We used standardized regression coefficients to assess the effect size of the predictor variables on the three response variables. Continuous predictor variables were standardized and scaled by dividing their mean by two standard deviations incontri gratis uniforme (Gelman, 2008 ). sFMR and the total number of predators were log10 transformed to normalize a right-skewed distribution. Multicollinearity of continuous predictor variables was not an issue because the variance inflation factor (VIF) of all continuous predictor variables remained below 1.5 for all models. We tested the linearity between the predictors and the response variables using a generalized additive mixed model (package gamm4 version 0.2-6). The predictors had an effective degree of freedom (edf) close to 1 and were therefore linearly related to the response variables. Model selection was performed by using the “drop1” protocol of Zuur et al. ( 2009 ) and the Akaike information criteria (AIC). The fit of the models was assessed using plots of model residuals.
step three Results
For the metabolic rate models on body condition, the final model included sFMR, age class, and days since the start of the data collection, whereas for predator number models, the final model only included number of predators and age class (Table 1). The sum of the field metabolic rate of predators (sFMR) was negatively related to the body condition index of hares (Marginal R 2 = .61) (Table 1). Adult hares had a 21.8% higher body condition index than subadult (p < .001), whereas the body condition index of hares increased during the research period from autumn–winter) (p = .017). For the number of predators' models, while age class was correlated to body condition, the number of predators was not (Table 1).
For both metabolic activities and you can predator matter models with the weight of the adrenal gland, the very last design included new predator directory and you can hare gender (Desk 2)
- a models derive from sized 66 hares inside thirteen search leases compiled over a period of 34 months.
- b Human body standing list (human anatomy size/hindfoot length; Murray, 2002 ), sFMR = sum of industry metabolic process, Decades = subadult or adult, Big date = months given that beginning of the analysis range, tNP = final amount out-of predators. The next parameters had been decrease regarding latest model step 1: part of hares take to and you will intercourse of hares; last model 2: part of hares shot, sex of hares, and you may months because the start of study range.
- c Variables was standard because of the dos SD (Gelman, 2008 ).
- d * = p < .05, *** = p < .001.
- e Subadult is actually resource category.
The entire field kcalorie burning out of predators (sFMR) try seriously pertaining to the weight of the adrenals (Marginal R 2 = .14) (Desk 2). The complete quantity of predators, although not, was unrelated toward lbs out of hare adrenals (Dining table 2). While doing so, adrenal glands of women was 0.04 ± 0.017 g ( ± SE) hefty than just that of people on the design with sFMR, however regarding design on the final number regarding predators. In the two cases, new percentage of hares test, ages classification, and you may days since research have been gathered are not related on the weight of the adrenals.
For both metabolic patterns and you can predator matter patterns with the lbs of adrenal gland, the very last model provided the newest predator list and you may hare sex (Table dos)
- a designs are based on size of hares in the 13 bing search rentals accumulated over a period of 34 months.
- b sFMR = sum of career metabolism, Gender = man or woman, tNP = total number regarding predators. The next details was basically fell regarding final Models 1 and you may 2: portion of hares’ try, many years classification, and weeks because start of the investigation collection.