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 1967-2020

Species Period
(yrs)		 Mean
annual
sample		 Trend Predicted
in first year		 Predicted
in last year		 Change Comment
Great Tit 53 478 Linear decline 8.23 eggs 7.14 eggs -1.09 eggs  
Blue Tit 53 691 Linear decline 9.36 eggs 8.66 eggs -0.7 eggs  
Grey Heron 53 14 Linear decline 4.02 eggs 3.36 eggs -0.66 eggs Small sample
Buzzard 53 37 Curvilinear 2.09 eggs 1.53 eggs -0.56 eggs  
Peregrine 53 20 Curvilinear 3.96 eggs 3.43 eggs -0.53 eggs Small sample
Magpie 53 39 Curvilinear 5.88 eggs 5.4 eggs -0.48 eggs  
Long-tailed Tit 53 48 Curvilinear 7.81 eggs 7.34 eggs -0.47 eggs  
Coal Tit 53 39 Curvilinear 8.83 eggs 8.39 eggs -0.44 eggs  
Great Crested Grebe 53 15 Linear decline 3.53 eggs 3.12 eggs -0.41 eggs Small sample
Meadow Pipit 53 41 Linear decline 4.35 eggs 4.04 eggs -0.31 eggs  
Woodpigeon 53 102 Linear decline 2.02 eggs 1.76 eggs -0.26 eggs  
Pied Wagtail 53 66 Linear decline 5.1 eggs 4.88 eggs -0.22 eggs  
Ring Ouzel 53 12 Linear decline 4.05 eggs 3.86 eggs -0.19 eggs Small sample
Greenfinch 53 79 Linear decline 4.76 eggs 4.58 eggs -0.18 eggs  
Linnet 53 126 Linear decline 4.74 eggs 4.59 eggs -0.15 eggs  
Wren 53 104 Curvilinear 5.57 eggs 5.43 eggs -0.14 eggs  
Chaffinch 53 95 Linear decline 4.29 eggs 4.15 eggs -0.14 eggs  
Reed Bunting 53 44 Linear decline 4.49 eggs 4.38 eggs -0.11 eggs  
Collared Dove 53 43 Linear decline 1.96 eggs 1.86 eggs -0.1 eggs  
Nightjar 53 23 Linear decline 1.96 eggs 1.87 eggs -0.09 eggs Small sample
Common Sandpiper 53 12 Curvilinear 3.99 eggs 3.91 eggs -0.08 eggs Small sample
Hen Harrier 53 11 Curvilinear 5.53 eggs 5.46 eggs -0.07 eggs Small sample
Grey Wagtail 53 41 Curvilinear 4.79 eggs 4.72 eggs -0.07 eggs  
Blackbird 53 246 Curvilinear 3.76 eggs 3.73 eggs -0.03 eggs  
Lapwing 53 185 Curvilinear 3.66 eggs 3.72 eggs 0.06 eggs  
Oystercatcher 53 157 Curvilinear 2.74 eggs 2.81 eggs 0.07 eggs  
Moorhen 53 109 Curvilinear 6.6 eggs 6.67 eggs 0.07 eggs  
Stonechat 53 42 Curvilinear 4.96 eggs 5.03 eggs 0.07 eggs  
Stock Dove 53 142 Curvilinear 2.08 eggs 2.18 eggs 0.1 eggs  
Carrion Crow 53 29 Curvilinear 4.03 eggs 4.14 eggs 0.11 eggs Includes Hooded Crow
Yellowhammer 53 42 Linear increase 3.4 eggs 3.52 eggs 0.12 eggs  
Dunnock 53 116 Curvilinear 3.89 eggs 4.03 eggs 0.14 eggs  
Skylark 53 33 Curvilinear 3.33 eggs 3.55 eggs 0.22 eggs  
Pied Flycatcher 53 440 Linear increase 6.6 eggs 6.86 eggs 0.26 eggs  
Redstart 53 58 Curvilinear 5.95 eggs 6.24 eggs 0.29 eggs  
Little Owl 53 26 Linear increase 3.35 eggs 3.73 eggs 0.38 eggs Small sample
Tree Sparrow 53 422 Curvilinear 4.78 eggs 5.18 eggs 0.4 eggs  
Starling 53 75 Linear increase 4.46 eggs 4.96 eggs 0.5 eggs  

2. Table of significant trends in Brood size measured between 1967-2020

Species Period
(yrs)		 Mean
annual
sample		 Trend Predicted
in first year		 Predicted
in last year		 Change Comment
Great Tit 53 1042 Linear decline 7.31 chicks 6.04 chicks -1.27 chicks  
Long-tailed Tit 53 40 Linear decline 6.6 chicks 5.43 chicks -1.17 chicks  
Blue Tit 53 1356 Linear decline 8.3 chicks 7.2 chicks -1.1 chicks  
Sand Martin 53 119 Curvilinear 4.85 chicks 3.92 chicks -0.93 chicks  
Carrion Crow 53 77 Curvilinear 2.95 chicks 2.37 chicks -0.58 chicks Includes Hooded Crow
Grey Heron 53 87 Linear decline 2.87 chicks 2.31 chicks -0.56 chicks  
Rook 53 71 Curvilinear 2.19 chicks 1.68 chicks -0.51 chicks  
Magpie 53 75 Curvilinear 3.4 chicks 2.98 chicks -0.42 chicks  
Yellow Wagtail 53 11 Linear decline 4.79 chicks 4.38 chicks -0.41 chicks Small sample
Chiffchaff 53 54 Linear decline 5.05 chicks 4.68 chicks -0.37 chicks  
Greenfinch 53 98 Linear decline 4.09 chicks 3.74 chicks -0.35 chicks  
House Sparrow 53 180 Linear decline 3.48 chicks 3.15 chicks -0.33 chicks  
Coal Tit 53 76 Curvilinear 7.45 chicks 7.14 chicks -0.31 chicks  
Hobby 53 32 Curvilinear 2.36 chicks 2.08 chicks -0.28 chicks  
Meadow Pipit 53 88 Linear decline 4.02 chicks 3.76 chicks -0.26 chicks  
Wood Warbler 53 47 Linear decline 5.53 chicks 5.28 chicks -0.25 chicks  
Ring Ouzel 53 26 Linear decline 3.75 chicks 3.52 chicks -0.23 chicks Small sample
Pied Wagtail 53 136 Linear decline 4.49 chicks 4.31 chicks -0.18 chicks  
Reed Bunting 53 62 Curvilinear 4.03 chicks 3.88 chicks -0.15 chicks  
Raven 53 76 Curvilinear 3.26 chicks 3.12 chicks -0.14 chicks  
Robin 53 240 Curvilinear 4.4 chicks 4.28 chicks -0.12 chicks  
Woodpigeon 53 147 Curvilinear 1.8 chicks 1.71 chicks -0.09 chicks  
Tree Pipit 53 33 Curvilinear 4.23 chicks 4.15 chicks -0.08 chicks  
Linnet 53 146 Curvilinear 4.11 chicks 4.03 chicks -0.08 chicks  
Buzzard 53 121 Curvilinear 1.85 chicks 1.78 chicks -0.07 chicks  
Dunnock 53 129 Curvilinear 3.41 chicks 3.37 chicks -0.04 chicks  
Sparrowhawk 53 63 Curvilinear 3.15 chicks 3.12 chicks -0.03 chicks  
Stonechat 53 85 Curvilinear 4.62 chicks 4.6 chicks -0.02 chicks  
Yellowhammer 53 64 Curvilinear 2.99 chicks 2.98 chicks -0.01 chicks  
Collared Dove 53 72 Curvilinear 1.74 chicks 1.76 chicks 0.02 chicks  
Grey Wagtail 53 86 Curvilinear 4.06 chicks 4.12 chicks 0.06 chicks  
Corn Bunting 53 14 Curvilinear 3.32 chicks 3.41 chicks 0.09 chicks Small sample
Spotted Flycatcher 53 125 Linear increase 3.68 chicks 3.8 chicks 0.12 chicks  
Skylark 53 63 Curvilinear 3.09 chicks 3.25 chicks 0.16 chicks  
Dipper 53 179 Curvilinear 3.43 chicks 3.64 chicks 0.21 chicks  
Willow Warbler 53 150 Linear increase 5.14 chicks 5.37 chicks 0.23 chicks  
Peregrine 53 64 Linear increase 2.37 chicks 2.61 chicks 0.24 chicks  
Merlin 53 61 Curvilinear 3.29 chicks 3.54 chicks 0.25 chicks  
Tree Sparrow 53 548 Curvilinear 3.86 chicks 4.13 chicks 0.27 chicks  
Little Owl 53 58 Linear increase 2.52 chicks 2.92 chicks 0.4 chicks  
Redstart 53 103 Curvilinear 5.15 chicks 5.57 chicks 0.42 chicks  
Moorhen 53 104 Curvilinear 2.52 chicks 3 chicks 0.48 chicks  
Jay 53 10 Linear increase 3.4 chicks 4.03 chicks 0.63 chicks Small sample
Starling 53 237 Linear increase 3.2 chicks 3.84 chicks 0.64 chicks  
Wren 53 138 Curvilinear 3.61 chicks 4.28 chicks 0.67 chicks  
Nuthatch 53 94 Linear increase 4.94 chicks 5.86 chicks 0.92 chicks  

3. Table of significant trends in Daily failure rate (eggs) measured between 1967-2020

Species Period
(yrs)		 Mean
annual
sample		 Trend Predicted
in first year		 Predicted
in last year		 Change Comment
Redshank 53 28 Linear decline 0.0394 nests/day 0.0119 nests/day -0.0275 nests/day Small sample
Magpie 53 45 Curvilinear 0.0332 nests/day 0.0062 nests/day -0.027 nests/day  
Long-tailed Tit 53 67 Curvilinear 0.0392 nests/day 0.0131 nests/day -0.0261 nests/day  
Dipper 53 133 Curvilinear 0.0293 nests/day 0.0055 nests/day -0.0238 nests/day  
Snipe 53 12 Linear decline 0.0315 nests/day 0.0119 nests/day -0.0196 nests/day Small sample
Yellowhammer 53 60 Curvilinear 0.0503 nests/day 0.0307 nests/day -0.0196 nests/day  
Wheatear 53 15 Linear decline 0.0222 nests/day 0.0034 nests/day -0.0188 nests/day Small sample
Woodlark 53 28 Curvilinear 0.0433 nests/day 0.0286 nests/day -0.0147 nests/day Small sample
Woodpigeon 53 116 Curvilinear 0.0455 nests/day 0.0314 nests/day -0.0141 nests/day  
Carrion Crow 53 45 Curvilinear 0.0215 nests/day 0.0076 nests/day -0.0139 nests/day Includes Hooded Crow
Great Crested Grebe 53 23 Curvilinear 0.029 nests/day 0.0164 nests/day -0.0126 nests/day Small sample
Stock Dove 53 132 Curvilinear 0.018 nests/day 0.0059 nests/day -0.0121 nests/day  
Pied Wagtail 53 89 Linear decline 0.0174 nests/day 0.0065 nests/day -0.0109 nests/day  
Wood Warbler 53 33 Curvilinear 0.0246 nests/day 0.0148 nests/day -0.0098 nests/day  
Robin 53 233 Curvilinear 0.0249 nests/day 0.0151 nests/day -0.0098 nests/day  
Starling 53 122 Linear decline 0.0113 nests/day 0.0019 nests/day -0.0094 nests/day  
Tawny Owl 53 68 Curvilinear 0.0118 nests/day 0.0025 nests/day -0.0093 nests/day Nocturnal species
Buzzard 53 30 Linear decline 0.0082 nests/day 0.0003 nests/day -0.0079 nests/day  
House Sparrow 53 132 Linear decline 0.011 nests/day 0.0032 nests/day -0.0078 nests/day  
Barn Owl 53 39 Linear decline 0.008 nests/day 0.0003 nests/day -0.0077 nests/day  
Rook 53 27 Linear decline 0.0103 nests/day 0.0026 nests/day -0.0077 nests/day Small sample
Grey Wagtail 53 61 Linear decline 0.017 nests/day 0.0096 nests/day -0.0074 nests/day  
Nuthatch 53 71 Linear decline 0.0086 nests/day 0.0018 nests/day -0.0068 nests/day  
Kestrel 53 45 Curvilinear 0.0079 nests/day 0.0012 nests/day -0.0067 nests/day  
Marsh Tit 53 22 Linear decline 0.0074 nests/day 0.0009 nests/day -0.0065 nests/day Small sample
Wren 53 148 Linear decline 0.0183 nests/day 0.012 nests/day -0.0063 nests/day  
Tree Sparrow 53 546 Linear decline 0.0085 nests/day 0.0028 nests/day -0.0057 nests/day  
Merlin 53 23 Linear decline 0.007 nests/day 0.0014 nests/day -0.0056 nests/day Small sample
Peregrine 53 28 Linear decline 0.0077 nests/day 0.0022 nests/day -0.0055 nests/day Small sample
Jackdaw 53 82 Curvilinear 0.0087 nests/day 0.0033 nests/day -0.0054 nests/day  
Redstart 53 88 Curvilinear 0.0146 nests/day 0.0095 nests/day -0.0051 nests/day  
Sparrowhawk 53 28 Linear decline 0.0043 nests/day 0.0006 nests/day -0.0037 nests/day Small sample
Spotted Flycatcher 53 110 Linear decline 0.0155 nests/day 0.0118 nests/day -0.0037 nests/day  
Raven 53 23 Curvilinear 0.0033 nests/day 0.0001 nests/day -0.0032 nests/day Small sample
Great Tit 53 924 Linear decline 0.0051 nests/day 0.0021 nests/day -0.003 nests/day  
Tree Pipit 53 17 Curvilinear 0.0415 nests/day 0.0387 nests/day -0.0028 nests/day Small sample
Pied Flycatcher 53 542 Curvilinear 0.006 nests/day 0.0032 nests/day -0.0028 nests/day  
Coal Tit 53 57 Linear decline 0.0042 nests/day 0.0017 nests/day -0.0025 nests/day  
Blue Tit 53 1229 Linear decline 0.0033 nests/day 0.002 nests/day -0.0013 nests/day  
Swallow 53 690 Curvilinear 0.0045 nests/day 0.004 nests/day -0.0005 nests/day  
Sand Martin 53 104 Curvilinear 0.0145 nests/day 0.0143 nests/day -0.0002 nests/day  
Grey Heron 53 16 Curvilinear 0.0001 nests/day 0.0002 nests/day 0.0001 nests/day Small sample
Greenfinch 53 110 Curvilinear 0.0271 nests/day 0.0277 nests/day 0.0006 nests/day  
Chiffchaff 53 58 Curvilinear 0.0205 nests/day 0.0216 nests/day 0.0011 nests/day  
Collared Dove 53 60 Curvilinear 0.0289 nests/day 0.0303 nests/day 0.0014 nests/day  
Treecreeper 53 22 Curvilinear 0.0232 nests/day 0.0247 nests/day 0.0015 nests/day Small sample
Little Grebe 53 14 Curvilinear 0.0359 nests/day 0.0376 nests/day 0.0017 nests/day Small sample
Dunnock 53 162 Curvilinear 0.0254 nests/day 0.0283 nests/day 0.0029 nests/day  
Linnet 53 175 Linear increase 0.0186 nests/day 0.0237 nests/day 0.0051 nests/day  
Reed Warbler 53 255 Curvilinear 0.0186 nests/day 0.0243 nests/day 0.0057 nests/day  
Stonechat 53 47 Linear increase 0.0055 nests/day 0.0115 nests/day 0.006 nests/day  
Sedge Warbler 53 38 Curvilinear 0.0149 nests/day 0.0225 nests/day 0.0076 nests/day  
Curlew 53 21 Curvilinear 0.0287 nests/day 0.0364 nests/day 0.0077 nests/day Small sample
Nightjar 53 29 Curvilinear 0.007 nests/day 0.0157 nests/day 0.0087 nests/day Small sample
Willow Warbler 53 69 Linear increase 0.009 nests/day 0.0205 nests/day 0.0115 nests/day  
Goldfinch 53 42 Linear increase 0.0187 nests/day 0.031 nests/day 0.0123 nests/day  
Meadow Pipit 53 52 Curvilinear 0.0213 nests/day 0.0343 nests/day 0.013 nests/day  
Moorhen 53 136 Linear increase 0.0104 nests/day 0.0268 nests/day 0.0164 nests/day  
Chaffinch 53 180 Curvilinear 0.0289 nests/day 0.0453 nests/day 0.0164 nests/day  
Oystercatcher 53 173 Curvilinear 0.0102 nests/day 0.0281 nests/day 0.0179 nests/day  
Lapwing 53 205 Curvilinear 0.0164 nests/day 0.0344 nests/day 0.018 nests/day  
Blackbird 53 358 Curvilinear 0.0241 nests/day 0.0429 nests/day 0.0188 nests/day  
Ringed Plover 53 124 Curvilinear 0.0252 nests/day 0.0444 nests/day 0.0192 nests/day  
Skylark 53 41 Curvilinear 0.037 nests/day 0.0568 nests/day 0.0198 nests/day  
Whinchat 53 20 Linear increase 0.0073 nests/day 0.0292 nests/day 0.0219 nests/day Small sample
Reed Bunting 53 52 Linear increase 0.0075 nests/day 0.0306 nests/day 0.0231 nests/day  

4. Table of significant trends in Daily failure rate (chicks) measured between 1967-2020

Species Period
(yrs)		 Mean
annual
sample		 Trend Predicted
in first year		 Predicted
in last year		 Change Comment
Sand Martin 53 124 Curvilinear 0.0396 nests/day 0.0032 nests/day -0.0364 nests/day  
Skylark 53 51 Linear decline 0.0482 nests/day 0.028 nests/day -0.0202 nests/day  
Magpie 53 44 Curvilinear 0.0234 nests/day 0.006 nests/day -0.0174 nests/day  
Grey Wagtail 53 60 Linear decline 0.0194 nests/day 0.0083 nests/day -0.0111 nests/day  
Jackdaw 53 73 Curvilinear 0.0133 nests/day 0.0032 nests/day -0.0101 nests/day  
Reed Warbler 53 195 Curvilinear 0.0228 nests/day 0.0128 nests/day -0.01 nests/day  
Tree Sparrow 53 380 Curvilinear 0.0157 nests/day 0.0064 nests/day -0.0093 nests/day  
Blackbird 53 289 Curvilinear 0.032 nests/day 0.0234 nests/day -0.0086 nests/day  
Merlin 53 31 Linear decline 0.0098 nests/day 0.0015 nests/day -0.0083 nests/day  
Redstart 53 64 Curvilinear 0.0149 nests/day 0.0071 nests/day -0.0078 nests/day  
Ring Ouzel 53 19 Curvilinear 0.0247 nests/day 0.0186 nests/day -0.0061 nests/day Small sample
House Sparrow 53 131 Curvilinear 0.0157 nests/day 0.0102 nests/day -0.0055 nests/day  
Carrion Crow 53 39 Linear decline 0.0064 nests/day 0.0012 nests/day -0.0052 nests/day Includes Hooded Crow
Yellowhammer 53 49 Curvilinear 0.0431 nests/day 0.038 nests/day -0.0051 nests/day  
Little Owl 53 26 Linear decline 0.0055 nests/day 0.0023 nests/day -0.0032 nests/day Small sample
Starling 53 136 Curvilinear 0.0067 nests/day 0.0036 nests/day -0.0031 nests/day  
Tawny Owl 53 110 Curvilinear 0.0034 nests/day 0.0005 nests/day -0.0029 nests/day Nocturnal species
Barn Owl 53 203 Curvilinear 0.0031 nests/day 0.0003 nests/day -0.0028 nests/day  
Nuthatch 53 78 Linear decline 0.0044 nests/day 0.0019 nests/day -0.0025 nests/day  
Collared Dove 53 54 Curvilinear 0.0212 nests/day 0.0192 nests/day -0.002 nests/day  
Peregrine 53 34 Linear decline 0.0028 nests/day 0.001 nests/day -0.0018 nests/day  
Kestrel 53 82 Linear decline 0.002 nests/day 0.0009 nests/day -0.0011 nests/day  
Great Tit 53 635 Curvilinear 0.0053 nests/day 0.0053 nests/day 0 nests/day  
Meadow Pipit 53 75 Curvilinear 0.0336 nests/day 0.034 nests/day 0.0004 nests/day  
Blue Tit 53 856 Curvilinear 0.0054 nests/day 0.0066 nests/day 0.0012 nests/day  
Treecreeper 53 22 Curvilinear 0.0134 nests/day 0.0151 nests/day 0.0017 nests/day Small sample
Swallow 53 571 Linear increase 0.0027 nests/day 0.0051 nests/day 0.0024 nests/day  
Moorhen 53 50 Linear increase 0.0002 nests/day 0.0034 nests/day 0.0032 nests/day  
Stonechat 53 79 Curvilinear 0.0153 nests/day 0.0185 nests/day 0.0032 nests/day  
Pied Flycatcher 53 458 Linear increase 0.0038 nests/day 0.0072 nests/day 0.0034 nests/day  
Woodpigeon 53 95 Curvilinear 0.0206 nests/day 0.0251 nests/day 0.0045 nests/day  
Linnet 53 126 Curvilinear 0.0138 nests/day 0.0185 nests/day 0.0047 nests/day  
Whinchat 53 33 Curvilinear 0.0235 nests/day 0.0284 nests/day 0.0049 nests/day  
Wren 53 101 Curvilinear 0.0087 nests/day 0.0153 nests/day 0.0066 nests/day  
Nightjar 53 27 Linear increase 0.0063 nests/day 0.0137 nests/day 0.0074 nests/day Small sample
Reed Bunting 53 52 Curvilinear 0.0272 nests/day 0.0398 nests/day 0.0126 nests/day  
Long-tailed Tit 53 45 Linear increase 0.0082 nests/day 0.0209 nests/day 0.0127 nests/day  
Corn Bunting 53 14 Curvilinear 0.0479 nests/day 0.0619 nests/day 0.014 nests/day Small sample
Garden Warbler 53 21 Linear increase 0.0115 nests/day 0.0281 nests/day 0.0166 nests/day Small sample
Wood Warbler 53 41 Curvilinear 0.0208 nests/day 0.0524 nests/day 0.0316 nests/day  

 

This report should be cited as: Massimino, D., Woodward, I.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