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Habitat Effects on the Breeding Performance of Three Forest-Dwelling Hawks.

Björklund H, Valkama J, Tomppo E, Laaksonen T - PLoS ONE (2015)

Bottom Line: In the European Boreal Zone, loss of old forest due to intensive forestry is suspected to cause declines in forest-dwelling raptors by reducing their breeding performance.None of the habitat variables affected significantly the breeding success of the common buzzard or the honey buzzard, or the brood size of any of the species.The amount of old spruce forest decreased both around goshawk and common buzzard nests and throughout southern Finland in 1992-2010.

View Article: PubMed Central - PubMed

Affiliation: The Zoology Unit, Finnish Museum of Natural History Luomus, University of Helsinki, Helsinki, Finland; Department of Biosciences, University of Helsinki, Helsinki, Finland.

ABSTRACT
Habitat loss causes population declines, but the mechanisms are rarely known. In the European Boreal Zone, loss of old forest due to intensive forestry is suspected to cause declines in forest-dwelling raptors by reducing their breeding performance. We studied the boreal breeding habitat and habitat-associated breeding performance of the northern goshawk (Accipiter gentilis), common buzzard (Buteo buteo) and European honey buzzard (Pernis apivorus). We combined long-term Finnish bird-of-prey data with multi-source national forest inventory data at various distances (100-4000 m) around the hawk nests. We found that breeding success of the goshawk was best explained by the habitat within a 2000-m radius around the nests; breeding was more successful with increasing proportions of old spruce forest and water, and decreasing proportions of young thinning forest. None of the habitat variables affected significantly the breeding success of the common buzzard or the honey buzzard, or the brood size of any of the species. The amount of old spruce forest decreased both around goshawk and common buzzard nests and throughout southern Finland in 1992-2010. In contrast, the area of young forest increased in southern Finland but not around hawk nests. We emphasize the importance of studying habitats at several spatial and temporal scales to determine the relevant species-specific scale and to detect environmental changes. Further effort is needed to reconcile the socioeconomic and ecological functions of forests and habitat requirements of old forest specialists.

No MeSH data available.


Related in: MedlinePlus

Changes (%) in proportions of (A) old spruce forest and (B) other old forest.Differences between the first and last breeding periods in arcsine square-root-transformed habitat proportions were tested within each radii for the Agen = goshawk, Bbut = common buzzard and Papi = honey buzzard with linear mixed-effect models (see S2 Table). Significant differences are indicated with asterisks. Number of nests (first / last breeding period): goshawk 420 / 269, common buzzard 292 / 137 and honey buzzard 76 / 19.
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pone.0137877.g003: Changes (%) in proportions of (A) old spruce forest and (B) other old forest.Differences between the first and last breeding periods in arcsine square-root-transformed habitat proportions were tested within each radii for the Agen = goshawk, Bbut = common buzzard and Papi = honey buzzard with linear mixed-effect models (see S2 Table). Significant differences are indicated with asterisks. Number of nests (first / last breeding period): goshawk 420 / 269, common buzzard 292 / 137 and honey buzzard 76 / 19.

Mentions: The proportion of old spruce forest declined significantly between the first and last breeding periods within 1000 m and 2000 m around goshawk nests, and within 1000 m around common buzzard nests (Fig 3A, S2 Table). At the nest-site scale (100 m), there was no significant difference in the proportion of old spruce forest between the first and last breeding periods for any of the species, although for the honey buzzard, the average proportion of old spruce forest was halved (Fig 3A). However, the sample size of the honey buzzard was low in the last breeding period.


Habitat Effects on the Breeding Performance of Three Forest-Dwelling Hawks.

Björklund H, Valkama J, Tomppo E, Laaksonen T - PLoS ONE (2015)

Changes (%) in proportions of (A) old spruce forest and (B) other old forest.Differences between the first and last breeding periods in arcsine square-root-transformed habitat proportions were tested within each radii for the Agen = goshawk, Bbut = common buzzard and Papi = honey buzzard with linear mixed-effect models (see S2 Table). Significant differences are indicated with asterisks. Number of nests (first / last breeding period): goshawk 420 / 269, common buzzard 292 / 137 and honey buzzard 76 / 19.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4589344&req=5

pone.0137877.g003: Changes (%) in proportions of (A) old spruce forest and (B) other old forest.Differences between the first and last breeding periods in arcsine square-root-transformed habitat proportions were tested within each radii for the Agen = goshawk, Bbut = common buzzard and Papi = honey buzzard with linear mixed-effect models (see S2 Table). Significant differences are indicated with asterisks. Number of nests (first / last breeding period): goshawk 420 / 269, common buzzard 292 / 137 and honey buzzard 76 / 19.
Mentions: The proportion of old spruce forest declined significantly between the first and last breeding periods within 1000 m and 2000 m around goshawk nests, and within 1000 m around common buzzard nests (Fig 3A, S2 Table). At the nest-site scale (100 m), there was no significant difference in the proportion of old spruce forest between the first and last breeding periods for any of the species, although for the honey buzzard, the average proportion of old spruce forest was halved (Fig 3A). However, the sample size of the honey buzzard was low in the last breeding period.

Bottom Line: In the European Boreal Zone, loss of old forest due to intensive forestry is suspected to cause declines in forest-dwelling raptors by reducing their breeding performance.None of the habitat variables affected significantly the breeding success of the common buzzard or the honey buzzard, or the brood size of any of the species.The amount of old spruce forest decreased both around goshawk and common buzzard nests and throughout southern Finland in 1992-2010.

View Article: PubMed Central - PubMed

Affiliation: The Zoology Unit, Finnish Museum of Natural History Luomus, University of Helsinki, Helsinki, Finland; Department of Biosciences, University of Helsinki, Helsinki, Finland.

ABSTRACT
Habitat loss causes population declines, but the mechanisms are rarely known. In the European Boreal Zone, loss of old forest due to intensive forestry is suspected to cause declines in forest-dwelling raptors by reducing their breeding performance. We studied the boreal breeding habitat and habitat-associated breeding performance of the northern goshawk (Accipiter gentilis), common buzzard (Buteo buteo) and European honey buzzard (Pernis apivorus). We combined long-term Finnish bird-of-prey data with multi-source national forest inventory data at various distances (100-4000 m) around the hawk nests. We found that breeding success of the goshawk was best explained by the habitat within a 2000-m radius around the nests; breeding was more successful with increasing proportions of old spruce forest and water, and decreasing proportions of young thinning forest. None of the habitat variables affected significantly the breeding success of the common buzzard or the honey buzzard, or the brood size of any of the species. The amount of old spruce forest decreased both around goshawk and common buzzard nests and throughout southern Finland in 1992-2010. In contrast, the area of young forest increased in southern Finland but not around hawk nests. We emphasize the importance of studying habitats at several spatial and temporal scales to determine the relevant species-specific scale and to detect environmental changes. Further effort is needed to reconcile the socioeconomic and ecological functions of forests and habitat requirements of old forest specialists.

No MeSH data available.


Related in: MedlinePlus