Heysham Bird Observatory: Gull feeding puzzle, lots of Chiffchaff and a Pearl trio

A dry sunny day with a light south(ish) wind.

Heysham Nature Reserve

Report by Jean:

Another ringing session at the Heysham "feeder ride" with even more Goldfinches! 17 were caught today. Here's the full list:

Blue Tit 1 new, 1 retrap

Great Tit 0 new, 1 retrap

Chiffchaff 6 new

Dunnock 0 new, 2 retraps

Bullfinch 1 new

Greenfinch 3 new

Goldfinch 13 new, 4 retraps

All retraps were recent (from mid September onwards).

Many of the Goldfinches, like the Chiffchaffs, are passing through. Some end up as far south as Spain for the winter.

4 Fieldfare seen this morning and 2 groups of Siskin over (heard only) - Nick Godden

South shore (Malcolm)

A walk from the saltmarsh then along the sea wall.

Shelduck 83 feeding on the mud.

Wigeon 143 resting by Red Nab then next to No.2 outfall.

Some of the Wigeon by No.2 outfall

Rock Pipit 3 (foreshore, Red Nab and Lighthouse)

Lighthouse Rock Pipit

Linnet 13 initially near the waterfall then flew across the harbour to the old sandworks.

Linnet

By this time it was 10:30. Looking north from the lighthouse were three huge swarms of feeding gulls more or less where the skear is.

One of three feeding groups of gulls, all this size.

A bit of a shaky clip, they were some distance away, but it shows the activity.

So, after lunch, I went out on the skear for a closer look.

By this time it was 13:15 and the gulls were still feeding, although only two and smaller groups now, one on the north side and one on the south side of the skear. This is the south side group. You can see the gulls diving into the water.

The gull bottom centre is diving in

The gull bottom, left of centre looks to have a small fish or at least
part of a small fish

They continued feeding till slack water at 14:00. Whatever is happening it is obviously something to do with these very low neap tides. The water only moves very slowly, so it must have been concentrating something at either side of the skear. Not shrimps as they are bottom feeders and the water would have been a couple of metres deep when I saw them from the north side. I need to give it some more thought, but my only current theory is that plankton was being concentrated in pockets, which then attracted small fish, likely Whitebait, which the gulls duly fed on. But it is hard to imagine shoals of whitebait hanging around for three hours whilst being attacked by gulls.

The gulls were mainly Black-Headed, but also young Herring and Lesser Black-Backed. Plus at least one Mediterranean gull. You would have to expect a repeat performance tomorrow.

No Eider or Mergansers seen

Great Crested Grebe 2