Basically, what I've managed to gleam from Prof (and DB) is that three main conditions ideally need to occur for migrant waders to appear:
1) Wind Direction
Southerlies in the spring and Northerlies in the autumn to drive birds inland from the coast. This is fairly self explanatory...
2) Rain Showers
Even if the wind is blowing in the right direction, if it's sunny or overcast waders will mostly pass high overhead or land on the larger Chingford Reservoirs if they need to feed. As such, you have to be prepared to get wet. Very wet. In fact, the wetter the better...
3) Poor Visibility
This might seem self-apparent, as mist and fog disorientates migrating birds all over the world. What is less obvious, however, is where you need to be checking... Essentially, poor visibility in Walthamstow could help but you really want to look for is poor visibility at the coast overnight to force migrating birds inland. In spring, for instance, it's important to check for mist and fog on the Sussex/Kent coast (Brighton) overnight and in the early morning.
So, on Saturday morning the stars aligned and conditions seemed like they would be ideal: a light south westerly of about 10mph; showers between 7-9am; and mist in Brighton until about 6am.
Despite getting well oiled the night before, I somehow managed to get onto the Reservoirs at 6.45am and headed straight for the Lockwood.... 4 Common Terns on No. 4 were new for the year, but there was very little to see on either of the Maynards. Knowing that I was the first person to get onto the Lockwood this morning, I climbed the bank in eager anticipation and walked to the Northern end, but aside from 2 Common Sandpiper and a female Wheatear there wasn't much about.
I headed back along the Eastern side and decided to wait on the ramp for an hour or so. Pretty soon, it started to drizzle, before getting heavier. At 8am, I noticed two large waders flying high from the Banbury with long, pretty straight bills. A few thoughts flashed through my mind (Whimbrels? Godwits?) but they were so high that I struggled to ID them and soon lost them to view over the High Maynard. I spent the next ten minutes kicking myself, while getting soaked to the bone.
Then, all of a sudden, one of the birds flew back from High Maynard calling and dropping fast. As it headed towards the rafts I could see that it was a Godwit! And what's more... it was actually going to land! It flew into the Southern Eastern corner but due to the curve of the reservoir, it had landed out of view. Without really thinking, I put out the news on twitter as a Black-tailed Godwit and started to walk towards the Southern end. On the way, I met Steven H and we both realised that we were probably going to flush the bird, so we waited until some other patch listers arrived before going any further. It briefly came into view in heavy rain, but we still hadn't managed to see it very well.
Pretty soon, Prof arrived on the South Western side. My phone started ringing as a fisherman climbed the bank and flushed the bird. Prof had managed to see the bird much more clearly and realised that it was a Bar-Tailed Godwit! More importantly, it was his 200th bird for the Patch! As it flew to the
Southern end we could see that he was right, as it didn't have any visible wing-bars.
Prof soon dashed off to work, but we walked to the Southern end and managed to find a Little Ringed Plover that had also been grounded by the shower. My second patch lifer in the space of an hour! As I hadn't seen an LRP for a long time, Stephen kindly talked me through some of the flight ID features as a few Sand Martins flew overhead.
At the Northern end, we managed to relocate the Godwit distantly on the North West bank for around 10 minutes, while Lol B confirmed that it was a female from the comfort of his house. After a while, it flew back towards the Southern end, where Graham H watched it feed and even managed to get a few record shots....
We walked back up the Western bank, but as the weather was clearing up the Little Ringed Plover had already moved on. Within a few minutes, Graham watched the Godwit head back towards the Northern end of the Lockwood climbing steadily until it was little more than a speck in the sky.
The weather had grounded the Godwit and the LRP for about 90 minutes but as soon as the sun started to appear, they were back on their way... AW