Sunday 26 February 2023

The battle lines are redefined

A cold light NE breeze. Overcast with a few sunny spells.

Heysham Nature Reserve 
Ringing report from Alan:

John and I went to Heysham and set just one mist net in the feeder ride between 10.00 and 14.00. It was rather cool with a light northerly breeze to start with which strengthened and veered towards the east later on - not a good direction for that ride. 34 birds were captured, 19 of which were retraps. There were fewer finches than we had hoped.

Dunnock 5 retraps

Robin 5

Long-tailed tit 2 + 4 retraps

Blue Tit 1 + 3 retraps

Great Tit 1 + 5 retraps

Greenfinch 5

Goldfinch 1 + 1 retrap

Bullfinch 1 retrap

Heysham skear, low water 10:00 (MD)
Unusually, no geese of any description seen or heard.
Shelduck pair on the water before flying off north (they are uncommon on this side of the harbour)
Eider 35 - this female was calling for her mate who was just a bit further out, unfortunately her calls aren't really audible in this clip, still it does show that they are not the drab brown duck that they appear at distance.

Great Crested Grebe 2
Red-breasted Merganser 9
Little Egret - none on the skear but one close inshore
Waders: Oystercatcher c1,000, Curlew c15, Bar-Tailed Godwit 4, Redshank 50+, Turnstone 30+, no Knot, Dunlin 10.
The waders only actually feed on the Honeycomb worms when their beds are damaged and the worms accessible. But most do feed on and around the smaller beds, as the crevices hide all sorts of invertebrates. In this clip there are Oystercatchers, Turnstone and Dunlin. One of the Oystercatcher finds a small crab.

The recent series of very high spring tides has damaged some of the Honeycomb worm beds. It's not the height of the tide that does the damage it is the force of the rapidly ebbing currents as huge volumes of water drains very quickly. Here it has stripped a large section down to the skear bottom.
The area on the right was the same as that on the left before this set of tides

This shot shows why the waders don't try and reach the worms in undamaged beds. This is the detail of the above face (I haven't pre-sized it in case you want to open it, to better see the detail). This bed is 20cm high, and when not feeding the 2cm worm retreats to the bottom of its tube.
Detail of Honeycomb worm tubes

As well as this area being stripped away, there are new "Grand Canyon like" features that were just narrow drains before.
Additional areas of Honeycomb worm beds swept away
I said on the 26th January that the battle line had been drawn for this year's struggle between the Mussels and the Honeycomb worms for dominance of the skear. There are still large areas of honeycomb worm beds, but this last set of tides has reduced the starting point for the worms, they will not regain this ground before the seed mussels arrive. 
Although I showed a clip earlier of the waders feeding on a small honeycomb worm bed, they rarely feed on the large areas covered by the worms. In contrast the mussel beds are major feeding areas for waders and gulls when the tide is out, and Eider when the beds are covered.