Summary1. Spatial analysis has become increasingly popular in the biological sciences, particularly in disciplines such as landscape ecology and landscape genetics. However, many statistical functions for performing spatial analysis are not readily available (except in the most limited manner) in common, easy-to-use statistical packages or geographic information systems (GIS) software. 2. Over the last decade, the software package Pattern Analysis, Spatial Statistics and Geographic Exegesis (PASSaGE) has been popular tool for conducting spatial statistics. PASSaGE is completely free and has a user-friendly graphical user interface. A new version of PASSaGE, rewritten from the ground up, has now been released and is available for download. 3. PASSaGE 2 is significantly more user friendly than the original release and provides an excellent platform for both scientific analysis and classroom training. PASSaGE 2 includes a broad array of spatial statistical analyses not commonly found in other software packages or GIS software, all in an easy-to-use framework. It includes support for one-, two-and three-dimensional spatial analysis, including a number of unique and newly developed approaches.

Landscape features exist at multiple spatial and temporal scales, and these naturally affect spatial genetic structure and our ability to make inferences about gene flow. This article discusses how decisions about sampling of genotypes (including choices about analytical methods and genetic markers) should be driven by the scale of spatial genetic structure, the time frame that landscape features have existed in their current state, and all aspects of a species' life history. Researchers should use caution when making inferences about gene flow, especially when the spatial extent of the study area is limited. The scale of sampling of the landscape introduces different features that may affect gene flow. Sampling grain should be smaller than the average home-range size or dispersal distance of the study organism and, for raster data, existing research suggests that simplifying the thematic resolution into discrete classes may result in low power to detect effects on gene flow. Therefore, the methods used to characterize the landscape between sampling sites may be a primary determinant for the spatial scale at which analytical results are applicable, and the use of only one sampling scale for a particular statistical method may lead researchers to overlook important factors affecting gene flow. The particular analytical technique used to correlate landscape data and genetic data may also influence results; common landscape-genetic methods may not be suitable for all study systems, particularly when the rate of landscape change is faster than can be resolved by common molecular markers.

Ten microsatellite loci were characterized for 34 locations from roundtail chub (Gila robusta complex) to better resolve patterns of genetic variation among local populations in the lower Colorado River basin. This group has had a complex taxonomic history and previous molecular analyses failed to identify species diagnostic molecular markers. Our results supported previous molecular studies based on allozymes and DNA sequences, which found that most genetic variance was explained by differences among local populations. Samples from most localities were so divergent species-level diagnostic markers were not found. Some geographic samples were discordant with current taxonomy due to admixture or misidentification; therefore, additional morphological studies are necessary. Differences in spatial genetic structure were consistent with differences in connectivity of stream habitats, with the typically mainstem species, G. robusta, exhibiting greater genetic connectedness within the Gila River drainage. No species exhibited strong isolation by distance over the entire stream network, but the two species typically found in headwaters, G. nigra and G. intermedia, exhibited greater than expected genetic similarity between geographically proximate populations, and usually clustered with individuals from the same geographic location and/or sub-basin. These results highlight the significance of microevolutionary processes and importance of maintaining local populations to maximize evolutionary potential for this complex. Augmentation stocking as a conservation management strategy should only occur under extreme circumstances, and potential source populations should be geographically proximate stocks of the same species, especially for the headwater forms.

A major technology break in snake biology was the publication of surgical protocols for implanting radiotransmitters in the body cavities of snakes. While many researchers have reported using some variant of these protocols successfully, protocol details often vary from study to study and best-practice procedures are not easily determinable given the variety of circumstances over which studies occur. Although professional society standards and federal regulations make explicit recommendations about this surgical procedure, some of the nonstandard techniques recommended for this protocol may raise the eyebrows of institutional animal care and use committees. In this commentary we discuss regulatory and logistical aspects of the intracoelmic radiotransmitter implant procedure for snakes, and we provide a pragmatic framework for choosing among surgical variables. (WILDLIFE SOCIETY

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