Wilden Marsh Heronry.
21st February 2012: It’s not just foxes, badgers, muntjac deer, mink, otters and goodness knows what else, that we have living on Wilden Marsh; we also have a long-established heronry. Heronry is the name given to the place where a colony of herons live and breed; our’s happens to be in the middle of deep and smelly bog.
UK herons are a protected species under the Wildlife and Countryside Act of 1981. Government licences to kill small numbers of herons can be issued in very limited circumstances: normally to owners of commercial fisheries where non-lethal methods have been shown to be ineffective.
It’s grey herons (Ardea cinerea) that live on Wilden Marsh, and these are the largest herons in Europe. They weight between 1 and 2 kilograms and stand up to a meter in height. The presence of a heronry is indicative of reasonable fresh water quality. Egg laying at the marsh heronry will begin towards the end of March.
Grey herons are top of the food chain predators; they feed mainly on fish, but will eat frogs, ells, voles, and ducklings as the opportunity presents itself. Their nearest competitor is the cormorant: a spring and summer marsh visitor. It won’t be long before I am photographing herons wading in North Pond, dining on frog, newt and eel.
It has been estimated that there are somewhere in the region of 15,000 heron pairs nesting within the UK. Their breeding season is February to June; 3 to 5 eggs are laid; incubation is within 25 to 28 days, and the young fledge at 50 to 55 days. The chicks are usually very noisy and emit really loud clacking sounds when a parent arrives at the nest with food. The parents feed the chicks regurgitated fish.
There is usually a sentry, or two, keeping watch over the heronry when the parents are away catching fish for the chicks. The sentries will sit patiently in tall trees quite some distance from the heronry. If they detect a movement, they will swoop down to investigate. The chicks stop clacking and sink to the bottom of their nests when they hear the scout’s warning call.
Young herons teach themselves to catch fish, and often find fish in garden ponds tempting.