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 1967-2015

Species Period
(yrs)
Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Great Tit 48 416 Linear decline 8.25 eggs 7.25 eggs -1 eggs  
Magpie 48 41 Linear decline 5.67 eggs 4.97 eggs -0.7 eggs  
Blue Tit 48 572 Linear decline 9.38 eggs 8.72 eggs -0.66 eggs  
Long-tailed Tit 48 46 Curvilinear 7.85 eggs 7.22 eggs -0.63 eggs  
Grey Heron 48 14 Curvilinear 4.15 eggs 3.66 eggs -0.49 eggs Small sample
Hen Harrier 48 11 Curvilinear 5.58 eggs 5.2 eggs -0.38 eggs Small sample
Great Crested Grebe 48 15 Linear decline 3.52 eggs 3.19 eggs -0.33 eggs Small sample
Peregrine 48 19 Linear decline 3.46 eggs 3.14 eggs -0.32 eggs Small sample
Buzzard 48 36 Curvilinear 2.1 eggs 1.84 eggs -0.26 eggs  
Meadow Pipit 48 42 Curvilinear 4.26 eggs 4 eggs -0.26 eggs  
Woodpigeon 48 97 Linear decline 2.02 eggs 1.79 eggs -0.23 eggs  
Pied Wagtail 48 67 Linear decline 5.1 eggs 4.91 eggs -0.19 eggs  
Greenfinch 48 84 Linear decline 4.76 eggs 4.58 eggs -0.18 eggs  
Linnet 48 127 Linear decline 4.75 eggs 4.6 eggs -0.15 eggs  
Ring Ouzel 48 11 Linear decline 4.05 eggs 3.9 eggs -0.15 eggs Small sample
Reed Bunting 48 44 Linear decline 4.51 eggs 4.37 eggs -0.14 eggs  
Chaffinch 48 99 Linear decline 4.29 eggs 4.16 eggs -0.13 eggs  
Moorhen 48 113 Curvilinear 6.58 eggs 6.46 eggs -0.12 eggs  
Common Sandpiper 48 12 Curvilinear 3.99 eggs 3.88 eggs -0.11 eggs Small sample
Nightjar 48 21 Linear decline 1.97 eggs 1.88 eggs -0.09 eggs Small sample
Swift 48 14 Curvilinear 2.44 eggs 2.35 eggs -0.09 eggs Small sample
Collared Dove 48 44 Linear decline 1.96 eggs 1.88 eggs -0.08 eggs  
Wren 48 99 Curvilinear 5.57 eggs 5.55 eggs -0.02 eggs  
Grey Wagtail 48 39 Curvilinear 4.78 eggs 4.77 eggs -0.01 eggs  
Oystercatcher 48 158 Curvilinear 2.76 eggs 2.79 eggs 0.03 eggs  
Stock Dove 48 133 Curvilinear 2.07 eggs 2.11 eggs 0.04 eggs  
Carrion Crow 48 31 Curvilinear 4.03 eggs 4.08 eggs 0.05 eggs Includes Hooded Crow
Lapwing 48 189 Linear increase 3.71 eggs 3.8 eggs 0.09 eggs  
Redshank 48 28 Curvilinear 3.89 eggs 4.02 eggs 0.13 eggs Small sample
Stonechat 48 40 Curvilinear 4.96 eggs 5.11 eggs 0.15 eggs  
Mistle Thrush 48 32 Linear increase 3.89 eggs 4.07 eggs 0.18 eggs  
Dunnock 48 115 Curvilinear 3.9 eggs 4.1 eggs 0.2 eggs  
Skylark 48 35 Curvilinear 3.33 eggs 3.56 eggs 0.23 eggs  
Redstart 48 55 Curvilinear 5.87 eggs 6.13 eggs 0.26 eggs  
Little Owl 48 25 Linear increase 3.35 eggs 3.7 eggs 0.35 eggs Small sample
Pied Flycatcher 48 395 Curvilinear 6.39 eggs 6.74 eggs 0.35 eggs  
Tree Sparrow 48 357 Curvilinear 4.75 eggs 5.16 eggs 0.41 eggs  
Starling 48 77 Linear increase 4.46 eggs 4.94 eggs 0.48 eggs  

2. Table of significant trends in Brood size measured between 1967-2015

Species Period
(yrs)
Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Great Tit 48 877 Linear decline 7.41 chicks 6.14 chicks -1.27 chicks  
Blue Tit 48 1058 Linear decline 8.3 chicks 7.35 chicks -0.95 chicks  
Long-tailed Tit 48 37 Linear decline 6.42 chicks 5.78 chicks -0.64 chicks  
Carrion Crow 48 78 Curvilinear 2.91 chicks 2.39 chicks -0.52 chicks Includes Hooded Crow
Grey Heron 48 90 Linear decline 2.85 chicks 2.39 chicks -0.46 chicks  
Chiffchaff 48 50 Linear decline 5.08 chicks 4.69 chicks -0.39 chicks  
Yellow Wagtail 48 12 Linear decline 4.78 chicks 4.44 chicks -0.34 chicks Small sample
Magpie 48 79 Curvilinear 3.34 chicks 3 chicks -0.34 chicks  
Greenfinch 48 104 Linear decline 4.1 chicks 3.76 chicks -0.34 chicks  
House Sparrow 48 164 Linear decline 3.48 chicks 3.18 chicks -0.3 chicks  
Coal Tit 48 73 Curvilinear 7.39 chicks 7.11 chicks -0.28 chicks  
Great Crested Grebe 48 13 Curvilinear 2.24 chicks 1.97 chicks -0.27 chicks Small sample
Wood Warbler 48 41 Linear decline 5.55 chicks 5.28 chicks -0.27 chicks  
Rook 48 74 Curvilinear 2.18 chicks 1.93 chicks -0.25 chicks  
Meadow Pipit 48 86 Linear decline 4.01 chicks 3.79 chicks -0.22 chicks  
Raven 48 73 Curvilinear 3.27 chicks 3.08 chicks -0.19 chicks  
Hobby 48 28 Curvilinear 2.33 chicks 2.15 chicks -0.18 chicks Small sample
Pied Wagtail 48 138 Linear decline 4.49 chicks 4.35 chicks -0.14 chicks  
Reed Bunting 48 62 Curvilinear 4.01 chicks 3.89 chicks -0.12 chicks  
Great Spotted Woodpecker 48 24 Curvilinear 3.78 chicks 3.68 chicks -0.1 chicks Small sample
Woodpigeon 48 136 Curvilinear 1.8 chicks 1.74 chicks -0.06 chicks  
Linnet 48 145 Curvilinear 4.09 chicks 4.06 chicks -0.03 chicks  
Buzzard 48 115 Curvilinear 1.86 chicks 1.89 chicks 0.03 chicks  
Mute Swan 48 68 Curvilinear 4.39 chicks 4.42 chicks 0.03 chicks  
Dunnock 48 128 Curvilinear 3.4 chicks 3.43 chicks 0.03 chicks  
Yellowhammer 48 65 Curvilinear 2.97 chicks 3.01 chicks 0.04 chicks  
Collared Dove 48 74 Curvilinear 1.74 chicks 1.79 chicks 0.05 chicks  
Spotted Flycatcher 48 126 Curvilinear 3.63 chicks 3.68 chicks 0.05 chicks  
Stonechat 48 79 Curvilinear 4.62 chicks 4.68 chicks 0.06 chicks  
Grey Wagtail 48 82 Curvilinear 4.03 chicks 4.13 chicks 0.1 chicks  
Tree Pipit 48 31 Curvilinear 4.28 chicks 4.42 chicks 0.14 chicks  
Peregrine 48 56 Linear increase 2.4 chicks 2.56 chicks 0.16 chicks  
Skylark 48 65 Curvilinear 3.1 chicks 3.31 chicks 0.21 chicks  
Sparrowhawk 48 66 Curvilinear 3.17 chicks 3.4 chicks 0.23 chicks  
Corn Bunting 48 14 Curvilinear 3.3 chicks 3.55 chicks 0.25 chicks Small sample
Willow Warbler 48 151 Linear increase 5.12 chicks 5.38 chicks 0.26 chicks  
Merlin 48 58 Linear increase 3.55 chicks 3.81 chicks 0.26 chicks  
Dipper 48 160 Curvilinear 3.43 chicks 3.74 chicks 0.31 chicks  
Tree Sparrow 48 468 Curvilinear 3.79 chicks 4.13 chicks 0.34 chicks  
Little Owl 48 53 Linear increase 2.52 chicks 2.89 chicks 0.37 chicks  
Redstart 48 98 Curvilinear 5.1 chicks 5.55 chicks 0.45 chicks  
Starling 48 238 Linear increase 3.25 chicks 3.71 chicks 0.46 chicks  
Jay 48 11 Linear increase 3.4 chicks 3.99 chicks 0.59 chicks Small sample
Wren 48 130 Linear increase 3.75 chicks 4.52 chicks 0.77 chicks  
Nuthatch 48 86 Linear increase 4.92 chicks 5.8 chicks 0.88 chicks  

3. Table of significant trends in Daily failure rate (eggs) measured between 1967-2015

Species Period
(yrs)
Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Cuckoo 48 14 Linear decline 0.0694 nests/day 0.0263 nests/day -0.0431 nests/day Small sample
Woodlark 48 26 Curvilinear 0.0687 nests/day 0.0344 nests/day -0.0343 nests/day Small sample
Cirl Bunting 48 15 Curvilinear 0.0416 nests/day 0.0138 nests/day -0.0278 nests/day Small sample
Long-tailed Tit 48 64 Curvilinear 0.0391 nests/day 0.0121 nests/day -0.027 nests/day  
Dipper 48 121 Curvilinear 0.0312 nests/day 0.0047 nests/day -0.0265 nests/day  
Redshank 48 29 Curvilinear 0.0459 nests/day 0.0202 nests/day -0.0257 nests/day Small sample
Magpie 48 48 Linear decline 0.0272 nests/day 0.002 nests/day -0.0252 nests/day  
Sand Martin 48 68 Curvilinear 0.0284 nests/day 0.0077 nests/day -0.0207 nests/day  
Yellowhammer 48 62 Curvilinear 0.0513 nests/day 0.0313 nests/day -0.02 nests/day  
Snipe 48 13 Linear decline 0.0319 nests/day 0.0127 nests/day -0.0192 nests/day Small sample
Wheatear 48 16 Linear decline 0.0215 nests/day 0.0044 nests/day -0.0171 nests/day Small sample
Carrion Crow 48 47 Curvilinear 0.0209 nests/day 0.0046 nests/day -0.0163 nests/day Includes Hooded Crow
Woodpigeon 48 110 Curvilinear 0.0461 nests/day 0.0299 nests/day -0.0162 nests/day  
Stock Dove 48 125 Curvilinear 0.0189 nests/day 0.0065 nests/day -0.0124 nests/day  
Pied Wagtail 48 91 Linear decline 0.018 nests/day 0.0067 nests/day -0.0113 nests/day  
Robin 48 233 Curvilinear 0.0249 nests/day 0.0143 nests/day -0.0106 nests/day  
Wood Warbler 48 26 Curvilinear 0.0239 nests/day 0.0143 nests/day -0.0096 nests/day Small sample
Tawny Owl 48 68 Curvilinear 0.0121 nests/day 0.0025 nests/day -0.0096 nests/day Nocturnal species
Starling 48 123 Linear decline 0.0111 nests/day 0.0024 nests/day -0.0087 nests/day  
Buzzard 48 30 Linear decline 0.0088 nests/day 0.0004 nests/day -0.0084 nests/day Small sample
Grey Wagtail 48 59 Linear decline 0.0176 nests/day 0.0095 nests/day -0.0081 nests/day  
Barn Owl 48 35 Linear decline 0.0081 nests/day 0.0004 nests/day -0.0077 nests/day  
Great Crested Grebe 48 23 Curvilinear 0.0272 nests/day 0.0195 nests/day -0.0077 nests/day Small sample
House Sparrow 48 121 Linear decline 0.011 nests/day 0.0036 nests/day -0.0074 nests/day  
Redstart 48 84 Curvilinear 0.0157 nests/day 0.0086 nests/day -0.0071 nests/day  
Nuthatch 48 65 Linear decline 0.009 nests/day 0.002 nests/day -0.007 nests/day  
Kestrel 48 44 Curvilinear 0.008 nests/day 0.0011 nests/day -0.0069 nests/day  
Tree Pipit 48 15 Curvilinear 0.0464 nests/day 0.0396 nests/day -0.0068 nests/day Small sample
Marsh Tit 48 21 Linear decline 0.0075 nests/day 0.001 nests/day -0.0065 nests/day Small sample
Jackdaw 48 77 Curvilinear 0.0088 nests/day 0.0029 nests/day -0.0059 nests/day  
Merlin 48 23 Linear decline 0.0073 nests/day 0.0015 nests/day -0.0058 nests/day Small sample
Wren 48 143 Linear decline 0.0181 nests/day 0.0126 nests/day -0.0055 nests/day  
Tree Sparrow 48 466 Linear decline 0.0082 nests/day 0.0032 nests/day -0.005 nests/day  
Peregrine 48 26 Linear decline 0.0073 nests/day 0.0026 nests/day -0.0047 nests/day Small sample
Sparrowhawk 48 30 Linear decline 0.0044 nests/day 0.0006 nests/day -0.0038 nests/day  
Treecreeper 48 23 Curvilinear 0.0244 nests/day 0.0208 nests/day -0.0036 nests/day Small sample
Great Tit 48 801 Curvilinear 0.006 nests/day 0.0026 nests/day -0.0034 nests/day  
Pied Flycatcher 48 485 Curvilinear 0.0063 nests/day 0.0031 nests/day -0.0032 nests/day  
Spotted Flycatcher 48 113 Curvilinear 0.0178 nests/day 0.0151 nests/day -0.0027 nests/day  
Coal Tit 48 56 Linear decline 0.0043 nests/day 0.0018 nests/day -0.0025 nests/day  
Raven 48 23 Curvilinear 0.0025 nests/day 0.0002 nests/day -0.0023 nests/day Small sample
Blue Tit 48 1006 Curvilinear 0.0045 nests/day 0.0025 nests/day -0.002 nests/day  
Greenfinch 48 117 Curvilinear 0.0274 nests/day 0.026 nests/day -0.0014 nests/day  
Chiffchaff 48 55 Curvilinear 0.022 nests/day 0.0212 nests/day -0.0008 nests/day  
Collared Dove 48 62 Curvilinear 0.0323 nests/day 0.0319 nests/day -0.0004 nests/day  
Dunnock 48 162 Curvilinear 0.0259 nests/day 0.0264 nests/day 0.0005 nests/day  
Grey Heron 48 17 Curvilinear 0.0001 nests/day 0.0008 nests/day 0.0007 nests/day Small sample
Curlew 48 21 Curvilinear 0.0284 nests/day 0.0302 nests/day 0.0018 nests/day Small sample
Reed Warbler 48 214 Curvilinear 0.0186 nests/day 0.0204 nests/day 0.0018 nests/day  
Sedge Warbler 48 40 Curvilinear 0.0154 nests/day 0.0203 nests/day 0.0049 nests/day  
Linnet 48 176 Linear increase 0.0184 nests/day 0.0238 nests/day 0.0054 nests/day  
Meadow Pipit 48 53 Curvilinear 0.0218 nests/day 0.0287 nests/day 0.0069 nests/day  
Little Grebe 48 14 Curvilinear 0.0355 nests/day 0.0428 nests/day 0.0073 nests/day Small sample
Whitethroat 48 45 Curvilinear 0.0103 nests/day 0.0178 nests/day 0.0075 nests/day  
Garden Warbler 48 24 Curvilinear 0.018 nests/day 0.0272 nests/day 0.0092 nests/day Small sample
Goldfinch 48 40 Linear increase 0.0191 nests/day 0.0283 nests/day 0.0092 nests/day  
Willow Warbler 48 69 Linear increase 0.009 nests/day 0.0192 nests/day 0.0102 nests/day  
Ringed Plover 48 128 Linear increase 0.022 nests/day 0.034 nests/day 0.012 nests/day  
Moorhen 48 139 Linear increase 0.0107 nests/day 0.0235 nests/day 0.0128 nests/day  
Lapwing 48 208 Curvilinear 0.0163 nests/day 0.0291 nests/day 0.0128 nests/day  
Skylark 48 44 Curvilinear 0.0377 nests/day 0.0506 nests/day 0.0129 nests/day  
Chaffinch 48 187 Curvilinear 0.0298 nests/day 0.0437 nests/day 0.0139 nests/day  
Nightjar 48 26 Linear increase 0.0162 nests/day 0.0308 nests/day 0.0146 nests/day Small sample
Blackbird 48 334 Curvilinear 0.0252 nests/day 0.0398 nests/day 0.0146 nests/day  
Reed Bunting 48 52 Linear increase 0.0076 nests/day 0.0258 nests/day 0.0182 nests/day  
Oystercatcher 48 174 Linear increase 0.0122 nests/day 0.0329 nests/day 0.0207 nests/day  
Whinchat 48 20 Linear increase 0.0058 nests/day 0.0315 nests/day 0.0257 nests/day Small sample

4. Table of significant trends in Daily failure rate (chicks) measured between 1967-2015

Species Period
(yrs)
Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Sand Martin 48 96 Curvilinear 0.0271 nests/day 0.0011 nests/day -0.026 nests/day  
Magpie 48 46 Curvilinear 0.0221 nests/day 0.0029 nests/day -0.0192 nests/day  
Skylark 48 53 Linear decline 0.0477 nests/day 0.0303 nests/day -0.0174 nests/day  
Grey Wagtail 48 58 Linear decline 0.0217 nests/day 0.0073 nests/day -0.0144 nests/day  
Reed Warbler 48 165 Curvilinear 0.0217 nests/day 0.0084 nests/day -0.0133 nests/day  
Jackdaw 48 69 Curvilinear 0.014 nests/day 0.0035 nests/day -0.0105 nests/day  
Yellowhammer 48 50 Linear decline 0.0382 nests/day 0.028 nests/day -0.0102 nests/day  
Blackbird 48 271 Linear decline 0.0281 nests/day 0.0195 nests/day -0.0086 nests/day  
Meadow Pipit 48 75 Curvilinear 0.0343 nests/day 0.0259 nests/day -0.0084 nests/day  
Tree Sparrow 48 324 Linear decline 0.0141 nests/day 0.0058 nests/day -0.0083 nests/day  
Merlin 48 29 Linear decline 0.0099 nests/day 0.0018 nests/day -0.0081 nests/day Small sample
Corn Bunting 48 15 Curvilinear 0.0513 nests/day 0.0432 nests/day -0.0081 nests/day Small sample
Redstart 48 61 Linear decline 0.0115 nests/day 0.0036 nests/day -0.0079 nests/day  
House Sparrow 48 121 Curvilinear 0.0161 nests/day 0.0085 nests/day -0.0076 nests/day  
Carrion Crow 48 40 Linear decline 0.007 nests/day 0.0011 nests/day -0.0059 nests/day Includes Hooded Crow
Collared Dove 48 55 Curvilinear 0.0222 nests/day 0.018 nests/day -0.0042 nests/day  
Barn Owl 48 164 Curvilinear 0.0034 nests/day 0.0003 nests/day -0.0031 nests/day  
Starling 48 138 Curvilinear 0.0069 nests/day 0.0039 nests/day -0.003 nests/day  
Tawny Owl 48 106 Curvilinear 0.0035 nests/day 0.0008 nests/day -0.0027 nests/day Nocturnal species
Nuthatch 48 71 Linear decline 0.0043 nests/day 0.0021 nests/day -0.0022 nests/day  
Woodpigeon 48 88 Curvilinear 0.0219 nests/day 0.0223 nests/day 0.0004 nests/day  
Stonechat 48 73 Curvilinear 0.0175 nests/day 0.0186 nests/day 0.0011 nests/day  
Swallow 48 557 Linear increase 0.0032 nests/day 0.0043 nests/day 0.0011 nests/day  
Cuckoo 48 16 Curvilinear 0.0263 nests/day 0.0275 nests/day 0.0012 nests/day Small sample
Spotted Flycatcher 48 102 Curvilinear 0.0086 nests/day 0.01 nests/day 0.0014 nests/day  
Whinchat 48 32 Curvilinear 0.0253 nests/day 0.027 nests/day 0.0017 nests/day  
Treecreeper 48 22 Curvilinear 0.015 nests/day 0.0168 nests/day 0.0018 nests/day Small sample
Moorhen 48 51 Linear increase 0.0003 nests/day 0.0026 nests/day 0.0023 nests/day  
Pied Flycatcher 48 404 Curvilinear 0.0029 nests/day 0.0058 nests/day 0.0029 nests/day  
Chaffinch 48 127 Curvilinear 0.0299 nests/day 0.0328 nests/day 0.0029 nests/day  
Wren 48 98 Linear increase 0.0074 nests/day 0.0106 nests/day 0.0032 nests/day  
Nightjar 48 24 Curvilinear 0.0018 nests/day 0.0085 nests/day 0.0067 nests/day Small sample
Linnet 48 126 Linear increase 0.0153 nests/day 0.0231 nests/day 0.0078 nests/day  
Long-tailed Tit 48 43 Linear increase 0.0076 nests/day 0.0208 nests/day 0.0132 nests/day  
Turtle Dove 48 11 Curvilinear 0.0215 nests/day 0.0349 nests/day 0.0134 nests/day Small sample
Garden Warbler 48 20 Linear increase 0.0113 nests/day 0.0264 nests/day 0.0151 nests/day Small sample
Wood Warbler 48 33 Curvilinear 0.0236 nests/day 0.0452 nests/day 0.0216 nests/day  
Cirl Bunting 48 21 Curvilinear 0.0607 nests/day 0.1101 nests/day 0.0494 nests/day Small sample