BTO's 75th Heronries Census Paul Westley
The Harnser, as the Grey Heron is named locally, is engrained in broadland history and needless to say it also forms the basis of the Ted Ellis Nature Reserve logo gracing the front cover of this newsletter.
In 1928 the British Trust for Ornithology set out to count every heron's nest in the country - no small undertaking. Last year witnessed the 75th anniversary of this event. Annually since 1928, volunteers have been monitoring a sample of heronries across the country to gain an insight into population trends. Full national surveys were carried out in 1954, 1964 and 1985. In the 75th anniversary year of the BTO's project, 2003 became the fourth full national survey year (BTO's Heronries Census is the longest-running single-species bird survey in the world).
As I have stated before, Wheatfen has held a successful heronry in Decoy Carr for many years. The figure of six active nests has been the rule of thumb over recent years, but not confirmed. The BTO's census was the impetus to monitor Wheatfen's herons and send in the resulting data.
To monitor the herons in safety needed a boat trip. On foot it is possible to get closish to the herons only after crossing difficult and dangerous fens and is, therefore, wholely inadvisable. Even by boat it was difficult to gain direct views of nests (apart from nests in the Parish Carr, bordering Parish Water), so notes had to be taken of where and how many birds were flying in. As the nestlings became vocal (and heron chicks are very vocal) you could pinpoint active nests by sound.
Whilst monitoring the area, two active nests were located on the adjacent Parish Carr (not within the Wheatfen boundaries, but viewable from the boundary dyke). It is not known if these birds have always nested here or whether they were birds from the Decoy Carr that have moved over to the other side of the dyke.
During the monitoring, one nest were located in Decoy Carr. Both sets of birds together doesn't total six. One has to wonder if the new dyke digging and dyke restoration around Decoy Marsh had disturbed the birds over the winter period and early spring. Bird pairing and nesting activity last year was extremely late starting. However, it has recently been suggested that herons are starting to nest in smaller dispersed heronries and even in ones and twos - maybe Wheatfen is reflecting this trend.
The considered opinion is that herons have made a steady increase in recent years - I'm sure mild winters have had a part to play in this. I look forward to this year to see how Wheatfen's herons fare.
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