Contents of report
Breeding Bird Survey
Common Birds Census
Constant Effort Sites
Nest Record Scheme
Waterways Bird Survey
What the categories mean
Return to BTO Home Page
Conservation Listings Long term trend

Table 4/Amber (European status)
Biodiversity Steering Group
Conservation Concern List

UK: Unknown
Shetland: Stable

Status Summary
Increasing nest failure rates during the egg stage is worrying for this species because of its unfavourable European conservation status. The increase represents a change from 13% to 42% of nests failing over the 27-day egg stage (26d incubation + 1d egg laying). It should be noted that, although many of the nest records come from Orkney, there are reasonable numbers of records also from Shetland, mainland Scotland and Western Isles. Population trends are not monitored by the BTO, but the UK Seabird Monitoring Programme shows that numbers on Shetland have fluctuated around a stable level between 1980-99 (Upton et al. 2000).
Annual breeding population changes are not currently monitored by BTO for this species
Table of productivity information for Red-throated Diver
Variable Period
Years Mean
Trend Predicted
in first year
in last year
Change Comment
Clutch size 18 1980-1998 29 None       Small sample
Brood size 18 1980-1998 42 Linear increase 1.25 chicks 1.44 chicks 0.19 chicks  
Daily failure rate (eggs) 18 1980-1998 17 Linear increase 0.005 nests/day 0.0199 nests/day 0.0149 nests/day Small sample
Daily failure rate (chicks) 18 1980-1998 22 None       Small sample


Insufficient data on laying date
available for this species



Insufficient data on CES
available for this species



The report should be cited as: Baillie, S.R., Crick, H.Q.P., Balmer, D.E., Bashford, R.I., Beaven, L.P., Freeman, S.N., Marchant, J.H., Noble, D.G., Raven, M.J., Siriwardena, G.M., Thewlis, R. and Wernham, C.V. (2001) Breeding Birds in the Wider Countryside: their conservation status 2000. BTO Research Report No. 252. BTO, Thetford. (

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Last updated: Last updated: 9 April, 2001

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