Lodmoor has become the place in recent years to go and enjoy the mass of Common Terns that arrive there every spring to rear their young. Last week we were very shocked to find out that the whole breeding colony had disappeared from the reserve leaving some very bare islands, sadly with lots of abandoned eggs. There must have been a very good reason for this happening as they spend a lot of energy travelling all the way from the mid Atlantic wintering grounds to come here and breed. So what happened? Toby Branston, our Dorset Ecology Manager takes up the story.
By now many local people would have noticed that the common tern colony from our Lodmoor salt marsh island have disappeared. There appears to have been a mass desertion event overnight on 13 -14th June which left over 62 nests with eggs abandoned. This event has been much discussed, not least on Dorset O&A with the cause open to some debate. Food resource could be a factor with disturbance to the abundance of their main prey item, sand eels by the cold spring. There is some evidence for this as birds were travelling further into Lyme Bay to fish rather than Weymouth Bay just over the sea wall and the link with low mackerel numbers. Canada geese have, as has been pointed out, increased in recent years on the saltmarsh and disturbance from them may have occurred. Disturbance from mammalian predation (fox, mink or stoat) is thought not to be a likely cause and we have found no evidence of mink presence. Indeed, a combination of factors might have caused a build up of stress to an unacceptable level for the birds which resulted in the drastic action witnessed. Sadly, it is not an uncommon occurrence and the common terns locally have deserted en-mass from the Fleet / Chesil in relatively recent years and formed subsequent new nesting grounds nearby, our islands being one of these some 10 or more years ago. We are hopeful that they may return to the islands next year but in the meantime we shall be looking further into the likely causes.
Following on from my last slightly cautious blog about the arrival of spring I can now safely say that things have definitely picked up at Radipole and Lodmoor. My walk to work yesterday morning was greeted with the sound of recently arrived Reed Warblers which were obviously keen to advertise their presence after their rather long northward journey from Africa. Likewise Sedge Warbler were doing the same under probably hundreds of Sand Martins and Swallows which were frantically feeding overhead. All very spring-like and very nice!
Other migrants on the move in recent days have included the first Whinchat of the spring, the odd unconfirmed reports of Cuckoo and Redstarts have featured a little more than in past springs. A Hoopoe was a nice surprise for a birdwatcher who was driving past the reserve last Thursday. It flew over Weymouth Way into the north end of the reserve. Wheatears have also been showing off, some of which were posing rather nicely for a photo...
Marsh Harrier action has led to some confusion in the last few weeks. Back in March things were looking as though Radipole was the chosen spot to set up home for the summer but things have dramatically changed with Lodmoor now being the favoured site but the appearance of another bird during the week might spice things up a little. Took this photo a couple of days when we both managed to surprise each other as our paths crossed!
To finish some very exciting news! You may have noticed that there’s lots of reed missing up near the North Hide? Well... it will be reappearing very soon in the form of a new roof for the Discovery Centre!
Is this weekend the end of the cold weather? I’d rather not risk saying it is but at least the Weymouth reserves feel a little more spring like. There’s been some real spring highlights over the last few weeks, perhaps best of all being up to six Garganey which have been seen well from the North hide at Radipole most days. This was taken when a few were hanging around the buddleia loop a few weeks ago.
Yesterday a stunning Osprey flew over the Discovery Centre and was enjoyed by loads of visitors at the time. As usual, it didn’t hang around and was keen to carry on its northward migration which meant no time to get a photo but this picture I took last week whilst I was counting migrating birds of prey in Gibraltar. Ospreys were quite numerous compared to past years so we might see a few more over Radipole and Lodmoor in the coming weeks.
Warblers are now turning up in good numbers. Chiffchaffs being most numerous but Willow Warblers now seem to be a little more obvious. Goldcrests are on the move and if your lucky you might spot a Firecrest which have also been migrating through. This was one trapped, ringed, and safely released at our office garden adjacent to Radipole yesterday morning. Stunning little birds!
There’ll be a chance to learn more about ringing and the chance to get close to other wildlife tomorrow at Radipole. The current weather forecast isn’t too promising but as it stands there’ll be a ringing demonstration from 9am near the North Hide but rain looks to set in from mid morning so come along early to beat the weather. If the rain comes in early we’ll have to abort! But for the rest of the day there’ll be displays in the visitor centre and pond dipping and possibly more!
Lots more things to blog about over the coming weeks including pics from some of our events which have been a roaring success over Easter but here's a taster of whats been going on!