Mid-September Ringing Update

I wasn't intending to do another mid-September update as the weather last weekend didn't look that great and so I thought any ringing was unlikely. However, as it turned out the conditions on Sunday 13th were perfect. It was evident first thing that it was going to be a good day as the nets were 'dripping' with birds on the first round. We were so busy that Barry and I alternated extracting and ringing whilst Maggie patiently scribed. By the end of the session we had ringed 267 new birds and had two controls, one Chiffchaff and one Blackcap and our second Common Redstart of the year, which was a cracking male.

Of course having caught so many birds, it dramatically altered the totals for the year to year comparisons, so I thought I should update the blog to reflect this, and bring it in line with the September 14th date used in previous years. The story with Sedge Warbler is still down, and well down at that, with this years total 40% below our average for the time of year. By contrast, the Reed Warbler is having a fantastic year, and the total is 58% up on the average, and heading towards our highest ever annual total. 

Summary of Key Species Ringing Total up to 14th September

Summary of Key Species Ringing Total up to 14th September

Grasshopper Warbler numbers are still trickling along, but with the total now standing at 118 numbers are over 260% below average. Other species totals below average are Willow Warbler, at 7% down, Garden Warbler at 34% down and Whitethroat at 2% down. 

The winners, as well as Reed Warbler, are Chiffchaff at 38% above average and the real winners Blackcap with a total of 448 birds ringed so far. This total is 116% above the average for the time of year, and if the pattern continues could see Blackcap elevated to the most numerous species ringed this year. In total we have ringed 2472 birds of 29 species, to date.

Titchfield Haven Bird Ringing - Late August update

It has been a very mixed bag this season at the Haven which has not been helped by the very changeable weather. Fortunately Barry is retired which means that he can do some sessions during the week in order to keep our effort constant, but Duncan and I are getting limited opportunities to ring at weekends. If we are lucky we may be able to get one session a week, which is great for catching up with sleep, or doing general birding, so we can't complain, but we would rather be ringing.

Despite the inconsistent weather conditions the overall ringing total for the year is holding up reasonably well, but unless there is going to be a very late surge in the numbers of migrants it is looking like this year the totals will be at best average. That said there are some notable exceptions; on the down side, the Grasshopper Warbler total remains exceptionally low with only 36 birds ringed to date. For the period 2010 to 2014 inclusive, by 23rd August the average is 143 birds, so this year's total is significantly lower that we would have expected. It won't be the lowest total since 1998 as we have already passed that, but could be within the bottom five.

Juvenile Grasshopper Warbler

On the flip side of that, the Reed Warbler total currently stands at 450, which is the highest total for the period 2010 to 2014 by 23rd August, and well above the average for that period which is 293. The overall total for all species for the period up to 23rd August stands at 1310 birds of 20 species. 

A summary of selected species from 2010 - 2015 up to 23rd August

A summary of selected species from 2010 - 2015 up to 23rd August

The only unusual record is a Common Nightingale that is only the sixth ever ringed at the site. There has been very little evidence of visible migration over the last few weeks, with the odd Tree Pipit and Yellow Wagtail and on 2nd August a Marsh Harrier. 

Common Nightingale - Note the pale tips to the tertials confirming this bird to be a juvenile, also the first primary can be seen extending 
beyond the longest primary covert, thereby confirming it as a Common not Thrush Nightingale (B. S. Duffin)

On the morning of 22nd August we held one of our public ringing events, which was well attended as usual. The session was steady, with 78 birds ringed, Reed and Sedge Warblers were as ever the most numerous species, but five Grasshopper Warblers were very welcome. Once again there was very little evidence of visible migration, the most notable species being Yellow Wagtail, with two birds and a single Common Swift. Just as we closed the nets a couple of sparring Sparrowhawks put in a great aerial display before drifting off to the east.

Sparring Sparrowhawks

After the session I stopped for a quick look off the sailing club at Hill Head with Simon Ingram, who had joined us for the mornings ringing session. There was a flock of around 100 terns roosting on the shingle but unfortunately, as is a common theme these days, the level of disturbance was very high with kayakers, fishermen and dog walkers continuously flushing the birds to the point where there was nowhere for them to settle. Simon was intent of finding a Black Tern and after a quick scan through the flock, looked out to sea, I concentrated of the roosting terns as there was a constant turnover of birds. It wasn't long before I picked out a cracking adult Roseate Tern, I quickly got Simon onto it and then we put the news out. The speed at which we did that enabled Graham Barrett, who was on the other side of the harbour, to get onto the bird, before once again, the flock was flushed, this time they did not return.

Bird Ringing Summary, Titchfield Haven - October 2014

With the autumn migration season at the Haven gradually drawing to a close, and the first Redwings and Bramblings of the autumn returning, I have been playing around with some of the species ringing totals. But rather than just focus on the last five years, I have looked back to 1998 at a selection of species. As well as looking at the capture totals between 1998 and 2014, it has also allowed me to look at the general trend of each species over that period. Initially I have looked at those species that we are unlikely to catch again this year but as the season progresses I will add other species. The table below provides information on a selection of passerines, including those that are regular and others that are more uncommon.

The table above looks at the ringing totals between 1998 and 2014 for a selection of passerines.
The totals in red are record years, the total figure is the total number of birds ringed in that year,
not just the total of the species shown.

As I have stated previously the total of 270 birds for Willow Warbler was a record for the site by a good number, as illustrated above. Between 1998 and 2014 the previous highest total was 158, and we have come close to catching 150 birds on three other occasions. Looking at the trend for the last 16 years there is a steady increase. It is difficult to interpret what this means but certainly the number of birds being caught each year is showing a gradual increase.

The Grasshopper Warbler total ended with a total of 340 birds, which is the fifth highest total ever for the species. Once again there is a strong upward trend for the species but that is likely to be slightly skewed by the amazing total of 950 birds in 2011.

The total of 151 Common Whitethroats is the second highest total for the species and once again the trend for the capture totals is a strong upward one. Looking at the totals it is evident that three of the last four years have produced the first, second and third highest totals which could suggest that the species has been having productive breeding seasons recently.

Another species showing a strong upward trend is Garden Warbler and this year's total of 67 was the third highest ever. It is interesting to note just how few birds are ringed annually, in comparison to other species such as Common Whitethroat and Blackcap. Could this indicate the smaller numbers of birds that breed in the British Isles or do Garden Warblers not migrate through the Haven in high numbers?

A species that we get asked about every year when we carry out public ringing events is the Aquatic Warbler. It is a species that is on most Hampshire birders wish list and a species that I have been fortunate to get to grips with on many occasions. Since 1972 only 16 Aquatic Warblers have been ringed at the Haven; the first was in 1977 but 15 have been between 1998 and 2009. We have had several years with multiple captures with the peak being 2006 when four birds were ringed.

Aquatic Warbler - Titchfield Haven 2009

Since 2009 we have not caught an Aquatic Warbler at Titchfield Haven and subsequently there is a strong downward trend for the species at the Haven. Aquatic Warbler is classified as Vulnerable and has declined rapidly in previous years due to the destruction of its habitat. Its decline has been stopped in some areas due to intensive management but in countries like Hungary the species has been quoted as declining to extinction. The decline in the species may be reflected in the lack of birds being caught at the Haven in recent years.

Titchfield Haven, Mid-September Update

It is now mid-September and what started as a slow season has turned out to be an excellent autumn. As I have mentioned in previous posts, we try to use standard trapping methods at the Haven, this includes using the same number of nets, ringing on only three mornings a week and the same tape lures. This allows us to directly compare our totals year on year. Of course the birds that we catch will not necessarily be from the breeding population in the UK, but are likely to be birds from other parts of Europe, as was illustrated so dramatically illustrated with the Pallas's Grasshopper Warbler a couple of weeks ago.

Looking at the nine key species that we study, it is evident that they have all had good years. The Sedge Warbler total currently stands at 1183, which is already our sixth highest total ever. Reed Warbler's seem to be one of the winners this year, as the total of 642 is already the second highest total ever, and the Willow Warbler total of 267 is the highest ever.

The Grasshopper Warbler total is the fifth highest total ever and Garden Warbler's appear to have had a good year as this total is our second highest ever. It is still early days for Chiffchaff, as this species is a later migrant, but the total to date is the second highest of the last five years. I was only today reading a post on the BTO Bird Ringing Demog Blog about large numbers of Blackcaps being ringed at western and central sites in the UK, and this is definitely the case at the Haven. We have already ringed 537 birds, which is the eighth highest total, but looking at the year to year comparisons, the total this year is already 180 more that at the same point in 2010 when the third highest total ever was recorded. The total for Common Whitethroat is on a par with our highest ever total, which was recorded in 2011 and the Cetti's Warbler is again indicating a strong breeding season.

There were no surprises over the last week, although we did catch our second Sparrowhawk and Green Woodpecker of the year and our first Spotted Flycatcher of the year.

Eastern Surprise - Pallas's Grasshopper Warbler, Titchfield Haven September 2014

With the current light easterlies and numerous eastern vagrants turning up in the country at present we were hopeful of something. But living on the south coast of Britain and with the Isle of Wight just off shore, one has to remain grounded, and so we were hopeful of a Wryneck or just maybe a Barred Warbler. In our wildest dreams we have never really considered the chance of a Pallas's Grasshopper Warbler and so when Barry returned from a net round with a very odd looking Grasshopper Warbler we didn't expect to see what appeared out of the bag.

Our initial impression was of a bird that was much darker than Grasshopper Warbler with yellow underparts and a finely spotted upper breast. The tail feathers were also extremely dark and the undertail coverts were un-streaked and a warm rusty colour. The bill was considerably larger that that of Grasshopper Warbler. Of course the features that give Pallas's Grasshopper Warbler its nickname of PG Tips are the pale tips to the tertials and the tips of the tail feathers. The pale tips to the tail feathers were not immediately obvious as the tail feathers were wet, but the pale fringing on the tertials, which forms a spot on the inner edge were quite blatant. The underside of the tail was very dark, almost black and the pale tips were extremely obvious from the underside. The series of photos below highlight the features of this truly stunning bird.

Pallas's Grasshopper Warbler - Titchfield Haven - August 2014

Pallas's Grasshopper Warbler - Titchfield Haven - August 2014

Pallas's Grasshopper Warbler - Titchfield Haven - August 2014

Pallas's Grasshopper Warbler showing pale tips to the tertials particularly
on the inner webs, and pale tips to the outer tail feathers - Titchfield Haven - August 2014

Pallas's Grasshopper Warbler, Note yellow underparts and fine spotting on the
throat- Titchfield Haven - August 2014

Pallas's Grasshopper Warbler note un-streaked, and rust coloured undertail coverts, dark underside to the tail
feathers with broad pale tips - Titchfield Haven - August 2014

For comparison the next couple of pictures show the Pallas's Grasshopper Warbler with a yellow form of common Grasshopper Warbler. The image below doesn't really show the true extent of the difference in bill size, which appeared significant with the two birds together. The pale tips to the tertials, neat fringing and overall dark plumage, especially on the crown are extremely obvious.

Pallas's Grasshopper Warbler (Left) Grasshopper Warbler (Right) - Titchfield Haven - August 2014

Pallas's Grasshopper Warbler (Left) Grasshopper Warbler (Right) - Titchfield Haven - August 2014

Pallas's Grasshopper Warbler (Left) Grasshopper Warbler (Right) - Titchfield Haven - August 2014

Pallas's Grasshopper Warbler breeds in Siberia, parts of Central Asia, Mongolia and further east. If accepted this record will be the first of this species in Hampshire, and an extremely rare record on the south coast of Britain for a species which is more typical of Fair Isle or the Shetland Isles.

Titchfield Haven - End of August Update 2014

This weeks ringing activities ended with a decidedly mixed weekend. Saturday started with strong winds and heavy rain whereas Sunday was still and calm after a clear night. We had planned one of our public events on the Saturday morning and were on the verge of calling it off when the rained eased and the wind dropped. The adverse overnight weather was not ideal for a good ringing total but that did mean that we had time to discuss the birds we caught in detail with our guests. We struggled to a total of only 37 birds which included Sedge (8), Reed (8), Grasshopper (2) and Cetti's Warblers (1), Whitethroats (8) and Blackcaps (4). As with most ringing sessions there is usually a stand out species and this sessions was a stunning juvenile male Eurasian Sparrowhawk. This was the first Sparrowhawk we have ringed this year and it certainly proved to be a crowd pleaser.

Juvenile Male Eurasian Sparrowhawk

It is relatively straight forward to age and sex Sparrowhawks, males are much smaller than females and therefore biometric measurements of a wing or tarsus can determine sex. Age is determined by the presence of chestnut fringing to the upper parts and bold heart shaped markings on the underparts. The iris colour is described as grey-olive in Baker (1993) for a first winter, becoming bright yellow, sometimes with a hint of orange in a second winter. This individual had a bright yellow iris which may suggest it was from an early brood. For comparison I have included an image of a second winter male that ringed in December 2012.

Second winter male ringed in December 2012 

In the image below the heart shaped tips to the feathers on the underparts are clearly evident as is the chestnut fringing on the subsequent images.

Juvenile Sparrowhawk showing heart shaped tips

Juvenile male Sparrowhawk showing broad chestnut fringing to upperparts

Juvenile male Sparrowhawk showing broad chestnut fringing to upper parts and tail

By contrast Sunday can only be described as a bit manic. The previous nights weather had evidently halted migration for a while and birds were desperate to get going. Our total was an excellent 324 birds including Sedge (108), Reed (49) and Grasshopper Warblers (40). Blackcaps had evidently started to move with 80 ringed, and Common Whitethroat numbers remained strong with another 14 ringed. Other species included a further 15 Willow Warblers, eight Chiffchaff, two Garden Warblers and our first Pied Flycatcher of the year.

I have updated the graph and table which compares this years total up to the 31st August with those of 14th September for the years 2010 to 2013. The outstanding total remains that of Willow Warbler which is evidently a record year for us. All the other key migrant species also appear to have had a good breeding seasons with the majority of the totals being above average and some, such as Reed and Cetti's Warblers already being above of close to the September 14th totals of previous years.

Regular readers of this blog may have noticed that I have been making some changes. One of those changes in the addition of a new page which provides some recent recoveries from the Haven, which is viewable by clicking on the tab at the top of the page.

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)

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).

The First Common Cuckoo ever ringed at Titchfield Haven - July 2014

The title pretty much gives away what the highlight of our first bird ringing session of the autumn at the Haven was today, and so I'll start this blog with a picture of it, a juvenile Common Cuckoo. It was a welcome reward for our hard work cutting in the net rides over the last week and the first Common Cuckoo ever ringed at the Haven.

Juvenile Common Cuckoo

The morning began with a 4am start and as usual our nets were set low in the hope of catching Grasshopper Warblers. Our quest started well and we started the season with nine new Grasshopper Warblers, all of them juveniles.

Juvenile Grasshopper Warbler (yellow form)

We caught most (six) of the Grasshopper Warblers in the first round, but added the odd single throughout the morning. The rounded tail shape is typical of the genus Locustella but the dark streaks along the shaft of the under tail coverts can be very variable in their extent.

Under-tail Coverts and Tail of Grasshopper Warbler

It was whilst extracting one of the Grasshopper Warblers that we heard an odd call. We recognised it as a juvenile begging call, but couldn't work out what it was, that is until we saw a Cuckoo fly over the top of the reeds. The very next round the bird, or another, was in the net. The bird was clearly still dependant on its unfortunate parents, who happened to be a pair of Reed Warblers, as its wing feathers had not fully grown. According to the BTO website the average wing length is 219mm, this birds wing was only 137mm. This was the first cuckoo I have ever had the pleasure to handle, other than a dead Yellow-billed Cuckoo that was found in Woolston, nr Southampton, many years ago. It was a truly stunning bird with heavily chestnut barred upper parts and strongly barred underparts. Most of the upper parts were pale fringed and the white nape patch, typical of a juvenile bird was clearly visible. The gape was a deep orange colouration, and was striking. After release the bird moved around the ringing area begging constantly, its busy parents in constant attendance.

Juvenile Common Cuckoo

Juvenile Common Cuckoo

Juvenile Common Cuckoo

Juvenile Common Cuckoo

Juvenile Common Cuckoo

A Common Kingfisher would have normally been a good candidate for bird of the session, but on this occasion the juvenile had to make do with the runners up spot. This bird was clearly a juvenile as the front of its tarsus and upper foot was brown and there were dark smudges on the breast, that almost formed a band. In colouration this individual was quite dull, the we considered that the crown feathers were more green-blue, than blue-green, making it a female, but this was the first of the year so we didn't sex it.

Juvenile Kingfisher

Juvenile Kingfisher

A juvenile Reed Bunting was another good bird for us at this location. This individual was sexed as a female due to the pattern and lack of black in the crown and throat feathers. Other species captured included Reed, Sedge and Cetti's Warbler, Blackcap and Whitethroat, Chiffchaff and Goldcrest.

Juvenile Reed Bunting (female)

A canary yellow Willow Warbler was the first of the autumn, and hopefully will be the first of many. They certainly appear to have had a good breeding season at Botley Wood.

Juvenile Willow Warbler

We have often had discussions about ageing Cetti's Warblers. Swensson suggests that there are no plumage differences between adult and juveniles, but adults undergo a complete moult post breeding, whereas juveniles undergo a partial mount. In most passerines this would mean that juvenile greater coverts are retained and thus a difference should be visible. A couple of years ago I read a paper that suggested this was indeed the case and we started looking and ageing birds based on this feature. Given the generally plain plumage, good light is needed to see the feature, but it is visible in some individuals. Today we ringed five Cetti's Warblers, one of which was undergoing its post juvenile moult and had retained two of its greater coverts. It will be interesting to see whether this feather is picked up throughout the autumn as we re-trap this bird, which we will undoubtedly do.

Cetti's Warbler Wing

The session finished with 74 birds ringed of 15 species; Reed Warbler (21), Grasshopper Warbler (9), Sedge Warbler (9), Chiffchaff (9), Blackcap (6), Cetti's Warbler (5), Wren (4), Whitethroat (3), Robin (2) and single Cuckoo, Kingfisher, Blue Tit, Willow Warbler, Goldcrest and Reed Bunting. Let's hope it's not all downhill from here.