29 August 2016

Green 0T0

We've been finding it quite difficult to catch up with any significant numbers of Mediterranean Gulls at our regular sites (Men-aver beach and Gillan Creek), so colour-ring sightings have been few and far between. But yesterday we did catch up with Green 0T0 which is an occasional visitor to Portscatho and the Helford river.

Distance and poor light weren't conducive to a decent photo of 0T0

Ringed as a chick in Vendée, France in 2011 Green 0T0 was first seen in Cornwall in September 2011, then again in October 2012. By December 2012 it was down in Portugal, moving east to Spain in February 2013. It was then back in France before being seen in southern Portugal the next winter. Since then it's only been seen in France, before returning to Cornwall in August 2014 and now August 2016.

This is one of the wider-ranging of the birds we've seen in the county, so hopefully it will continue to wander!

27 August 2016

Chats and pipits

Just two of us ventured out yesterday to make the most of the calm weather at Gunwalloe. As we've not been able to run the CES this year (due to an inaccessible net ride) we could use 'tape' lures to increase our catch of migrant warblers. It worked!

Our catch of 104 birds was excellent, especially considering most of these came from a single 40' net and a net right out in the open at the edge of the new turnip field. The main species were Whitethroat (19), Sedge Warbler (17) and Chiffchaff (10), though the highlights were three Tree Pipits (the first we've ever caught here) and three Stonechats (two juveniles and an adult male).

Other sessions this weekend have seen the group ringing Spotted Flycatcher and a dozen Grasshopper Warblers at Nanjizal and a very smart Whinchat at Marazion.

21 August 2016

2016 Barn Owl numbers

With all the monitoring of first-brood Barn Owls now finished, we can get a good picture of how the season went. The table shows the standard figures we work out every year and it's clear that 2016 was a pretty dismal affair.

2011 2012 2013 2014 2015 2016
Sites visited 32 34 32 44 41 47
Unoccupied 2 (6%) 7 (21%) 12 (38%) 11 (27%) 11 (27%) 12 (26%)
Occupied but no breeding 13 (41%) 2 (6%) 7 (22%) 7 (18%) 7 (12%) 8 (17%)
Average clutch size (where observed) 4.8 4.1 3.6 4.6 4.6 4.6
Average brood size (where observed) 3.1 3.1 2.4 3.5 3.5 2.8
Number of chicks ringed 33 46 19 63 70 47

Whilst the number of sites we monitor has increased (and will increase more with some very generous funding from Paradise Park), and occupancy remained average, productivity was very low. The average clutch size was similar to previous years but brood sizes were lower than the last couple of years. We also saw four complete failures which is still very unusual in the county.

We think this is due to the cold, wet spring weather, which meant that many birds were either not in good enough condition to breed, or did breed but didn't find the food to raise larger broods. We also found that many birds were developing very slowly, so several visits to ring chicks found that they were just too small, so extra visits were needed. This also meant that there were quite a few 'abandoned' chicks brought in to the Screech Owl Sanctuary; not all survived to fuully-grown, but those that did were also ringed by the group before release.

This poor season seems to have been mirrored across the west of the UK and we can only hope that this will improve in future years.

19 August 2016

Injured Peregrines, Portland Stormies and a super-fat Sedge Warbler

We recently received details of some of our ringed birds that had been found elsewhere, both recaptured alive and found dead.

The saddest was the finding of two injured Peregrines, both ringed as chicks in the same nest near Botallack in May. One was found grounded with a broken metacarpal near Helston on 15th August and a second was found the next day near St Just, with a broken humerus and ulna. Both are now receiving veterinary care and we hope they'll recover enough to be released again.

Another interesting set of movements involved three Storm Petrels, all moving between Hot Point, Lizard and Portland Bird Observatory in Dorset (just over 200km). Over the summer we caught two birds originally ringed at Portland Bill (2699028 and 2699030) and have just heard that a bird we ringed on 5th July was recaught there on 19th July. These are the first movements of Stormies between us and Portland, so to have three in a summer is rather coincidental!

Last but not least was a more expected recapture of one of our Reed Warblers on the Isles of Scilly. D791823 was ringed at Marazion Marsh on 8th August 2015 and recaught at Porthellick, St Mary's on 10th June 2016.

Movements of the Peregrines (red), Storm Petrels (blue) and Reed Warbler (green)
On the ringing front, we've been battling the wind and Cornish mizzle to fit in some mist-netting sessions, but have only really managed a couple of Swallow roost catches (totalling 144 birds (and one Sand Martin)) and a couple of mornings in the reedbed, ringing 70 warblers and Reed Buntings. You know migration is well underway though when you catch a Sedge Warbler completely covered in fat. The bird below (excuse the rubbish photo) felt like a tube of butter, being completely covered in stored fat. Considering the fat-free weight of a Sedge Warble can be as little as 9.5g, this bird weighed in at 19.8g!

6 August 2016

Not often you get four controls in one net

Last night our numbers were swollen by visitors from up-country, allowing us to us divide our time between nocturnal netting sites on the Lizard. First stop was Gunwalloe where we netted the Swallow roost for the first time, starting off well catching a decent number of warblers and a couple of Reed Buntings (very much lacking in recent years). Numbers of Swallows soon increased, but the roost was rather disrupted by a pack of Starlings also choosing to roost close to the nets, of which we caught a small number. But once these were cleared, Swallows dropped back in and we ended the night with 50 Swallows (along with nine Reed and eight Sedge Warblers).

With most of the team staying to process Swallows, two decamped to Hot Point, Lizard to set nets for Storm Petrels. In amongst a very eerie sea fret, we netted through to 3am, catching 60 birds. The highlight though was one net round which produced five ringed birds (in the same net)! These included birds from Portland Bill (Dorset), Dingle peninsula (Co Kerry), a recapture of a bird we ringed in July 2015 and incredibly two birds carrying rings from the Channel Islands Ringing Scheme.

These birds will almost certainly have been ringed on the small island of Burhou, but we'll have to wait for confirmation. This is rather exceptional though, as to the end of 2015 only 12 Channel Islands ringed Storm Petrels had been recaptured in Britain & Ireland (four of which have unsurprisingly been in Cornwall).

Just for a brief distraction we also caught a bat, which we think was a Pipistrelle... ***UPDATE*** It was apparently a Whiskered Bat!