Titchfield Haven Bird Ringing - Year End Summary 2012

As I mentioned in a previous post, the autumn migration is pretty much over and so with very few birds passing through the ringing area at Titchfield Haven, it was time to call it a day, well season. Overall it was an interesting year that was made all the more frustrating by some very variable weather conditions, but whilst there were some very low totals for some species, others had a record year.

Selected Annual Ringing Totals Titchfield Haven 2012

The season finished with a total of 2579 birds ringed between early July and the end of October 2012, with the most numerous species ringed being sedge warbler (635), followed by blackcap (371),  grasshopper warbler (360), reed warbler (304) and chiffchaff (291). I have previously discussed what a fantastic year 2011 was totals wise, and the following graph and table illustrate this.

Five Year Totals for Selected Species

During 2011, 1436 sedge warblers were ringed in the autumn period, during 2012 only 635 were ringed, 44% of the 2011 total. Grasshopper warbler followed a similar pattern, with the 2012 total being only 38% of the 2011 total. The totals for whitethroat, garden warbler and chiffchaff were equally low with the 2012 totals being 22%, 27% and 34% of 2011 totals, respectively.

Five Year Totals for Selected Species (the figures in red represent the
highest annual total for that species)

But whilst the totals for many species were much lower, common redstart and firecrest had their highest ever totals this year with five and seven, respectively ringed. Blackbird and song thrush totals were the highest for over 10 years, although the numbers of birds ringed were still fairly low. Overall the 2012 total was the lowest autumn total at Titchfield Haven since 2006.

Annual Titchfield Haven Ringing Totals 2008 - 2012 

Given the above results it would appear that several bird species suffered poor breeding success during the summer of 2012. It is considered that the poor weather conditions throughout the breeding season may have been a contributing factor, but poor weather over the Mediterranean during the spring migration may have meant that less adult birds returned to breed. The recently published State of UK's Birds 2012 report details that the number of breeding birds in the UK has declined by 44 million since 1966. Changes in land use and management, and loss and fragmentation of habitat have been cited as some of the reasons for the decline, along with cold and wet weather. Given the apparent effect the weather this summer has had on breeding birds, the declines of some species could be much faster if the trend of colder and wetter summers continues. 

The First Winter Blackcap in the Garden...or is it a Late Migrant?

I spent the day at home today and so had the chance to put a net up in the garden. The usual suspects were present, blue tit, great tit, coal tit and great spotted woodpecker, but also a couple of marsh tits. Marsh tits are regular visitors to my garden in the winter and over the last 12 years I have ringed nine new birds in my garden. I did not have my binoculars handy and therefore could not see whether these birds had been ringed before, but I will keep an eye out. 

A steady trickle of blue tits were passing through the garden, when a juvenile male blackcap turned up in the net. I had glimpsed a male blackcap earlier in the day in another part of the estate and suspect that this is the same bird.

Juvenile Male Blackcap

This bird was in immaculate condition, the wing and tail feathers were very fresh and it was in good condition, having a fat score of 1 and a muscle score of 2.

Juvenile Male Blackcap

My immediate impression was that this bird was a winter visitor that had just arrived, but given that there is still a scattering of migrants present in the UK, such as subalpine warbler in Cornwall, a few dusky warblers and chiffchaffs, it could just be a late summer migrant. The next few months will determine that..

Winter Bird Ringing - 18th November 2012

With the autumn migration pretty much over, bird ringing at the usual ringing area at Titchfield Haven has now finished. Typically that would be the end of ringing at the Haven for me and I would move to other sites, but this year there is a back up plan in place. Over the last couple of years a nearby field has been sow with Quinoa, the crop failed last year due to the dry weather, but this year the crop did very well, and subsequently a decent crop of bird food is present.

Field of Quinoa

Over the last few weeks the numbers of reed buntings present have steadily increased to the point where over 100 were present, so we thought we would try and catch them. The weather was amazing this morning, a crisp, clear, still and frosty morning, so we met up early to set the nets before first light. The weather conditions were ideal for bird ringing and as the sun got up the birds began to arrive, reed buntings were first, followed by brambling, lesser redpoll, chaffinch and bullfinch.

Female Reed Bunting

The session began well, with a handful of reed buntings, a dunnock and chaffinch. Sexing reed buntings is generally straight forward since male birds have white visible in the collar, a largely olive or greyish rump, a black band on throat feathers and around two-thirds of each crown feather is black. But despite handling quite a few reed buntings some of them can be quite tricky to age.

Juvenile Type Tail Feathers

Adult birds usually moult completely post breeding and replace both wing and tail feathers from the end of July to September. Adults therefore tend to have fresh primary tips and tail feathers, whereas juveniles are worn, in addition the feathers in juvenile birds are narrow and pointed. However, the variability in the pointedness of tail features and extent of abrasion on individual birds is great. The image above shows juvenile type features, they are pointed and worn, whereas the tail below has broad and rounded tail feathers that show little wear and therefore are indicative of an adult bird.

Adult Type Tail Feathers

The session was going well and it was not long before we had ringed over 20 reed buntings, four chaffinch's, two dunnock a robin and a superb adult male common kestrel. This bird was in fantastic condition, and looked stunning with his grey head, and tail with its black sub-terminal band.

Adult Male Common Kestrel

An interesting footnote for this blog is the re-capture of a reed bunting that I ringed in my garden on 11th March 2012. This bird was re-trapped at Titchfield Haven on 30th October at Titchfield Haven, not a massive movement but still its always nice to have one of your birds controlled.

Greater Horseshoe Bat - A Pleasant Surprise

It was an early start this morning as we had to travel to Somerset and survey a site before heading onto Taunton for a meeting. We arrived at the site in plenty of time and did what we had to do before coming across a small cave set in a limestone escarpment.

Small Cave in Limestone Escarpment

The cave itself looked fairly shallow, but on entering, it was possible to see that the cave extended upwards into the limestone. Looking around we located loads of large bat droppings on the cave floor; the droppings were in three parts and measured about 10 millimetres in length and about 2.5 millimetres wide. The size and shape of the droppings looked very reminiscent of greater horseshoe bats, so we investigated further.

Large Bat Droppings on Floor of Cave

Looking up there was the bat, a greater horseshoe, wings wrapped around it and torpid. Greater horseshoe bats are mainly restricted to the South-west of England and South Wales so it was not an unexpected find, but nonetheless still exciting.

Roosting Greater Horseshoe

Horseshoe bats are from the genus Rhinolophus and there are two species resident in the UK, Lesser R. hipposideros and greater R. ferrumequinum. When roosting the two species are readily distinguished since greater horseshoe is tablespoon sized, where as lesser horseshoe is teaspoon sized. The two species habitat preferences include woodlands and linear features such as mature hedgerows and woodland edges. Lesser Horseshoes echolocate at around 110 kilohertz, whereas greater horseshoes at around 82kHz. These are species that we rarely encounter in Hampshire so it is always good to see one when surveying out of the county.