Breeding performance
  1. Clutch size
  2. Brood size
  3. Egg-stage nest failure rate
  4. Chick-stage nest failure rate

1. Table of significant trends in Clutch size measured between 1967-2018

Species Period
(yrs)		 Mean
annual
sample		 Trend Predicted
in first year		 Predicted
in last year		 Change Comment
Great Tit 51 464 Linear decline 8.31 eggs 7.14 eggs -1.17 eggs  
Blue Tit 51 664 Linear decline 9.44 eggs 8.63 eggs -0.81 eggs  
Grey Heron 51 14 Linear decline 4.01 eggs 3.4 eggs -0.61 eggs Small sample
Long-tailed Tit 51 48 Curvilinear 7.79 eggs 7.22 eggs -0.57 eggs  
Peregrine 51 20 Curvilinear 3.9 eggs 3.33 eggs -0.57 eggs Small sample
Magpie 51 40 Curvilinear 5.87 eggs 5.32 eggs -0.55 eggs  
Buzzard 51 37 Curvilinear 2.07 eggs 1.62 eggs -0.45 eggs  
Great Crested Grebe 51 15 Linear decline 3.52 eggs 3.14 eggs -0.38 eggs Small sample
Meadow Pipit 51 42 Curvilinear 4.27 eggs 3.98 eggs -0.29 eggs  
Woodpigeon 51 101 Linear decline 2.02 eggs 1.76 eggs -0.26 eggs  
Pied Wagtail 51 67 Linear decline 5.09 eggs 4.88 eggs -0.21 eggs  
Hen Harrier 51 11 Curvilinear 5.52 eggs 5.32 eggs -0.2 eggs Small sample
Ring Ouzel 51 11 Linear decline 4.05 eggs 3.88 eggs -0.17 eggs Small sample
Greenfinch 51 80 Linear decline 4.75 eggs 4.58 eggs -0.17 eggs  
Linnet 51 127 Linear decline 4.75 eggs 4.6 eggs -0.15 eggs  
Chaffinch 51 96 Linear decline 4.29 eggs 4.16 eggs -0.13 eggs  
Common Sandpiper 51 12 Curvilinear 3.99 eggs 3.88 eggs -0.11 eggs Small sample
Wren 51 101 Curvilinear 5.56 eggs 5.45 eggs -0.11 eggs  
Collared Dove 51 43 Linear decline 1.96 eggs 1.87 eggs -0.09 eggs  
Spotted Flycatcher 51 76 Linear decline 4.27 eggs 4.19 eggs -0.08 eggs  
Grey Wagtail 51 40 Curvilinear 4.78 eggs 4.73 eggs -0.05 eggs  
Moorhen 51 110 Curvilinear 6.6 eggs 6.6 eggs 0 eggs  
Oystercatcher 51 158 Curvilinear 2.76 eggs 2.82 eggs 0.06 eggs  
Lapwing 51 187 Curvilinear 3.67 eggs 3.74 eggs 0.07 eggs  
Stock Dove 51 140 Curvilinear 2.08 eggs 2.16 eggs 0.08 eggs  
Carrion Crow 51 30 Curvilinear 4.03 eggs 4.11 eggs 0.08 eggs Includes Hooded Crow
Stonechat 51 41 Curvilinear 4.95 eggs 5.05 eggs 0.1 eggs  
Dunnock 51 116 Curvilinear 3.88 eggs 4.02 eggs 0.14 eggs  
Skylark 51 34 Curvilinear 3.33 eggs 3.55 eggs 0.22 eggs  
Redstart 51 58 Curvilinear 5.93 eggs 6.22 eggs 0.29 eggs  
Little Owl 51 26 Linear increase 3.35 eggs 3.72 eggs 0.37 eggs Small sample
Tree Sparrow 51 416 Curvilinear 4.78 eggs 5.18 eggs 0.4 eggs  
Starling 51 75 Linear increase 4.46 eggs 4.94 eggs 0.48 eggs  

2. Table of significant trends in Brood size measured between 1967-2018

Species Period
(yrs)		 Mean
annual
sample		 Trend Predicted
in first year		 Predicted
in last year		 Change Comment
Great Tit 51 1002 Linear decline 7.43 chicks 6.03 chicks -1.4 chicks  
Blue Tit 51 1272 Linear decline 8.41 chicks 7.19 chicks -1.22 chicks  
Long-tailed Tit 51 40 Linear decline 6.6 chicks 5.47 chicks -1.13 chicks  
Sand Martin 51 107 Curvilinear 4.71 chicks 3.68 chicks -1.03 chicks  
Carrion Crow 51 77 Curvilinear 2.94 chicks 2.39 chicks -0.55 chicks Includes Hooded Crow
Grey Heron 51 87 Linear decline 2.86 chicks 2.34 chicks -0.52 chicks  
Chiffchaff 51 52 Linear decline 5.06 chicks 4.69 chicks -0.37 chicks  
Magpie 51 76 Curvilinear 3.4 chicks 3.06 chicks -0.34 chicks  
Greenfinch 51 99 Linear decline 4.09 chicks 3.75 chicks -0.34 chicks  
House Sparrow 51 175 Linear decline 3.48 chicks 3.16 chicks -0.32 chicks  
Rook 51 71 Curvilinear 2.2 chicks 1.89 chicks -0.31 chicks  
Wood Warbler 51 41 Linear decline 5.56 chicks 5.25 chicks -0.31 chicks  
Meadow Pipit 51 87 Curvilinear 3.93 chicks 3.69 chicks -0.24 chicks  
Hobby 51 31 Curvilinear 2.36 chicks 2.13 chicks -0.23 chicks  
Coal Tit 51 75 Curvilinear 7.47 chicks 7.24 chicks -0.23 chicks  
Ring Ouzel 51 23 Linear decline 3.77 chicks 3.55 chicks -0.22 chicks Small sample
Pied Wagtail 51 136 Linear decline 4.5 chicks 4.32 chicks -0.18 chicks  
Raven 51 75 Curvilinear 3.27 chicks 3.11 chicks -0.16 chicks  
Reed Bunting 51 62 Curvilinear 4.03 chicks 3.91 chicks -0.12 chicks  
Woodpigeon 51 144 Curvilinear 1.8 chicks 1.72 chicks -0.08 chicks  
Robin 51 239 Curvilinear 4.41 chicks 4.33 chicks -0.08 chicks  
Linnet 51 147 Curvilinear 4.1 chicks 4.05 chicks -0.05 chicks  
Buzzard 51 119 Curvilinear 1.86 chicks 1.84 chicks -0.02 chicks  
Dunnock 51 129 Curvilinear 3.41 chicks 3.39 chicks -0.02 chicks  
Kestrel 51 190 Curvilinear 3.78 chicks 3.77 chicks -0.01 chicks  
Yellowhammer 51 64 Curvilinear 2.98 chicks 2.97 chicks -0.01 chicks  
Tree Pipit 51 32 Curvilinear 4.24 chicks 4.25 chicks 0.01 chicks  
Stonechat 51 83 Curvilinear 4.63 chicks 4.64 chicks 0.01 chicks  
Collared Dove 51 72 Curvilinear 1.74 chicks 1.76 chicks 0.02 chicks  
Mute Swan 51 68 Curvilinear 4.46 chicks 4.53 chicks 0.07 chicks  
Sparrowhawk 51 64 Curvilinear 3.14 chicks 3.22 chicks 0.08 chicks  
Grey Wagtail 51 84 Curvilinear 4.07 chicks 4.16 chicks 0.09 chicks  
Spotted Flycatcher 51 125 Linear increase 3.69 chicks 3.8 chicks 0.11 chicks  
Corn Bunting 51 14 Curvilinear 3.3 chicks 3.44 chicks 0.14 chicks Small sample
Skylark 51 63 Curvilinear 3.09 chicks 3.26 chicks 0.17 chicks  
Peregrine 51 63 Linear increase 2.39 chicks 2.6 chicks 0.21 chicks  
Willow Warbler 51 150 Linear increase 5.14 chicks 5.36 chicks 0.22 chicks  
Dipper 51 172 Curvilinear 3.43 chicks 3.67 chicks 0.24 chicks  
Tree Sparrow 51 537 Curvilinear 3.84 chicks 4.14 chicks 0.3 chicks  
Merlin 51 60 Curvilinear 3.32 chicks 3.63 chicks 0.31 chicks  
Little Owl 51 57 Linear increase 2.51 chicks 2.9 chicks 0.39 chicks  
Redstart 51 101 Curvilinear 5.13 chicks 5.57 chicks 0.44 chicks  
Moorhen 51 104 Curvilinear 2.52 chicks 3.08 chicks 0.56 chicks  
Starling 51 237 Linear increase 3.22 chicks 3.8 chicks 0.58 chicks  
Jay 51 11 Linear increase 3.39 chicks 4.03 chicks 0.64 chicks Small sample
Wren 51 134 Curvilinear 3.59 chicks 4.29 chicks 0.7 chicks  
Nuthatch 51 92 Linear increase 4.93 chicks 5.83 chicks 0.9 chicks  

3. Table of significant trends in Daily failure rate (eggs) measured between 1967-2018

Species Period
(yrs)		 Mean
annual
sample		 Trend Predicted
in first year		 Predicted
in last year		 Change Comment
Magpie 51 46 Curvilinear 0.0322 nests/day 0.0045 nests/day -0.0277 nests/day  
Redshank 51 28 Linear decline 0.0396 nests/day 0.0123 nests/day -0.0273 nests/day Small sample
Long-tailed Tit 51 66 Curvilinear 0.0396 nests/day 0.0131 nests/day -0.0265 nests/day  
Dipper 51 130 Curvilinear 0.0305 nests/day 0.0054 nests/day -0.0251 nests/day  
Yellowhammer 51 61 Curvilinear 0.05 nests/day 0.028 nests/day -0.022 nests/day  
Snipe 51 13 Linear decline 0.0318 nests/day 0.012 nests/day -0.0198 nests/day Small sample
Woodlark 51 27 Curvilinear 0.0477 nests/day 0.0286 nests/day -0.0191 nests/day Small sample
Wheatear 51 15 Linear decline 0.0219 nests/day 0.0038 nests/day -0.0181 nests/day Small sample
Carrion Crow 51 46 Curvilinear 0.0212 nests/day 0.0061 nests/day -0.0151 nests/day Includes Hooded Crow
Woodpigeon 51 115 Curvilinear 0.0457 nests/day 0.0308 nests/day -0.0149 nests/day  
Stock Dove 51 130 Curvilinear 0.0185 nests/day 0.0063 nests/day -0.0122 nests/day  
Pied Wagtail 51 90 Linear decline 0.0175 nests/day 0.0067 nests/day -0.0108 nests/day  
Robin 51 233 Curvilinear 0.0248 nests/day 0.0145 nests/day -0.0103 nests/day  
Great Crested Grebe 51 23 Curvilinear 0.0295 nests/day 0.0193 nests/day -0.0102 nests/day Small sample
Tawny Owl 51 68 Curvilinear 0.0116 nests/day 0.0022 nests/day -0.0094 nests/day Nocturnal species
Starling 51 122 Linear decline 0.0112 nests/day 0.0021 nests/day -0.0091 nests/day  
Grey Wagtail 51 60 Linear decline 0.0172 nests/day 0.0095 nests/day -0.0077 nests/day  
Buzzard 51 30 Linear decline 0.0081 nests/day 0.0004 nests/day -0.0077 nests/day  
House Sparrow 51 130 Linear decline 0.011 nests/day 0.0033 nests/day -0.0077 nests/day  
Barn Owl 51 39 Linear decline 0.0078 nests/day 0.0004 nests/day -0.0074 nests/day  
Nuthatch 51 70 Linear decline 0.0091 nests/day 0.0018 nests/day -0.0073 nests/day  
Wood Warbler 51 27 Curvilinear 0.0244 nests/day 0.0172 nests/day -0.0072 nests/day Small sample
Kestrel 51 44 Curvilinear 0.008 nests/day 0.0013 nests/day -0.0067 nests/day  
Wren 51 145 Linear decline 0.0183 nests/day 0.0119 nests/day -0.0064 nests/day  
Marsh Tit 51 22 Linear decline 0.0073 nests/day 0.001 nests/day -0.0063 nests/day Small sample
Redstart 51 87 Curvilinear 0.015 nests/day 0.009 nests/day -0.006 nests/day  
Jackdaw 51 81 Curvilinear 0.0087 nests/day 0.0032 nests/day -0.0055 nests/day  
Tree Sparrow 51 537 Linear decline 0.0084 nests/day 0.0029 nests/day -0.0055 nests/day  
Merlin 51 23 Linear decline 0.0068 nests/day 0.0015 nests/day -0.0053 nests/day Small sample
Peregrine 51 28 Linear decline 0.0073 nests/day 0.0024 nests/day -0.0049 nests/day Small sample
Sparrowhawk 51 29 Linear decline 0.0042 nests/day 0.0006 nests/day -0.0036 nests/day Small sample
Raven 51 23 Curvilinear 0.0034 nests/day 0.0002 nests/day -0.0032 nests/day Small sample
Tree Pipit 51 16 Curvilinear 0.044 nests/day 0.0408 nests/day -0.0032 nests/day Small sample
Pied Flycatcher 51 528 Curvilinear 0.0062 nests/day 0.0032 nests/day -0.003 nests/day  
Spotted Flycatcher 51 111 Curvilinear 0.0175 nests/day 0.0148 nests/day -0.0027 nests/day  
Great Tit 51 901 Linear decline 0.005 nests/day 0.0023 nests/day -0.0027 nests/day  
Sand Martin 51 91 Curvilinear 0.0107 nests/day 0.008 nests/day -0.0027 nests/day  
Coal Tit 51 57 Linear decline 0.0042 nests/day 0.0018 nests/day -0.0024 nests/day  
Blue Tit 51 1185 Curvilinear 0.0039 nests/day 0.0023 nests/day -0.0016 nests/day  
Greenfinch 51 112 Curvilinear 0.027 nests/day 0.0255 nests/day -0.0015 nests/day  
Swallow 51 689 Curvilinear 0.0047 nests/day 0.004 nests/day -0.0007 nests/day  
Treecreeper 51 23 Curvilinear 0.0239 nests/day 0.0237 nests/day -0.0002 nests/day Small sample
Grey Heron 51 16 Curvilinear 0.0001 nests/day 0.0003 nests/day 0.0002 nests/day Small sample
Curlew 51 21 Curvilinear 0.0277 nests/day 0.028 nests/day 0.0003 nests/day Small sample
Chiffchaff 51 57 Curvilinear 0.0209 nests/day 0.0213 nests/day 0.0004 nests/day  
Collared Dove 51 61 Curvilinear 0.0301 nests/day 0.0312 nests/day 0.0011 nests/day  
Dunnock 51 162 Curvilinear 0.0257 nests/day 0.0279 nests/day 0.0022 nests/day  
Little Grebe 51 14 Curvilinear 0.0358 nests/day 0.04 nests/day 0.0042 nests/day Small sample
Reed Warbler 51 228 Curvilinear 0.0192 nests/day 0.0242 nests/day 0.005 nests/day  
Stonechat 51 47 Linear increase 0.0056 nests/day 0.0109 nests/day 0.0053 nests/day  
Linnet 51 176 Linear increase 0.0184 nests/day 0.0241 nests/day 0.0057 nests/day  
Sedge Warbler 51 38 Curvilinear 0.015 nests/day 0.0208 nests/day 0.0058 nests/day  
Whitethroat 51 45 Curvilinear 0.0099 nests/day 0.0163 nests/day 0.0064 nests/day  
Garden Warbler 51 25 Curvilinear 0.0167 nests/day 0.0268 nests/day 0.0101 nests/day Small sample
Willow Warbler 51 69 Linear increase 0.0091 nests/day 0.0196 nests/day 0.0105 nests/day  
Goldfinch 51 41 Linear increase 0.0188 nests/day 0.0302 nests/day 0.0114 nests/day  
Nightjar 51 29 Curvilinear 0.0079 nests/day 0.0198 nests/day 0.0119 nests/day Small sample
Meadow Pipit 51 52 Curvilinear 0.0221 nests/day 0.0342 nests/day 0.0121 nests/day  
Lapwing 51 207 Curvilinear 0.016 nests/day 0.03 nests/day 0.014 nests/day  
Chaffinch 51 182 Curvilinear 0.029 nests/day 0.0433 nests/day 0.0143 nests/day  
Moorhen 51 137 Linear increase 0.0103 nests/day 0.0259 nests/day 0.0156 nests/day  
Ringed Plover 51 125 Curvilinear 0.0253 nests/day 0.0424 nests/day 0.0171 nests/day  
Blackbird 51 355 Curvilinear 0.0246 nests/day 0.0418 nests/day 0.0172 nests/day  
Skylark 51 42 Curvilinear 0.0373 nests/day 0.0551 nests/day 0.0178 nests/day  
Oystercatcher 51 174 Curvilinear 0.0102 nests/day 0.0282 nests/day 0.018 nests/day  
Whinchat 51 20 Linear increase 0.0069 nests/day 0.0293 nests/day 0.0224 nests/day Small sample
Reed Bunting 51 52 Linear increase 0.0074 nests/day 0.0302 nests/day 0.0228 nests/day  

4. Table of significant trends in Daily failure rate (chicks) measured between 1967-2018

Species Period
(yrs)		 Mean
annual
sample		 Trend Predicted
in first year		 Predicted
in last year		 Change Comment
Sand Martin 51 114 Curvilinear 0.0314 nests/day 0.0016 nests/day -0.0298 nests/day  
Skylark 51 51 Linear decline 0.0483 nests/day 0.0284 nests/day -0.0199 nests/day  
Magpie 51 44 Curvilinear 0.0228 nests/day 0.0043 nests/day -0.0185 nests/day  
Reed Warbler 51 177 Curvilinear 0.0235 nests/day 0.0116 nests/day -0.0119 nests/day  
Grey Wagtail 51 59 Linear decline 0.0192 nests/day 0.0089 nests/day -0.0103 nests/day  
Jackdaw 51 72 Curvilinear 0.0138 nests/day 0.0036 nests/day -0.0102 nests/day  
Blackbird 51 286 Curvilinear 0.0318 nests/day 0.0225 nests/day -0.0093 nests/day  
Tree Sparrow 51 376 Curvilinear 0.0157 nests/day 0.0064 nests/day -0.0093 nests/day  
Merlin 51 31 Linear decline 0.0101 nests/day 0.0015 nests/day -0.0086 nests/day  
Redstart 51 63 Curvilinear 0.0145 nests/day 0.0061 nests/day -0.0084 nests/day  
House Sparrow 51 129 Curvilinear 0.0156 nests/day 0.0087 nests/day -0.0069 nests/day  
Yellowhammer 51 49 Curvilinear 0.0434 nests/day 0.0377 nests/day -0.0057 nests/day  
Carrion Crow 51 39 Linear decline 0.0064 nests/day 0.0012 nests/day -0.0052 nests/day Includes Hooded Crow
Collared Dove 51 54 Curvilinear 0.0212 nests/day 0.0179 nests/day -0.0033 nests/day  
Barn Owl 51 196 Curvilinear 0.0033 nests/day 0.0003 nests/day -0.003 nests/day  
Starling 51 137 Curvilinear 0.0068 nests/day 0.0038 nests/day -0.003 nests/day  
Stock Dove 51 84 Linear decline 0.0104 nests/day 0.0075 nests/day -0.0029 nests/day  
Tawny Owl 51 109 Curvilinear 0.0034 nests/day 0.0006 nests/day -0.0028 nests/day Nocturnal species
Meadow Pipit 51 75 Curvilinear 0.0344 nests/day 0.0317 nests/day -0.0027 nests/day  
Nuthatch 51 77 Linear decline 0.0042 nests/day 0.002 nests/day -0.0022 nests/day  
Peregrine 51 34 Linear decline 0.0029 nests/day 0.001 nests/day -0.0019 nests/day  
Kestrel 51 80 Linear decline 0.002 nests/day 0.0009 nests/day -0.0011 nests/day  
Great Tit 51 617 Curvilinear 0.0056 nests/day 0.0058 nests/day 0.0002 nests/day  
Spotted Flycatcher 51 101 Curvilinear 0.0087 nests/day 0.0095 nests/day 0.0008 nests/day  
Stonechat 51 78 Curvilinear 0.0155 nests/day 0.0173 nests/day 0.0018 nests/day  
Swallow 51 572 Linear increase 0.0028 nests/day 0.0049 nests/day 0.0021 nests/day  
Woodpigeon 51 93 Curvilinear 0.0204 nests/day 0.0229 nests/day 0.0025 nests/day  
Whinchat 51 33 Curvilinear 0.0237 nests/day 0.0264 nests/day 0.0027 nests/day  
Moorhen 51 50 Linear increase 0.0002 nests/day 0.0032 nests/day 0.003 nests/day  
Pied Flycatcher 51 446 Linear increase 0.0038 nests/day 0.007 nests/day 0.0032 nests/day  
Corn Bunting 51 14 Curvilinear 0.0492 nests/day 0.0535 nests/day 0.0043 nests/day Small sample
Wren 51 99 Linear increase 0.0072 nests/day 0.0116 nests/day 0.0044 nests/day  
Linnet 51 126 Linear increase 0.0162 nests/day 0.0215 nests/day 0.0053 nests/day  
Nightjar 51 26 Curvilinear 0.002 nests/day 0.0085 nests/day 0.0065 nests/day Small sample
Reed Bunting 51 52 Curvilinear 0.0277 nests/day 0.04 nests/day 0.0123 nests/day  
Long-tailed Tit 51 45 Linear increase 0.008 nests/day 0.0208 nests/day 0.0128 nests/day  
Garden Warbler 51 21 Linear increase 0.0116 nests/day 0.0269 nests/day 0.0153 nests/day Small sample
Wood Warbler 51 34 Curvilinear 0.0224 nests/day 0.0487 nests/day 0.0263 nests/day  

 

This report should be cited as: Woodward, I.D., Massimino, D., Hammond, M.J., Barber, L., Barimore, C., Harris, S.J., Leech, D.I., Noble, D.G., Walker, R.H., Baillie, S.R. & Robinson, R.A. (2020) BirdTrends 2020: trends in numbers, breeding success and survival for UK breeding birds. BTO Research Report 732. BTO, Thetford. www.bto.org/birdtrends