On Parasitism

Effects of Redhead Nest Parasitism on Mallards

Bird brood parasitism

For many animals, the effort to rear their young is considerable. In birds, this often includes building nests, incubating eggs, feeding the chicks, and protecting them from predators. Perhaps for this reason, about 1% of birds (around 100 species) save themselves the effort and cheat instead. They are obligate brood parasites, laying their eggs in the nests of other species and leaving the hos...

Parasitism and invasive species: effects of digenetic trematodes on mussels

The brown mussel Perna perna in South Africa is threatened by the introduction of the invasive Mediterranean mussel Mytilus galloprov~ncialis. Whilst the indigenous P. perna has been found to be commonly infected by digenetic trematodes, the invasive M galloprovincial~s is free of trematodes, which mav give it a competitive advantage in direct or indirect interactions between the 2 mussels. The...

Host recombination is dependent on the degree of parasitism.

Parasites and hosts are involved in a continuous coevolutionary process leading to genetic changes in both counterparts. To understand this process, it is necessary to track host responses, one of which could be an increase in sex and recombination, such as is proposed by the Red Queen hypothesis. In this theoretical framework, the inducible recombination hypothesis states that B-chromosomes (g...

Diel rhythms of tick parasitism on incubating African penguins.

1. Ticks (Ornithodoros capensis Neumann) were most abundant on incubating host African penguins (Spheniscus demersus Linnaeus) at 24.00 hours and least abundant during 09.00-12.00 hours during 4 day periods in May and October at 3 h intervals. 2. Ticks were three times as abundant in May, the start of the breeding season, as in October, at its end. 3. Air temperature and humidity appear less im...