Sunday, 18 April 2010

17th April 2010 - Heron Ringing 2

Gary, myself and Jake set out again this morning to pay our second visit to the Heronry at Warnham LNR, but were joined by assistants Eddie and Matt and two other ringers John and Janet.

It was another successful morning with 12 new birds being ringed from five nests, including two birds from a nest that had not been noticed before! So far this year, of the 24 nesting trees that have been identified over the last two years, one nest is in a leaning tree which is too dangerous to climb but very active with at least 3 young, three trees have no nest, one nest is unused, two nests have been fully predated and 22 birds ringed from eight nests, meaning that there are still nine more nests to do! Gary managed to film the last nest that we ringed today see below:

During the morning the Heronry was visited twice by up to two Buzzard and a couple of Crows that were circling over and certainly looking for a potential meal. I am sure that once the chicks get to a certain size they are too much of a challenge, but I would have thought that the eggs would be fairly prone to corvids and even squirrels! The video above shows what we have noticed doing this that the chicks at different ages have different techniques for dealing with predators. The smallest preferring to huddle down, pretending not to exist while the bigger ones going for the more aggressive approach!

Another interesting thing has been the food that the odd chick has coughed up. There have been a couple of Goldfish (seemingly the most popular diet) and a Perch last week, while this week we had a Common Frog and the first two regurgitated pellets (below). The pellets which are the collection of indigestible materials which the birds bring up to expel just like owls and other birds of prey.
The obvious contents of which were quite exciting - the small one seemed to be the whole remains of a Great Diving Beetle, while the large one was quite varied with an obvious crab claw on top. Considering that the Heronry is, at closest, 31km from the coast as the crow (or Heron) flies is this as far as the parents will travel to find food for the young? It would be great to get these analysed to see what species remains are present.

Birds ringed:
Grey Heron - 12

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