Sunday 9 September 2018

Titchfield Haven Ringing Group - August 2018 Update

It has been nearly two years since my last post and I have been asked several times recently how our ringing studies have been going at Titchfield Haven, so here is an update.

We embarked on this year’s ringing with some trepidation; the extreme cold weather earlier in the year followed by the late arrival of some summer migrants and an almost two-month period without any rainfall, in the south of England at least, must have had an impact of our bird populations. For example, male nightingales at my study site had arrived late and in much fewer numbers, 50% less than in 2017, but those that did arrive appear to have bred successfully. Willow Warbler and chiffchaff numbers also appeared lower than usual whereas nightjar numbers were much higher.

As usual we commenced our ringing in the first week of July and weather permitting and keep going until early/mid-November. We have continued to ensure a consistent level of effort and use the same number of nets in the same locations as we have since 1998.

The ringing totals for the year up to the end of August, showing July and August separately and a grand total are below.

In isolation this does not mean much so some basic comparison of the more regular species is presented below.

As can be seen with Grasshopper Warbler, the numbers are once again low by our standards, and have been for the preceding three years. The average number of birds caught across the comparison period to the end of August is 228, 2018 is proving to be well below average for this species. Obviously the average is skewed by the astonishing total of 2011, but even looking at the Median (192) this years totals is well below average.

The Sylvia warbler graph focuses on the three most numerous species that we catch, Common Whitethroat, Garden Warbler and Blackcap. The numbers that we catch year on year are highly variable, comparison with the average shows that for Whitethroat we are slightly below the average of 45 and Garden Warbler we are pretty much on the average of 39. Blackcap numbers are slightly below the average of 64. The variability of annual captures during the analysed period means that the averages do not change significantly when looking at the Median.

Through July and August the most numerous species we ring are Reed and Sedge Warblers. Reed Warblers are common breeders on the site so the early captures usually involve local breeding birds. The Sedge Warbler is a much rarer breeder and therefore most of our captures are migrants. Sedge Warbler numbers, at least early on, felt good to us but to the end of August the total was well below the average of 700. The Reed Warbler total for 322 is slightly below our average for the period (339). As with Grasshopper Warbler, 2011 was a very good year for Sedge Warblers, so will be skewing the results. Looking at the Median for Sedge Warbler (567) we are much closer to the average, but still down.

As with Reed and Sedge, Chiffchaffs breed on the reserve, whereas Willow Warblers do not and therefore our early captures of Chiffs relates to local breeders. This year breeding Chiffchaffs have been notable by their absence and this is reflected in the total of just five birds to the end of August. This total is well down on the average which stands at 25. By contrast it has been a good August for Willow Warblers, with the 130 bird total above the 121 average. Looking at the Median (120) the Willow total is still above average.

To finish up I thought I would share a few milestones that we passed in this, our 21st year, of ringing in this part of the reserve. These figures relate to new birds ringed and don't include retrapped birds and those controlled.

14/07/18      5,100th      Grasshopper Warbler
20/07/18      2,900th      Blue Tit
21/07/18      20,000th    Sedge Warbler
10/08/18      1,100th      Cetti's Warbler
11/08/18      350th          Song Thrush
18/08/18      10th           Tree Pipit

Saturday 1 October 2016

Back in the Bay of Biscay - September 2016

There is not a year that goes by without me taking a trip out on the open water in search of seabirds and cetaceans. This year I chose Biscay, and a late season visit at that. As with recent years I travelled on the Pont-Aven, departing Portsmouth on the evening of 27th September, arriving in Santander late afternoon on the 28th and then into Plymouth on the late afternoon of 29th September. 

I had arranged to go on the trip with my good friend Dylan Walker, hoping for a relaxing time catching up on seabirds and cetaceans. But unbeknown to us there was an Orca trip on the same ship, and as we arrived at the ferry terminal I immediately saw two people, Glenn Overington and Elfyn Pugh, who I knew and had guided with back in the days of the Company of Whales and trips on P&O's Pride of Bilbao. It was great to catch up with these guys again, and good to know that there would be some experienced eyes looking out.

Day 1 - Portsmouth to Santander
On the morning of the 28th the sea was like a mill pond and the 'oily calm' made for perfect cetacean watching conditions.  Unfortunately as we headed south the weather slowly deteriorated and by mid afternoon the choppy sea and strong swell made viewing difficult.

This trip turned out to be excellent for seabirds and by the end of day one we had seen over a thousand shearwaters. Great Shearwater was probably the most numerous species, Sooty was the next and then Cory's. Balearic was present in smaller numbers and at least two Macaronesian (Barolo's) were reported but we did not see any. 

Great Shearwater
Great Shearwater
Great Shearwater
Cory's Shearwater
Mixed Shearwater flock  
Mixed Shearwater flock

Shearwaters were most numerous in the southern bay where towards the end of the day we encountered several large feeding flocks. European Storm-petrel numbers were as high as I have ever seen and I estimate that we must have seen over 300 birds. Other species recorded included Northern Gannet, Sabine's Gull, Great Skua, Sandwich Tern and Arctic Skua.

Recent trips into the Bay of Biscay have proved pretty fruitless for me for the large rorqual whales, but I had heard that Fin Whales were now being seen in good numbers. It is great to report that this trip was indeed much more like the trips of old, and we did in fact have eight encounters with Fin Whales and numerous unidentified rorqual blows. It is always frustrating not to clinch an ID but the nature of the whale watching experience on a ferry is very different to a bespoke whale watching trip where it is possible to approach species more closely. It was even more frustrating when we were shown some images that Glenn had taken in the Bay the week before, which clearly showed a Blue Whale. A couple of Minke Whales and a small group of Pilot Whales were also recorded, but unfortunately on the opposite side of the ship to us.

Fin Whale - blowing
Fin Whale
Fin Whale - preparing to dive
Fin Whale

The rough sea state made looking for Cuvier's Beaked Whales difficult, but we still managed to see several although getting prolonged views was not easy. We saw two large beaked whales swimming in parallel, which were suggestive of Bottle-nosed Whale but unfortunately after three tantalisingly brief views we passed them by and they were lost to view. Dolphin numbers were good, but not spectacular; we recorded Common, Striped and Bottle-nosed

Common Dolphins
Common Dolphin
Leaping Bottle-nosed Dolphins
Striped Dolphins

Other species recorded over the course of the day included several Ocean Sunfish, a shark species, Tuna and Moon Jellyfish.

Day 2 - Santander to Plymouth
The second day starts well clear of the deep water canyons of the Bay and as such the species encountered are more limited.

Northern Gannet was the most numerous species, with the most numerous shearwater being Balearic. We did also add Manx to the shearwater list but other than a few Sooty's there was little of note. In fact bird wise the most noteworthy species was a flock of nine Grey Phalaropes which were put up as the ship passed and circled close several times before heading off.

Common Dolphin was the only species we encountered, and we did so on several occasions. Others on the ship recorded Harbour Porpoise and Risso's Dolphin, but on the opposite side to us.

All in all it was a cracking trip with a great mix of seabirds and cetaceans, and I will certainly be booking a trip for next year.

Sunday 25 September 2016

Titchfield Haven Ringing Group Update - September 2016

Since my last post things have not really improved in terms of our ringing totals for this year, and a spell of bad weather during September has meant that our ringing effort has also suffered. The graphs below illustrate our totals for the usual species for the period 7th July to 24th September for the years 2011 to 2016. We have at least had a few sessions where we have ringed over 100 birds, but generally the numbers of birds have remained low, and the overall total has now dropped below that of 2012, our previous worst year.

There have still been some highlights and the latest one was the capture of our first Brown long-eared bat. We have previously caught Pipistrelles and Daubenton's so it was nice to add a new species. Being a licenced bat worker and very experienced at extracting bats from mist nets it was left to me to extract it.

Brown Long-eared  Bat - Titchfield Haven

To make the graphs easier to interpret I have grouped similar species onto a graph rather than put them all on one. Sedge and Reed Warbler totals remain low and well below average; for the period 1998 to 2015 for the whole season for these two species the total is 841 and 459, respectively, so it is looking like Sedge will be down but Reed may end up around the average.

Sedge and Reed Warbler totals between 7th & 24th September 2011 - 2016

Chiffchaff migration is in full swing at present and the numbers are not looking too bad but Willow Warblers are all but over. We did catch one new Willow Warbler this weekend, but the total of 74 is unlikely to grow much more, which will make this year's total our 4th worst since 1998.

Chiffchaff and Willow Warbler totals between 7th & 24th September 2011 - 2016

The totals of the three species of Sylvia warbler are significantly lower than the average. For the period 7th - 24th the average is 116 for Whitethroat, 55 for Garden Warbler and 471 for Blackcap. For each of these three species the totals are 50% below average.

Whitethroat, Garden Warbler & Blackcap totals between 7th & 24th September 2011 - 2016

Both Cetti's Warbler and Grasshopper Warbler numbers are below average; the Grasshopper Warbler total is at least already higher than last year's total of 135 but is still 62% down on the average.

Cetti's Warbler and Grasshopper Warbler totals between 7th & 24th September 2011 - 2016

Overall, this year is the lowest total in the period 2011 to 2016 but as mentioned earlier our ringing effort is down. This year we have only managed to ring on 29 days compared with 39, 35, 34, 32 and 31 for the period 2011 to 2015.

Sunday 11 September 2016

Looking for the palmations

When news broke last night (10th September) of a Semi-palmated Sandpiper on the south scrape at Titchfield Haven I was surprised that I hadn’t received a text from one of usual crew who circulate news, however it soon became apparent why not. There had been several reports throughout the course of the day of two Little Stints on the south scrape and one of those birds had evidently been re-identified from photos posted on the Hampshire Ornithological Society website as a Semi-p. I was planning to go ringing at the Haven in the morning so if it was still there I thought I would go and have a look. I don’t actually know how many Semi-p’s have now been recorded in Hampshire, but with the exception of one that I caught at Farlington Marshes in 1995 (then the second for the County) most have been in the west of the County at Pennington/Keyhaven. 

Adult Semi-palmated Sandpiper - Farlington Marshes 1995

There were clearly a few local birders who were a bit miffed at having overlooked this bird, but let’s face it they are tricky birds to ID and it is very easy to just take someones word that a bird is what it is and just enjoy it without really questioning its ID, I am sure most birders have done it, and will do so again. It is also quite easy to get hooked up on looking for obvious (or not so) features, such as black or pale legs on a Chiffchaff or Willow Warbler, or palmations between toes on a semi-p to separate it from Little Stint, rather than look at actual features, such as feather patterns or primary projections. But with some species there are only subtle differences and as such with limited experience they can be easily overlooked.

I was fortunate in that the bird was still present today and so after what turned out to be one on the busier ringing sessions of the season so far, the ringing team trudged over to the south scrape for a look. Initially the bird was preening on island I, but eventually it settled on the mud in the north-west corner of the scrape just in front of the hide and began to feed. I spent the first twenty minutes or so just grilling the bird, noting the short primary projection, the strongly streaked dark crown, which was sharply demarcated from the distinct supercilium, the dark ear coverts, the well defined and finely streaked side of the breast and short bill. 

Juvenile Semi-palmated Sandpiper - Titchfield Haven 2016

Juvenile Semi-palmated Sandpiper - Titchfield Haven 2016

Juvenile Semi-palmated Sandpiper - Titchfield Haven 2016

There was evidence of a slight ‘V’ on the mantel from some angles, but it was much reduced from that present on the accompanying Little Stint, and no evidence of the split supercilium, which again is usually evident on Little Stint. At times the bird was very close and yet despite my best efforts I could not make out the palmations.

For comparison a Little Stint - Farlington Marshes 2016 

As I eluded to above in many circumstances the palmations can be very difficult to see, so it is not really a feature worth looking for, unless circumstances allow. In the hand, like the bird at Farlington Marshes in 1995, they were very obvious (see below). 

Palmations of Adult Semi-palmated Sandpiper - Farlington Marshes 1995 
They were also obvious on a Western Sandpiper roosting on a rock in California that I saw in 2012. 

Western Sandpiper - California
Note the palmations and also the length and shape of the bill compared with the Semi-p

I have got one shot where it looks like a palmation is present, but with the bird feeding in soft mud they were generally difficult to make out.

Juvenile Semi-palmated Sandpiper - Titchfield Haven 2016. 
It appears just about possible to see one of the palmations on the birds left leg.

All in all it was a cracking morning with just shy of 150 birds ringed, including our first Firecrest of the autumn followed by a superb Semi-p with a Little Stint as a supporting cast.
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