Appendix 1. Land-Use Metrics Derived Through FRAGSTATS Describing Forest Fragmentation

Appendix 1. Land-use metrics derived through FRAGSTATS describing forest fragmentation at class- and landscapea-level.

Class level variablesb / Description
CA / Class area (ha).
NP / Number of class patches.
TE / Sum of perimeter of class patches (m).
SHAPE / Average of total length of patch edge to the minimum possible perimeter for a maximally compact patch ratios, computed for same class type.
PARA / Ratio of the patch perimeter (m) to area (m2).[pij =intTrue+intBack+extTrue+extBack+extLike]
COREd / Average of areas (m2) within the patches that are further than the specified depth-of-edge distance from the patch perimeter divided by 10,000 (ha).
PROX / Average of all patches within the buffer, of the ratio of patch area (m2) to nearest neighbor edge-to-edge distance (m).
MESH / Sum of all same class patches area squared, divided by the total landscape area (m2), divided by 10,000 (ha).
Landscapelevel
variablesc / Description
LAND_AREA / Forest area (ha).
LAND_NP / Number of patches.
LAND_TE / Sum of perimeters of all patches (m).
LAND_SHAPE / Average of total length of patch edge to the minimum possible perimeter for a maximally compact patch ratios, computed for all patches.
LAND_PARA / Ratio of the patch perimeter (m) to area (m2).[pij =intTrue+intBack+extTrue+extBack+extLike]
LAND_COREd / Average of areas (m2) within the patches that are further than the specified depth-of-edge distance from the patch perimeter divided by 10,000 (ha).
LAND_PROX / Sum of patch area (m2) divided by the nearest edge-to-edge distance squared (m2) between the patch and the focal patch of all forest patches whose edges are within a specified distance (m) of the focal patch.
LAND_MESH / Sum of all patches area squared, divided by the total landscape area (m2), divided by 10,000 (ha).
aVariable descriptions from McGarigal et al. (2002).
bIncludes only the specified focal habitat type within the landscape. Calculated for the following habitat types: oak woods, black locust woods and woods of other trees.
cIncludes all habitat types within 1000 m radius surrounding each sampling point.
dEdge depth was set at 50 m for birds based on the range of edge effects for different taxa presented in Paton (1994)

Appendix 2. Results of PCA carried out on eight habitat structure variables. The highest factor loadings are in bold type.

Variables / Factor loadings
PC1 / PC2 / PC3
Number of trees per hectar (NT/ha) / -.707 / .303 / .106
Total biomass volume (m3) (BV) / .717 / -.083 / .027
Shrub density (SD) / .040 / .001 / .993
Mean tree height (m) (TH) / .942 / -.099 / -.029
Coefficient of variation of tree height (%) (CVH) / .061 / .897 / -.093
Mean tree diameter (cm) (DBH) / .929 / .133 / -.015
Coefficient of variation of tree diameter (%) (CVD) / .179 / .894 / .056
Canopy height (m) (CH) / .923 / .032 / .056
Percentage variance explained / 45.66 / 21.62 / 12.68

Appendix 3

List of species, frequencies of occurrence and results of GAMs regarding presence/absence in relation to habitat structure predictors (PCA scoresof habitat structure variables) in winter. The classification of species as generalists (G) or specialists (S) is not applied to species with a frequency of occurrence < 0.5 (#)

Common name /
Scientific name / Frequency of occurrence (%) / Predictor / Estimate / SE / p /
Guild
Robin / Erithacus rubecula / 67.5 / G
Great tit / Parus major / 60.5 / G
Blackbird / Turdus merula / 49 / G
Blue tit / Parus caeruleus / 48 / PC1 / 0.76491 / 0.16503 / *** / S
Marsh tit / Parus palustris / 47 / G
Wren / Troglodytes troglodytes / 45.5 / PC1 / 0.3035 / 0.1459 / * / S
Chaffinch / Fringilla coelebs / 44.5 / G
Great spotted woodpecker / Picoides major / 38 / PC1 / 0.5394 / 0.1566 / *** / S
Jay / Garrulus glandarius / 33.5 / PC1 / 0.4409 / 0.1566 / ** / S
Nuthatch / Sitta europaea / 33 / PC1 / 0.6835 / 0.1673 / *** / S
Long tailed tit / Aegithalos caudatus / 27 / G
Goldcrest / Regulus regulus / 23.5 / G
Short-toed treecreeper / Certhia brachydactyla / 18.5 / PC1 / 0.5003 / 0.1894 / ** / S
Lesser spotted woodpecker / Picoides minor / 17.5 / PC1 / 0.6308 / 0.1986 / ** / S
Hawfinch / Coccothraustes coccothraustes / 12 / PC1 / 0.6994 / 0.2332 / ** / S
Green woodpecker / Picus viridis / 10 / PC1 / 0.6283 / 0.2476 / <0,1 / S
Brambling / Fringilla montifringilla / 7 / PC3 / 0.5729 / 0.2631 / <0,1 / G
Song trush / Turdus philomelos / 6.5 / PC1 / 0.7976 / 0.31 / * / S
Fieldfare / Turdus pilaris / 6.5 / G
Chiffchaff / Phylloscopus collybita / 4.5 / G
Blackcap / Sylvia atricapilla / 4 / G
Mistle Thrush / Turdus viscivorus / 2 / G
Firecrest / Regulus ignicapillus / 1.5 / G
Wood pigeon / Columba palumbus / 1.5 / G
Redwing / Turdus iliacus / 1 / G
Coal Tit / Parus ater / 1 / G
Hooded crow / Corvus corone / 1 / G
Siskin / Carduelis spinus / 1 / G
European Goldfinch / Carduelis carduelis / 1 / G
Magpie / Pica pica / 0.5 / #
Eurasian Bullfinch / Pyrrhula pyrrhula / 0.5 / #
Rock Bunting / Emberiza cia / 0.5 / #

Appendix 4

List of species, frequencies of occurrence and results of GAMs regarding presence/absence in relation to habitat structure predictors (PCA scoresof habitat structure variables) in spring. The classification of species as generalists (G) or specialists (S) is not applied to species with a frequency of occurrence < 0.5 (*)

Common name / Scientific name / Frequency of occurrence (%) / Predictor / Estimate / SE / p / Guild
Blackbird / Turdus merula / 65.5 / PC1 / 0.5182 / 0.1619 / ** / S
Great tit / Parus major / 58 / G
Robin / Erithacus rubecula / 57 / G
Blackcap / Sylvia atricapilla / 56 / G
Great spotted woodpecker / Picoides major / 33 / PC1 / 0.7396 / 0.1703 / *** / S
Blue tit / Parus caeruleus / 32 / PC1 / 0.8733 / 0.1799 / *** / S
Jay / Garrulus glandarius / 31 / PC1 / 0.337 / 0.1572 / * / S
Wood pigeon / Columba palumbus / 26 / G
Chaffinch / Fringilla coelebs / 25 / PC1 / 0.4897 / 0.1709 / ** / S
Wren / Troglodytes troglodytes / 21 / PC1 / 0.583 / 0.1844 / ** / S
Nuthatch / Sitta europaea / 21 / PC1 / 1.2091 / 0.2271 / *** / S
PC3 / -0.396 / 0.1934 / *
Song trush / Turdus philomelos / 16 / PC1 / 0.7411 / 0.2134 / *** / S
Long tailed tit / Aegithalos caudatus / 16 / G
Marsh tit / Parus palustris / 16 / G
Chiffchaff / Phylloscopus collybita / 12 / PC3 / -0.8375 / 0.2842 / ** / S
European Turtle-Dove / Streptopelia turtur / 12 / G
Green woodpecker / Picus viridis / 7.5 / G
Short-toed treecreeper / Certhia brachydactyla / 6.5 / PC1 / 0.5224 / 0.2938 / <0.1 / S
Eurasian Golden-Oriole / Oriolus oriolus / 4.5 / G
Cirl Bunting / Emberiza cirlus / 4.5 / G
Nightingale / Luscinia megarhynchos / 4 / G
Lesser spotted woodpecker / Picoides minor / 4 / PC1 / 0.9742 / 0.405 / * / S
Common Cuckoo / Cuculus canorus / 4 / PC1 / 0.9437 / 0.4016 / * / S
Common Starling / Sturnus vulgaris / 3.5 / G
Hawfinch / Coccothraustes coccothraustes / 3.5 / PC1 / 1.2994 / 0.478 / ** / S
Wood Warbler / Phylloscopus sibilatrix / 1.5 / G
Hooded crow / Corvus corone / 1.5 / G
Magpie / Pica pica / 1.5 / G
Common Pheasant / Phasianus colchicus / 1.5 / G
Wryneck / Jinx torquilla / 0.5 / #
Spotted Flycatcher / Muscicapa striata / 0.5 / #
European Greenfinch / Carduelis chloris / 0.5 / #
Northern Bobwhite / Colinus virginianus / 0.5 / #