I haven’t uploaded anything to the blog since I reported on our week in East Anglia, Leeds and Derbyshire as I have been very busy preparing for the main bird ringing season.
Although we ring birds throughout the year, the maximum activity both from the birds and from the ringers is in the ‘autumn’ period from mid July to mid November. Many people roll their eyes when you describe late July as ‘autumn’ with comments like ‘we haven’t even had summer yet’ but if you’re to describe the northbound birds in March, April and May as being on spring migration, then the south bound movement which can start as early as June and is well underway by mid to late July must be the autumn migration. Indeed in early June late northbound migrants like Sanderling and some Reed Warblers can overlap with southbound ones like Green Sandpipers.
As July progresses local breeders leave their natal area and disperse and the first long distant passerine migrants like Sedge and Willow Warblers reach our sites. To continue to monitor the numbers and movements of these birds we need to be ready.
The first thing that needs to be done is to clear all our ringing areas of several months of bramble, black thorn, fern, gorse and nettle growth. In some locations a strimmer can be used in others local regulations mean it has to be done with a pair of shears. This net ride is at our Fleets Lane site in Poole.
July/August is the most fascinating time of the year for the ringer as young birds have either to start/are undergoing/or have completed the post-juvenile moult and adults are undergoing a full or partial moult depending on moult strategy of the species concerned. This 1st year Garden Warbler has undergone it’s partial post-juvenile moult before migrating and will undergo a complete moult during the winter in Africa. This species is very much the exception in the Sylvid babblers (members of this genus have been shown to be babblers and are not related to other warblers at all) as adults also have a complete moult in Africa. In almost all of the other Sylvias adults have a complete moult before migrating and hence have fresh plumage just like 1st year birds, making ageing more tricky.
Another common Sylvid babbler is the Blackcap. Juveniles of both sexes have dark brown crowns and the black cap of the male only appears during the post-juvenile moult. This is thought to be an evolutionary strategy that prevents the adult male treating his own sons as rivals.
A partial post-juvenile moult means that the bird replaces body feathers on the head, body and on some or all of the wing coverts but not the primaries, secondaries or tail. Often the primary coverts and one or more of the outer greater coverts remain unmoulted as can be seen in this Blackcap. After the moult is complete careful evaluation of the contrast between (in this case) the single unmoulted outer greater covert and the new inner ones will allow this bird to be aged as a 1st year until it has a full moult at this time in 2016.
To show how complicated this moult business is, take a look at this juvenile Great Spotted Woodpecker (you will have to take my word that it has the red crown of a juvenile). Although it is only a few months old it is already undergoing a full moult with four outer primaries still to be replaced, the 5th growing and the rest completed. Strangely in its 1st year this species moults either none or some (but not all) of its primary coverts, so in the spring the primaries are fresh and the coverts are abraded.
This time of year is by far the best for ringing at our rather muddy site at Lytchett Bay. Reed and Sedge Warblers are present in abundance and there is always a remote possibility of the ringing the globally endangered Aquatic Warbler that passes through in very small numbers.
As well as Acrocepahalus warblers we also ring small numbers of Kingfishers every autumn. These birds move down the rivers to the estuaries after breeding. Usually only one or two are present at the site but up to twelve are been ringed annualy showing an ongoing migration. We often catch a bird we have ringed in previous years and one of our birds was re-trapped in Totten, Southampton.
Kingfishers can be aged by the colour of the upper surfaces of their (tiny) feet, smoky in 1st years, orange in adults. The colour of the base of the lower mandible can be used to sex them, orange tones in females (in this photo) and black in males (as in the previous photo), although this difference is more marked in adults.
The RSPB has been managing some of the fields at Lytchett Bay and has built a view-point overlooking one of the ponds and has just installed an information board ….
…. on exactly the same day that Wessex Water put up this sign on the lane that leads to the viewpoint (and to their water treatment works). Talk about a lack of joined up thinking!
On the other side of Lytchett Bay is Lytchett Heath, an area owned by Dorset Wildlife Trust. We have permission to ring on the heath and nearby reedbeds. A busy morning last week resulted in the capture of over 100 birds including this male Bearded Tit. This is another bird of uncertain affinities, it certainly isn’t a tit, it has been allied with the Asian parrotbills, but now resides in a family of its own. It’s English name is also controversal, not a tit, so the name Bearded Reedling has been used, but it’s not ‘bearded’ either. I suppose Moustached Reedling would be a step too far.
The most surprising bird at our Lytchett Heath session was this Common Redstart in full juvenile plumage. Birds are not thought to migrate until they have almost completed their post-juvenile moult, so this bird probably hatched nearby. Although relatively numerous in the New Forest, this is a scarce breeder in Dorset, for example the 2011 Dorset Bird Report mentions just three sites, seven singing males and four fledged young for the whole county.
The name of the 14 Old World species of redstart, is derived from the colour of their tail, the Old English for tail being ‘steort’. Pioneer ornithologists in America found an unrelated bird (now classified as a New World Warbler) with red in the tail and called it American Redstart, but the name ‘redstart’ was carried over to a multitude of related warblers in the Neotropics, all of which have white not red in the tail. Recent attempts to rename these Neotropical warblers as ‘whitestarts’ has met with ambivalence.
In complete contrast to my early morning and muddy ringing sessions we attended a lovely birthday celebration hosted by our friend, fellow birder and moth-er from Swanage, Phyl England.
Phyl, here seen with Paul Morton, is celebrating her 80th, yes 80th birthday!
Of course, as the hired Brownsea ferry cruised around the islands of Poole Harbour, we celebrated in the traditional manner.
I was expecting that we would sail around the back of Brownsea, past the castle and the lagoon and return to Poole Quay ….
…. but instead we went past the Haven Hotel and out of the harbour mouth ….
…. towards the rock pinnacles of Old Harry.
Indeed we went so far past Old Harry that we wondered if Phyl and her family had arranged to be dropped off at Swanage.
Expecting a mainly social event, I had only brought my pocket camera so I couldn’t do justice to this beautiful red moonrise.
It was almost dark by the time we passed the Studland ferry re-entered the harbour.
…. and with the full moon shining on the water ….
…. we got back to Poole Quay about 2220. Thank you very much for a lovely evening Phyl.
And finally Margaret’s daughter Janis has been looking after this little dog, Kitzie, for a friend.
I’m not much of a dog person, but have to admit that he was quite endearing (and no, we have no plans to get one).
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