Innate and learned aspects of vole urine UV‐reflectance use in the hunting behaviour of the common kestrel Falco tinnunculus

Abstract

Some birds are known to use the UV reflectance in their feeding strategy. Knowing that the common kestrel Falco tinnunculus is able to recognise vole trails by perceiving the UV reflectance of their scent marks, this study was designed to investigate whether the use of scent marks in the UV range has an innate component, or if it is only acquired with experience. We tested the preference of 44 experienced adult and 49 naïve juvenile common kestrels in four types of arenas: (1) scent‐marked and covered with a UV transmitting filter (UV+SC), (2) scent‐marked and covered with a UV blocking filter (UV‐SC), (3) sprinkled with water and covered with a UV transmitting filter (UV+W), and (4) sprinkled with water and covered with a UV blocking filter (UV‐W). We assessed the birds’ preference by counting the number of visual scans and visits to each arena. The distribution of scans differed from random in both adults and juveniles. The birds scanned the UV+SC arena more often than the others. Since naïve individuals showed the same preference as experienced ones, we hypothesised that the association between vole scent UV reflectance and vole presence has an innate component in the common kestrel. Nevertheless, adults differed from juveniles because they perceived the scented arenas from the water sprinkled ones, in fact, adults scanned the UV‐SC arena more frequently than both UV+W and UV‐W arenas. This result suggests that the ability of detecting UV cues has a learned component.

Ultraviolet sensitivity and colour vision in raptor foraging

“…With this new information, we used visual modelling to quantify the chromatic signals involved in two model systems of raptor-vole and raptor-songbird interactions. It has been suggested that UV signals have a predominant role in these interactions, either as cues for raptor hunting behaviour or as 'hidden' songbird signals concealed from raptors (Viitala et al, 1995;Håstad et al, 2005) (and see Zampiga et al, 2006;Zampiga et al, 2008). Our analyses show that raptors do not use UV cues for detection in these interactions, and our data suggest that it is unlikely that bank vole and field vole urine provide any visual cue that raptors can use.…”

Seeing through the lizard’s trick: do avian predators avoid autotomous tails?

“…The ontogenetic flexibility of foraging behaviour may vary considerably among even closely related species (e.g. [42,44]), but theoretically one would expect specialist foragers to have genetically fixed foraging techniques, and generalists to have flexible (learned) methods (cf. [42,45]).…”

Do house mice use UV cues when foraging?

“…For example, it has been experimentally shown that birds can use UV cues in foraging. Diurnal avian predators are able to scan for potential hunting areas by using the scent markings of voles visible in UV light (Viitala et al 1995;Koivula and Korpimäki 2001;Zampiga et al 2006; but see Kellie et al 2004), but nocturnal owls probably cannot (Koivula et al 1997). In addition, redwings (Turdus iliacus) are attracted by UV-reflecting berries (Siitari et al 1999;Honkavaara et al 2004), and blue tits (Parus caeruleus) find cabbage moth larvae faster if the illumination includes UV light (Church et al 1998).…”