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1

Applications of the eater-food model to predator-prey-food cycles

100%
Garding L.
Polish Journal of Ecology
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2007
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tom 55
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nr 1
This note gives five applications of the eater-food interaction model (Gårding 2005) where cycle length is a function of the eater average birth rate defined as the inverse of average life span. The model extends to an analysis of predator-prey-food cycles (Gårding 2000). Here the cycle length is the same as that of en eater-food interaction whose average ’birth rate’ is the sum of the average birth rates of the predator-prey and prey-food interactions.
2

The response of lions (Panthera leo) to changes in prey abundance on an enclosed reserve in South Africa

84%
Bissett C., Bernard R. T. F., Parker D. M.
Acta Theriologica
|
2012
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tom 57
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nr 3
Large mammalian carnivores place significant pressure on their prey populations and this is exacerbated within the fenced reserves of Africa. However, foraging theory predicts that diet switching by predators may mitigate this pressure. In this study, we use data collected between 2003 and 2007 from an enclosed system in the Eastern Cape Province of South Africa to examine the response of lions Panthera leo to changes in the abundance of two important prey species — kudu Tragelaphus strepsiceros and warthog Phacochoerus africanus. As the relative abundance of warthogs increased, the number of kudu kills decreased significantly, whereas warthog kills became significantly more frequent. A similar pattern was observed for lion prey preference and the switch from kudu to warthog was also reflected in a significant decrease in the mean prey mass. Our results suggest that a diet shift occurs in lions and that the change in diet is primarily in response to an increase in warthog numbers. Prey switching may promote the persistence of predator–prey systems, which is particularly important for fenced systems where natural immigration of prey is not possible. However, continued collection and analysis of long-term observational data from the multipredator, multiprey systems of Africa is required to facilitate a full understanding of predator–prey dynamics.
3

Induced defence in the ciliate Euplotes octocarinatus is reduced when alternative prey are available to the predator

84%
Kolaczyk A., Wiackowski K.
Acta Protozoologica
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1997
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tom 36
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nr 1
4
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Content available

Impact of prey field variability on early cod larval survival: a sensitivity study of a Baltic cod Individual-based Model

67%
Schmidt J. O., Hinrichsen H.-H.
Oceanologia
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2008
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tom 50
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nr 2
205-220
Existing coupled biophysical models for Baltic larval cod drift, growth and survival use idealised constructed mean prey fields of nauplius distributions. These simulations revealed the best feeding conditions for Baltic cod larvae longer than 6 mm. For shorter, first feeding larvae (between 4.5 and 6 mm) pronounced differences in growth and survival were observed, which depend on food availability and to a lesser degree on ambient temperature. We performed runs with an Individual-based Model (IBM) for Baltic cod larvae in order to demonstrate how natural variability in prey abundance influences the survival success of first feeding larvae. In the Baltic, this larval stage lives mainly between 20 and 40 m depth and feeds exclusively on the nauplii of different calanoid copepods (Acartia spp., Pseudocalanus acuspes, Temora longicornis and Centropages hamatus). Prey data obtained from vertically stratified samples in the Bornholm Basin (Baltic Sea) in 2001 and 2002 indicate a strong variability at spatial and temporal scales. We calculated larval survival and growth in relation to natural variation of prey fields, i.e. species-specific nauplius abundance. The results of the model runs yielded larval survival rates from 60 to 100% if the mean size of nauplii species was taken and lower survival if prey consisted of early nauplius stages only.
5
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The influence of raptors (Falconiformes) and ravens (Corvus corax) on populations of game animals

67%
Gryz J., Krauze-Gryz D.
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
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2014
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tom 86
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