Sunday, 18 May 2014

Oxwich Marsh and Margam Park 17 May 2014

Oxwich Marsh

A beautiful day at Oxwich.  Virtually windless for the first few hours, bright, sunny and warm.  While the weather conditions were very pleasant, they were not ideal for ringing however, as the nets became more visible in the sunshine.  This appears to have limited the catch, with only 39 birds trapped.  However, it did result in some good invertebrate activity, with numerous butterflies and dragonflies on the wing.  The catch was as follows:

Species New Re-trapped Total
Swallow 1 0 1
Wren 2 0 2
Robin 4 1 5
Blackbird 1 0 1
Sedge Warbler 2 0 2
Reed Warbler 3 0 3
Blackcap 1 0 1
Willow Warbler 1 2 3
Blue Tit 0 1 1
Chaffinch 1 0 1
Greenfinch 1 5 6
Goldfinch 1 3 4
Siskin 3 4 7
Reed Bunting 0 2 2
Total: 21 18 39
The only unexpected bird of the day was a swallow.  It was caught in a net in the reedbed that was close to, but not over, a channel.  The bird showed a cloacal protrusion (CP), so was a male.  However, we also measured the tail feathers, as these can be used to confirm sex in adult birds when this is not apparent from their breeding condition.  Adult males have a tail fork (the distance between the shortest and longest tail feathers) of >51mm, and females 35-58mm.  Total tail length in adult males is 93-132mm, and in females 76-112.  The total tail length of our birds (106mm) fell into the zone of overlap between sexes, but the tail fork was 60mm, suggesting a male (as confirmed by the CP).
Young birds were a feature of the catch, with the first juvenile chaffinch of the year being particularly welcome.  Juvenile siskins, robins and a blackbird were also noted.  There was also the first strong evidence of local breeding in goldfinch, as a female with a very clear brood patch (score 4) was noted.  The early trickle of reed and sedge warbler is good news, as August and September result in the largest captures of these species.

The 2014 totals for the site are as follows:

Species New Re-trapped Total
Kingfisher 1 0 1
Great Spotted Woodpecker 1 8 9
Swallow 1 0 1
Wren 7 11 18
Dunnock 6 16 22
Robin 6 9 15
Stonechat 2 0 2
Blackbird 3 0 3
Cetti's Warbler 2 3 5
Grasshopper Warbler 1 0 1
Sedge Warbler 6 0 6
Reed Warbler 6 2 8
Blackcap 10 0 10
Wood Warbler 1 0 1
Chiffchaff 8 0 8
Willow Warbler 9 4 13
Goldcrest 2 1 3
Coal Tit 2 0 2
Blue Tit 70 103 173
Great Tit 15 61 76
Magpie 1 0 1
Chaffinch 52 9 61
Greenfinch 155 37 192
Goldfinch 183 40 223
Siskin 59 46 105
Bullfinch 3 2 5
Reed Bunting 71 42 113
Total: 683 394 1077

Many thanks to Charlie Sargent and Keith Vaughton for their help and company this morning.  Some further photos of birds and other wildlife recorded are below

Owain Gabb
17/05/2014


Sedge warbler















Small copper















Hairy dragonfly














Garden tiger caterpillar

















Margam Park

Heather Coats, Chris Newberry and I were joined by Wayne Morris of the Cardiff Ringing Group. It was a warm, sunny morning with the only clouds in the sky rising from the nearby steelworks. We erected one hundred and two metres of net in three areas, one close to the pond and two along fence lines at opposite ends of the site.

Our total for the day was :
Species                  New            Retrap
Robin                        3                     1
Blackcap                   4
Chiffchaff                                         1
Willow Warbler         4
Blackbird                   3                     1
Wren                         1                     1
Dunnock                    1

A comparison of the tails of two Willow Warblers.

While on site we checked the nestboxes we had erected earlier in the year only to find that the only occupants were Common Wasps (Vespula vulgaris) the nest of one may be seen below.



Cedwyn Davies






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