The focus of birding interest on the reserve is often the lagoons, scrub and grassland, but this week's spectacle is in the estuary. We've noticed it each day on the incoming and outgoing tide: many hundreds of birds in a feeding frenzy in the channel closest to the saltmarsh. Black-headed gulls, herring gulls, grey herons and little egrets are all involved, noisily feeding in the water. We think it's because of a huge influx of either sprats or mackerel, as both have been seen in abundance on local shorelines recently. One fisherman told us that he'd never seen anything like it in his lifetime. This morning, 124 little egrets were among the throng, a record count for the reserve - the graph of peak annual counts illustrates how little egrets have become increasingly abundant on the river, with numbers typically peaking in late summer. We love this photo by Dave Williams, on our Flickr page.

It's all gone a bit 'back-endish' this week, with temperatures falling and an autumnal feeling to each morning. Many of the summer warblers have already left us, though there are plenty of chiffchaffs around the trails. House martins, too, are still feeding over the water, but far fewer swallows. There were 28 wigeon on the reserve this morning, fresh arrivals from the north, and a goldcrest today is also an indication of the changing seasons. It's been a good week for wagtails, with a few white wagtails dropping in from Iceland as they head south, and up to 120 pied wagtails also on the move, probably from Scotland.

The long-staying garganey and great white egret remain here, although the latter seems to spend more time in the estuary than on the lagoons now. A male common scoter has frequented the Deep Lagoon since Tuesday (6th), a scarce but annual visitor here. A wheatear was a nice sight on the Paddocks on Wednesday (7th), while this week's waders include spotted redshank and curlew sandpiper (both until 4th only), greenshank, ruff, green sandpiper, knot, whimbrel, green and common sandpiper, and ringed plover. 20 goosanders on the estuary was a high count for the site, while a yellow-legged gull on Monday (5th) was a good find, as was a count of 27 Sandwich terns on Saturday (3rd). Six barnacle geese, of unknown origin, were on the lagoons on Wednesday (7th).

After mentioning in last week's blog that migrant hawker dragonflies had been seen mating, a female was ovipositing (egg-laying) in one of the ponds this week, which we're sure is the first breeding attempt here. Look out for common darters too, ekeing out the last of the warm sunshine to bask on rocks and handrails.