Shelagh K. Tupper

The role of a generalized ultraviolet cue for blackbird food selection

Birds utilize ultraviolet (UV) wavelengths for plumage signaling and sexual selection. Ultraviolet cues may also be used for the process of avian food selection. The aim of our study was to investigate whether a UV cue and a postingestive repellent can be used to condition food avoidance in red-winged blackbirds (Agelaius phoeniceus). We found that birds conditioned with an UV-absorbent, postingestive repellent subsequently avoided UV-absorbent food. Thus, the UV-absorbent cue (coupled with 0-20% of the conditioned repellent concentration) was used to maintain avoidance for up to 18 days post-conditioning. Similarly, birds conditioned with the UV-absorbent, postingestive repellent subsequently avoided UV-reflective food. Thus, conditioned avoidance of an UV-absorbent cue can be generalized to an unconditioned, UV-reflective cue for nutrient selection and toxin avoidance. These findings support the hypothesized function of UV vision for avian food selection, the implications of which remain to be explored for the sensory and behavioral ecology within agronomic and natural environments.

Functional significance of ultraviolet feeding cues in wild turkeys

WERNER, S. J., R. BUCHHOLZ, S. K. TUPPER, S. E. PETTIT AND J. W. ELLIS. Functional significance of ultraviolet feeding cues in wild turkeys. PHYSIOL BEHAV 00:000-000, 2013.- Most birds are able to sense ultraviolet (UV) visual signals. Ultraviolet wavelengths are used for plumage signaling and sexual selection among birds. The aim of our study was to determine if UV cues are also used for the process of food selection in wild turkeys (Meleagris gallopavo). We used avoidance conditioning to test the hypothesis that UV feeding cues can be used functionally for foraging behavior in wild turkeys. Female turkeys exhibited no avoidance of untreated food and 75-98% avoidance of food treated with an UV-absorbent, postingestive repellent (0.5-4% anthraquinone; wt/wt) during repellent exposure. Male turkeys exhibited 78-99% avoidance of food treated with 0.5-4% anthraquinone. Female and male turkeys that consumed more than 200mg and 100mg of anthraquinone, respectively, subsequently avoided food treated only with an UV-absorbent cue. In contrast, unconditioned females consumed 58% more food treated with the UV-absorbent cue than untreated food. Thus, wild turkeys do not prefer foods associated with UV wavelengths regardless of feeding experience. We also observed 1) a weak negative correlation between body condition and intestinal parasite infection and 2) moderate, positive correlations between consumption of food treated with the conditioned UV cue and intestinal parasite infection among male turkeys. The UV feeding cue was used to maintain food avoidance during the four days subsequent to postingestive conditioning. Moreover, the consequences of consuming food treated with the postingestive, UV-absorbent repellent were necessary for conditioned avoidance of the UV-absorbent cue. These findings suggest functional significance of UV feeding cues for avian foraging behavior, the implications of which will enable subsequent investigations regarding the sensory physiology and behavioral ecology of wild birds.

Longevity of DayGlo fluorescent particle marker used to mark birds in flight pen and field

Spray application of fluorescent particles is a widely used and very valuable technique for marking birds. This remains one of the few practical means to mark large numbers of birds for monitoring movement, despite recent availability of a variety of more technologically advanced options. We monitored the longevity of the DayGlo fluorescent particle marker on red-winged blackbirds under simulated field conditions in a flight pen, and in an observational field experiment. In the pen study we banded 52 red-winged blackbirds with individually numbered leg bands, and sprayed them with DayGlo fluorescent particle marker from a distance of ~50u2009cm, on 1 December 2004. These birds were recaptured and DayGlo fluorescent particle marks assessed 11 times until 10 August 2005. All 31 surviving birds at the conclusion of the study (i.e. after 254 days) retained at least some DayGlo fluorescent particle marker on one or more body regions. Wings retained DayGlo fluorescent particle marks longer than other body regions and thus could be used to identify marks in large-scale collections. Roosting wild blackbirds aerially marked in September and October 2005 retained marks through June 2006, 263 days after marking. The formulation used is inexpensive (US

Economic Impacts of Blackbird Damage to the Rice Industry

4.00u2009L−1), easy-to-apply at many scales and practical for many species (e.g. starlings, blackbirds, sparrows, gulls and shorebirds).