Each Summer, lots of visitors ask us about the water levels in the lagoons, especially those viewing from the Coffee Shop where the changes are most apparent. Some people suggest that there should be more water in the lagoons, but the birds think otherwise. As wading birds fly south from their short Arctic breeding season, they need invertebrate-rich mud to refuel. They will travel down to west Africa, so have some way to go yet.
Managing water at Conwy can be a challenge. The lagoons sit high (three metres) above the tidal river and there is no watercourse coming into the lagoons, so through the Summer, we are dependent on what falls from the sky. We try to fill the lagoons as high as possible by early April, so that ground-nesting birds will feel protected from the islands, the deep water deterring mammals such as foxes and badgers. As soon as the air warms up and plants grow, the water levels start to drop. A combination of evaporation (the sun and wind) and transpiration (by the reeds) lowers the level of the shallow lagoon by 1cm every day. You don't have to be a maths genius to work out that, in a lagoon only 70 cm deep at maximum, it can soon disappear.
The level can, of course, be offset by rainfall. Since 1 April, we have had 31.7cm of rain (almost exactly the same as 31.4cm in the same period last year), so this only partially compensates. But that's fine, because we don't want a lagoon full of water in late summer, we want plenty of sticky mud to feed passing waders. They will tell us whether we've got it right, by coming to Conwy, actively feeding and staying for a day or two. So, what do they think of it this week?
A little stint has been present since Sunday (and is still here today, 23rd) - thanks to Susan Morris for the photo; a curlew sandpiper was here yesterday (22nd); four black-tailed godwits have been feeding on the lagoon this week, and yesterday there were three bar-tailed godwits, two knots, 10 ringed plovers, whimbrel and greenshank, several of these having stayed over since Sunday. A couple of snipe have been actively feeding in the shallow lagoon and a green sandpiper was here on Friday.
A female/juvenile garganey was still present on the shallow lagoon this morning, having been reported sporadically over the last 10 days; and three black terns were present for a few hours on the island in front of Carneddau Hide last Friday (19th), the first here for several years (thanks to Henry Cook for the photo).
So, we think that the birds think we've got it about right. To find out what they're eating, we are doing the annual survey of benthic (mud) invertebrates this week; we got very muddy collecting the samples today, and our expert volunteers will be analysing them tomorrow.
Other highlights this week include a flock of 70 linnets on Sunday (21st); a juvenile spotted flycatcher reported today; the first raven of the autumn on Monday (22nd); the last swifts reported to us were on Saturday (20th) - will we see any more this year?
Emperor dragonflies and common darters have been flying in the sunshine; common blue butterflies have been abundant, as the new generation hatches; and our night-time trail camera recorded two otters together last night, which we are delighted about!
A great white egret has been here since Thursday (4th), feeding in and roosting around the Shallow Lagoon; we think (based on the markings on its bill) that it's the same bird that was here in late July and then went missing for a week - possibly moving to the RSPB's Langford Lowfields nature reserve in Nottinghamshire. Thanks to Jon Young for the photo.
A juvenile little stint was a great find here on Saturday morning (9th), staying for the weekend, while other waders this week have included whimbrels, green and common sandpipers, ringed plover, up to eight black-tailed godwits and a small flock of dunlins. A few snipe are starting to return to the lagoons for the winter too.
Kingfisher has been seen regularly, a redstart was along the estuary path on Friday (5th) and an Arctic tern was on the deep lagoon on Thursday (4th).
Mid August is the time we say goodbye to our local breeding swifts - six were here yesterday (10th); will they be the last?
The weather hasn't been great for insects this week, but when the sun shone, we've seen common darter dragonfly, common blue butterfly and gatekeepers; lots of gatekeepers!
Southbound bird migration hasn't really got into full swing yet, so our attention has focused this week on some of the smaller winged animals that make their home at Conwy. Volunteers Rob and Ruth Morgan conduct a weekly transect walk around the reserve, monitoring butterflies, dragonflies and bumblebees, while Bob Evans spends nights here catching moths, when the rest of us are fast asleep.
Rob and Ruth had a busy survey this morning, with nine butterfly species (including large skipper, the second-generation of common blues, and comma), four bumblebees (including the recently colonised tree bumblebee), and just two dragonfly species - but one was a golden-ringed dragonfly, an occasional visitor here from upland habitats. But the most abundant insect were the six-spot burnet moths, of which there are thousands here at the moment, occupying virtually every flower head - look at thistles, knapweed and field scabious and you can't fail to see one.
Last weekend's Big Wild Sleepout provided an opportunity for many families to come and spend a night sleeping under canvas at the reserve. Bob brought his moth traps, and we waited impatiently on Sunday morning to see what he'd caught, having a good look at impressive and colourful species such as poplar hawk-moth, ruby tiger and garden tiger (in the photo above by @wildtraps).
But while we were all being impressed by the colourful ones, Bob had his eye on two rather mundane moths which he was certain were barred rivulets (above). He was quite excited by this because he remembered catching a single one here last summer, and he knew they are a very localised species around the UK, and especially in North Wales. Now confirmed, these three individuals have proved to be the first records in our vice-county (Denbighshire) for 40 years. And the last record, in 1976, was in Glan Conwy - before the nature reserve had been created, so they've presumably been hanging on somewhere for all that time.
Over the next few weeks, we'll be looking carefully at their food plant (red bartsia) to see if we can find any caterpillars, and so prove breeding here.
The Big Wild Sleepout was a lot of fun, with Gwynedd Bat Group helping us to hear several different bats species calling at high-frequency, and local astronomers showing us the stars and the International Space Station (the white streak in @JonathanHarty's excellent photo).
Bird-wise, waders this week include green sandpiper, dunlin and black-tailed godwits daily, while rain last Friday (29th) brought turnstones, greenshanks and whimbrels. An Arctic tern was a surprise on Monday morning (1st), and it looked much healthier than one found washed up on the shoreline the previous day. A water rail (today) is the first seen here for several months, but kingfishers have been seen or heard almost daily. A flock of a dozen linnets have been feeding regularly on the grassland behind Carneddau Hide, and visitors also reported twite on the causeway over the weekend.
A family of young shovelers here for a few days are puzzling us. They are well-grown, but we didn't see them as chicks - could they have been hiding from us the last few weeks. If they did hatch here, it's the first ever nesting record for the reserve.
Finally, the great white egret that stayed for ten days left overnight on Thursday 28th, though not before @PeteWood1981 took this stunning photo of it bathing. The black tip to the end of the upper mandible proved useful when we spotted a photo on Twitter of a great white egret that arrived at the RSPB's Langford Lowfield nature reserve in Nottinghamshire, and we're pretty certain that was 'our' bird. Is it now back on the Continent, we wonder?