26/03/2018
This year marks the 90th
anniversary for the British Trust for Ornithology's (BTO) Heronries Census,
which has been carried out annually since 1928 and represents the
longest-running dataset for any breeding bird in the world.
The census started out as a
one-off survey for the journal British Birds and currently
covers around two-thirds of the UK’s heronries annually.
The long-term trend since 1928
shows a slow but small increase in Grey
Heron numbers. The survey also charts the effect
that severe winter weather has had on the species’ population over the years.
The hard winter of 1962-63 produced the largest dip, but currently Grey Heron
has yet to fully recover from the cold winters of 2008-09 to 2010-11.
Ian Woodward, Heronries Census
Organiser at the BTO, said: “Thanks to the volunteers who have taken part in
the census over the years, we have a very good picture of where our heronries
are and, more importantly, how they are doing. However, more recently we have
also been able to chart the rise of Little
Egrets breeding here in the UK, many of which have joined our
Grey Heron colonies.”
No comments:
Post a Comment