Publications for Stephen Dodd

Effect of GPS tagging on behaviour and marine distribution of breeding Arctic Terns Sterna paradisaea

Tracking tags have been used to map the distributions of a wide variety of avian species, but few studies have examined whether the use of these devices has impacts on the study animals that may bias the spatial data obtained. As Global Positioning System (GPS) tags small enough for deployment on terns (family: Laridae) have only recently become available, until now tracking of this group has been conducted by following unmanipulated individuals by boat, which offers a means of comparing distributions obtained from GPS-tracking. We compared the utilization distributions (UDs) of breeding Arctic Terns Sterna paradisaea obtained by GPS-tracking 10 individuals over 2 weeks, with UDs derived from contemporaneous visual boat tracks from 81 individuals. The 50% and 95% UDs of both methods had high similarity scores, indicating good agreement in the density distributions derived from the two methods. The footprints of the UDs of tagged birds were ~ 75–80% larger, which may reflect an effect of tagging on foraging range or the occasional inability to follow by boat individuals which roamed further from the colony. We also compared the nest attendance and chick provisioning rates of adults that were (1) fitted with a GPS tag and leg-flag, (2) handled and marked with a leg-flag but not tagged and (3) fitted with a leg-flag in a previous year but unhandled in the year of the study. There was some evidence that birds fitted with both a GPS tag and leg-flag spent slightly less time at the nest compared with unhandled birds and those fitted with a leg-flag only. Both treatments where birds were fitted with a leg-flag in the year of the study had similarly lower provisioning rates to those of unhandled control birds > 48 h after handling, suggesting that negative effects on provisioning are due to capture and handling or leg-flag attachment rather than to GPS tag attachment/loading per se. Overall brood-provisioning rate was compensated for by the increased effort by the unhandled partner. Our study suggests that despite slight effects of GPS-tagging on behaviour, the estimates of marine density distribution obtained were very similar to those of unmanipulated birds.

Date
01 January 2021
RSPB Authors
Stephen Dodd, Dr Ian Johnstone, Dr Mark Bolton
Authors
Seward, Adam Taylor, Rachel C Perrow, Martin R Berridge, Richard J Bowgen, Katharine M
Published in
Ibis 163 (1): 197-212
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What can seabirds tell us about the tide?

Small global positioning system (GPS) trackers are now routinely used to study the movement and behaviour of birds at sea. If the birds rest on the water they become "drifters of opportunity" and can be used to give information about surface currents. In this paper, we use a small data set from satellite-tracked razorbills...

Date
01 November 2019
RSPB Authors
Dr Mark Bolton, Dr Ellie Owen, Stephen Dodd
Authors
Cooper, M., Bishop, C., Lewis, M., Bowers, D., Bolton, M., Owen, E. & Dodd, S.
Published in
Ocean Science 14 (6): 1483-1490
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Have Welsh agri-environment schemes delivered for focal species? Results from a comprehensive monitoring programme

Agri-environment schemes (AES) have been criticized for being inadequately monitored and for not delivering the expected benefits to nature. Consequently, the Welsh Government funded a comprehensive programme of monitoring of AES between 2009 and 2012. The AES assessment focused on Tir Gofal (which translates as Land in Care) but also included the Organic Farming Scheme, and monitoring focused on a range of taxa of conservation importance: arable plants, grassland fungi, bats (six species), butterflies (three species), birds (five species), water vole and brown hare. Field surveys were carried out on matched farms and fields within and outside of AES. Response variables were spatial trends of abundance, occurrence and species richness, and were modelled against AES status. Existing data were also available for two bird species. Few differences were observed between AES and non-AES farms and fields. Those that were observed were for species that use arable habitats (which are uncommon in Wales): arable plants, yellowhammers and brown hares. The lack of differences in non-arable habitats may reflect the smaller contrast between AES and non-AES management in these habitats. It may also reflect the original condition of habitat entered into AES prescriptions, as most non-arable prescriptions were defined by mandatory management of existing habitats, rather than optional habitat creation or restoration, which is the case for most arable prescriptions. Despite the lack of differences observed, AES may help to maintain populations of species, making it more likely that they will persist in the landscape. There is evidence, from this monitoring programme and elsewhere, that AES can increase the populations of species, when well targeted and implemented.Policy implications. Our results indicate that Welsh Agri-environment schemes (AES) have been only partly successful in achieving their stated aim of maintaining and enhancing species abundance. They can be used to improve AES design and management, both in Wales and more widely, by identifying and promoting effective management interventions, and by identifying ineffective management interventions and seeking alternatives. Comprehensive monitoring of AES, combined with specific targets regarding expected outcomes, is essential to determine whether AES are providing value for money.

Date
01 April 2019
RSPB Authors
Dr Michael MacDonald, Stephen Dodd, Dr Ian Johnstone
Authors
MacDonald, M. A. Angell, R. Dines, T. D. Dodd, S. Haysom, K. A. Hobson, R. Johnstone, I. G. Matthews, V. Morris, A. J. Parry, R. Shellswell, C. H. Skates, J. Tordoff, G. M. Wilberforce, E. M.
Published in
Journal of Applied Ecology
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Factors affecting the foraging behaviour of the European shag: implications for seabird tracking studies

Seabird tracking has become an ever more popular tool to aid environmental procedures such as the designation of marine protected areas and environmental impact assessments. However, samples used are usually small and little consideration...

Date
03 April 2014
RSPB Authors
Stephen Dodd
Authors
Soanes, L., Arnould, J.P.Y., Dodd, S.G., Milligan, G. & Green, J.A.
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Predation of black-legged kittiwake chicks Rissa tridactyla by a peregrine falcon Falco peregrinus: Insights from time-lapse cameras

We directly recorded predation of Black-legged Kittiwake chicks (Rissa tridactyla) by a Peregrine Falcon (Falco peregrinus) using a remote time-lapse camera. Between 20 July 2013 and 23 July 2013, all four nests in the camera's field of...

Date
01 March 2014
RSPB Authors
Stephen Dodd
Authors
Collins, P.M., Green, J.A., Dodd, S., Shaw, P.J.A. & Halsey, L.G.
Published in
The Wilson Journal of Ornithology
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Negative impacts of hunting and suction-dredging on otherwise high and stable survival rates in curlew Numenius arquata

Capsule: A stable annual survival rate of 90% was estimated for adult Curlew Numenius arquata from 1974 to 2011. Survival was reduced by mechanized cockle harvesting and hunting prior to the UK ban in...

Date
05 April 2013
RSPB Authors
Stephen Dodd
Authors
Taylor, R.C. & Dodd, S.G.
Published in
Bird Study
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How many seabirds do we need to track to define home-range area?

In recent years, marine predator and seabird tracking studies have become ever more popular. However, they are often conducted without first considering how many individuals should be tracked and ...

Date
25 March 2013
RSPB Authors
Stephen Dodd
Authors
Soanes, L.M., Arnould, J.P.Y., Dodd, S.G., Sumner, M.D. & Green, J.A.
Published in
Journal of Applied Ecology
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Pre-breeding foraging and nest site habitat selection by lesser spotted woodpeckers

Lesser Spotted Woodpeckers Dendrocopos minor have dramatically declined and retracted in range in Britain. Pre-breeding foraging may be critical and, although work has been carried out elsewhere in ...

Date
01 September 2012
RSPB Authors
Derek Gruar, Stephen Dodd
Authors
Charman, E.C., Smith, K.W., Dodd, S., Gruar, D.J. & Dillon, I.A.
Published in
Ornis Fennica
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Drivers of low breeding success in the lesser spotted woodpecker Dendrocopos minor in England: testing hypotheses for the decline

Capsule The breeding success of Lesser Spotted Woodpeckers Dendrocopos minor is now lower in England than previously reported and also lower than found in studies elsewhere in Europe. Aims To quantify...

Date
24 February 2012
RSPB Authors
Stephen Dodd, Prof Richard Gregory, Derek Gruar
Authors
Charman, E.C., Smith, K.W., Dillon, I.A., Dodd, S., Gruar, D.J., Cristinacce, A., Grice, P.V. & Gregory, R.D.
Published in
Bird Study
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Plant and invertebrate resources for farmland birds in pastoral landscapes

On 16 UK livestock holdings within pastoral landscapes, we investigated the provision of plant and invertebrate resources for farmland birds in spring barley and winter wheat cereal-based whole crop...

Date
12 June 2011
RSPB Authors
Stephen Dodd, Dr David Buckingham, Dr Will Peach
Authors
Westbury, D.B., Mortimer, S.R., Brook, A.J., Harris, S.J., Kessock-Phillip, R., Edwards, A.R., Chaney, K., Lewis, P., Dodd, S., Buckingham, D.L. & Peach, W.J.
Published in
Agriculture Ecosystems & Environment
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