Ringing and birding Summer 2017- plus an unexpected bonus in October.   Leave a comment

This post covers a few of the ringing and birding activities during the summer of 2017 plus a post script about a Dorset Mega in October.

 

Most of the birds we ring at Durlston and beyond are small passerines so I felt it would be useful for my trainees to get some experience in handling larger birds such as geese or swans. Fortunately we were all free to join the annual Canada Goose ringing session at Chew Valley Lake in Somerset.

 

Margaret, my trainees Ginny and Chris, Olly, another ringer from our group and I drove up to Chew Valley. Most of us went out on the boats to round the geese up. Unfortunately for the ringing program many of the geese were feeding in a shallow, weed filled area where the boats couldn’t get so the total number ringed/processed was smaller than usual.

 

As they moult most of their flight feathers simultaneously the geese are flightless in early July so using some well-practiced boat maneuvers, the flock was shepherded ashore and into a corral.

 

Each of us was handed a goose and we proceeded to the a table where the ‘scribe’, ably assisted by Margaret, handed out the rings and recorded the details.

 

Although they had never held such a large bird before Ginny and Chris managed very well and were able to close the large ‘L’ rings around the goose’s tarsus.

 

Chris enjoying his visit to Chew Valley. This may be a rather inelegant view of a Canada Goose but it is the safest and easiest way to carry one.

 

Closing a large ring on a large bird involves a very different technique to say ringing warblers or garden birds. Although an introduced bird, the monitoring the movement and population growth of alien species like Canada Geese is very important, so ringing these birds is so much more than just an outing for trainees.

 

In the end the ringers compared their ‘war wounds’, a torn t-shirt, a few scratches and a bit of (human) blood on your sleeve.

 

A Collared Dove was an unusual bird ringed in my garden this summer. This species naturally colonised the UK from the 1950s onwards and now is an established breeder throughout the country. However they were introduced to the Caribbean from where they have spread to the USA and in a very short period colonised much of North America.

 

Our ringing at Durlston commenced on the 19th July with local breeders like this  Common Whitethroat (note the grey head and pale eye of an adult)  ….

 

…. but the highlight was this 1st year Nightingale. As we also trapped an adult in the spring it is likely that the species has bred locally. Like many woodland birds Nightingales have declined markedly. Our ringing group had ringed 99 Nightingales prior to 2017 but none of those were after 1994 showing the scale of the decline.

 

Details of wing length, weight and moult status are recorded. This year a few Willow Warblers must have bred near or at Durlston as we trapped a few adults in moult as well as juveniles. Willow Warblers used to be common breeders but with climate change their range has shifted northwards. This bird is missing its 6th primary, a little tricky, as the exact shape of this feather is what proves categorically that it not a Chiffchaff. However there were enough other features to prove its identity beyond doubt.

 

One feature that is sometimes seen on young birds is ‘growth bars’. As a bird is growing its remiges and retrices (primaries, secondaries and tail feathers) in the nest, the quantity and quality of food delivered to it will vary depending on the weather. This can affect the growth of the feathers and as the feathers are grown simultaneously appear as a bar across the tail. Growth bars across the primaries and secondaries are usually much less obvious than across the tail. This Reed Warbler is notable because of the strength of the growth bars across all the flight feathers. It must pointed out that this is not a plumage characteristic of the species but an anomaly in this particular bird.

 

Of the more unusual captures, this Northern Wheatear was notable.

 

One of the features of ringing this summer/autumn was the capture of nine Nightjars, seven in August and two in September . All were juveniles and presumably were on migration, or at least undergoing making postnatal dispersal prior to migration as the species is not known to breed on the limestone grasslands and scrub at Durlston. Most likely we only discovered their occurrence in the park because this year we took to arriving on site that bit earlier, typically about 0430 in August.

 

On one occasion a Nightjar was trapped just on dawn so we were able to photograph it in what appears to be daylight. In fact it was still quite gloomy, I was just using a very slow shutter speed!

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Another benefit of getting the nets up before dawn has been the capture of a record number of Grasshopper Warblers. Most years we ringed 10-30 of these skulky little warblers, last year that rose to over 100, this year to over 200 with 65 on a single day. This huge increase cannot just be attributed to earlier starts, the species must have had a very good breeding season. We also had our first Grasshopper Warbler ‘control’, a bird ringed last autumn in Hampshire. We also ‘controlled’ a Tree Pipit, a Willow Warbler and two Reed Warblers, all ringed in various parts of the UK but our only Bullfinch recovery was a bird we ringed in the spring that was found killed by a Sparrowhawk in a garden less than a mile away.

 

I mentioned in my previous st that we visited London for the day. On our way from Victoria coach station to Trafalgar Square we passed through St Jame’s Park.

 

Many people think the only ‘wildlife’ in London parks are the pigeons but in fact a lot of wildlife lives there.

 

That said many of the wildfowl are introduced, if this female Smew had been seen on a reservoir in the east of the UK in winter it would unhesitatingly be treated as wild but in St Jame’s Park in July – no way.

 

The existence of free flying birds like this White-headed Duck (WHD) in ornamental collections confuses the true status of any potential vagrants to the UK. Before Ruddy Ducks escaped from captivity and became established in the UK, WHDs (away from collections) were very rare. The commoner Ruddy Ducks became the more vagrant WHDs were seen. Logic was that British Ruddy Ducks wintering in Spain were pairing up with WHDs and returning to the UK with them in tow. Of course it was this interbreeding with Spanish native WHDs that forced the UK authorities to eliminate the Ruddy Duck, but guess what once the UK Ruddy Ducks were gone then so were apparently wild WHDs as well. Clear evidence that those WHDs away from collections in parks etc were genuine vagrants from Spain.

 

Whatever you think of the status of wildfowl, there is no doubt that this Grey Heron was wild even if it was walking around on well used public footpaths.

 

Although I continued my ‘New Year Resolution’ to go ringing or birding every day, July wasn’t a great time for rare birds. A few nice waders were seen at Lytchett Bay but a highlight of early August was this American Bonaparte’s Gull that pitched up on Brownsea Island. Bonaparte’s Gull was not named after Emperor Napoleon but after his ornithologist nephew Charles.

 

Several weeks later, on 22nd August to be precise, we had a most unexpected treat when an another American bird, a Yellow Warbler turned up on Portland. This is migrates relatively early in North America and so seldom gets caught up in the severe weather systems that propel migrant New World warblers all the way across the Atlantic. However the remnants of a hurricane reached the UK just the day before and was undoubtedly the reason why the lovely bird graced our shores. Photo by Chris Minvalla.

POST SCRIPT

Nothing to do with summer 2017 but yesterday (17/10/17), only minutes after I had returned from a very busy morning’s ringing at Durlston I heard that a warbler first seen two days ago at St Aldhelm’s Head had been identified as a Two-barred Warbler (formerly known as Two-barred Greenish Warbler). So it was an immediate turn round and a quick return to Purbeck, the site is just 4 miles west of Durlston. The weather by this time had deteriorated, but in spite of the rain I had nice views but got no photographs. I left about 4pm by which time less than 20 birders had seen the bird. Along with the Yellow Warbler above this was a new species for my British and of course Dorset, Lists. Fortunately for twitchers across the UK it remained overnight and was seen by hundreds today. Fortunately my ringing colleague Chris and his father Tony saw the bird well and Tony has given me permission to use his excellent photo.

 

Two-barred (Greenish) Warbler – formerly treated as a race of Greenish Warbler, hence the inclusion of ‘greenish’ in its former name, breeds no closer than central Siberia from the upper Tungusta/Lower Yenisey rivers east to Sakhalin, northern China and North Korea. Although formerly lumped with the more westerly cousin it has been shown to act as a separate species in the area of overlap. This is about the 6th record for the UK but the first for Dorset. This ends a 30 year bugbear, I ignored reports of a ‘funny Yellow-browed Warbler’ on the island of Gugh, Scilly in 1987 only to find the day after I returned home that it was the UK’s first Two-barred! So it wasn’t just hurricane strength winds that occurred in mid-October 1987 and mid-October 2017. Photo by Tony Minvalla.

 

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