Nestling sex and behaviour determine the host preference of insect vectors in avian nests.

Sexual differences in pathogen prevalence in wildlife often arise from varying susceptibility influenced by factors such as sex hormones and exposure to pathogens. In the case of vector-borne pathogens, host selection by insect vectors determines the exposure of hosts to infections, largely affecting the transmission of these infectious diseases. We identify the blood-feeding patterns of insect vectors in Blue Tit (Cyanistes caeruleus) nestlings in a 3-year study.

A long-term study on the impact of climatic variables on two common nest-dwelling ectoparasites of the Eurasian blue tit (Cyanistes caeruleus).

We explored the potential influence of temperature and precipitation on the abundance of two nest-dwelling ectoparasites (blowflies and mites) of Eurasian blue tits (Cyanistes caeruleus) during a period of 21 years and compared the results with those of a shorter period. The abundance of blowflies was negatively related to precipitation, which could prevent flies from locating their host, and laying date. In addition, blowflies were positively related to brood size (more food implies more parasites) and the interaction between precipitation and temperature.

Differential effects of environmental climatic variables on parasite abundances in blue tit nests during a decade.

Models on climate change have predicted an increase of temperature over the earth's surface with potential drastic effects on living organisms. We analyzed the relationships between climatic conditions (temperature, rainfall, and wind speed) and the abundance of blood-sucking flying insects (biting midges and blackflies) and nest-dwelling ectoparasites (mites, fleas, and blowflies) collected from blue tit nests during bird breeding seasons for a period of 10 years. Average temperature, rainfall, and wind speed showed significant differences among years.

Experimental manipulation of cavity temperature produces differential effects on parasite abundances in blue tit nests at two different latitudes.

Although different predictive models forecast that climate change will alter the distribution and incidence of parasitic diseases, few studies have investigated how microclimatic changes may affect host-parasite relationships. In this study, we experimentally increased the temperature inside nest boxes of the blue tit during the nestling period at two different latitudes (central Spain and central Germany) to determine its effect on parasite abundance. The two localities have contrasting climate conditions: the southern one in Spain is warmer and drier than the northern one in Germany.