Fitting models of multiple hypotheses to partial population data: investigating the causes of cycles in red grouse.
Am Nat
; 174(3): 399-412, 2009 Sep.
Article
in En
| MEDLINE
| ID: mdl-19627232
ABSTRACT
There are two postulated causes for the observed periodic fluctuations (cycles) in red grouse (Lagopus lagopus scoticus). The first involves interaction with the parasitic nematode Trichostrongylus tenuis. The second invokes delayed regulation through the effect of male aggressiveness on territoriality. Empirical evidence exists to support both hypotheses, and each hypothesis has been modeled deterministically. However, little effort has gone into looking at the combined effects of the two mechanisms or formally fitting the corresponding models to field data. Here we present a model for red grouse dynamics that includes both parasites and territoriality. To explore the single and combined hypotheses, we specify three versions of this model and fit them to data using Bayesian state-space modeling, a method that allows statistical inference to be performed on mechanistic models such as ours. Output from the three models is then examined to determine their goodness of fit and the biological plausibility of the parameter values required by each to fit the population data. While all three models are capable of emulating the observed cyclic dynamics, only the model including both aggression and parasites does so under consistently realistic parameter values, providing theoretical support for the idea that both mechanisms shape red grouse cycles.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Territoriality
/
Trichostrongylosis
/
Behavior, Animal
/
Bird Diseases
/
Trichostrongylus
/
Galliformes
/
Models, Biological
Type of study:
Etiology_studies
Limits:
Animals
Language:
En
Journal:
Am Nat
Year:
2009
Document type:
Article
Affiliation country:
United kingdom