Wednesday, 27 August 2014

A History of Grasshopper Warblers at Titchfield Haven

Bird ringing studies began at Titchfield Haven in 1973 and in those days the Grasshopper Warbler Locustella naevia was a regular breeder at the site. Between 1973 and 1998 the species was one that was only occasionally caught with 18 birds ringed, the totals are as follows; 1 in 1973, 1 in 1974, 1 in 1979, 1 in 1981, 1 in 1986, 1 in 1990, 8 in 1992 and 4 in 1994. In 1999, the year after I began ringing at the Haven, we decided to try and target Grasshopper Warblers in order to understand more about the migration of the species.

Juvenile Grasshopper Warbler - Titchfield Haven 2014

We sought advice from Trevor Squire, who in those days was the lead ringer at the Icklesham site in East Sussex, as they were catching good numbers annually, and set about our task. We set our nets low to the ground and used tape lures of a singing male Grasshopper Warbler. These were set to come on 1.5 hours before sunrise, as British Trust for Ornithology  guidelines recommend. In our first year we caught 31 birds and were pretty chuffed with our results, but had no idea how the numbers would increase in the future. 

In Birds of Hampshire (Published by the Hampshire Ornithological Society in 1993) Grasshopper Warbler was described as "A scarce summer visitor which has declined considerably since 1970". Cumulative totals of singing males between 1966 and 1990 showed a decline from 139 to 52, so the species was evidently undergoing a dramatic decline in Hampshire. Today the breeding status of Grasshopper Warbler in Hampshire is hanging by a thread with only 12 singing males recorded in 2012 (2013 and 2014 figures are not yet available). 

Despite the decline in breeding numbers, the autumn totals at Titchfield Haven increased from the 31 in 1999 to an annual average of 281 birds. The peak was an exceptional total of 950 birds ringed in 2011, which was also a record year for many species. The total number of birds ringed at the Haven from 1999 to 24th August 2014 stands at 4502, with the grand total standing at 4523.

One of the most interesting facts that we have learnt is the numbers of birds that pass over the Haven during the autumn migration. It is also interesting to note that the first birds are recorded during the second week in July, and can be recorded up to the second week in October, albeit in much smaller numbers. The peak migration period for the species are the last two weeks of August, although there is an initial peak during the last two weeks of July and good numbers are still recorded during the first two weeks in September.

So what else have we learnt? Unfortunately there are not many sites other than the Haven and Icklesham that are ringing Grasshopper Warblers and that is reflected in the number of recoveries and controls that we have had (see below). The hope is that more ringers will try and ring pulli and adults on their breeding grounds so that we could gain a better understanding of where the birds that pass through the Haven come from and are going to. To date we have only had two foreign recoveries, one from France and one from Senegal.

Recoveries and Controls
Y096313             N     3J                      24/07/11          Wheldrake Ings Nature Reserve, Wheldrake, York
                         C      3    Recaptured  14/08/11  IRP   Titchfield Haven National Nature Reserve (SUFF), Hampshire (341
                                                                                km, S, 21 days)
R586576             N      3                       21/08/05  TDC    Titchfield Haven National Nature Reserve (SUFF), Hampshire
                         C      4    Recaptured  25/01/07          Parc National du Djoudj, Fleuve, Senegal, Senegal (4054 km, SSW,
                                                                                1 yr 157days)
R586596           N      3                       23/08/05  BSD   Titchfield Haven National Nature Reserve (SUFF), Hampshire
                         X      0    Dead           30/06/08          Enstone, Oxfordshire (127 km, N, 2 yrs 312days)
T098831            N      3                       17/09/06  BSD   Titchfield Haven National Nature Reserve (SUFF), Hampshire
                         X      0    Long dead   19/02/07          Selbourne, Hampshire (36 km, NE, 155 days)
T617642            N      3                       02/08/08  BSD   Titchfield Haven National Nature Reserve (SUFF), Hampshire
                         C      4    Recaptured  27/06/10          Ailsworth Heath, nr Peterborough (207 km, NNE, 1 yr 329days)
V680118           N      3                       29/08/09  TDC    Titchfield Haven National Nature Reserve (SUFF), Hampshire
                         C      4    Recaptured  15/05/10          Hasfield Ham, Gloucestershire (142 km, NNW, 259 days)
V680191           N      3                       05/09/09  TDC    Titchfield Haven National Nature Reserve (SUFF), Hampshire
                         C      3    Recaptured  11/09/09          Villeton, Lot-et-Garonne, France (727 km, S, 6 days)
Y457414           N      3                       15/09/12  DAB   Titchfield Haven National Nature Reserve (SUFF), Hampshire
                         C      4    Recaptured  12/04/14          Bicester, Oxfordshire (113 km, N, 1 yr 209days)

Saturday, 23 August 2014

Titchfield Haven Ringing Update - 23rd August

There is no doubt what the headline species, in terms of numbers has been so far this year, and that is Willow Warbler. We have continued to catch good numbers this week, with another 37 added which brings the total this year to 222. This is already by far the best annual total for the site ever, which surely must indicate a good breeding season for the species.

Juvenile Willow Warbler - one of 19 caught today

Grasshopper Warbler numbers have also started to build this week with 69 new birds added. The total of 31 birds ringed on 23rd included six adults, which were the first of the year. Adult and juvenile Grasshopper Warblers undergo a partial post juvenile or post nuptial moult. In juvenile birds this is not really obvious as all the feathers are fresh, but in adults it results in a mixture of new, fresh feathers and very tatty, worn feathers. There seems to be no strategy as to what feathers are replaced, as throughout the body, head, wing and tail feathers, random feathers can be replaced. The Images below illustrate this.

Adult Grasshopper Warbler crown, note mixture of new (fresh) and old (worn) feathers
Very worn wing feathers of the adult Grasshopper Warbler
Very worn tail feathers of adult Grasshopper Warbler

Of the other key warbler species, Sedge Warbler numbers are on a par with the record numbers of 2011 and 2013, and Reed Warbler numbers are the highest of the last five years. Garden Warbler numbers are also on a par with the record year of 2011 and Blackcap numbers are significantly higher than at this point in any of the last five years. Chiffchaff and Whitethroat are also high and are the second highest totals in the last five years for both species. Cetti's Warbler numbers are also the highest of the last five years, although the numbers have slowed in recent days as the breeding birds have moved away from the ringing area and into the reed beds.

Table summarising key species total up to 23rd August in the last five years
Graph illustrating key species totals over the last five years.

Other notable species ringed this week were the second Lesser Whitethroat and Treecreeper of the year. Both species are only ever trapped in small numbers at The Haven.

Juvenile Lesser Whitethroat - the second of the year
Treecreeper - the second of the year

We had ringed over 220 birds by the end of the session 23rd August. Sedge Warbler (still no Aquatics) was the most numerous species with 69 birds ringed, followed by Reed Warbler (46), Blackcap (35) and Grasshopper Warbler (31).

Friday, 22 August 2014

Bunny Meadows and Curbridge - August 2014

The autumn migration is in full swing now and as I had a day off I decided to spend at least parts of the day birding a few local sites in the hope of finding some migrants. I started at Bunny Meadows around mid morning to coincide with the high tide, as this is usually a good site for waders. As I arrived it was just off high tide and a few waders and gulls were taking advantage of the last remaining areas of intertidal, whereas others were already roosting on the vegetated Islands.

Black-headed Gull - Bunny Meadows

Black-headed Gulls were the most numerous gull species with 104 present, Great Black-backed (3) and Herring (7) were also present but only in small numbers. At this time of year the islands are well vegetated and some waders were making the most of this cover, whilst others roosted on patches of bare mud. Black-tailed Godwits were the most numerous wader species present with at least 148 birds present.

Black-tailed Godwits - Bunny Meadows

Most of the godwits present were adults and moulting into their winter plumage but there were also a few juveniles present too. 

Black-tailed Godwits - Juvenile in middle and adults

As well as the godwits there was also a good selection of other waders present. Curlew (2), Redshank (5), Dunlin (1), Turnstone (1), Ringed Plover (24) and a Whimbrel were the species that I found, but some were difficult to identify in the tall vegetation.

Two Ringed Plover and Dunlin - Bunny Meadows 
Whimbrel - Bunny Meadows

I continued past the islands to the remains of the old causeway, another good bird roosting location. There were good numbers of waders here too, with Redshank (60), Black-tailed Godwit (2), Greenshank (2), Oystercatcher (5), Lapwing (5) and Grey Plover (5) present. Two of the Grey Plovers were adults and three were juveniles, one of the adults had colour rings on its legs, and eventually it put both legs down so I could get the combination. The bird was ringed at Hamble Point by Farlington Ringing Group in January 2009, the subsequent sightings are provided below the image.

Grey Plovers - Both adults, with one bird colour-ringed (see inset) - Bunny Meadows

First Ringed        02-Jan-09 Hamble Point, Southampton Water, Hampshire, S England
Resighted           26-Dec-11 Bunny Meadows, Warsash, River Hamble, Hampshire, S England
Resighted           27-Dec-11 Bunny Meadows, Warsash, River Hamble, Hampshire, S England
Resighted           18-Nov-12 Bunny Meadows, Warsash, River Hamble, Hampshire, S England
Resighted           18-Nov-12 River Hamble, Hampshire, S England
Resighted           16-Sep-13 Hook Links scrape, Hook-with-Warsash, Southampton Water, Hampshire, S England
Resighted           04-Feb-14 Bunny Meadows, Warsash, River Hamble, Hampshire, S England
Resighted           22-Aug-14 Bunny Meadows, Warsash, River Hamble, Hampshire, S England

With the tide now dropping fast my next stop was Curbridge, further up the Hamble Estuary. Curbridge has been good to me in recent weeks and today was no exception. I started at the Horse and Jockey pub entrance and immediately picked up three Common Sandpipers and a couple of Kingfishers. There were small numbers of Curlew (2) and Whimbrel (2) and a handful of Little Egrets (5). There were at least 600 gulls present on the intertidal, which is not unusual, but the fact that at least 287 of them were Mediterranean Gulls was astonishing. Flocks of several hundred post breeding Mediterranean Gulls often form on the arable fields around Titchfield Haven, but I have never seen this many at Curbridge before. One of the adult birds had a green colour ring on its left tarsus, but unfortunately it was too far away to see if any letters were on it.

Mediterranean Gulls, Adults and Juveniles and Black-headed Gulls - Curbridge

Wednesday, 20 August 2014

Titchfield Haven - Mid August 2014 Update

I am slightly behind with the update for last weekends bird ringing at Titchfield Haven as I have been playing around with my blog template, I hope you like it. Having finished with that for now, and having received an update of the ringing totals, here it is. 

The season has been progressing steadily and the table below details the capture totals up to 17th August for 2011, 2012, 2013 and 2014 and the 23rd August for 2010. Looking at the figures it appears that some species have had a good breeding season once again, the most notable being Willow Warbler. The highest total for Willow Warbler ringed at the Haven in a year is 259 birds from 1981, but that total was skewed as 91 birds were ringed in a small patch of willow near the beach huts along the Meon Shore. The next highest total is 158 birds, from 2010. As of the 17th August, 185 birds have been ringed and interestingly we have captured three different adult birds that were undergoing their post nuptial moult, we have only ever caught one bird before.

Sedge Warbler numbers are also high, although not as high as in 2011 or 2013, and Reed Warblers also appear to have had a good year. Grasshopper Warbler numbers appear to be generally low, but this may yet improve as we caught 17 and 12 respectively, on the 14th and 16th August. Garden Warbler, Chiffchaff, Blackcap and Whitethroat numbers are at best average, but Cetti's Warbler seems to have had another good breeding season.

There were no real surprises to report species wise this week but we did catch our first Lesser Whitethroat of the year, hopefully the first of many.

Saturday, 16 August 2014

All at Sea - Biscay August 2014

August is probably the peak month for seeing both seabirds and cetaceans in European waters and so I decided to book on another trip across the Bay of Biscay. I booked to go on Brittany Ferries Pont Aven from Portsmouth to Santander and then to Plymouth from 12th to 14th August. It is a slightly frustrating trip since there is no return to Portsmouth unless you stay on the ship for another three days, therefore I had to get a coach back from Plymouth. The ship usually leaves at 17:15 but our departure was slightly delayed due to road closures on the motorway. Given the time of departure there was no time for birding, so once we were out of the port I headed down for something to eat and then an early night. 

Day 1 Portsmouth to Santander
The first days birding commenced at 6am by which time we were heading south and into the Bay of Biscay. We had a full days birding ahead as we were due to arrive in Santander at around 18:00. As the light became good enough to bird, the first Great Shearwaters appeared, quickly followed by the first Northern Gannets. A couple of distant large shearwaters were left unidentified before the first Cory's Shearwaters appeared. The remnants of Hurricane Bertha meant that it was a breezy crossing, and the sea state was ranging between 5 and 7 making it difficult to pick up cetaceans.

Great Shearwater - Biscay

The first dolphins of the trip were a distant pod of Bottle-nosed, that in typical fashion, ignored the boat and concentrated on what they were doing. They stayed low in the water and so were difficult to pick up, but those that were fortunate to get onto them got good views. The second pod where much more fun, a group of Common Dolphins. Around 50 animals came into the bow of the ship, to ride the bow wave.

Common Dolphins - Biscay
Common Dolphin - Biscay
We were treated to numerous encounters with Common Dolphins for the remainder of the day with pod sizes varying from 50 to 5. Some of them had very small calves, whereas others like in the image below were much larger.

Common Dolphins, Presumed mother and calf - Biscay

As we continued south the weather conditions began to calm but there was no sign of any large whales. There was however a steady passage of shearwaters with both Greats and Cory's giving excellent views as they flew alongside the ship.

Great Shearwater - Biscay
Cory's Shearwater - Biscay

Occasional Northern Gannets drifted alongside the ship, and where we recorded them plunge diving, dolphins were usually in close attendance.

Northern Gannet - Biscay

As we passed over the deep water, which in places is 4500 metres deep, we encountered our only Striped Dolphins of the trip. Unlike to Common Dolphins they headed for the back of the ship to play in the wake. Approximately 50 individuals were seen on both sides of the ship.

Striped Dolphin - Biscay

There were periods where it was very quiet, but at around 15:00 activity picked up again. Initially it was just the sight of isolated Cory's or Great Shearwaters and then a Great Skua took off from the water to avoid getting hit by the boat.

Great Skua (Bonxie) - Biscay 2014

At 15:15 we encountered a flock of Shearwaters, that appeared evenly split between Great and Cory's. Many birds were sat on the water whilst others were milling around feeding.

Cory's and Great Shearwaters - Biscay

The flock was quite distant so I began scanning and immediately picked up a small, apparent pale faced shearwater milling around. I have seen what is now known as Barolo Shearwater, but previously Little and Macronesian, before so grabbed my camera in the hope of getting a record shot, presuming it to be that species.

Cory's, Great Shearwaters and possible Boyd's Shearwater (far right and top) - Biscay

However, having looked at the images it was evident that several of the features that I would have expected to be visible on Barolo were not present, and in fact the bird appears to show features consistent with Boyd's Shearwater instead. The bird was obviously smaller than a Manx Shearwater, the wings appeared more rounded and it gave the impression of being more long tailed. This feature was accentuated by the longest undertail feathers being dark.  The eye did not clearly stand out as would be expected in Barolo, but the cheeks and side of the head appeared much whiter than in Manx. The bill was obviously short, and in the bottom left photo appears to be pale with a dark tip. The underwing has wholly dark primaries and there is a hint of a dark bar on the underwing coverts, towards the leading edge. Unfortunately I didn't get exact GPS co-ordinates but I do have them from 14:30 which were 44.31.590N  004.03.512W, at the time the ship was travelling at 24knots.

Possible Boyd's Shearwater - Biscay

Continuing south we picked up a couple of flocks of Dunlin, six Arctic Terns and two Grey Phalaropes.

By the end of day 1 we had recorded the following: Great Shearwater 61, Cory's Shearwater 62, Unidentified large Shearwater 4, Possible Boyd's Shearwater 1, unidentified small shearwater 2, Great Black-backed Gull 1, Lesser Black-backed Gull 4, Great Skua 1, Northern Gannet 25, Dunlin 20, Grey Phalarope 2, Arctic Tern 6 and Yellow-legged Gull 100+, Bottle-nosed Dolphin 9, Common Dolphin 120, Striped Dolphin 20.

Day 2 Santander to Plymouth
In stark contrast to the previous day, at dawn on day 2, the sea was flat calm. As expected in such conditions we were immediately picking up Common Dolphins. Unfortunately as we progressed north the sea state got worse, and occasional heavy showers, made viewing very difficult. Several other encounters with Common Dolphins occurred, but that was it for the trip with regard to cetaceans.

Common Dolphins - Biscay

The light was quite poor at times but we were still able to pick out good numbers of shearwaters. Great and Cory's were once again present in good numbers and Manx Shearwaters were becoming more numerous. Balearic Shearwaters were also more numerous and at one point we recorded a mixed flock of 50 Manx and Balearic.

Balearic Shearwater - Biscay
Northern Gannets became much more numerous as we headed back north, and a tight flock of 12 Little Tern headed south. Northern Fulmars also became more frequent, but only ever single birds.

2nd Calendar Year Northern Gannet - English Channel

During one of the brighter periods, several Cory's Shearwaters were flying alongside the ship, giving excellent views. The ship took the inland route between the west coast of France and the Island of Ouessant, and where the calmer waters met the open sea two adult Sabine's Gulls were loitering.

Cory's Shearwater - English Channel 
Cory's Shearwater - English Channel
There was still a steady stream of large shearwaters in view, even with landfall in site, but by this time Manxie's were the most numerous. Three Kittiwakes made a brief past and one British Storm-petrel was a welcome sight.

Manx Shearwater - English Channel
Manx Shearwater - English Channel

By the end of day 2 we had recorded the following: Northern Fulmar 10, Northern Gannet 210, Cory's Shearwater 40, Great Shearwater 42, Little tern 12, Manx Shearwater 46, Balearic Shearwater 35, Lesser Black-backed Gull 2, Great Black-backed Gull 14, Sabine's Gull 2, Shag 1, British Storm-petrel 1, Great Skua 3, Ringed Plover 6, Kittiwake 3, Herring Gull 30+ and Common Dolphin 99.

Monday, 11 August 2014

Titchfield Haven, Bird Ringing Update - August 2014

I have previously mentioned the slow start to the ringing season for us, but despite this the fine weather over the last month had helped us get back on track, and then came what was left of hurricane Bertha. This didn't stop our ringing activities on Saturday (9th) but Sunday (10th) was a complete washout. Despite this slight setback we have to date (up to 9th August) ringed 1233 birds of 29 species. As with previous years I have put together a summary of the nine most common warbler species that we catch at the site, and drawn comparisons with the last four years.

Summary of the Nine most Common Warbler Species ringed at Titchfield Haven

As can be seen from the data Sedge Warbler is again the most common species with 555 new birds ringed, followed by Reed Warbler with 260. Both species are on a par with the numbers ringed in 2010, and so maybe this year is not going to prove to be a spectacular year like 2011. Willow Warbler numbers are the highest of the five years, but only just, which is a promising sign. Grasshopper Warbler numbers are below average with only 103 ringed to date. Cetti's Warbler once again appears to have had a good breeding season with the second highest total of the last five years and Chiffchaff numbers appear to be consistent with previous years. Blackcap and Whitethroat numbers are low at present, but these species traditionally are slow starters with the peak numbers coming through in September.

Summary of Nine most Common Warbler Species

Of course there are always the odd surprises when ringing at the Haven and I have already posted about the Cuckoo, which was a real treat for us all. Other highlights have included a Woodcock, again a first for the site, three Kingfishers and a Bearded Tit. The Cuckoo will be probably end up being the best bird of the year, but it will undoubtedly be backed up by a Wood Warbler. We have only ever ringed a handful of Wood warblers at the site and those have mainly been captured in July; the individual below was captured during the first week of August.

Wood Warbler - Titchfield Haven (Barry Duffin)

Wood Warblers are a large a distinctive Phylloscopus warbler with bright green upper parts that contrast strongly with the pure white underparts. The under tail coverts are also pure white and the throat and upper breast is bright yellow, all in all a striking bird.

Wood Warbler (left) Willow Warbler (right)
Wood Warbler (left) Willow Warbler (right)

Sunday, 10 August 2014

Colonists and Non-natives, Isle of Wight - August 2014

The news of a pair of breeding (European) Bee-eaters on National Trust land on the Isle of Wight has now been widely publicised and a steady stream of birders have been going to see the event. Living so close to the Isle of Wight, I was eager to go and get a glimpse of this colourful and spectacular species and so arranged to go over after bird ringing on the 9th August. This is the third time Bee-eaters have been recorded nesting in the UK, the first was back in 1955 when two pairs raised seven young and the second was in 2002 when a pair nested in a quarry in County Durham. 

Initially this rare event was shrouded in secrecy because of the danger of egg thieves stealing the unhatched eggs, but the news was widely circulated once the chicks had hatched. The Bee-eaters have made their nest in a small sandy hill on the Wydcombe Estate and a public viewing area has been set up so that visitors can enjoy the birds, without disturbing them. Details of where to find it can be found here.

Bee-Eater Merops apaister - Wydcombe Estate, Isle of Wight

There are apparently four birds present at the site, the breeding pair and two helpers. We saw at least two birds, as we had two birds together at one point, but otherwise there were just single birds coming and going and hunting in the area. We did get some great views when birds were hunting nearby, on one occasion a large dragonfly was taken, or attempting the see off the local raptors, there were Common Buzzards and Sparrowhawks in the area, but the views were generally distant and so no good for photography (see above). The nest site is hidden from view for obvious reasons so one can only imagine what it is like, but it will certainly include soft sand that will enable the birds to burrow in and create a nest chamber. 

My best experiences of breeding Bee-eaters have been during my visits to south-eastern Turkey, where I visited a mixed Blue-cheeked and European Bee-eater colony. These birds were nesting in a mound (see below), maybe the Isle of Wight birds are in a similar location.

Bee-eater Merops apaister Colony South-eastern Turkey - 2012

Being such fantastic birds I couldn't publish a post about Bee-eaters with only the distant shot that I used at the start of this post and so I have included a couple of shots from my last Turkey trip. 

Bee-eater Merops apaister - South-eastern Turkey - 2012
Bee-eater Merops apaister - South-eastern Turkey - 2012

As we were leaving the Bee-eater site I noticed a Jersey Tiger moth settled on a concrete fence post, so of course we had to stop for a photo. Jersey Tiger was formerly a migratory species only but became established on the Isle of Wight during the 1990s, its range has now expanded onto the mainland. It is a day flying species and on warm days can be seen nectaring on the flowers of Buddlieas and thistles. 

Jersey Tiger Moth Euplagia quadripunctaria - Wydcombe Estate, Isle of Wight

As we had made the effort to come onto the Island our next destination was to visit Ventnor in search of Wall Lizards. Unlike the two previous species, which have naturally colonised the Island, the Wall Lizard is considered to be an introduction. The exact date of the first introduction in the town is not known, but there is information to suggest it was as early as 1841. However according to the Surrey Amphibian and Reptile (SARG) Group website, the first reliable published record dates back to 1960. Whatever the exact date is, the species is now well established on the south coast of the Isle of Wight, with a preference for walls and other rocky habitats that are well-exposed to the sun. The Wall Lizards at this site appears to occupy their own ecological niche and where they does come into contact with the native Viviparous Lizard Zootoca vivipara there is apparently no evidence to suggest a negative impact.

Wall Lizard Podarcis muralis - Ventnor, Isle of Wight
Wall Lizard Podarcis muralis - Ventnor, Isle of Wight
Wall Lizard Podarcis muralis - Ventnor, Isle of Wight
Juvenile Wall Lizard Podarcis muralis - Ventnor, Isle of Wight
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