Blood parasites, leucocytes and plumage brightness in the Cirl Bunting,Emberiza cirlus

Abstract

1. Although a female preference for pairing with brightly plumaged males has been reported in many species, the reasons for this choice are not fully understood. 2. Parasites have been proposed as playing an important role in shaping these preferences because, by pairing with brightly coloured individuals, females can obtain parasite‐free and/or more healthy mates. 3. In this paper one of the predictions of this hypothesis is tested, namely a higher health level in brightly coloured individuals, by analysing the relationships among blood parasites, leucocyte levels and plumage brightness in the Cirl Bunting, Emberiza cirlus. 4. Two species of blood parasites were detected. Whereas a lower body condition was detected in individuals infected by Leucocytozoon cambournaci, no such differences were associated with Plasmodium relictum infections. Infected individuals showed higher total leucocyte counts than non‐infected individuals. 5. Colour intensity of carotenoid derived colorations was negatively correlated to the relative proportion of lymphocytes and positively correlated to the relative presence of heterophils. Furthermore, the size of yellow feathered areas was positively correlated with the absolute number of leucocytes and the relative presence of heterophils. Only some of these relationships were found for non‐carotenoid derived traits. 6. These results suggest that male plumage yellow coloration in the Cirl Bunting is a reliable indicator of health status and supports the hypothesis that females obtain more parasite‐free mates if they pair with brightly coloured individuals.

Iridescent structural colour production in male blue-black grassquit feather barbules: the role of keratin and melanin

“…Coloration properties of secondary sexual traits may provide reliable information about an individual's genetic quality (Figuerola et al 1999), aggressiveness (Alonzo-Alvarez et al 2004) or reproductive strategy (Badyaev & Hill 2002), which may be used by individuals during agonistic or mate choice interactions (Searcy & Nowiki 2005).…”

Relationships Between Leukocytes and Hepatozoon Spp. In Green Frogs, Rana Clamitans

“…Few other studies have assessed relationships between hematozoa and leukocytes; these studies often detect elevated numbers of lymphocytes (Rose et al, 1979;Dufva and Allander, 1995;Ots and Hõ rak, 1998;Figuerola et al, 1999). We have not found such studies for amphibians.…”

Prevalencia parasitaria en el gorrión altiplanero (Spizella wortheni): especie endémica de México y en peligro de extinción

“…La relación heterófilo/linfocito (H/L) fue de 0.48. A pesar de la infección los valores se encuentran en el rango de media previamente reportado para otras especies de las familias Emberizidae y Passerellidae: Emberiza cirlus (L=56.29, H=37.4, E=5.59, M=0.59, H/L=0.66;Figuerola et al 1999), Zonotrichia capensis (L=71.4, H=20.2, E=2.3, B=3.1 M=2.9, H/L=0.30; Ruiz et al 2002), Pipilo aberti (L=39.8, H=51.3, E=7.5, B=0.6, M=1.4, H/L=0.91;Fokidis et al 2008) y Spizella breweri (L=55, H=37.25, E=2.25, B=1, M=4.5, H/L=0.88, datos obtenidos en un estudio paralelo al presente no publicados). La relación entre el conteo de los eosinófilos en aves con infecciones intestinales es ambigua; a pesar de que se ha se ha mostrado una asociación limitada entre nemátodos y el número de eosinófi-los, los estudios experimentales con antígenos parasitarios no indujeron esosinofilia, y en el caso de inoculación de coccidias los niveles de eosinófilos circulantes en sangre se mantuvieron bajos (revisado en Rose et al 1979y Mitchell et al 2008.…”