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Trends of the Common Forest Birds in Latvia

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11.12.2018 • Organised by the • 40 – 50 routes Latvian Latvian Ornithological counted annually society breeding • Volunteer based bird • Started in 2005 • A part of the Biodiversity counts monitoring programme – Funded by the Nature Trends of the common Conservation forest birds in Latvia Agency Ainārs Auniņš Transects Systematic + random position of routes • Predefined layout of «monitoring squares» • Observer chooses desirable square • Location of the route whithin a square chosen randomly Route length 4 km: 2 transect lines 2km long 1 km apart; 8 sections N Section Section maps length – 500 m • 8 sections Distance • 500 m Counting • All belts and in 3 • 0 – 25 m from transect observations • 25 – 100 m from transect counting distance • >100 m from transect mapped belts • Field form times filled for each 4 times • 0 20 III – 1 IV section • 1 20 IV – 30 IV per • 2 10 V – 25 V season • 3 5 VI – 20 VI 1 11.12.2018 Breeding bird monitoring routes (2005 – 2018) • Annual population indices > 100 bird species • Annual population trends > 100 Outputs bird species • Annual Farmland Bird Index and Forest bird index • Population estimates Trend classification principles • TRIM (TRends and Trend Indices for Monitoring data) Strong increase analysis – ln countij ~ sitei + yearj – Imputation of Moderate increase missing data – Population indices – Linear trend Stable (multicative slope; S) – Confidence Moderate decline interval CI = S ± 1.96 SE – Trend Steep decline classification Uncertain 0.85 0.90 0.95 1.00 1.05 1.10 1.15 Confidence interval of the trend Population trends Trends by ecosysytems 2005 - 2018 2013 - 2018 All birds Forest birds Trend 2005 - 2013 - 2005 - 2013 - 2018 2018 2018 2018 Steep decline 2 8 2 1 Moderate decline 11 19 5 10 Africa Africa S Asia S Asia Stable Europe Europe 28 4 14 2 Resident Resident Moderate 28 7 12 5 increase Strong increase 0 0 0 0 Uncertain 37 68 21 36 Total 106 106 54 54 2 11.12.2018 Specialists vs non-specialists • Migration strategy • GLM Forest • Food • Slope ~ … 2005 – 2018 2013 - 2018 • Edge • Weight: 1/SE of birds: preference/avoidance trend slope trends by • Specialist/non- specialist (EBCC) • ALL PREDICTORS traits • Nesting strategy UNINFORMATIVE – Hole/open nesting ΔAIC < 2 – Nest height – Clutch size • Species used: – Northern Goshawk Accipiter gentilis – Eurasian Sparrowhawk Accipiter nisus Forest bird index Food – Hazel Grouse Bonasa bonasia – Grey-headed Woodpecker Picus canus – Black Woodpecker Dryocopus martius 2005 – 2018 2013 - 2018 – Lesser-spotted Woodpecker Dryobates minor – White-backed Woodpecker Dendrocopos leucotos – Three-toed Woodpecker Picoides tridactylus – Mistle Thrush Turdus viscivorus – Wood Warbler Phylloscopus sibilatrix – Goldcrest Regulus regulus – Red-breasted Flycatcher Ficedula parva – Pied Flycatcher Ficedula hypoleucos Granivores Granivores – Long-tailed Tit Aegithalos caudatus Insectivores Insectivores Raptors Raptors – Marsh Tit Poecile palustris Soil invertebrates Soil invertebrates – Willow Tit Poecile montanus Water invertebrates Water invertebrates • Geometric mean index Omnivores Omnivores – Crested Tit Lophophanes cristatus • No species weighting – Coal Tit Periparus ater – Eurasian treecreeper Certhia familiaris – Spotted nutcracker Nucifraga caryocatactes – Common crossbill Loxia curvirostra – Eurasian bullfinch Pyrrhula pyrrhula – Hawfinch Coccothraustes coccothraustes Great-spotted Woodpecker White-backed Woodpecker Dendrocopos major Dendrocopos leucotos Crested Tit Lophophanes cristatus Coal Tit Periparus ater Woodpeckers Tits Black Woodpecker Lesser-spotted Woodpecker Middle-spotted Woodpecker Dryocopus martius Dryobates minor Leiopicus medius Willow Tit Poecile montanus Great Tit Parus major Grey-headed Woodpecker Three-toed Woodpecker Picus canus Picoides tridactylus Marsh Tit Poecile palustris Eurasian blue tit Cyanistes caeruleus 3 11.12.2018 Eurasian Hobby Falco subbuteo Bird of prey Hazel Grouse Bonasa bonasia Common Buzzard Buteo buteo Eurasian Sparrowhawk Accipiter nisus EBCC 2005 - 2015: 0.966 ± 0.0107 Lesser-spotted Eagle Clanga pomarina Northern Goshawk Accipiter gentilis 2005-2018: steep decline S = 0.8864 ± 0.0238 2013-2018: uncertain S= 0.9939 ± 0.1036 9 Redwing Turdus iliacus Redwing Turdus iliacus 1961 - 1990 2070 - 2099 EBCC 2005 - 2015: 0.968 ± 0.0033 2005-2018: steep decline S = 0.8873 ± 0.0232 2013-2018: steep decline S= 0.7116 ± 0.0742 Redwing Turdus iliacus Summary 1980 - 1984 • The forest species are not performing overall worse than other ecosystem species • The 2 steep declining birds are linked to forests • Species 5-year trends are worse than 13-year trends • Variance in trend slopes is 2000 - 2004 2013 - 2017 larger in forest species occurring all-year round • The tested traits do not explain variance in the trends of forest species • Forest bird index has been overall stable with non- significant declining trend 4 11.12.2018 Thank you! Special thanks to the many volunteer birdwatchers collecting the data! 5.
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