Nest ectoparasites increase physiological stress in breeding birds: an experiment.
Parasites are undoubtedly a biotic factor that produces stress. Heat shock proteins (HSPs) are important molecules buffering cellular damage under adverse conditions. During the breeding season, blue tit Cyanistes caeruleus (L.) adults are affected by blood parasites, nest-dwelling parasites and biting flies, potentially affecting their HSP-mediated responses. Here, we treated females with primaquine to reduce blood parasites and fumigated nests with permethrin to reduce nest-dwelling parasites to test whether these treatments affect HSP60 level during the breeding season. Medicated females, but not controls, had a significant reduction of the intensity of infection by Haemoproteus spp. blood parasites. However, final intensity of infection did not differ significantly between groups, and we did not find an effect of medication on change in HSP60 level. Fumigation reduced the abundance of nest-dwelling parasites (mites, fleas and blowfly larvae) and engorged biting midges in nests. Females breeding in non-fumigated nests increased HSP60 levels during the season more than those breeding in fumigated nests. Furthermore, the change in HSP60 level was positively correlated with the abundance of biting midges. These results show how infections by nest ectoparasites during the breeding period can increase the level of HSPs and suggest that biting midges impose physiological costs on breeding female blue tits. Although plausible, the alternative that biting midges prefer to feed on more stressed birds is poorly supported by previous studies.
Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), J. Gutiérrez Abascal 2, 28006, Madrid, Spain. jmartinez@becarios.ulpgc.es
Josué
J
Martínez-de la Puente
Santiago
S
Merino
Gustavo
G
Tomás
Juan
J
Moreno
Judith
J
Morales
Elisa
E
Lobato
Javier
J
Martínez
D000818:Animals; D001715:Bird Diseases / Q000097:blood / Q000469:parasitology / Q000503:physiopathology*; D002519:Ceratopogonidae / Q000502:physiology; D018834:Chaperonin 60 / Q000097:blood; D004478:Ectoparasitic Infestations / Q000097:blood / Q000503:physiopathology / Q000662:veterinary*; D005260:Female; D016787:Haemosporida / Q000502:physiology; D007299:Insect Bites and Stings / Q000097:blood / Q000503:physiopathology; D007306:Insecticides; D009425:Nesting Behavior / Q000502:physiology; D046109:Passeriformes / Q000469:parasitology; D026023:Permethrin; D011319:Primaquine / Q000627:therapeutic use; D011529:Protozoan Infections, Animal / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology*; D012098:Reproduction / Q000502:physiology; D013312:Stress, Physiological
D018834:Chaperonin 60; D007306:Insecticides; D026023:Permethrin; D011319:Primaquine