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Male incubation feeding and fleas

Cite this dataset

Peralta-Sánchez, Juan Manuel; Nilsson, Jan-Åke (2021). Male incubation feeding and fleas [Dataset]. Dryad.


Parasites exert a strong selection pressure on their hosts as manifested in behavioural antiparasite traits to reduce negative impacts on fitness. The numerous nest-dwelling ecto-parasites residing in avian nests make altricial birds excellent model-systems for investigating the relationship between parasites and their hosts. Here, we experimentally increased natural levels of hen fleas (Ceratophyllus gallinae) in blue tit (Cyanistes caeruleus) nests during incubation, and tested their effects on parental incubation behaviours and reproductive performance. Our experimental addition of fleas resulted in an increase in feeding effort of males to incubating females. Frequency of male feedings was also positively related to clutch size. These results suggest that males increase their reproductive effort in flea manipulated and large broods. This will, at least partly, compensate female costs in nests with high ecto-parasite density and many nestlings. Furthermore, nestling mass at day 6 in experimental nests decreased with brood size, which was not the case in nests with a natural level of fleas. In line with male incubation feeding, parents may try to compensate for the costs inflicted by the fleas but can only partly compensate when brood size is large.


Fleas were experimentally added to manipulated nestboxes of blue tits.

Male incubation feeding to their females was estimated and the rate compared between control and manipulated nests.

Usage notes

Meta data

Treatment: Nests with an addition of extra fleas during incubation or unmanipulated nests serving as controls.

Area: The two nest box areas included in this study.

Clutch size: Number of eggs produced.

Brood size: Number of young hatched.

Fledgling: Number of young that fledged.

Feedings: Number of male feedings to their incubating female during 2 h.

Incubation: The length of the incubation period in hours.

Mass 6: The mean mass of nestlings at an age of 6 days.

Mass 14: The mean mass of nestlings at an age of 14 days.

Time in: Proportion of the total observation time that the female was inside the nest box.

Fl success: Fledging success calculated as the ratio between number of fledged and number of hatched nestlings.

Hatching success: Hatching success calculated as the ratio between number of hatched nestlings and clutch size.