+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Functional response and prey defence level in an experimental predator-prey system

Evolutionary Ecology Research uary; 8(1): 115-128

Functional response and prey defence level in an experimental predator-prey system

Questions: How do defences expressed only in the presence of predators (inducible defences) affect the relationship between the number of prey eaten and prey density (the predator's functional response)? What is the relationship between prey defence level and vulnerability? Do inducible defences show features that are likely to stabilize predator-prev dynamics on theoretical grounds? Organisms: We conducted experiments in a laboratory system. The prey was the protist Euplotes octocarinatus, exposing different levels of a morphological inducible defence. The predator was the turbellarian Stenostomum virginianian. Methods: We analysed the data using non-linear mixed effects models that combine non-linear curve fitting with random effects. Results: This predator's functional response was a sigmoid Holling-Type III. The induced defence lowered the maximum number of prey that predators ate, suggesting that the defence increased the predator's handling time. The level of defence expressed by Euplotes depended on the level of predator cue. There was a negative exponential decline in the number of prey eaten with increasing level of defence. Low levels of defence were thus effective and further increases in defence improved prey survival only slightly. The possibility for prey to become nearly invulnerable, the effectiveness of low levels of defence, and variation in vulnerability all suggest that this inducible defence can stabilize community dynamics.

(PDF 0-2 workdays service: $29.90)

Accession: 012106988

Related references

Experimental studies on acarine predator-prey interactions: the effects of predator density on prey consumption, predator searching efficiency, and the functional response to prey density. Canadian Journal of Zoology, 604: 611-629, 1982

Experimental studies on acarine predator-prey interactions: effects of predator age and feeding history on prey consumption and the functional response (Acarina: Phytoseiidae). Canadian Journal of Zoology, 597: 1387-1406, 1981

I Functional response prey-predator system while the prey population has group defense ability. Journal of Lanzhou University Natural Sciences. Oct 28; 365: 24-29 Sum 131, 2000

The effects of predator functional response and prey productivity on predator prey stability a graphical approach. Ecology (Washington D C) 57(3): 609-612, 1976

Consequences of size structure in the prey for predator-prey dynamics: the composite functional response. Journal of Animal Ecology 77(3): 520-528, 2008

Predator functional response and prey survival: direct and indirect interactions affecting a marked prey population. Journal of Animal Ecology 75(1): 101-110, 2006

Functional response of 2 phytoseiid mites to increased prey populations and effects initial predator to prey ratios. Piffl, E (Ed ) Proceedings Of The 4th International Congress Of Acarology, Saalfelden, Austria, Aug 1974 752p Akademiai Kiado: Budapest, Hungary Illus P647-652, 1979

Should "handled" prey be considered? Some consequences for functional response, predator-prey dynamics and optimal foraging theory. Journal of Theoretical Biology 227(2): 167-174, 2004

Functional response of two phytoseiid mites to increased prey populations and effects initial predator: prey ratios. International Congress of Acarology, 4: 647-651, 1979

Experimental studies on acarine predator prey interactions the effects of predator density on immature survival adult fecundity and emigration rates and the numerical response to prey density acarina phytoseiidae. Canadian Journal of Zoology 60(4): 630-638, 1982