Impact of Nest Predators on Migratory Woodpigeons Columba palumbus in Central Europe — Breeding Densities and Nesting Success in Urban Versus Natural Habitats

AbstractAmong hypotheses explaining nest-site selection, the potential-prey-site hypothesis predicts that birds place nests in areas with many potential nest sites, while the nest-concealment hypothesis predicts nest placement in sites with greater surrounding vegetation. We examined these hypotheses by comparing habitat attributes between Dusky Flycatcher (Empidonax oberholseri) nest sites and random sites, successful and unsuccessful nests, and nests depredated by birds versus mammals. Nesting success was 28% (n = 167), and predation was the most important cause of nest failure (96%) during the study (1998–2000) at our site in northeastern California. We identified 28 nest predators using surveillance cameras. Sciurid mammals were the most common predators (17 of 28, 61%), with Cooper's Hawks (Accipiter cooperii; 25%), small owls (11%), and Steller's Jays (Cyanocitta stelleri; 3%) accounting for the rest. Raptors preyed on nestlings more frequently than on eggs, while small mammals depredated nestlings and eggs in proportion to their availability. Dusky Flycatchers nested in larger shrub patches with greater shrub cover than at random sites, supporting the potential-prey-site hypothesis. Successful nests were in larger shrub patches surrounded by fewer seedlings and saplings compared to depredated nests, providing equivocal support for the potential-prey-site hypothesis. Nests depredated by birds were less concealed, located in smaller shrub patches, surrounded by fewer seedlings and saplings, and were closer to the shrub edge than nests depredated by mammals. Our results, strengthened by identification of nest predators, suggest that differences in search strategies among predators may constrain the ability of Dusky Flycatchers to optimize nest-site selection.Depredadores de Nidos, Selección de Sitios de Anidación y Éxito de Anidación de Empidonax oberholseri en un Bosque Manejado de Pino PonderosaResumen. Entre las hipótesis que explican la selección de sitios de anidación, la de “presa potencial” predice que las aves ubican sus nidos en lugares con muchos sitios de anidación, mientras que la de “ocultación del nido” predice la ubicación de nidos en sitios con mayor vegetación circundante. Nosotros examinamos estas hipótesis comparando características del hábitat entre sitios de anidación del mosquerito Empidonax oberholseri y sitios aleatorios, entre nidos exitosos y no exitosos, y entre nidos depredados por aves y por mamíferos. Entre 1998 y 2000 en un área del noreste de California, el éxito de anidación fue del 28% (n = 167) y la depredación fue la causa más importante del fracaso de los nidos (96%). Identificamos 28 depredadores de nidos utilizando cámaras. Los mamíferos sciúridos fueron los depredadores más comunes (17 de 28, 61%), mientras que los demás nidos fueron depredados por Accipter cooperii (25%), búhos pequeños (11%) y Cyanocitta stelleri (3%). Las aves rapaces se alimentaron con mayor frecuencia de pichones que de huevos, mientras que los mamíferos pequeños depredaron pichones y huevos en proporción a su disponibilidad. Los mosqueritos anidaron en parches con mayor cobertura de arbustos que sitios aleatorios, lo cual apoya la hipótesis de presa potencial. Los nidos exitosos se ubicaron en parches de arbustos más grandes rodeados por menos plántulas y renovales en comparación con los nidos depredados, lo que apoya equívocamente la hipótesis de presa potencial. Los nidos depredados por aves estuvieron menos ocultos, ubicados en parches de arbustos más pequeños, rodeados por menos plántulas y renovales, y estuvieron más cerca del borde del matorral que los nidos depredados por mamíferos. Nuestros resultados, fortalecidos por la identificación de los depredadores, sugieren que las diferencias en las estrategias de búsqueda entre depredadores pueden limitar la habilidad de los mosqueritos para optimizar la selección de sitios de anidación.

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Effects of invasive plant species on species diversity: implications on ruderal vegetation in Bratislava City, Slovakia, Central Europe

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.3621 ◽

2019 ◽

Vol 88 (2) ◽

Cited By ~ 2

Author(s):

Alena Rendeková ◽

Karol Mičieta ◽

Michal Hrabovský ◽

Mariana Eliašová ◽

Ján Miškovic

Keyword(s):

Invasive Species ◽

Species Diversity ◽

Central Europe ◽

Invasive Plant ◽

Urban Ecosystem ◽

Ruderal Vegetation ◽

Natural Habitats ◽

Environmental Threats ◽

Negative Effect ◽

Invasive Taxa

Invasive species pose one of the most serious global environmental threats. Our study aimed to examine the correlation between the proportion of invasive alien taxa and species diversity of ruderal vegetation in the urban ecosystem of Bratislava, located in Central Europe. Ruderal habitats serve as the means of spread of invasive species to seminatural and natural habitats. Twenty-six invasive taxa were recorded among the ruderal vegetation of Bratislava. The majority of the recorded invasive species were neophytes, which came from North America and represent the Asteraceae family. Half of them were introduced accidentally, whereas the remaining species were introduced deliberately. Correlation and regression analyses showed that the proportion of invasive taxa has a negative effect on the species diversity of all the analyzed syntaxa in the ruderal vegetation of Bratislava.

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Avian Nesting Success in Forested Landscapes: Influence of Landscape Composition, Stand and Nest-Patch Microhabitat, and Biotic Interactions

The Auk ◽

10.1093/auk/118.4.1018 ◽

2001 ◽

Vol 118 (4) ◽

pp. 1018-1028 ◽

Cited By ~ 3

Author(s):

Amanda D. Rodewald ◽

Richard H. Yahner ◽

J. Brawn

Keyword(s):

Brood Parasitism ◽

Nest Survival ◽

Landscape Composition ◽

Nesting Success ◽

Habitat Characteristics ◽

Parasitism Rates ◽

Forested Landscapes ◽

Daily Nest Survival ◽

Landscape Types ◽

Nest Predators

AbstractAlthough area and isolation effects on avian communities in highly fragmented landscapes are well known, importance of landscape composition in more forested landscapes remains poorly understood. We determined if the type (agriculture and silviculture) and extent (percentage within 1 km radius) of disturbance within forested landscapes influenced avian nesting success, and then examined if differences in stand-level habitat structure, nest-patch microhabitat, distance of nests to habitat edges, brood parasitism rates, and nest-predator abundance were potential underlying mechanisms of observed associations between landscape composition and nesting success. We monitored active songbird nests (n = 341), surveyed Brown-headed Cowbirds (Molothrus ater) and nest predators, and measured stand-level and nest-patch microhabitat from May–July 1998 and 1999. Each of 10 study sites was located within contiguous mature forest in central Pennsylvania and contained either agricultural or silvicultural disturbances (n = 5 each). Sites of the two landscape types had similar ranges of disturbance within 1 km (21–55% for agriculture, 18–51% for silviculture). Daily nest survival for all species combined (94.0 ± 0.55 in agriculture and 96.9 ± 0.87 in silviculture) and midstory-canopy nesters (93.8 ± 0.97 in agriculture and 97.4 ± 0.75 in silviculture) were greater within forested landscapes disturbed by silviculture than by agriculture, but rates did not significantly differ between landscapes for ground nesters (92.2 ± 1.32 in agriculture and 94.6 ± 1.63 in silviculture) or understory nesters (95.4 ± 1.60 in agriculture and 95.0 ± 1.47 in silviculture). Nest survival was not significantly associated with disturbance extent. Rates of brood parasitism were low, with only 11% of nests containing cowbird eggs or young. Neither nest fate nor differences in daily nest survival between the two landscape types were explained by variation in brood parasitism rates, stand-level or nest-patch habitat characteristics, or distance of nests to edges. Instead, the lower nest success within forested landscapes disturbed by agriculture was best explained by greater abundances of some avian and small mammalian predators (American Crow [Corvus brachyrhynchos] and squirrels) in those landscapes in one or both years. Results suggest that landscape composition within forested landscapes significantly influences avian nesting success by altering interactions between nest predators and nesting birds.

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Genetic Structure and Relationships among Wild and Cultivated Grapevines from Central Europe and Part of the Western Balkan Peninsula

Genes ◽

10.3390/genes11090962 ◽

2020 ◽

Vol 11 (9) ◽

pp. 962

Author(s):

Goran Zdunić ◽

Katarina Lukšić ◽

Zora Annamaria Nagy ◽

Ana Mucalo ◽

Katarina Hančević ◽

...

Keyword(s):

Genetic Diversity ◽

Central Europe ◽

Balkan Peninsula ◽

Gene Pools ◽

Natural Habitats ◽

Central European ◽

Genetic Diversity And Structure ◽

Wild Grapevine ◽

Western Balkan Region ◽

Balkan Region

The genetic diversity and relationship between wild (Vitis vinifera L. subsp. sylvestris (Gmel.) Hegi and cultivated (V. vinifera L. subsp. vinifera) grapevine in the western Balkan region and Central Europe have not been studied together previously, although this area has a rich viticultural past. Here, we studied wild grapevine populations sampled from their natural habitats in several countries of the western Balkan region and Central Europe. Their genetic diversity and structure were compared to cultivars that are traditionally in use in this region. A sample set of 243 accessions was genotyped at 20 nuclear microsatellite loci, including 167 sylvestris and 76 diverse vinifera cultivars. The genetic diversity of the wild grapevines was lower than that of cultivars by all genetic parameters. Both hierarchical and nonhierarchical clustering methods differentiated two main groups, indicating clear separation between wild and cultivated vines but also revealed clear gene flow between the cultivated and wild gene pools through overlaps and admixed ancestry values in the graphs. There was greater affinity to the wild grapes in Central European cultivars than in Balkan cultivars. Fine arrangement of the structure among cultivated grapevines showed differentiation among Central European and Balkan cultivars. These results confirm the divergence of wild grapes from vinifera and highlight the “crossroad” role of the western Balkan peninsula in the broader context of European viticulture.

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Species Richness and Nesting Success of Migrant Forest Birds in Natural River Corridors and Anthropogenic Woodlands in Southeastern South Dakota

The Condor ◽

10.1093/condor/108.1.140 ◽

2006 ◽

Vol 108 (1) ◽

pp. 140-153

Author(s):

Dale J. Gentry ◽

David L. Swanson ◽

Jay D. Carlisle

Keyword(s):

Species Richness ◽

Nesting Success ◽

Forest Birds ◽

Individual Species ◽

Natural Habitats ◽

Riparian Corridors ◽

Neotropical Migrant ◽

Riparian Woodlands ◽

Migrant Birds ◽

River Corridors

AbstractForest fragmentation is thought to be partially responsible for declines in many Neotropical migrant birds due to the combined effects of higher rates of brood parasitism and increased predation near forest edges. A majority of the forested habitat in the northern prairie region is found in riparian corridors, but this native habitat has been much reduced from its historical extent. However, additional woodland nesting habitat has been established within the last century in the form of isolated woodlots on farms. We compared abundance, species richness, and nesting success of migrant forest birds breeding in native riparian corridors and anthropogenic woodlots. The two habitats had similar bird abundances but native riparian woodlands were more species-rich than woodlots. We located a total of 650 nests, with 320 nests of 15 species in woodlots and 331 nests of 25 species in riparian corridors. Nesting success was not significantly different between the two habitats for all species combined or for individual species with ≥15 nests in each habitat. Nests above 5 m were more successful than lower nests, but distance to woodland edge did not influence nesting success. Nests initiated in the middle and late portions of the nesting season were more successful than early season nests, significantly so in woodlots. Thus, anthropogenic woodlots were as suitable as natural habitats for successful nesting. However, many of the Neotropical migrants occurring in riparian habitats were absent from woodlots, which suggests that riparian corridors are especially important habitats for breeding birds in the northern prairie region.

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Nest caging as a conservation tool for threatened songbirds

Wildlife Research ◽

10.1071/wr14136 ◽

2014 ◽

Vol 41 (7) ◽

pp. 598 ◽

Cited By ~ 7

Author(s):

Richard E. Major ◽

Michael B. Ashcroft ◽

Adrian Davis

Keyword(s):

Reproductive Success ◽

Nest Success ◽

Nesting Success ◽

Wire Mesh ◽

Management Tool ◽

Negative Effects ◽

Artificial Nests ◽

Endangered Population ◽

Precocial Birds ◽

Nest Predators

Context Enclosing nests in cages to exclude predators is a management tool frequently used to increase the reproductive success of threatened ground-nesting precocial birds. This technique has seldom been used with passerines, despite the predicted increased benefit for altricial species due to their longer period of nest dependency. Aims The aims of this study were to determine (1) whether cages could be installed around the nests of a threatened, shrub-nesting passerine without causing parental desertion, and (2) whether caged nests could successfully exclude the dominant nest predators and increase nesting success. Methods Cages with four different mesh sizes (1000 mm, 200 mm, 100 mm, 50 mm) were installed sequentially in trials at four nests in a secure population and three nests in an endangered population of white-fronted chats (Epthianura albifrons) to investigate susceptibility to desertion. Trials using 160 caged and uncaged artificial nests were used to determine the efficacy of 50-mm wire mesh in preventing access to eggs by potential nest predators. Key results Parent birds accepted nest cages, which reduced predation rates on artificial nests from 96% to 14%. Infrared-triggered cameras revealed that corvids were responsible for 94% of predation episodes. Nest success of caged white-fronted chat nests was 85% (n = 7). Conclusions Nest cages do not appear to have negative effects on nest success of white-fronted chats, and may considerably increase reproductive success. Implications Nest cages may aid conservation of the endangered population of white-fronted chats and other endangered songbird species.

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Introduction: Rare Species and Near-Natural Habitats in Central Europe

Species Conservation in Managed Habitats ◽

10.1002/9783527688845.ch1 ◽

2016 ◽

pp. 1-12

Keyword(s):

Central Europe ◽

Rare Species ◽

Natural Habitats

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Indicators of avian nest predation and parental activity in a managed boreal forest: an assessment at two spatial scales

Canadian Journal of Forest Research ◽

10.1139/x04-169 ◽

2005 ◽

Vol 35 (2) ◽

pp. 374-382 ◽

Cited By ~ 2

Author(s):

Jacques Ibarzabal ◽

André Desrochers

Keyword(s):

Landscape Structure ◽

Nest Predation ◽

Spatial Scales ◽

Edge Length ◽

Nesting Success ◽

Tamiasciurus Hudsonicus ◽

Indirect Measure ◽

Indirect Measures ◽

Total Core Area ◽

Nest Predators

Studies of avian nesting success at the landscape level often use a single indirect measure to evaluate nest predation or parental activity. During two summers at Forêt Montmorency, Quebec, we analyzed and compared three indirect measures of nest predation risk: detection of two nest predators, (1) red squirrel (Tamiasciurus hudsonicus Erxleben) and (2) gray jay (Perisoreus canadensis L.), (3) depredation of bait, and direct observations of parental activity (mostly food transported by adults) at 316 stations over a 230-km2 area. We assessed the relationship between these indicators and three landscape-structure variables (total forested area, total core area, and total edge length) at two spatial scales (83 and 1610 ha). Nest predators were generally present at <30% of stations, <20% of baits were depredated, and >40% of stations exhibited evidence of broods. Bait depredation and the detection of jays or squirrels were correlated, but we found no associations between nest predation and parental activity indicators. Indicators of nest predation and parental activity were not significantly heterogeneous over the study area, despite substantial variation of landscape structure. We argue that parental activity indicators may be more reliable than nest predation indicators, but only as a coarse way to detect variation in nesting success.

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