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El valor dels espais agraris periurbans Framis, H. Aproximació a
la distribució i abundància del mussol comú (Athene
noctua) als espais periurbans de la ciutat de Mataró i a la
zona agrícola de les Cinc Sènies-Valldeix Approach to the distribution and abundance of little owl (Athene noctua) in periurban areas and arable land around the city of Mataró (Barcelona) The historical loss of open and agricultural land around the city of Mataró has been followed by an expansion of forest and, in particular, urban areas. Suitable habitats for bird species such as little owl (Athene noctua) are becoming scarcer. Open areas still encompass agricultural lands, as well as multi-use lands, which result from their proximity to a large city, and which are referred to as peri-urban habitats. An area of about 1,600 ha was surveyed in spring 2007 by means of the playback method, in tandem with direct observations and interviews with landowners in an initial attempt to locate owl territories. Although an audibility range of 400 m was suggested, stations were placed at variable distances, depending on topography and acoustics, which posed a very real problem considering the proximity of a city containing over 116,000 inhabitants. Sixty-four playback stations generated between 56 and 60 little owl territorial responses, which when combined with our tandem methodology, resulted in at least 27 owl territories; specifically, an approximate density of 1.6 singing males per km2. However, this result is considered provisional due to the dual possibilities of double-counting and low response rates stemming from our proximity to a large urban area. Our little owl survey also elicited responses from other nocturnal raptors in the study area, including the tawny owl (Strix aluco), scops owl (Otus scops) and barn owl (Tyto alba). Suitable sites for the little owl are found throughout the extensive agricultural areas east of the city. Interestingly enough, peri-urban degraded sites in the northern part of Mataró, where scattered trees and uncultivated fields can be found alongside small orchards, have become owl-inhabited areas, showing the link between this species and agricultural habitats. The promotion of urban orchards, a development now occurring in other regional cities, combined with carob tree (Ceratonia siliqua) plantations, will hopefully encourage local authorities to halt the ongoing reduction of open habitats. A crown of well-preserved open habitat would not only enhance a neglected ecosystem, but would also act as a connector between the traditional agricultural lands east of the city and the forested habitats to the north. Other practical protective measures are proposed in the forth-coming regional guide to nocturnal raptor conservation. |
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