With respect to the former, mammalian metabolic rates exhibit significant variation across zoogeographical zones, potentially due to differences in mean climatic variables or climatic variability (Lovegrove 2000).
Distribution models characterize dimensions, generally mean climatic variables, of the current realized niche of a species based on presence-absence data and then use future climate forecasts to project changes in the distribution of suitable habitat for a species.
Mean values for climatic variables in Cyclamen based on distribution data.
Mean values for climatic variables for internal nodes of the Cyclamen phylogeny.
Correlation analyses indicate that erosion rates are more closely correlated with topographic variables, such as mean local relief and mean slope, than all of the climatic variables; and mean local relief and decadal-scale erosion rates show a linear relationship in these tectonically active mountains.
In comparison to our results using standard niche modeling techniques, the primary problem with the model and predictions used by Rodda et al. [2] is that only two climatic variables (mean monthly temperature and mean monthly rainfall) were used, and that the model lacked true presence records for the Burmese python.
As the two climatic variables, mean annual temperature and variance in monthly mean temperature, were not significantly correlated (n = 9, r = −0.46, P = 0.21), we explored both of them in the correlations analyses.
We developed "weather" models by relating climatic variables (mean temperature, rainfall, rainfall seasonality and temperature seasonality) from the three month, six month and one year period preceding each bird record over a 58 year period (1950 2008).
Anatomical parameters of earlywood (laEW, cdEW, and wtEW) and latewood (laLW, cdLW, and wtLW) were compared to climatic variables: mean air temperature and total precipitation for spring (April–June) and summer (July September), respectively.
The geographic variables considered were altitude and latitude; and the climatic variables were minimal mean temperature, maximal mean temperature, mean temperature and thermal amplitude.
To test our hypothesis, we used a multiple regression analysis to check the relationship between the population growth rate as a dependent variable and guanaco population size (in natural logs), sheep population size (in natural logs), and climatic variables (annual mean precipitation in mm/year, and winter mean temperature in °C) as independent variables.
