<abstract xmlns="http://www.w3.org/1999/xhtml"> In 2008, a coordinated census of Jackdaw Corvus monedula was carried out to assess breeding population, distribution and nest site selection in Slovenia. Data collection continued for unsurveyed areas in the 2009-2011 period, including information on former colonies and threats. A total of 663-794 Jackdaw pairs were recorded at 86 sites, while total Slovene breeding population was estimated to be in the range of 700-900 pairs. Over one third of pairs were recorded in Central Slovenia, notably the largest city Ljubljana (20.8%), followed by almost a quarter in the Podravje region. Most colonies numbered between 2 and 5 pairs, the largest occupying the Bežigrad district of Ljubljana (82-87 pairs). Large-scale density in geographically more or less uniform areas ranged from 3.65 pairs/10 km2 in the Sava plain to 0.15 pairs/10 km2 in mostly mountainous area in northern Slovenia. The majority of Jackdaws selected buildings for nesting (82.2% of pairs), while nesting in trees occurred less frequently (14.7%) and was almost entirely confined to the two easternmost regions of Slovenia. Nesting in cliffs was recorded at just two sites in Slovene Istria (3.1%). Average colony size differed significantly in relation to nest site type, with colonies in rock walls being on average the largest (median = 9.5 pairs), followed by colonies on buildings (6) and those in trees the smallest (3). Among pairs nesting on buildings, multi-storey residential buildings predominated (34.2%). A substantial percentage of population nested also on churches and tower blocks (14.4% and 13.5%, respectively). The highest percentage of pairs utilised holes in roofs (26.9%), followed by eaves (18.0%) and chimney pots (14.7%). Tree-nesting pairs occupied mostly small woods situated in open agricultural landscape. The most commonly used tree species was Beech Fagus sylvatica (53.1% of pairs) which hosted 14 of the total 16 forest colonies. For Jackdaws nesting in urban parks and avenues, plane trees Platanus sp. were the most important (30.6% of pairs). Their population stronghold was in lowlands, with 88.1% of pairs recorded at elevations under 400 m and the highest living colony in Slovenia at 578 m a.s.l. Jackdaws occurred on at least 54 specific sites in the past but became extinct there or declined severely by the time of this study. A minimum of 217-254 pairs were estimated lost at these sites, constituting a decline of 24% in c. 10-20 years. According to the IUCN criteria, Jackdaw would qualify as Vulnerable (VU) on the Red List of Slovenia. The commonest known cause of extinction/decline is renovation of buildings, a threat that is projected to escalate in the near future.</abstract>

In 2008, a coordinated census of Jackdaw Corvus monedula was carried out to assess breeding population, distribution and nest site selection in Slovenia. Data collection continued for unsurveyed areas in the 2009-2011 period, including information on former colonies and threats. A total of 663-794 Jackdaw pairs were recorded at 86 sites, while total Slovene breeding population was estimated to be in the range of 700-900 pairs. Over one third of pairs were recorded in Central Slovenia, notably the largest city Ljubljana (20.8%), followed by almost a quarter in the Podravje region. Most colonies numbered between 2 and 5 pairs, the largest occupying the Bežigrad district of Ljubljana (82-87 pairs). Large-scale density in geographically more or less uniform areas ranged from 3.65 pairs/10 km2 in the Sava plain to 0.15 pairs/10 km2 in mostly mountainous area in northern Slovenia. The majority of Jackdaws selected buildings for nesting (82.2% of pairs), while nesting in trees occurred less frequently (14.7%) and was almost entirely confined to the two easternmost regions of Slovenia. Nesting in cliffs was recorded at just two sites in Slovene Istria (3.1%). Average colony size differed significantly in relation to nest site type, with colonies in rock walls being on average the largest (median = 9.5 pairs), followed by colonies on buildings (6) and those in trees the smallest (3). Among pairs nesting on buildings, multi-storey residential buildings predominated (34.2%). A substantial percentage of population nested also on churches and tower blocks (14.4% and 13.5%, respectively). The highest percentage of pairs utilised holes in roofs (26.9%), followed by eaves (18.0%) and chimney pots (14.7%). Tree-nesting pairs occupied mostly small woods situated in open agricultural landscape. The most commonly used tree species was Beech Fagus sylvatica (53.1% of pairs) which hosted 14 of the total 16 forest colonies. For Jackdaws nesting in urban parks and avenues, plane trees Platanus sp. were the most important (30.6% of pairs). Their population stronghold was in lowlands, with 88.1% of pairs recorded at elevations under 400 m and the highest living colony in Slovenia at 578 m a.s.l. Jackdaws occurred on at least 54 specific sites in the past but became extinct there or declined severely by the time of this study. A minimum of 217-254 pairs were estimated lost at these sites, constituting a decline of 24% in c. 10-20 years. According to the IUCN criteria, Jackdaw would qualify as Vulnerable (VU) on the Red List of Slovenia. The commonest known cause of extinction/decline is renovation of buildings, a threat that is projected to escalate in the near future.

Numbers, distribution and nest site characteristics of Jackdaw Corvus monedula in Slovenia and its conservation status

Društvo za opazovanje in proučevanje ptic Slovenije, Kamenškova 18, SI–2000 Maribor,

Acrocephalus

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

In 2008, a coordinated census of Jackdaw Corvus monedula was carried out to assess breeding population, distribution and nest site selection in Slovenia. Data...

Numbers, distribution and nest site characteristics of Jackdaw Corvus monedula in Slovenia and its conservation status

Publié en ligne: 21 mars 2017

Pages: 123 - 150

Reçu: 11 juin 2016

Accepté: 29 janv. 2017

DOI: https://doi.org/10.1515/acro-2016-0007

Mots clés
Jackdaw, Corvus monedula, Slovenia, census, nest-site selection, conservation

© by Luka Božič

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Numbers, distribution and nest site characteristics of Jackdaw Corvus monedula in Slovenia and its conservation status

Publié en ligne: 21 mars 2017

Pages: 123 - 150

Reçu: 11 juin 2016

Accepté: 29 janv. 2017

DOI: https://doi.org/10.1515/acro-2016-0007

Mots clésJackdaw, Corvus monedula, Slovenia, census, nest-site selection, conservation

© by Luka Božič

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Mots clés
Jackdaw, Corvus monedula, Slovenia, census, nest-site selection, conservation