Meeting Abstract
P3.148 Sunday, Jan. 6 Ultraviolet visual sensitivity in avian brood parasites and their hosts AIDALA, Z.*; HAUBER, M.E.; The Graduate Center, CUNY; Hunter College, CUNY; The Graduate Center, CUNY; Hunter College, CUNY zacharyaidala@gmail.com
Sensitivity to ultraviolet (UV) light (< 400 nm) mediates a diverse array of avian behaviors including foraging, mate choice, and egg recognition. Among brood parasites (birds which lay their eggs in the nests of others) and their hosts, some host species use differences in UV-reflectance to distinguish between own and foreign eggs. Recent evidence suggests that even seemingly non-mimetic parasitic eggs may be accepted due to color-matching in the UV portion of the avian-visible spectrum. However, the degree of UV-sensitivity of many brood parasite hosts is poorly understood. DNA sequencing of the short wavelength sensitive type 1 (SWS1) opsin gene allows for accurate prediction of a focal species’ maximal photoreceptor sensitivity regarding violet sensitivity (VS) at > 400 nm and ultraviolet sensitivity (UVS) at < 400 nm. We report predicted maximal SWS1 opsin sensitivities among Passeriformes hosts of obligate brood parasitic birds: the North American brown-headed cowbird (Molothrus ater) as well as the New Zealand shining-bronze cuckoo (Chrysococcyx lucidus) and long-tailed cuckoo (Urodynamis taitensis). We expected covariation in SWS1 UVS/VS status with rejecter/acceptor behaviors in focal hosts, yet we detected no evidence of such a relationship. Despite the lack of support for the UV-matching hypothesis, these results will allow for more accurate visual modeling analyses within specific parasite-host systems due to the new information regarding predicted SWS1 maximal sensitivities reported here. Future research will investigate full avian-visible spectrum sensitivity differences in hosts using opsin sequencing and microspectrophotometric analyses with the expectation that rejecter hosts will have visual systems that are better able to detect parasitic eggs.
