Wednesday 28 April 2021

Slight lull, hopefully before a not so slight a storm

The cold NE breeze freshened by 08:00. Mainly overcast with some brief sunny spells.

Pete checked from north wall 07:30 - 08:30:
Arctic Tern 22 + 9 in (before the wind freshened)
Sandwich Tern 2 blogging
Guillemot 5
Red-breasted Merganser 13
Great Crested grebe 4
Eider not counted 
House Martin 2 in
Pete must have been bored, he took this shot of me, back in full winter plumage
 I must wear that hat more often, makes me look like I have hair!
This is what I was looking at, the two blogging Sandwich Tern
Eventually a total of eight went through
The patch of rocks where I am standing is all that remains of the old Tanker Jetty. The two buoys out from the north wall are where the original floating ends of the jetty (for some reason they were called dolphins) kept the jetty end at the same relative height to the unloading tankers. These rocks are only exposed on spring tides and are covered in anemones.
Five closed anemones waiting for the tide to return

Pete also managed a quick check of the outflows:
Mediterranean gull at least 1 second calendar year
Common gull - lots!
The Dark-bellied Brent goose was further down the coast at Cockersands today.

Middleton Nature Reserve - mid afternoon
What a difference a week makes at this time of year, that's how long it's been since my last visit. The leaves are all bursting out and within two minutes of arriving at the bottom car park I'd heard six warbler species:
Cetti's warbler ( eventually 2)
Lesser Whitethroat (eventually 3)
Willow Warbler
Sedge Warbler (eventually 3)

Later in the circuit I also managed 
Common Whitethroat 2
Reed Warbler 1
No sign of Grasshopper Warbler this afternoon

Swift 2
Swallow 1

Mute 9 plus 2 breeding pairs
Mallard 3 males 2 females - the one with chicks now on the main pond
Coot 3 (Tim Butler pond bird with 3 chicks)
Moorhen 3

Finally another tale of Hermit Crabs (MD):
Just a little later than this last year, I explained the difficulties a Hermit crab has when they move to a shell that is too large for them (see post 13th May 2020 - there is a shortcut link to dates on the sidebar to the right), and I'll  probably do the same again this year! But today's tale is the opposite problem, when their shell is too small. This one was on the skear a couple of days ago, I saved it for a quieter day.
This Hermit Crab was laying prostrate out of its shell. I thought it had died of exposure, it was a warm day, and it was exposed.
But when I touched its leg it retracted slightly, so not dead yet.
I then noticed the fresh damage to the shell, either side of the barnacle.

It was obviously in a shell too small to offer it full protection, both from predation and the sun. So I picked it up to place it in a pool. To my surprise, instead of retracting as far as it could, it became quite animated.
I don't normally shake - I'll put it down to excitement!

This is a front on view

This is the detail of the shell damage. Small peck holes, so not a crow or gull.
There is no way that this crab would have been stranded here, unless it was unwell.
The only benefit of a small shell is that it is relatively light and manoeuvrable.
More likely a wader (oystercatcher?) has brought it here and tried to get it out,
I do believe the barnacle may have saved it, but surprised there is no obvious damage to the crab

Whether it was the attack or the subsequent exposure it clearly needed to recover. I placed it in a pool and set about trying to find a larger shell for it to move into. The tide was already coming in so I didn't have long.
The first shell I found was the same size, but at least not damaged. Unfortunately already occupied by a small Hermit Crab.
This small crab (you can just make out a couple of legs) is prone to being stranded
with such a relatively large, unwieldy, shell, but at least it is well protected.

After about 10 minutes I found a full size common Whelk shell, but again occupied and by a crab the same size as the first crab. 
The crab seems quite large when in feeding mode as it is above. But when I picked it up and it retracted, you can see there is plenty of room for "growth". A full sized crab fits this size shell perfectly, they can't fully retract but their large claw fully covers the opening.

By this time, the tide had already reached the pool where I left the first crab. I'd done all I could, but it was a shame that I couldn't find a better shell for it, I'm confident it would have switched. So I resolved to keep the next empty shell I find for potential other opportunities, but so far I've not found one, they are obviously prime real estate!
I referred above to growth in inverted commas, that's because they grow by shedding their old exoskeleton, which in this crab species is just the head legs and claws, the rest is just a fleshy muscle. The new exoskeleton then swells and hardens. They are just starting to shed now. This is a discarded outer skeleton.
Note the large right hand claw used to block the shell entrance 

Heysham is fortunate enough to be the host of a LDBWS open weekend this weekend. I will post these details again tomorrow and Friday:

LDBWS Heysham 'open weekend' this Sat & Sun.

The second LDBWS field meeting of 2021 is a two-parter! Seawatching and landbird migrant sessions at Heysham Head this Saturday May 1st (7 'til 11AM) AND Sunday May 2nd (also 7 'til 11).

The first half of May sees the peak of Arctic Tern and Arctic Skua passage, as they fly into the inner bay on their Spring migration. Meet Shaun Coyle, Dan Haywood and other seasoned society seawatchers in the carpark of St. Peter’s Churchyard Heysham (suggested parking- Knowlys Rd or the pay-and-display in the village) at 7AM for a two-hour+ session over the dropping tide.

If you're not an early riser we'll be birding in the area till 11 AM but note that for terns etc., early morning is usually best.

As well as looking for terns, skuas and auks on the move we may also see offshore swallow and swift passage and search for songbirds making landfall on the headland. Telescopes can be useful but are by no means essential– binoculars are fine.

We would also like to offer short guided walks around nearby Middleton NR at this double-morning event, where the focus would be singing scrub and wetland warbler species. Please let us you know if this appeals and we can make arrangements.

Contact to express your interest in the event (stating which day you would like to join us) so we can gauge numbers and plan– note we’ll be moving around using the ‘rule of six’ but there will be plenty of space on the head!''

Please note that this open weekend event replaces the May 8th event-- when weather is predicted to be foul. Looking good for this weekend though!