Meta-analysis of home range studies of Terrapene carolina and Terrapene ornata
Meta-analysis is a statistical technique that permits the use of multiple independent studies so broad patterns can be examined in ways that single studies cannot. It can have the advantage of larger sample size, which provides greater discriminating power. By performing a meta analysis of box turtle home ranges, instead of a simple narrative review, we can rigorously summarize what is known and not known about eastern box turtle home range, and test hypotheses regarding the factors that influence home range. Meta-analysis requires a thorough literature search, especially for unpublished reports, to avoid bias and a rigorous set of rules are needed to decide which studies are included. Studies are assigned weights, primarily based on sample size and Previous studies on the home ranges of box turtles have show varying results between ad within populations. This may be due the diversity of techniques used during data collection, how the collected coordinates were analyzed to measure home range, or sample size. Dodd, 2011, listed many Terrapene studies which reported home range data, but there has never been a systematic review, to quantitatively summarize evidence across studies.
After a thorough search of the literature, including unpublished thesis, to avoid publication bias, we found 21 studies analyzing Terrapene carolina home range sizes and 10 studies analyzing the home range sizes of Terrapene ornata. These led to 84 separate reported home ranges for T. carolina, and 30 reported homeranges for T. ornata. A meta-analysis of data from these papers was conducted to quantify the effects of sex, latitude, sample size, number of captures, tracking method, analysis method, and duration of study on T. carolina home range size estimation. The effects on home range size caused by translocation and repatriation were also considered. Linear regressions showed no correlation between the duration of the study or the latitude the study took place. The most statistically significant factors in home range variability were translocation and sex were shown to have the largest effects on the variability in home range size.