Saturday, 25 April 2015

Oxwich Marsh 25 April: return of the Warblers

Over the course of the week the weather forecast had not remained consistent for more than a few hours, varying between perfect for ringing and borderline unsuitable on a regular basis.  In the event the conditions were not great, with a moderate south-westerly wind for most of the morning.  This resulted in some of the nets billowing, and was likely to have contributed to a lower catch than might otherwise have been expected.  However, after some early showers, the day was dry.

We put nets in scrub and open reed bed habitats.  A total of 560 feet.  46 birds were captured.

The breakdown was as follows:

Species New Re-trapped Total
Great Spotted Woodpecker 0 1 1
Wren 0 1 1
Cetti's Warbler 2 1 3
Grasshopper Warbler 1 0 1
Sedge Warbler 1 0 1
Reed Warbler 0 1 1
Whitethroat 0 1 1
Blackcap 4 0 4
Chiffchaff 0 1 1
Great Tit 0 6 6
Chaffinch 1 7 8
Greenfinch 1 1 2
Goldfinch 3 2 5
Siskin 4 4 8
Reed Bunting 1 2 3
Total: 18 28 46

The highlights of the catch were two new Cetti's warblers (plus one of the regulars which was re-trapped), a sedge warbler, a grasshopper warbler, a reed warbler and a whitethroat.  Both the whitethroat and reed warbler were re-traps from 2014: the whitethroat was ringed as a juvenile on 20 July; the reed warbler was first captured on 24 April (1 year and 1 day ago).  Neither had been recaptured following initial ringing, and both had therefore been to sub-Saharan Africa since we had seen them for the first and only time.  The capture of the grasshopper warbler was particularly welcome, as we didn't catch the species in spring 2014. Two were reeling on the marsh this morning.
Reed warbler

Grasshopper warbler

Grasshopper warbler

Drinker moth caterpillar

Thanks to Darren Hicks, Wayne Morris, Charlie Sargent and Heather Coats for company and assistance this morning.

Owain Gabb

Friday, 17 April 2015

Oxwich Marsh 13, 15 & 19 April 2014

We have completed three ringing sessions over the past week, with the main aim of capturing some migrant passerines.  The weather, and results to date, have been mixed.  Combined totals are as follows:

Species New Re-trapped Total
Great Spotted Woodpecker 2 2 4
Swallow 1 0 1
Dunnock 0 3 3
Robin 0 2 2
Blackbird 0 1 1
Cetti's Warbler 1 1 2
Blackcap 9 0 9
Chiffchaff 2 0 2
Goldcrest 1 0 1
Long-tailed Tit 1 0 1
Blue Tit 6 12 18
Great Tit 3 22 25
Chaffinch 8 9 17
Greenfinch 8 8 16
Goldfinch 30 13 43
Siskin 5 1 6
Reed Bunting 1 3 4
Total: 78 77 155
The highlights have been obtaining good evidence that siskin is breeding locally for the second successive year (based on capture of birds with brood patches and cloacal protrusions), catching our first swallow of the year during an evening session, and trapping good numbers of goldfinch, taking the newly ringed total for the species at Oxwich in 2015 to well over 100.

Captures of migrants have been relatively limited to date: the swallow, a few blackcaps, chiffchaffs and a willow warbler.  Despite the return to the reed bed of sedge warbler by 15 April, reed warbler by 18 April and grasshopper warbler by 11 April, none have been trapped to date.

Many thanks to Heather Coats, Cedwyn Davies, Keith Vaughton, Charlie Sargent, Wayne Morris, Lyndon Jeffrey, Darren Hicks, Phil Mead and Valerie Wilson for company and assistance over the three sessions.
Some photos, all of which were taken by Keith (and include a treecreeper from an earlier visit) are below.

Owain Gabb


Male great spotted woodpecker

Male blackcap

Thursday, 16 April 2015

Migrants return to the Park

           I met with Heather Coats and Chris Newberry for a 06:00 start at Margam Park this morning. The rather cool conditions at the outset soon changed to sunny, cloudless skies. We erected a twelve and an eighteen metre net close to the pond which sheltered a pair of mallards and their recently hatched brood. Two further eighteen metre nets were set along the fence line on the opposite side of our site.
           Our first visit to the pond nets turned up a female blackcap and a chiffchaff. Through the morning the same nets continued to produce blackcap, a chiffchaff and a willow warbler.

                The pair of eighteen metre nets produced only one bird during the morning but it was a green woodpecker which was the second we have caught on the site this year.

              Mid-way through the session I placed a pair of two-shelf  nets along the vegetation boundary in the hope of catching some of the supercharged birds that were chasing each other haphazardly around the area. It paid off with a female mistle thrush and a chiffchaff to round off the session.

Total for the day:
Green Woodpecker

Blue Tit

Willow Warbler



Mistle Thrush


                Thanks to Heather and Chris.

Tuesday, 7 April 2015

Oxwich Marsh 6 April 2015: news of controls

A very pleasant morning at Oxwich.  The skies were open and there was a barely discernible northerly breeze.  We put nets in the scrub around the feeders (200 feet), in the fen meadow (180 feet) and in a new net ride through semi-natural woodland and rhododendron scrub near one of the main channels through the marsh.  Only the feeder nets proved fruitful.
The catch was more diverse than in recent weeks, and we caught our first sub-Saharan migrant of the year (willow warbler).  The breakdown was as follows:

Species New Re-trapped Total
Wren 0 1 1
Dunnock 0 3 3
Robin 0 2 2
Blackbird 0 2 2
Cetti's Warbler 0 2 2
Chiffchaff 1 1 2
Willow Warbler 1 0 1
Blue Tit 5 1 6
Great Tit 0 8 8
Magpie 1 0 1
Chaffinch 2 2 4
Greenfinch 1 0 1
Goldfinch 5 1 6
Siskin 0 1 1
Reed Bunting 0 2 2
Total: 16 26 42

Of particular interest were the willow warbler , a re-trap chiffchaff (ringed on the marsh in September 2014 and either now on passage or back to breed [no brood patch or cloacal protruberance was apparent]) and a magpie.  We have trapped one magpie a year for the past three years.  Beautiful and feisty birds in the hand, they can be aged based on the shape and pattern of the first and second (pattern only applies) primaries.
We also controlled a siskin.  This bird had been initially ringed in Minehead, Somerset in 2012, and was also captured at the marsh in June 2014, so we already knew some of its history.  It will be interesting to see if the siskin numbers now start to build, as they did in 2014.  There is no evidence of it at present. 
The two Cetti's warblers were re-traps from 2014.  More interesting news recently received from the BTO, however, concerned a Cetti's warbler initially ringed at Magor Marsh, Monmouthshire in July 2012 and re-trapped at Oxwich in November 2014.  Clearly Cetti's warblers disperse (as is demonstrated by the continued extension of their range in the UK), but to re-trap a bird that has moved almost 100km since ringing is great.

So, how are the results from 2015 so far looking in comparison to the same period in 2014?  The table below provides a breakdown of unique birds for the period 1 Jan to 6 April for the respective years.

Species 2015 2014
Jack Snipe 1
Snipe 2
Green Woodpecker 1
Great Spotted Woodpecker 1 2
Wren 8 5
Dunnock 16 8
Robin 15 4
Blackbird 2
Song Thrush 1
Cetti's Warbler 2 2
Chiffchaff 5 3
Willow Warbler 1
Goldcrest 5 3
Long-tailed Tit 9
Blue Tit 113 113
Great Tit 37 29
Treecreeper 1
Magpie 1
Chaffinch 78 29
Greenfinch 88 108
Goldfinch 120 129
Siskin 2 11
Lesser Redpoll 1
Bullfinch 8 4
Reed Bunting 25 70
Total 543 522

Any comparison between years must be very cautious.  We have put up more net in 2015 than we did last year (although returns from extra nets have been limited), have visited the site more regularly, and sessions have varied a little in length.  Weather plays a massive part in determining the size of catches on any given day.  We have had permanent feeders in place since 2013 (albeit these are moved around within the site / rides), but another significant difference is there has been no ground-feeding in 2015.  Pheasants have taken up residence around the feeders and have been hoovering up all spilt fragments of seed, so ground-feeding has been pointless.
Comparisons are therefore limited and qualified.  The most notable difference has been is in the number of reed buntings trapped.  This may relate directly to the lack of ground feeding.  Interestingly, chaffinch numbers are notably higher in 2015 than the equivalent months of 2014, however, and this bird also typically forages on the ground.  Overall, the number of birds per session is lower in 2015 than in 2014.  By this time in 2014 we had only completed 9 sessions (58 unique birds / session), whereas we have completed 14 to date in 2015 (39 unique birds / session).  So the higher number of birds relates to extra effort, not to any evidence that there are more birds in the marsh.
Many thanks to Heather Coats, Charlie Sargent, Keith Vaughton, Darren Hicks and Valerie Wilson for company and assistance this morning.
Some pictures of birds from the session are below.
Owain Gabb
Control Siskin (Owain Gabb)

The first willow warbler of 2015 (Charlie Sargent)

Magpie (Charlie Sargent)