[R-sig-eco] von Bertalanffy growth model with explanatory variables and repeated measures

Good day, We are comparing size-at-age curves for polar bears in Southern Hudson Bay, Ontario, Canada. We hypothesized that polar bears grew more slowly and possibly had smaller maximum sizes in recent years compared to previously. Preliminary examination of the data supports this hypothesis,

[R-sig-eco] inference from GLMM fit using glmer

Good day R.sig.ecology members. We seem to have detected highly significant fixed effects from a GLMM fit using glmer, despite having a fairly small sample size (30 observations, 4 groups in the random factor). We are hoping that group members can either verify that we are interpreting these r

[R-sig-eco] Minta's (1992) tests of temporal interactions

Hello, Is anyone aware of an R package for performing the tests described by Minta (1992) Tests of spatial and temporal interaction among animals. Ecological Applications 2:178 - 188? Thank you, Eric [[alternative HTML version deleted]] ___

[R-sig-eco] save graphics as tiff

Good day list members, I can't save my plot as a .tiff using Cairo (error message: "not supported") or the tiff() function (error message: "unable to start tiff device"). Does anyone know of a fix for this, or another way to save a plot as a tiff? Thank you, Eric Howe [[alternat

[R-sig-eco] omit levels from boxplots

Good day list members, I was wondering if anyone knows a way to omit specific columns or anova cells from boxplots. E.g. I produce a boxplot as: >boxplot(y ~ ageclass + sex,data=dat) where ageclass has 4 levels (including 1-year-old), and sex has 2 levels, but the only males inclu

[R-sig-eco] using dpik (pkg KernSmooth) to estimate bandwiths for kernel home range estimation

Hi list members, I'm trying to use the dpik function (pkg = KernSmooth) to calculate bandwidths (following Wand & Jones 1995) for use in estimating kernel home ranges from location data. I was hoping to use function kernelUD (pkg =adehabitatHR) to estimate the home ranges, passing the dpik ban

[R-sig-eco] Spatiotemporal interactions among animals

Hello, Does anyone know if there's an R package that implements the methods of Minta (1992) "Tests of spatial and temporal interaction among animals", for testing for attraction to / avoidance of areas of overlap and other animals within areas of overlap? Thanks, eric [[alternative

[R-sig-eco] function clusthr in adehabitatHR

Good day list members, I'm using the function clusthr in the adehabitatHR package to replicate an analysis begun years ago using Ranges6 software. Authors used Kenward et al.'s (2001) modified nearest-neighbor cluster analysis to generate outlier-exclusive convex polygons. They used Kenward et

[R-sig-eco] memory size limits

Hello, When trying to fit spatially-explicit capture recapture models with a larger number of parameters, using the package secr, I get the following error message: > gH.yr.sH.jc.session=secr.fit(seeh69, model=list(g0~h2+yr, sigma~h2+jc+session), mask=masklist,CL=T,detectfn=1,timecov=timecovs,

Re: [R-sig-eco] hierarchical partitioning: type of R-squared

Good day Clement, and R users, I've used the hier.part package. I think that conceptually, if the form of relationship with the dependent variable differs among independent variables, hier.part won't provide unbiased results. Different samples from the same population should yield the same est

[R-sig-eco] significance of penalized regression coefficients from ridge regression

Hi all, I've been struggling with multicollinearity in a time series data set. My 2 predictors are collinear because there is a biennial pattern in the data (masting shrubs), and one of the predictors is just the response variable (berry production) at t-1, and the other (a measure of soil mois