Nest-box use by Boreal Owls (Aegolius funereus) in the Pyrenees Mountains in Spain

Lopez B.C., Potrony D., López A., Badosa E., Bonada A., Saló R. (2010) Nest-box use by Boreal Owls (Aegolius funereus) in the Pyrenees Mountains in Spain. Journal of Raptor Research. 44: 40-49.
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Doi: 10.3356/JRR-09-32.1

Resum:

The Boreal Owl (Aegolius funereus) is a nocturnal forest-dwelling species widely distributed throughout the world. One of the least studied and most southerly populations of this species lives in the Pyrenees Mountains. This population, 500600 pairs, probably suffered a slight decline during recent decades due to forestry management practices. The use of nest boxes may become necessary to protect this species in southern Europe. The objective of this study was to establish a standard protocol for nest-box installation, based on the analysis of occupation rates of nest boxes installed during the last 20 yr and the comparison of reproductive data for nest boxes and natural nest cavities. Our results indicated that nest boxes should be installed at high elevations (above 2000 m asl), below 4 m aboveground, and preferably facing south or southeast. We also found that most territories are located where maximum July temperatures are

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Explaining the successful introduction of the alpine marmot in the Pyrenees

López B.C., Pino J., López A. (2010) Explaining the successful introduction of the alpine marmot in the Pyrenees. Biological Invasions. 12: 3205-3217.
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Doi: 10.1007/s10530-010-9712-0

Resum:

Alpine marmots were introduced into the northern Pyrenees between 1948 and 1988 from individuals captured in the French Alps, in order to bolster food sources for the golden eagle and brown bear. The marmot's subsequent occupation of the southern Pyrenees has been extremely fast. From an initial population of ~400 individuals, the present population in the southern Pyrenees is estimated to be of more than 10,000 individuals. The objective of this study was to assess what were the mechanisms that have enabled such a fast occupation of the territory. We studied habitat preferences and habitat selection of the alpine marmot in the southern Pyrenees both at the micro- and meso-scale, and compared our results with similar data in the bibliography on their native region. We also compared climatic data from both the native and introduction sites. Our results indicate relatively low climate (precipitation and temperature) matching between the two sites but a relatively high habitat matching. Marmots negatively select high woody cover and the presence of conifers in their home range, while they choose alpine and sub-alpine meadows close to rivers with boulders. Furthermore, the marmot population is independent of snow cover duration. We conclude that the successful establishment in the Pyrenees by the alpine marmot is explained both by the habitat- and climate-matching mechanisms. In both aspects, marmots show a generalist response. Meso-scale GIS-derived variables were non significant when analyzed together with local, micro-scale variables from field measurements. © 2010 Springer Science+Business Media B.V.

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