 pairs found; the average size of the colony was 45.2 pairs (+88.8,...
moreDuring 2017 a census was carried out of heron and cormorant colonies in the Veneto and Trentino-Alto Adige. 145 colonies were monitored, with a total of between 6299-6818 pairs found; the average size of the colony was 45.2 pairs (+88.8, 1SD) while only 17 colonies had more than 100 pairs. In the province of Bolzano there were 8 colonies, in Trento 10 and in the Veneto 127. Nine species were confirmed to have bred: Grey Heron (2216-2420 pairs), Cattle Egret (630-661), Little Egret (707-780), Night Heron (324-358), Purple Heron (266- 280), Great White Egret (2), Squacco Heron (29-33), Cormorant (930-952) and Pygmy Cormorant (1195-1322), while breeding of Sacred Ibis is considered only possible. For the Veneto only, data is available from 1987- 2017: the total number of breeding birds in heron colonies, after a sharp increase between 1987 and 2000, thereafter remained relatively stable at around 4000 pairs. From 2000 at 2017 the trend of individual species is contrasting: Grey Heron and Cattle Egret numbers have grown rapidly or very rapidly, while Little Egret and Purple Heron are in marked decline. For Night and Squacco Herons the estimates are less certain. Cormorant and Pygmy Cormorant numbers, between 2000 and 2017, have risen sharply.
