Citation:

HEMMINGS, V., J. JAEGER, M. SREDL, M. SCHLAEPFER, R. JENNINGS, C. PAINTER, D. F. BRADFORD, AND R. BRETT. PHYLOGEOGRAPHY OF RANA YAVAPAIENSIS AND RANA ONCA: PRELIMINARY FINDINGS WITH CONSERVATION IMPLICATIONS. Presented at Annual Meeting of California-Nevada Amphibian Populations Task Force, Las Vegas, NV, January 18 - 20, 2007.

Impact/Purpose:

The primary objectives of this research are to:

Develop methodologies so that landscape indicator values generated from different sensors on different dates (but in the same areas) are comparable; differences in metric values result from landscape changes and not differences in the sensors;

Quantify relationships between landscape metrics generated from wall-to-wall spatial data and (1) specific parameters related to water resource conditions in different environmental settings across the US, including but not limited to nutrients, sediment, and benthic communities, and (2) multi-species habitat suitability;

Develop and validate multivariate models based on quantification studies;

Develop GIS/model assessment protocols and tools to characterize risk of nutrient and sediment TMDL exceedence;

Complete an initial draft (potentially web based) of a national landscape condition assessment.

This research directly supports long-term goals established in ORDs multiyear plans related to GPRA Goal 2 (Water) and GPRA Goal 4 (Healthy Communities and Ecosystems), although funding for this task comes from Goal 4. Relative to the GRPA Goal 2 multiyear plan, this research is intended to "provide tools to assess and diagnose impairment in aquatic systems and the sources of associated stressors." Relative to the Goal 4 Multiyear Plan this research is intended to (1) provide states and tribes with an ability to assess the condition of waterbodies in a scientifically defensible and representative way, while allowing for aggregation and assessment of trends at multiple scales, (2) assist Federal, State and Local managers in diagnosing the probable cause and forecasting future conditions in a scientifically defensible manner to protect and restore ecosystems, and (3) provide Federal, State and Local managers with a scientifically defensible way to assess current and future ecological conditions, and probable causes of impairments, and a way to evaluate alternative future management scenarios.

Description:

The closely related aridland frogs Rana onca (Relict Leopard Frog) and Rana yavapaiensis (Lowland Leopard Frog) have both experienced dramatic population declines. Rana onca currently occurs naturally at only 6 disjunct sites in southern Nevada. Rana yavapaiensis is present across central and SE Arizona, but it is patchily distributed in portions of its Arizona range and has disappeared from California and most of its New Mexico range. Although recent observations from Sonora, Mexico exist, the status of these populations is unknown. Our project will inform conservation strategies for both species by investigating phylogeography and population structure. In our current analysis of 202 frog samples, preliminary results from

mitochondrial DNA (mtDNA) markers (ND2 and a portion of cyt b genes) recovered the previously observed phylogenetic break between R. onca and R. yavapaiensis. Levels of sequence divergence and applied rates of sequence evolution allow us to postulate that these

species' DNA gene lineages separated during the early Pleistocene, possibly prior to the onset of major climatic oscillations. A recently discovered population of leopard frogs from the western Grand Canyon (i.e., Surprise Canyon) represents a R. yavapaiensis population with clear

mtDNA distinction from other R. yavapaiensis populations in Arizona and Mexico. This disjunct population may have separated from Arizona and Mexico populations prior to the latest Pleistocene glacial period. Surprisingly, R. yavapaiensis from across its main distribution in Arizona and into Mexico shows very little genetic diversity, suggesting a recent range expansion from some unsampled location in Mexico.

Record Details: