It has been a busy week or two for ringing here on the island, despite the breezy weather. Last week we had the NGB group here, and so were trying out a range of different activities to catch and ring birds, from using portable Heligoland traps on the beach to grappling around in earth burrows for fluffy Manx Shearwater chicks. This week has seen a ringing course held at the observatory, and so a similar suite of activities is taking place. This week, however, has seen the quality and quantity of birds step up a notch. We have managed to catch lots of waders, like Turnstones and Dunlins, when only a handful of each are usually ringed on the island each year; we have caught n adult Barn Owl in one of the sheds, which is the first for over 10 years; and some slightly calmer conditions has allowed for a little bit of mist netting for migrant passerines, like Spotted Flycatchers, Willow Warblers and Goldcrests. I thought I would produce something of a summary of our ringing activities over the last two weeks, although this is by no means a detailed account!
Let’s start with the star of the show…the portable Heligoland trap. This brilliant device is erectable in just under 10 minutes, using flexible tent poles and a hinged ‘goal post’ as the main frame. The hoops gradually get smaller towards the catching end, where there is also a baffle to prevent escape during catching. The funnel shape allows fairly straight-forward catching, but it involves a lot of running and some good feeding resources within the trap…
pushing birds into the catching box
James extracted birds from the makeshift catching box
The primary purpose of the trap is to catch Rock Pipits on one of the beaches on the island- we fit these Rock Pipits with small clip colour rings, which allows easy subsequent identification of individuals in the field. This helps to determine movements of island birds and also the suspected influxes of littoralis Rock Pipits that occurs in the autumn (i.e. large arrival of birds without colour rings).
A Rock Pipit fitted with its new bling
The ageing of the Rock Pipits and Meadow Pipits at this time of year can be a little tricky at times. After observing plenty of individuals, you start to get your eye in on the features used for ageing. I have tried to produce some examples in the images below…
Rock Pipit wing coverts. Note the neat pale edging to the Greater Coverts in the adult bird, compared to the diffuse edges of the GC in the juvenile. Also note the two adult-type median coverts in the juvenile. At this time of year, the presence of active wing moult in the primaries and secondaries is a helpful feature to look out for (=adult)
Meadow Pipit wing coverts. Both juvenile birds show similar Greater Covert colouration and pattern, with diffuse edges. However, the median coverts in the upper bird are adult-type, compared to the ‘toothed’ MC in the lower
It isn’t just pipits that we catch in the trap…
Pied Wagtails and smart White Wagtails like this one sometimes find their way in. We have also been having a brilliant run of catching waders- we have now managed to catch three Turnstones three Dunlins and a Redshank in the trusty trap!
One of the highlights of this week was the trapping of this awesome adult male Barn Owl…
The bird was roosting in an owl box in one of the out buildings during the day, and so a small hand net placed over the entrance to the box did the trick nicely. The bird was aged as an adult due to the lack of barring on the central tail feather, the presence of small comb-like ridges on one of the claws, and the moult underway in the primaries. The bird can easily be sexed as a male by the lack of spotting on the breast and axillaries
Although it is nearing the end of the season for Manx Shearwaters, there are still plenty of chicks slimming down in the earth burrows, wandering out at night to give their wings a bit of exercise before their flight to South America.
Some of the chicks have a good week or two left (top), whilst others have lost much of their down and are converting the large fat reserves into muscle, ready for their long flight. The weights of some chicks can be over 700grams, compared to around 400grams in an adult!
Today was a fantastic day for ringing, as a small woosh net was brought out and set up on Solfach. All the careful preparation and setup paid off before too long, with catch after catch producing Turnstones, Dunlins and Ringed Plovers to be ringed- a great exercise that will hopefully produce some great recovery results!
starting to set up the bungees for the leading edge of the woosh net
Setting the woosh net takes a lot of preparation, but is worth it for the birds! These images are of the team rolling up the edge of the net . This has to be done carefully to ensure nothing sags in the net as it is fired off
And on to the waders. We have ringed perhaps 12 Turnstones, five Dunlins and three Ringed Plovers in the last few days, which is brilliant! This is considering that we usually ring about two of the former species per year. It has been great to practice biometric measurements of the incredibly varying Dunlin bill and tarsus lengths, whilst getting a close look at the gorgeous feather details in these birds…
It was interesting to find large weight differences between birds- some weighed over 130 grams, whilst others were below 85 grams!
All the Turnstones we have trapped have been age 3 – or juveniles. Many of the adult birds would be in primary moult now, with some worn feathers showing up and gaps in the wing where new primaries/secondaries are being grown
Both the above birds are juvenile birds, with nice pale edging to the mantle, scapulars and some coverts. The brown facial and breast markings also indicate to an age 3
Each plover was checked for palmations on the between inner two toes, just in case a sneaky Semipalmated Plover tried to make an appearance
We have managed to catch a few Dunlins too, both in the Heligoland trap, the Woosh Net, and also dazzling at nigh on the beach. Due to a large variation in the length of the bills and tarsus (and general size for that matter) within the various races of this species, we take a few different biometric measurements on each bird
A nice Age 3 Dunlin, but with many adult mantle and scapulars coming through as the bird moults into winter plumage. The chestnut fringed coverts and back feathers are all juvenile-type
And I shall finish with this image of a male Goldcrest. Passerine mist netting has been somewhat poor due to the indy weather, but we managed to open some nets in a reed bed one evening to target a wagtail roost, where we caught four or five White Wagtails and a couple of Swallows.