SIMON TUCKER
The Marsh Tit project kicked off in October 2012 and initially delivered a good number of birds: 17 new birds ringed in the first 6 months. During 2013 / 14 an additional 7 birds were colour ringed.
The first 6 months of the Marsh Tit project identified 21 individual Marsh Tits in the area:
The Firs 1
Somerford Common 6
Ravensroost Woods 9
Red Lodge Estate 3
Webb’s Wood 2
Of those identified up to 31st March 2013, 15 were trapped again in the period up to the 31st March 2013:
Somerford Common 4
Ravensroost Woods 7
Red Lodge Estate 2
Webb’s Wood 1
Subsequently 5 of those original birds have been retrapped since 1st April 2013. These were distributed as follows:
Somerford Common 2
Ravensroost Woods 2
Red Lodge Estate 1
One of these birds, D056634, was ringed on the 10th October 2012 and most recently retrapped on the 6th February 2014, having not been retrapped since the end of 2012. Hopefully this means that a number of the other birds are surviving but have just avoided being retrapped.
The new birds ringed between 1st April 2013 and 31st March 2014 were distributed as follows:
Somerford Common 3
Ravensroost Woods 3
Red Lodge Estate 1
Of these birds, juveniles (BTO age code 3J, indicating recently fledged birds, and therefore likely to have been born locally) were trapped in Ravensroost (1) and Somerford Common (2).
It is possible that one reason for the reduced catch is the mildness of the winter. In previous years the majority of catches have taken place in and around the feeding stations when active: perhaps they have managed to maintain feeding territories away from these stations due to the mild weather.
At the outset of the project, outside of the breeding season, it wasn’t possible to accurately sex the birds. As previously described: they are sexually monomorphic and the BTO discourage the use of single characteristics for sexing birds. Svensson says that a wing length of < 65mm indicates a female bird and >=65mm indicates a male, which would identify these birds as being 11 females and 3 males. Subsequent data from the breeding season shows that the BTO are right to be circumspect.
The following birds were retrapped in breeding condition and able to be sexed on the presence or absence of a brood patch (female) or cloacal protuberance (male):
The Colours notation is as follows:
L: = Left Leg R: = Right Leg
The first colour for each leg is at the top of the tarsus with second colour below it.
M = standard BTO Metal ring
B = Dark Blue
P = Pale Blue
Y = Yellow
G = Dark Green
R = Dark Red
O = Orange
N = Black (Noir)
GR = Dark Grey
The ringed birds are as follows:
I will be asking the BTO for permission to use Marsh Tit lures throughout the year to try and establish all nesting territories within the woods.
I was given a copy of Richard Broughton’s PhD thesis submission: Habitat Modelling and the Ecology of the Marsh Tit (Poecile palustris).
It makes sobering reading given the fragmented nature of the Braydon Forest – however it also gives key identifiers on how these issues might be overcome. The following is quoted directly from his thesis:
“The key factors determining Marsh Tit occupation in woodland appear to be the area and maturity of the wood, and its proximity and connectivity to neighbouring woodland patches that hold existing populations. Maximising these elements would, therefore, aid conservation of Marsh Tits or the recolonisation of the former range. Specific criteria include providing a minimum of 4.5 ha of mixed deciduous woodland to accommodate a single pair, a mature tree canopy exceeding 15 m in height and 80% canopy closure, and a minimum of 40% ground coverage by understorey vegetation that largely exceeds 4 m in height. Maintaining or increasing the area of woodland in the landscape, and also the connectivity between woods via hedgerows or tree lines, would have clear benefits. Populations in woods more than c.2.5 km apart are unlikely to exchange recruits on a regular basis, and this distance and frequency will be reduced if connective trees or hedgerows are intermittent or scarce. Connectivity between woods could be improved by the planting of hedges or fast-growing ‘stepping stones’ of shrubs or trees, such as willows or sallows (Salix spp.), Silver Birch or European Elder (Sambucus nigra).
Extensive coppice management would appear to be detrimental to Marsh Tits by destroying existing habitat and arresting woodland maturation. Marsh Tits in the Monks Wood study area were demonstrably able to tolerate small areas of infrequent coppicing, such as ‘scallop’ cuts along rides or glades, but rotational coppicing on a compartmental basis has the potential to seriously degrade Marsh Tit habitat by limiting the height and maturity of trees and shrubs and preventing tree canopy closure. Nest-sites do not appear limiting for Marsh Tits in British woods, and provision of nest-boxes may instead lead to increases in the density of potential competitor species, such as the Blue Tit and Great Tit. While the evidence for a widespread negative impact of inter-specific competition or a ‘predator pit’ (Millon et al. 2009) is currently lacking or inconclusive, the precautionary principle suggests that routine provision of nest boxes for tits should be avoided in woods where Marsh Tits are to be retained or encouraged.”
This would indicate that Ravensroost’s ancient woodland and 25 year coppice cycle will continue to support a population of Marsh Tit, provided sufficient attention is paid to maintaining the canopy, whereas the 8-year coppice cycle will be unproductive. Removal of titmice nest boxes might be considered as a course of action: perhaps trialling their removal in the northern part of Ravensroost?
Persuading local landowners to maintain and improve the hedgerow and copse habitats between the larger fragments of woodland, establishing well-defined wildlife corridors to link them together, will benefit the species expanding their potential habitat range.
The Forestry Commission sites are supporting large tracts of suitable habitat for the Marsh Tit: my intention will be to try and map them throughout each of the sites, both visually and by ringing different areas of the woods
I would like to thank the Wiltshire Wildlife Trust, the Forestry Commission and Natural England for giving me permission to work on their land and for seeing value in this project. Especially I would like to thank Neil Pullen, Tom Blythe, Ellie Jones, Robin Griffith and Steve Brudenell.
I would like to thank the Swindon Wildlife Group and the Forestry Commission for their financial help towards providing feed for the sites. Thanks for the physical help in setting up and taking down nets and scribing to all of those who came to help, particularly on the coldest mornings.
A big thank you to my trainer Dr Ian Grier for his invaluable help, support and guidance throughout.
As ever, a big thanks to my wife Lilian, for her continuing uncomplaining support and tolerance of being woken up at unearthly hours at least once a week but more often twice since October 2013.
Svensson, Lars: Identification Guide to European Passerines 4th Edition 1992
Published by the author, distributed by the British Trust for Ornithology
Birds of the Western Palaearctic – interactive DVD edition comprising both the original BWP by Cramp & Simmons and the Concise Edition, published by Birdguides Ltd.
Richard K Broughton: Habitat Modelling and the Ecology of the Marsh Tit (Poecile palustris) PhD Thesis submission, August 2012
Balmer, Gillings, Caffrey, Swann, Downie & Fuller: Bird Atlas 2007 – 11.
Published by BTO Books