Experimental manipulation of temperature reduce ectoparasites in nests of blue tits (Cyanistes caeruleus).

Castaño-Vázquez, Francisco; Martínez, Javier; Merino, Santiago; Lozano, Marco

9 May 2018

Several models predict changes in distributions and incidence of diseases associated to climate change. However, there are few studies on how microclimatic changes could affect host-parasite relationships. In the present study, we experimentally manipulated the temperature inside nest-boxes occupied by blue tits (Cyanistes caeruleus) during the breeding season. The temperature was increased using heat mats located under the nest material in order to know its effect on parasitic abundance (i.e., nest-dwelling ectoparasites, blood-sucking flying insects and hemoparasites) and host condition (i.e., nestlings and adults). The experimental procedure increased the temperature 3ºC on average and reduced the relative humidity about six units. The abundance of mites (Dermanyssus gallinoides) and blowfly pupae (Protocalliphora azurea) was significantly reduced in heated nest-boxes. In addition, a not significant lower prevalence of flea pupae (Ceratophyllus gallinae) was found in heated nests. However, hemoparasite infection of adult blue tits and the condition of adult and nestling blue tits were not affected by the heat treatment. In conclusion, the present heat treatment reduced nest-dwelling ectoparasites without any apparent benefit for the host.

Doi
10.1111/jav.01695