Combining spatial modelling and radar to identify and protect avian migratory hot-spots

• Published in: Current zoology Vol. 60; no. 5; pp. 680 - 691
• Main Authors: Desholm, Mark, Gill, Rashpal, Bøvith, Thomas, Fox, Anthony D.
• Format: Journal Article
• Language: English
• Published: 01.10.2014
• ISSN: 1674-5507; 2396-9814
• DOI: 10.1093/czoolo/60.5.680

Abstract Migrating landbirds are known to follow coast lines and concentrate on peninsulas prior to crossing water bodies, especially during daylight but also at night, creating enhanced potential collision hazards with man-made objects. Knowing where these avian migration “hot-spots” occur in time and space is vital to improve flight safety and inform the spatial planning process (e.g. environmental assessments for offshore windfarms). We developed a simple spatial model to identify avian migration hot-spots in coastal areas based on prevailing migration orientation and coastline features known, from visual and radar observations, to concentrate migrating landbirds around land masses. Regional scale model validation was achieved by combining nocturnal passerine movement data gathered from two tier radar coverage (long-range dual-polarization Doppler weather radar and short-range marine surveillance radar) and standardised bird ringing. Applied on a national scale, the model correctly identified the ten most important Danish coastal hot-spots for spring migrants and predicted the relative numbers of birds that concentrated at each site. These bird numbers corresponded well with historical observational data. Here, we provide a potential framework for the establishment of the first three-dimensional avian airspace sanctuaries, which could contribute to more effective conservation of long-distance migratory birds.