The influence of wildlife water developments and vegetation on rodent abundance in the Great Basin Desert

Rodent communities have multiple functions including comprising a majority of the mammalian diversity within an ecosystem, providing a significant portion of the available biomass consumed by predators, and contributing to ecosystem services. Despite the importance of rodent communities, few investigations have explored the effects of increasing anthropogenic modifications to the landscape on rodents. Throughout the western United States, the construction of artificial water developments to benefit game species is commonplace. While benefits for certain species have been documented, several researchers recently hypothesized that these developments may cause unintentional negative effects to desert-adapted species and communities. To test this idea, we sampled rodents near to and distant from wildlife water developments over 4 consecutive summers. We employed an asymmetrical before-after-control-impact (BACI) design with sampling over 4 summers to determine if water developments influenced total rodent abundance. We performed an additional exploratory analysis to determine if factors other than free water influenced rodent abundance. We found no evidence that water developments impacted rodent abundance. Rodent abundance was primarily driven by vegetation type and year of sampling. Our findings suggested that water developments on our study area do not represent a significant disturbance to rodent abundance and that rodent abundance was influenced by the vegetative community and temporal factors linked to precipitation and primary plant production. Our findings represent one of the 1st efforts to determine the effects of an anthropogenic activity on the rodent community utilizing a manipulation design

Field replication of classwide peer tutoring.

We conducted a large-scale field replication study of classwide peer tutoring applied to spelling instruction (Greenwood, Delquadri, & Hall, 1984). Two hundred and eleven inner-city students in four schools participated during their first- and second-grade school years. The effects of classwide peer tutoring were compared to teacher instructional procedures and pretest probes using a group replication design (Barlow, Hayes, & Nelson, 1984). Analysis of group and individual results indicated that (a) both teacher instructional procedures and classwide peer tutoring were effective in increasing spelling performance above pretest levels, (b) peer tutoring produced statistically greater gains relative to the teachers' procedures for both low and high student groups formed on pretest levels, (c) these outcomes were representative of groups, classes, individuals, and years during the project, and (d) participant satisfaction with the program was generally high. A separate analysis of the social importance of treatment outcome revealed differential findings for low and high groups related to pretest levels. Implications of these findings are discussed