Selective predation and productivity jointly drive complex behavior in host-parasite systems

February 02, 2005

What provokes sudden, dramatic outbreaks of diseases, large fluctuations in parasite abundance, and rapid termination of epidemics? The search for drivers of these complex behaviors has become more urgent as epidemics in wildlife populations continue to arise. Recently ecologists have realized that other species may strongly shape disease dynamics. Predators are particularly interesting because they often prefer to attack parasitized hosts. Could predators catalyze these behaviors?

To answer this question, Spencer R. Hall, Meghan A. Duffy, and Carla E. Cáceres studied a simple model which shows how predators that strongly prefer parasitized hosts can introduce "Allee effects" for parasites at lower productivity and sudden but unavoidable extinction of parasites at higher productivity. In the former case, parasites have difficulty invading a host population, while in the latter case, parasites cannot persist with their hosts, even if they can invade. When predators less strongly prefer parasitized hosts, these dramatic behaviors diminish, but predators can still trigger large fluctuations of parasite abundance at higher productivity.

Surprisingly, when predators show no preference for or even avoid parasitized hosts, interactions between the two enemies can drive both host and parasite unavoidably extinct. These findings stress the importance of the biological and ecosystem background in which hosts and parasites interact.
-end-


University of Chicago Press Journals

Related Parasites Articles from Brightsurf:

When malaria parasites trick liver cells to let themselves in
A new study led by Maria Manuel Mota, group leader at Instituto de Medicina Molecular, now shows that malaria parasites secrete the protein EXP2 that is required for their entry into hepatocytes.

How deadly parasites 'glide' into human cells
A group of scientists led by EMBL Hamburg's Christian Löw provide insights into the molecular structure of proteins involved in the gliding movements through which the parasites causing malaria and toxoplasmosis invade human cells.

How malaria parasites withstand a fever's heat
The parasites that cause 200 million cases of malaria each year can withstand feverish temperatures that make their human hosts miserable.

New studies show how to save parasites and why it's important
An international group of scientists published a paper, Aug. 1, 2020, in a special edition of the journal Biological Conservation that lays out an ambitious global conservation plan for parasites.

More flowers and pollinator diversity could help protect bees from parasites
Having more flowers and maintaining diverse bee communities could help reduce the spread of bee parasites, according to a new study.

How Toxoplasma parasites glide so swiftly (video)
If you're a cat owner, you might have heard of Toxoplasma gondii, a protozoan that sometimes infects humans through contact with contaminated feces in litterboxes.

Parasites and the microbiome
In a study of ethnically diverse people from Cameroon, the presence of a parasite infection was closely linked to the make-up of the gastrointestinal microbiome, according to a research team led by Penn scientists.

Clocking in with malaria parasites
Discovery of a malaria parasite's internal clock could lead to new treatment strategies.

Feeding bluebirds helps fend off parasites
If you feed the birds in your backyard, you may be doing more than just making sure they have a source of food: you may be helping baby birds give parasites the boot.

Scientists discover how malaria parasites import sugar
Researchers at Stockholm University has established how sugar is taken up by the malaria parasite, a discovery with the potential to improve the development of antimalarial drugs.

Read More: Parasites News and Parasites Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.