Heron Rookery

Heron Rookery. . , In the trees, on the island in front of you, are the nests of a colony of Great Blue Herons. They look like loose bundles of sticks a yard across and are often near the ends of tree branches., Herons usually gather in isolated areas away from people, and are not so easily seen as they are here. This setting may say something about the improved quality of the river, the number of fish, the inaccessibility of the island and the probable lack of raccoons., . There were no nests in 2006 , . 4 in 2007 , . 34 in 2008 , . How many can you count now?, These are fish-eating birds. , Look for them along the shoreline as they struggle to swallow surprisingly large fish whole, some are 12 inches long or more. It sometimes takes several minutes! , . Long, thin legs enable them to wade in water up to 24 inches deep , . Long, widely spaced toes help them to balance on slippery rocks and in moving water. , . The long neck, held in an S shape, acts like a spring to drive the sharp beak forward like a spear. , . The skin on the mouth and neck can stretch 4 or 5 inches across., Things to Look For:, February: They court and build nests. , Both males and females bring sticks (about ½ inch thick) and call out to one another. The bird in the nest will often stretch its neck up straight into the air and then pump it down as the gift is brought. As a part of pair bonding, they may stand together on the nest and stretch their necks down as if looking under for an intruder. Occasionally, you may see a sort of lip-lock slow dance as they clasp the tips of their bills together and sway side to side. They mate nad lay eggs shortly after the nest is done. They are noisy during courtship., March: They brood their eggs: , The birds are quiet at this time. One sits alone on the nest (3 to 5 blue eggs spaced a couple of days apart) while the other feeds somewhere on the river. The fed bird returns and switches place with little fanfare. Sometimes one will bring a small branch or some grass: occasionally they may do the “head down” display and even scissor their necks together. Incubation takes about a month., April and May: They feed their young in the nest. , This is the height of the fish migration --- shad and herring in particular --- so food is as plentiful as will ever be. Adults regurgitate partly digested fish into the beaks of the babies. Later, however, they place it in the middle of the nest and let the fledglings fight over it. In years with little food, the youngest one or two will always starve. In this way, the population reflects the capacity of the environment --- and the survivors are fully healthy. Look for youngsters peering out of the nests as later walking around on the nest. See if you can spot the ring of white around the edges of some nest where weak or timid youngsters failed to squirt their droppings over the rim., June: The youngsters are feeding in the river , with their parents. Juveniles look like their parents – or slightly fatter --- but have all dark heads instead of just a black cap. Soon the family breaks up and juveniles form feeding flocks for a while. The parents separate., July or August: some of the trees may be dead. , The droppings, caustic with ammonia and nitrates, sometimes burn the tree roots. In the winter, many of the nests will fall apart in storms. But even the dead trees will be useful for nesting next year and new nests will be built or re-conditioned., The Latin name for this bird is Ardea Herodias: “Arrowhead Heron”. They live and breed along the eastern part of the USA from Canada to Texas., Paid for by the Richmond Audubon Society