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 1967-2016

Species Period
(yrs)
Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Great Tit 49 432 Linear decline 8.34 eggs 7.16 eggs -1.18 eggs  
Magpie 49 41 Linear decline 5.66 eggs 4.95 eggs -0.71 eggs  
Long-tailed Tit 49 47 Curvilinear 7.81 eggs 7.18 eggs -0.63 eggs  
Grey Heron 49 14 Linear decline 4.02 eggs 3.42 eggs -0.6 eggs Small sample
Peregrine 49 20 Curvilinear 3.83 eggs 3.25 eggs -0.58 eggs Small sample
Great Crested Grebe 49 15 Linear decline 3.51 eggs 3.16 eggs -0.35 eggs Small sample
Blue Tit 49 605 Curvilinear 8.79 eggs 8.44 eggs -0.35 eggs  
Buzzard 49 36 Curvilinear 2.06 eggs 1.72 eggs -0.34 eggs  
Hen Harrier 49 11 Curvilinear 5.56 eggs 5.24 eggs -0.32 eggs Small sample
Meadow Pipit 49 42 Curvilinear 4.26 eggs 4 eggs -0.26 eggs  
Wood Warbler 49 22 Linear decline 5.85 eggs 5.59 eggs -0.26 eggs Small sample
Woodpigeon 49 99 Linear decline 2.02 eggs 1.79 eggs -0.23 eggs  
Pied Wagtail 49 68 Linear decline 5.1 eggs 4.9 eggs -0.2 eggs  
Greenfinch 49 83 Linear decline 4.75 eggs 4.58 eggs -0.17 eggs  
Linnet 49 128 Linear decline 4.74 eggs 4.6 eggs -0.14 eggs  
Ring Ouzel 49 11 Curvilinear 3.94 eggs 3.81 eggs -0.13 eggs Small sample
Reed Bunting 49 44 Linear decline 4.5 eggs 4.37 eggs -0.13 eggs  
Chaffinch 49 98 Linear decline 4.29 eggs 4.17 eggs -0.12 eggs  
Common Sandpiper 49 12 Curvilinear 3.99 eggs 3.88 eggs -0.11 eggs Small sample
Moorhen 49 112 Curvilinear 6.59 eggs 6.49 eggs -0.1 eggs  
Collared Dove 49 44 Linear decline 1.96 eggs 1.88 eggs -0.08 eggs  
Nightjar 49 21 Linear decline 1.96 eggs 1.88 eggs -0.08 eggs Small sample
Blackcap 49 45 Curvilinear 4.52 eggs 4.45 eggs -0.07 eggs  
Wren 49 101 Curvilinear 5.56 eggs 5.5 eggs -0.06 eggs  
Grey Wagtail 49 40 Curvilinear 4.79 eggs 4.77 eggs -0.02 eggs  
Oystercatcher 49 158 Curvilinear 2.76 eggs 2.8 eggs 0.04 eggs  
Stock Dove 49 136 Curvilinear 2.07 eggs 2.13 eggs 0.06 eggs  
Lapwing 49 189 Curvilinear 3.67 eggs 3.75 eggs 0.08 eggs  
Stonechat 49 41 Curvilinear 4.96 eggs 5.08 eggs 0.12 eggs  
Mistle Thrush 49 32 Linear increase 3.9 eggs 4.06 eggs 0.16 eggs  
Dunnock 49 116 Curvilinear 3.88 eggs 4.05 eggs 0.17 eggs  
Skylark 49 35 Curvilinear 3.33 eggs 3.56 eggs 0.23 eggs  
Redstart 49 56 Curvilinear 5.89 eggs 6.16 eggs 0.27 eggs  
Pied Flycatcher 49 405 Curvilinear 6.38 eggs 6.71 eggs 0.33 eggs  
Little Owl 49 25 Linear increase 3.36 eggs 3.71 eggs 0.35 eggs Small sample
Tree Sparrow 49 378 Curvilinear 4.76 eggs 5.17 eggs 0.41 eggs  
Starling 49 76 Linear increase 4.45 eggs 4.94 eggs 0.49 eggs  

2. Table of significant trends in Brood size measured between 1967-2016

Species Period
(yrs)
Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Great Tit 49 923 Linear decline 7.52 chicks 6.04 chicks -1.48 chicks  
Long-tailed Tit 49 39 Linear decline 6.53 chicks 5.61 chicks -0.92 chicks  
Carrion Crow 49 78 Curvilinear 2.92 chicks 2.39 chicks -0.53 chicks Includes Hooded Crow
Grey Heron 49 89 Linear decline 2.86 chicks 2.36 chicks -0.5 chicks  
Chiffchaff 49 51 Linear decline 5.09 chicks 4.67 chicks -0.42 chicks  
Blue Tit 49 1138 Curvilinear 7.38 chicks 6.97 chicks -0.41 chicks  
Greenfinch 49 103 Linear decline 4.1 chicks 3.76 chicks -0.34 chicks  
House Sparrow 49 168 Linear decline 3.49 chicks 3.17 chicks -0.32 chicks  
Coal Tit 49 74 Curvilinear 7.39 chicks 7.08 chicks -0.31 chicks  
Rook 49 73 Curvilinear 2.19 chicks 1.89 chicks -0.3 chicks  
Wood Warbler 49 41 Linear decline 5.55 chicks 5.26 chicks -0.29 chicks  
Magpie 49 78 Curvilinear 3.38 chicks 3.1 chicks -0.28 chicks  
Meadow Pipit 49 88 Linear decline 4.03 chicks 3.77 chicks -0.26 chicks  
Ring Ouzel 49 23 Linear decline 3.76 chicks 3.55 chicks -0.21 chicks Small sample
Great Crested Grebe 49 14 Curvilinear 2.24 chicks 2.05 chicks -0.19 chicks Small sample
Hobby 49 29 Curvilinear 2.33 chicks 2.14 chicks -0.19 chicks Small sample
Raven 49 74 Curvilinear 3.29 chicks 3.14 chicks -0.15 chicks  
Pied Wagtail 49 138 Linear decline 4.49 chicks 4.35 chicks -0.14 chicks  
Reed Bunting 49 62 Curvilinear 4.02 chicks 3.89 chicks -0.13 chicks  
Woodpigeon 49 141 Curvilinear 1.8 chicks 1.74 chicks -0.06 chicks  
Linnet 49 147 Curvilinear 4.11 chicks 4.09 chicks -0.02 chicks  
Yellowhammer 49 65 Curvilinear 2.96 chicks 2.94 chicks -0.02 chicks  
Buzzard 49 117 Curvilinear 1.85 chicks 1.85 chicks 0 chicks  
Dunnock 49 129 Curvilinear 3.4 chicks 3.41 chicks 0.01 chicks  
Stonechat 49 82 Curvilinear 4.62 chicks 4.65 chicks 0.03 chicks  
Mute Swan 49 69 Curvilinear 4.41 chicks 4.46 chicks 0.05 chicks  
Collared Dove 49 74 Curvilinear 1.74 chicks 1.79 chicks 0.05 chicks  
Grey Wagtail 49 83 Curvilinear 4.05 chicks 4.15 chicks 0.1 chicks  
Tree Pipit 49 31 Curvilinear 4.27 chicks 4.38 chicks 0.11 chicks  
Peregrine 49 58 Linear increase 2.4 chicks 2.58 chicks 0.18 chicks  
Skylark 49 65 Curvilinear 3.09 chicks 3.28 chicks 0.19 chicks  
Sparrowhawk 49 66 Curvilinear 3.17 chicks 3.37 chicks 0.2 chicks  
Corn Bunting 49 14 Curvilinear 3.3 chicks 3.53 chicks 0.23 chicks Small sample
Willow Warbler 49 151 Linear increase 5.13 chicks 5.39 chicks 0.26 chicks  
Dipper 49 162 Curvilinear 3.43 chicks 3.72 chicks 0.29 chicks  
Tree Sparrow 49 491 Curvilinear 3.8 chicks 4.13 chicks 0.33 chicks  
Merlin 49 59 Curvilinear 3.35 chicks 3.69 chicks 0.34 chicks  
Little Owl 49 54 Linear increase 2.52 chicks 2.89 chicks 0.37 chicks  
Redstart 49 99 Curvilinear 5.1 chicks 5.51 chicks 0.41 chicks  
Starling 49 238 Linear increase 3.24 chicks 3.73 chicks 0.49 chicks  
Jay 49 11 Linear increase 3.38 chicks 4.02 chicks 0.64 chicks Small sample
Wren 49 132 Curvilinear 3.6 chicks 4.38 chicks 0.78 chicks  
Nuthatch 49 88 Linear increase 4.93 chicks 5.8 chicks 0.87 chicks  

3. Table of significant trends in Daily failure rate (eggs) measured between 1967-2016

Species Period
(yrs)
Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Cuckoo 49 14 Linear decline 0.066 nests/day 0.0303 nests/day -0.0357 nests/day Small sample
Magpie 49 47 Curvilinear 0.0317 nests/day 0.0039 nests/day -0.0278 nests/day  
Dipper 49 122 Curvilinear 0.0328 nests/day 0.0058 nests/day -0.027 nests/day  
Long-tailed Tit 49 65 Curvilinear 0.0388 nests/day 0.0118 nests/day -0.027 nests/day  
Redshank 49 29 Linear decline 0.0394 nests/day 0.013 nests/day -0.0264 nests/day Small sample
Woodlark 49 26 Curvilinear 0.0564 nests/day 0.0302 nests/day -0.0262 nests/day Small sample
Cirl Bunting 49 15 Curvilinear 0.0418 nests/day 0.0166 nests/day -0.0252 nests/day Small sample
Yellowhammer 49 62 Curvilinear 0.0509 nests/day 0.0302 nests/day -0.0207 nests/day  
Snipe 49 13 Linear decline 0.0321 nests/day 0.0122 nests/day -0.0199 nests/day Small sample
Wheatear 49 15 Linear decline 0.0217 nests/day 0.0042 nests/day -0.0175 nests/day Small sample
Woodpigeon 49 113 Curvilinear 0.0459 nests/day 0.0302 nests/day -0.0157 nests/day  
Carrion Crow 49 47 Curvilinear 0.0213 nests/day 0.0057 nests/day -0.0156 nests/day Includes Hooded Crow
Stock Dove 49 127 Curvilinear 0.0192 nests/day 0.0067 nests/day -0.0125 nests/day  
Pied Wagtail 49 91 Linear decline 0.018 nests/day 0.0065 nests/day -0.0115 nests/day  
Robin 49 234 Curvilinear 0.025 nests/day 0.0147 nests/day -0.0103 nests/day  
Tawny Owl 49 68 Curvilinear 0.0119 nests/day 0.0024 nests/day -0.0095 nests/day Nocturnal species
Wood Warbler 49 27 Curvilinear 0.0233 nests/day 0.0138 nests/day -0.0095 nests/day Small sample
Starling 49 123 Linear decline 0.0112 nests/day 0.0022 nests/day -0.009 nests/day  
Sand Martin 49 80 Curvilinear 0.0144 nests/day 0.0056 nests/day -0.0088 nests/day  
Great Crested Grebe 49 23 Curvilinear 0.0279 nests/day 0.0192 nests/day -0.0087 nests/day Small sample
Barn Owl 49 37 Linear decline 0.0084 nests/day 0.0004 nests/day -0.008 nests/day  
Buzzard 49 30 Linear decline 0.0081 nests/day 0.0004 nests/day -0.0077 nests/day Small sample
Grey Wagtail 49 60 Linear decline 0.0172 nests/day 0.0097 nests/day -0.0075 nests/day  
House Sparrow 49 124 Linear decline 0.011 nests/day 0.0035 nests/day -0.0075 nests/day  
Nuthatch 49 67 Linear decline 0.0092 nests/day 0.0019 nests/day -0.0073 nests/day  
Redstart 49 85 Curvilinear 0.0153 nests/day 0.0084 nests/day -0.0069 nests/day  
Kestrel 49 43 Curvilinear 0.008 nests/day 0.0012 nests/day -0.0068 nests/day  
Marsh Tit 49 22 Linear decline 0.0074 nests/day 0.001 nests/day -0.0064 nests/day Small sample
Tree Pipit 49 15 Curvilinear 0.0452 nests/day 0.0389 nests/day -0.0063 nests/day Small sample
Merlin 49 23 Linear decline 0.0074 nests/day 0.0014 nests/day -0.006 nests/day Small sample
Wren 49 145 Linear decline 0.0182 nests/day 0.0123 nests/day -0.0059 nests/day  
Jackdaw 49 78 Curvilinear 0.0089 nests/day 0.0032 nests/day -0.0057 nests/day  
Tree Sparrow 49 491 Linear decline 0.0085 nests/day 0.003 nests/day -0.0055 nests/day  
Sparrowhawk 49 30 Linear decline 0.0045 nests/day 0.0006 nests/day -0.0039 nests/day Small sample
Treecreeper 49 23 Curvilinear 0.0238 nests/day 0.02 nests/day -0.0038 nests/day Small sample
Great Tit 49 838 Curvilinear 0.0059 nests/day 0.0025 nests/day -0.0034 nests/day  
Pied Flycatcher 49 497 Curvilinear 0.0062 nests/day 0.0032 nests/day -0.003 nests/day  
Coal Tit 49 56 Linear decline 0.0043 nests/day 0.0017 nests/day -0.0026 nests/day  
Raven 49 23 Curvilinear 0.0025 nests/day 0.0001 nests/day -0.0024 nests/day Small sample
Blackcap 49 58 Curvilinear 0.0231 nests/day 0.0212 nests/day -0.0019 nests/day  
Blue Tit 49 1073 Curvilinear 0.0043 nests/day 0.0025 nests/day -0.0018 nests/day  
Spotted Flycatcher 49 113 Curvilinear 0.0179 nests/day 0.0161 nests/day -0.0018 nests/day  
Greenfinch 49 115 Curvilinear 0.0273 nests/day 0.0259 nests/day -0.0014 nests/day  
Peregrine 49 27 Curvilinear 0.0027 nests/day 0.0016 nests/day -0.0011 nests/day Small sample
Curlew 49 21 Curvilinear 0.0277 nests/day 0.0267 nests/day -0.001 nests/day Small sample
Collared Dove 49 62 Curvilinear 0.0313 nests/day 0.0312 nests/day -0.0001 nests/day  
Chiffchaff 49 57 Curvilinear 0.0218 nests/day 0.0217 nests/day -0.0001 nests/day  
Grey Heron 49 17 Curvilinear 0.0001 nests/day 0.0006 nests/day 0.0005 nests/day Small sample
Dunnock 49 163 Curvilinear 0.0258 nests/day 0.0269 nests/day 0.0011 nests/day  
Reed Warbler 49 221 Curvilinear 0.0192 nests/day 0.0225 nests/day 0.0033 nests/day  
Sedge Warbler 49 39 Curvilinear 0.0152 nests/day 0.0197 nests/day 0.0045 nests/day  
Little Grebe 49 14 Curvilinear 0.0351 nests/day 0.0398 nests/day 0.0047 nests/day Small sample
Stonechat 49 46 Linear increase 0.0056 nests/day 0.0106 nests/day 0.005 nests/day  
Linnet 49 177 Linear increase 0.0184 nests/day 0.0238 nests/day 0.0054 nests/day  
Whitethroat 49 45 Curvilinear 0.01 nests/day 0.0162 nests/day 0.0062 nests/day  
Meadow Pipit 49 53 Curvilinear 0.0216 nests/day 0.0292 nests/day 0.0076 nests/day  
Garden Warbler 49 24 Curvilinear 0.0176 nests/day 0.0271 nests/day 0.0095 nests/day Small sample
Goldfinch 49 41 Linear increase 0.019 nests/day 0.0289 nests/day 0.0099 nests/day  
Willow Warbler 49 69 Linear increase 0.0089 nests/day 0.0201 nests/day 0.0112 nests/day  
Lapwing 49 209 Curvilinear 0.0158 nests/day 0.0271 nests/day 0.0113 nests/day  
Ringed Plover 49 127 Linear increase 0.0221 nests/day 0.034 nests/day 0.0119 nests/day  
Skylark 49 43 Curvilinear 0.0375 nests/day 0.0513 nests/day 0.0138 nests/day  
Chaffinch 49 186 Curvilinear 0.0295 nests/day 0.0435 nests/day 0.014 nests/day  
Moorhen 49 139 Linear increase 0.0105 nests/day 0.0245 nests/day 0.014 nests/day  
Nightjar 49 26 Curvilinear 0.0091 nests/day 0.0238 nests/day 0.0147 nests/day Small sample
Blackbird 49 344 Curvilinear 0.025 nests/day 0.0405 nests/day 0.0155 nests/day  
Oystercatcher 49 174 Curvilinear 0.0103 nests/day 0.029 nests/day 0.0187 nests/day  
Reed Bunting 49 52 Linear increase 0.0075 nests/day 0.0278 nests/day 0.0203 nests/day  
Whinchat 49 20 Linear increase 0.0062 nests/day 0.0303 nests/day 0.0241 nests/day Small sample

4. Table of significant trends in Daily failure rate (chicks) measured between 1967-2016

Species Period
(yrs)
Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Sand Martin 49 107 Curvilinear 0.0237 nests/day 0.0009 nests/day -0.0228 nests/day  
Magpie 49 45 Curvilinear 0.0224 nests/day 0.0034 nests/day -0.019 nests/day  
Skylark 49 52 Linear decline 0.0481 nests/day 0.0293 nests/day -0.0188 nests/day  
Reed Warbler 49 170 Curvilinear 0.0238 nests/day 0.0112 nests/day -0.0126 nests/day  
Grey Wagtail 49 59 Linear decline 0.0205 nests/day 0.008 nests/day -0.0125 nests/day  
Jackdaw 49 70 Curvilinear 0.0144 nests/day 0.0039 nests/day -0.0105 nests/day  
Blackbird 49 278 Curvilinear 0.0315 nests/day 0.0216 nests/day -0.0099 nests/day  
Yellowhammer 49 50 Linear decline 0.038 nests/day 0.0283 nests/day -0.0097 nests/day  
Merlin 49 30 Linear decline 0.0103 nests/day 0.0016 nests/day -0.0087 nests/day Small sample
Tree Sparrow 49 345 Linear decline 0.0143 nests/day 0.0056 nests/day -0.0087 nests/day  
House Sparrow 49 124 Curvilinear 0.0158 nests/day 0.0083 nests/day -0.0075 nests/day  
Redstart 49 62 Linear decline 0.0107 nests/day 0.0041 nests/day -0.0066 nests/day  
Meadow Pipit 49 76 Curvilinear 0.0347 nests/day 0.0283 nests/day -0.0064 nests/day  
Carrion Crow 49 40 Linear decline 0.0068 nests/day 0.0012 nests/day -0.0056 nests/day Includes Hooded Crow
Collared Dove 49 55 Curvilinear 0.0209 nests/day 0.0163 nests/day -0.0046 nests/day  
Corn Bunting 49 14 Curvilinear 0.0509 nests/day 0.0472 nests/day -0.0037 nests/day Small sample
Starling 49 138 Curvilinear 0.0069 nests/day 0.0037 nests/day -0.0032 nests/day  
Barn Owl 49 176 Curvilinear 0.0033 nests/day 0.0003 nests/day -0.003 nests/day  
Tawny Owl 49 108 Curvilinear 0.0033 nests/day 0.0006 nests/day -0.0027 nests/day Nocturnal species
Nuthatch 49 73 Linear decline 0.0043 nests/day 0.002 nests/day -0.0023 nests/day  
Stonechat 49 77 Curvilinear 0.0164 nests/day 0.0171 nests/day 0.0007 nests/day  
Whinchat 49 32 Curvilinear 0.024 nests/day 0.0249 nests/day 0.0009 nests/day  
Treecreeper 49 22 Curvilinear 0.0142 nests/day 0.0151 nests/day 0.0009 nests/day Small sample
Swallow 49 567 Linear increase 0.0033 nests/day 0.0043 nests/day 0.001 nests/day  
Spotted Flycatcher 49 102 Curvilinear 0.0087 nests/day 0.0097 nests/day 0.001 nests/day  
Woodpigeon 49 92 Curvilinear 0.0216 nests/day 0.0229 nests/day 0.0013 nests/day  
Blue Tit 49 737 Linear increase 0.0066 nests/day 0.0081 nests/day 0.0015 nests/day  
Moorhen 49 51 Linear increase 0.0003 nests/day 0.0025 nests/day 0.0022 nests/day  
Pied Flycatcher 49 416 Linear increase 0.0038 nests/day 0.0068 nests/day 0.003 nests/day  
Wren 49 99 Linear increase 0.0073 nests/day 0.0111 nests/day 0.0038 nests/day  
Nightjar 49 24 Curvilinear 0.0018 nests/day 0.0083 nests/day 0.0065 nests/day Small sample
Linnet 49 127 Linear increase 0.0157 nests/day 0.0224 nests/day 0.0067 nests/day  
Reed Bunting 49 52 Curvilinear 0.0272 nests/day 0.0349 nests/day 0.0077 nests/day  
Long-tailed Tit 49 44 Linear increase 0.0077 nests/day 0.0207 nests/day 0.013 nests/day  
Garden Warbler 49 21 Linear increase 0.0117 nests/day 0.0258 nests/day 0.0141 nests/day Small sample
Wood Warbler 49 34 Curvilinear 0.0232 nests/day 0.0465 nests/day 0.0233 nests/day  
Cirl Bunting 49 21 Linear increase 0.0057 nests/day 0.0691 nests/day 0.0634 nests/day Small sample