Layers of nocturnal insect migrants at high-altitude: the influence of atmospheric conditions on their formation

• Published in: Agricultural and forest entomology Vol. 12; no. 1; pp. 113 - 121
• Main Authors: Wood, Curtis R, Clark, Suzanne J, Barlow, Janet F, Chapman, Jason W
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.02.2010; Blackwell Publishing Ltd
• Subjects: Altitude; Animal migration; Differential advection; entomological radar; Entomology; insect layering; Insects; nocturnal boundary layer; temperature inversion; United Kingdom > UK
• ISSN: 1461-9555; 1461-9563
• DOI: 10.1111/j.1461-9563.2009.00459.x

1 Radar studies of nocturnal insect migration have often found that the migrants tend to form well-defined horizontal layers at a particular altitude. 2 In previous short-term studies, nocturnal layers were usually observed to occur at the same altitude as certain meteorological features, most notably at the altitudes of temperature inversion tops or nocturnal wind jets. 3 Statistical analyses are presented of 4 years of data that compared the presence, sharpness and duration of nocturnal layer profiles, observed using continuously-operating entomological radar, with meteorological variables at typical layer altitudes over the U.K. 4 Analysis of these large datasets demonstrated that temperature was the foremost meteorological factor that was persistently associated with the presence and formation of longer-lasting and sharper layers of migrating insects over southern U.K.