Fishy pits

Pike and crayfish sushi appears to be on the Christmas menu of the Great Northern Diver currently residing at Nazeing gravel pits in the Lee Valley.  A largish crayfish brought up from the depths was dispatched with some skill.   Nazeing is not the most exciting of the valley waters for the birder but being one of the largest of the gravel pits, it does occasionally specialise in stray seabirds.   Black-throated and Red-throated Divers have made long-staying appearances, as well as visits by Velvet Scoter, Long-tailed Duck and Fulmar.  In the dim and distant, a Little Bittern was also seen, not that there’s much habitat for it today.  Prior to the 1970s, Nazeing held huge numbers of diving duck, mainly Tufted Duck and Pochard.  Numbers declined sharply and remained low until recent years when numbers have increased again, probably due to reduced disturbance as the amount of sailing has declined. 

The lack of aquatic vegetation, either submerged or marginal, results in minimal numbers of herbivorous wildfowl, even Coots are remarkably sparse.  However, fish populations are good, as evidenced by the numbers of Great Crested Grebes (usually up to 50) and Goosander (20+ at peak).  Nazeing is currently one of the best sites for Goosander in the valley, with the last 15 years seeing a significant shift in Goosander distribution from the Lee Valley reservoirs to the gravel pits.  The size and openness of the lakes attract passage terns and gulls.  The northern lake intermittently supports a small gull roost; in the past with up to 10,000 birds nightly, mainly Black-headed and Common Gulls, with the occasional Med Gull.  When spring tern passage is underway, a quick check is often productive.  If Arctics or Blacks are about, there a fair chance Nazeing will pull one.