Sunday, 28 August 2011

Grasshopper Warblers Just Keep on Coming!!

Regular readers of this blog will be well aware of the high numbers of Grasshopper Warblers being captured at Titchfield Haven during the 2011 autumn bird ringing season.....well they just keep on coming!!

Grasshopper Warber Titchfield Haven 2011

The week of 22nd August began with a couple of early morning ringing sessions, which due to work commitments I was unable to attend, but nonetheless produced 83 groppers. A massive 71 of these were captured on the 23rd, the second highest daily total ever. A three day Bank Holiday weekend gave me the chance to get in on the action, and with nothing much else planned I chose to ring on all three days. I will update this blog with the end of August totals in due course, but Saturday 27th was notable in its own right. 

Whilst opening the nets it was evident that there were lots of Groppers around due to their distinctive contact call, but we never imaged just how many. By the end of the session we had captured and ringed 105 Grasshopper Warblers, one third of the total capture total, and the highest ever total captured in one day at Titchfield Haven. A further 25 were captured on the 28th August, bringing our total for August to 439, with the overall total for July and August to a record 709, and we still have one day to go!!!! 

I will keep you posted......

Friday, 26 August 2011

Back in the Bay of Biscay 16th – 18th August 2011

The day P&O announced the end of the sea crossing from Portsmouth, England to Bilbao, Spain and back, across the Bay of Biscay on the Pride of Bilbao, was a sad day for those of us who were regular travellers on the trip. So, when I was offered a chance to co-guide on a trip from Portsmouth to Santander, Spain on Brittainy Ferries’ Pont – Aven, I jumped at the chance. The Pont – Aven is a much younger ship than the old P&O workhorse, the facilities are more modern and the ship is much faster. But the most significant change is that the ship departs from Portsmouth and returns from Santander to Plymouth, England, which presents immediate logistical problems. 

The ferry set sail from Portsmouth at 17:00, and by the time we had boarded and had something to eat, it was time for an early night in preparation for a full days whale-watching/birding on the following day. The 17th began with a 06:30 start up on deck 10, the highest deck on the Pont–Aven, in search of seabirds and cetaceans. The faster speed of this ship meant that we were already south of the Brittainy peninsula and in good cetacean waters by dawn, but unlike the old Pride of Bilbao, the Pont-Aven offers no opportunity to view directly forward and crosses the whole of the bay in one day, travelling over both the northern and southern shelf edges of the abyssal plain before arriving in Santander.

Common Dolphin, Bay of Biscay

Our encounters began with a group of over 20 common dolphins coming into the bow to play..

Common Dolphin, Bay of Biscay

....before moving down the sides to play in the wake...

Common Dolphin, Bay of Biscay

......and  excite  our 70 clients, who had opted to travel on this whale and dolphin adventure.

Cory's Shearwater, Bay of Biscay

Over the last couple of years the numbers of seabirds recorded in the Bay of Biscay have been low, and this trip seemed to be following this pattern. Although we still managed some good views of Cory's Shearwater, Sabine,s Gull, three Great Shearwater's and a hand full of British Storm-petrels. Northern Gannets and Great Skuas provided constant interest......

Great Skua, Bay of Biscay

....with the occasional Arctic Skua make up the supporting cast.

Sun Fish, Bay of Biscay

Those lucky enough to looking over the side of the ship were rewarded with a view of an Ocean  Sunfish as the ship steamed by.

Fin Whale, Bay of Biscay

But the most notable feature of this trip was the return of the Fin Whale, the second largest mammal in The World!!! This species has been absent from the bay for the last few years, but this year there has been an increase in sightings, although not back to the numbers of the mid 1990s. In total we recorded 34 large rorqual whale blows, meaning either Sei, Fin or Blue Whale, seven of these we were able to confirm as Fin Whale, the remainder were left unidentified.

Fin Whale, Bay of Biscay

Among the Large Rorqual sightings we also encountered three Sperm Whales, two were very distant, but one provided close views, and revealed its distinctive short, sideways, bushy blow and small unobtrusive dorsal fin. Unfortunately we sped past this encounter and were unable to see the whale dive and show its tail flukes.

Sperm Whale, Bay of Biscay

In February 2005 I was fortunate to be travelling in New Zealand and encountered several Sperm Whales off Kaikoura, South Island. In the Bay of Biscay there are only three species which show their tail flukes whilst diving, Hump-backed and Blue Whale are very rare, although the latter was seen this year and photographed.

Sperm Whale Diving, New Zealand 2005

Of the three, the Sperm Whale is the the most likely to be encountered, and this trip proved to be no exception.

The return from Santander to Plymouth produced a good numbers of Common Dolphins and  Harbour Porpoises, with seabird sightings including more Great and Arctic Skuas, Manx and Balearic Shearwaters and a handful of British Storm Petrels.

Sunday, 14 August 2011

Bird Ringing at Titchfield Haven - Mid August 2011 Update

Well it is now the middle of August and the autumn migration appears to be in full swing, and despite some extremely unseasonal weather at times, we have managed five ringing sessions  between the 2nd and 14th August, including a record day on 6th August, when 345 new birds were captured. Sedge and Reed Warblers have been the most numerous species with 555 and 145 respectively, captured, although Grasshopper Warblers continue to break all previous records with 141 new birds captured. The combined total for the July and August total for Grasshopper Warbler now stands at 408 for the year, and it is only mid-August!! 

Willow Warbler numbers peaked on 2nd August with 17 new birds captured; the monthly total  now stands at 50, with 87 in total for the year...a very low total for the species. Locally Garden Warblers did not seem to have a good breeding season, and yet new captures this autumn have also been at record numbers, including a massive 23 new birds on 6th August. 

Garden Warbler - August 2011

During July a majority of birds captured were adult, whereas during August juvenile birds have been the most numerous. Both adult and juvenile birds undergo a partial moult in the summer and a complete moult in the winter. In autumn adult birds can be aged by the presence of slight wear on the tips of the wing and tail feathers and especially the tertials. Juvenile feathers are fresh as in the image below.

Wing of Juvenile Garden Warbler

Garden Warblers can be a difficult species to age on occasions, but the presence of a fault bar on the tail, caused by a deficiency of food in the nest, can make ageing much easier. A total of 57 new birds have been captured to date.

Tail of Juvenile Garden Warbler showing Fault Bar

The Common Whitethroat is a species that appeared to be in steep decline back in the 1980s, but this year the numbers captured have been high, maybe indicating a good breeding season. During July, 25 new birds were captured and a further 41 in August, bringing the total to date to 66. Juvenile birds undergo a partial moult in summer, and are perhaps most easily identified by their dark grey-brown or greyish-olive iris. 

Juvenile Common Whitethroat

The juvenile wing can be recognised by diffusely patterned greater coverts, which have darker centres which grade more diffusely into the rufous edges. In addition there is often a contrast between the outer juvenile coverts and the in moulted adult type feathers.

Wing of Juvenile Common Whitethroat

In juvenile birds the outer tail feathers are uniform light brown, or edged and tipped pure white, but they are obviously fresh and contrast with the rest of the tail.

Tail of Juvenile Common Whitethroat

Overall a total of 1035 birds, of 17 species have been captured to date in August, a total which has already surpassed the 883 birds captured in July.

Thursday, 4 August 2011

Bird Ringing Throughout July 2011 at Titchfield Haven

Well here we are, the beginning of August already so I thought it would an ideal time to provide a summary of the months ringing at Titchfield Haven. In all we carried out 11 ringing sessions, with the first on 10th July through to the last on 31st July. A total of 884 new birds were ringed and the peak day was 30th July, when 145 birds were ringed, and numbers have been steadily building throughout the month for most species.

Grasshopper Warbler

Those regular followers of this blog will have already got wind of the most notable news during July, and that is the extraordinary number of Grasshopper Warblers moving through. We have always caught large numbers of this species at Titchfield Haven, with our peak being in 2009, when a massive 569 birds were captured. That year we had ringed 58 birds by the end of July, whereas this year we have ringed 267 new birds, by the end of July!!! The other interesting fact is that we have only captured one adult bird, which we are assuming means that this species has had a very good breeding season.

Cetti's Warbler
In stark contrast to Grasshopper Warblers, Reed Warbler numbers have been low, with only 109 new birds ringed, and Sedge warbler numbers have been decidedly average with 339 new birds ringed. The interesting fact about Sedge Warblers is that on some days nearly 50% of the birds captured have been adult, does this mean they have had a bad breeding season? Cetti's Warbler is one of our specialty species and we can easily catch over 100 new birds in a season, during July we only captured 7 new birds, perhaps another example of a bad breeding season.

Common Kingfisher

Blackcap, Garden Warbler and Whitethroat numbers started slowly, but by the end of July we had amassed 21, 11 and 25 respectively; totals of 37 Willow Warbler and 16 Chiffchaff were again decidedly average, although Willow Warbler numbers tend to peak in August and Chiffchaff in September. Three juvenile Common Kingfishers added a bit of colour to our ringing sessions, with one caught on the 15th and two on the 31st.  

Common Redstart

And the only real surprise was our first Common Redstart of the season, a species that we do not usually capture until August or even September.
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