Saturday, 23 April 2016

Oxwich Marsh 23 April 2016

A light northerly wind strengthened and gradually swung around to the south-east over the course of the morning.

We put up a total of 580 feet of net, the majority of which was along a bund through the reed bed. Prior to dawn at least three grasshopper warblers could be heard reeling, and it was clear that there were also a few sedge warblers in. Reed warblers were conspicuous by their absence, however.

The catch was made up as follows:

Species
New
Recaptured
Total
Sparrowhawk
1
0
1
Wren
0
1
1
Dunnock
0
2
2
Blackbird
0
2
2
Grasshopper Warbler
1
0
1
Sedge Warbler
2
1
3
Blackcap
3
0
3
Willow Warbler
2
0
2
Blue Tit
1
0
1
Great Tit
0
11
11
Chaffinch
2
1
3
Greenfinch
1
0
1
Goldfinch
25
9
34
Siskin
7
3
10
Reed Bunting
1
3
4
Total:
46
33
79


The features were a second calendar year male sparrowhawk (sexed on biometrics), the second grasshopper warbler and the first few sedge warblers of the year, and a total of 34 goldfinches, the majority of which were un-ringed suggesting there is some passage going on at present.

Sparrowhawk (Keith Vaughton)

A few points of interest from comparison of the year to date with the same period during the past two years are as follows:

  • We have done better for non-passerines than in 2015 or 2014, with two sparrowhawk, a water rail, five jack snipe and six common snipe captured to date. Numbers of great spotted woodpeckers (4) are consistent with previous years, but we have not captured a green woodpecker yet this year (and had done so by this time in 2015).
  • We are a little ahead of where we were at this point in the past two years with regard to sub-Saharan migrants. We captured one spring grasshopper warbler in 2015 and none in 2014 (and already have two this year), while our first sedge warblers are earlier than 2015 and we have captured more willow warblers than we had at this point last year. We had already captured our first reed warblers by this date in 2014, however. 
  • Greenfinch numbers (39 unique birds to date) are considerably down on this point in 2015 (by which time we had captured 98), which was, in turn, considerably down on 2014 (134). It will be interesting to see whether this indicates a decline in the population, as in 2015 considerable numbers of juvenile birds from July onwards counterbalanced far lower spring totals than were captured in 2014.
  • Larger numbers of siskin (115 birds unique to date as opposed to 7 in 2015 and 38 in 2014). These birds are showing variation in brood patch development in particular, suggesting that some of the local birds are now breeding, while there is still some passage going on (or alternatively a substantial non-breeding population).

A good session in pleasant weather.

Thanks to Heather Coats, Keith Vaughton, Wayne Morris, Darren Hicks, Val Wilson and Phil Mead for company and assistance this morning.

Owain Gabb
23/04/2016

Grasshopper warbler (Keith Vaughton)
Reed bunting (Keith Vaughton)
Sedge warbler (Keith Vaughton)

Sunday, 17 April 2016

Oxwich Marsh 17 April 2016: the first gropper of the year

A light north to north-westerly wind that strengthened slightly over the morning, along with variable cloud cover, made for reasonable conditions for a session

The catch was larger than in recent weeks, and was made up as follows:

Species
New
Recaptured
Total
Wren
2
3
5
Dunnock
0
3
3
Blackbird
1
1
2
Song Thrush
2
0
2
Grasshopper Warbler
1
0
1
Blackcap
2
0
2
Chiffchaff
2
0
2
Blue Tit
2
3
5
Great Tit
1
4
5
Chaffinch
2
0
2
Greenfinch
3
2
5
Goldfinch
17
12
29
Siskin
6
10
16
Reed Bunting
2
3
5
Total:
43
41
84

Grasshopper warbler
The most interesting features of the day were a grasshopper warbler, caught in the middle of the reedbed, and two blackcaps (a male and female).

A grasshopper warbler had been heard reeling at dawn close to where the bird was captured, so it is reasonable to assume that the individual was male, albeit it had not developed a cloacal protrusion as is only likely to have arrived very recently. The blackcap are also likely to have been new in, as no alarming or singing birds had been present during previous sessions.

Other migrants present in and around the marsh were willow warbler and reed warbler, both of which were heard singing, but neither of which were captured during the session. 

There appears to be passage of goldfinch taking place at present, as indicated by the relatively large catch of 29 birds this morning. Other species are getting on with breeding however, including siskin, blackbird and dunnock, while it is likely that the two song thrushes (both males with cloacal protrusions) may have been involved in a territorial dispute as they were in the same net line.

One other feature of the morning was a couple of appearances by a cream-crown marsh harrier, confirmed as a female (as opposed to an [unsexed] first winter bird) by Emma on second viewing. 

Thanks are due to Wayne Morris, Paul Aubrey, Emma Cole, Val Wilson, Dan Rouse and Espen Quinto-Ashman for company and assistance this morning.

Owain Gabb
17/04/2016

Friday, 8 April 2016

Oxwich Marsh 8 April 2016

A light to moderate north-westerly wind, albeit a little stronger than forecast, and a bright start made for reasonably good ringing conditions this morning.

As the longer distance migrants are starting to come through, and conditions were conducive, we put some net through the reed bed, in some wet scrub and around the feeders. In the event almost all the birds, were caught close to the feeders.

The catch was as follows:

Species
Ringed
Recaptured
Total
Wren
0
2
2
Dunnock
0
2
2
Robin
0
1
1
Blackbird
0
1
1
Song Thrush
0
1
1
Chiffchaff
2
0
2
Willow Warbler
2
0
2
Long-tailed Tit
1
1
2
Blue Tit
1
0
1
Great Tit
2
5
7
Magpie
0
1
1
Chaffinch
0
1
1
Brambling
1
0
1
Greenfinch
2
0
2
Goldfinch
2
3
5
Siskin
5
6
11
Reed Bunting
1
0
1
Total:
19
24
43

The features of the catch were the first willow warblers of the year, a recaptured magpie from 2014, a late brambling, and a nice catch of eleven siskin.

Brambling (Keith Vaughton)
The brambling was unexpected. It was a second calendar year female bird. It showed five retained greater coverts, while the tail shape also indicated that it was a bird fledged in 2015 (albeit this feature becomes less reliable as the winter goes on and cannot be relied upon alone according to Svensson (1992)). As expected, the bird did not show a brood patch - that would have made the capture even more interesting!
Magpie (Keith Vaughton)

The magpie was aged based on the shape and extent of white on the first primary (adult outer primaries show more white / have a more limited black tip). It was interesting that it was a recapture: it was initially ringed (as a second calendar year bird) in May 2014, and is therefore likely to be getting fairly close to four years of age. It showed a well developed, engorged brood patch, indicating it is breeding on the marsh.

Other species showing cloacal protrusions or brood patches, indicating local breeding, were dunnock, robin, blackbird, long-tailed tit, greenfinch, goldfinch, siskin and reed bunting.

Willow warbler (Keith Vaughton)
There was no indication of grasshopper warbler, reed or sedge warbler in the marsh this morning. It will be interesting to see if any of these species have arrived by next week. In 2015 we recorded the first grasshopper warbler on 11 April, the first sedge warbler on 15 April and the first reed warbler on 18 April.

Finally, news of a control goldfinch. A bird ringed on 25 March 2016 had made a trip of 386 km in a west north-westerly direction to arrive at Gleninach Quay, Ballyvaughan, County Clare, Ireland eleven days later. An interesting movement - certainly our best for a goldfinch to date.

Thanks to Keith Vaughton, Paul Aubrey, Emma Cole and Phil Mead for company and assistance this morning.

Owain Gabb
08/04/2016