Perry Williams

Photo of Perry Williams, Extension

Perry Williams

Associate Professor

Summary

Research

Statistical and mathematical methods for estimating population processes to improve wildlife management and conservation.

 

Teaching

Wildlife Population Dynamics (Undergrad)

Hierarchical Modeling for Natural Resources (Grad)

Education

B.A. Saint Olaf College 2006 - Biology
M.S. University of Minnesota 2008 - Wildlife Ecology
M.S. Colorado State University 2015 - Statistics
Ph.D. Colorado State University 2016 - Wildlife Ecology

News & Journal Articles, Fact Sheets, Reports...

Datasets
Geospatial data for Great Basin perennial montane watersheds - geomorphology, hydrology, vegetation, disturbance and species Board, David I.; Dilts, Thomas E.; Weisberg, Peter J.; Knight, Anna C.; Chambers, Jeanne C.; Lord, Mark L.; Miller, Jerry R. 2020, Fort Collins, CO: Forest Service Research Data Archive.
Fact Sheets
Climate variability and the specialist-generalist spectrum of germination strategies exhibited by a group of herbaceous, arid land plants. Barga, S., Dilts, T., Leger, E. A. 2017, Oecologia, 185, 437–452.
Journals
Changes in selection of resources with reproductive state in a montane ungulate. Blum, M.E., Stewart, K.M., Shoemaker, K.T. et al. 2023, Movement Ecology 11, 20
Improved topographic ruggedness indices more accurately model fine-scale ecological patterns. Dilts, T.E., Blum, M.E., Shoemaker, K.T. et al. 2023, Landscape Ecology, 38, 1395–1410
Pygmy rabbit habitat network reveals threats and opportunities for management and conservation. Dilts, Thomas E.; Zeller, Katherine A.; Cushman, Samuel A.; Larrucea, Eveline S.; Crowell, Miranda M.; Byer, Nathan W.; Shoemaker, Kevin T.; Matocq, Marjorie D. 2023, Landscape Ecology, Volume 38, pages 1971–1989
Drivers and predictions of ice phenology in mountain lakes in the Western United States derived from remote sensing. Caldwell, T.J., S. Chandra, T.P. Albright, A.A. Harpold, T. Dilts, J.A. Greenberg, S. Sadro, and M.D. Dettinger. 2021, Limnology and Oceanography.
Phenology-based classification of invasive annual grasses to the species level. Weisberg, P. J., Dilts, T. E., Greenberg, J. A., Johnson, K. N., Pai, H., Sladek, C., … Ready, A. 2021, Remote Sensing of Environment, 263, 112568
Rapidly Accelerating Deforestation in Cambodia’s Mekong River Basin: A Comparative Analysis of Spatial Patterns and Drivers. Lohani, S., Dilts, T. E., Weisberg, P. J., Null, S. E., Hogan, Z. S. 2020, Water, 12(8), 2191
Evidence of widespread topoclimatic limitation for lower treelines of the Intermountain West, United States. Urza, A. K., Weisberg, P. J., Dilts, T. E. 2020, Ecological Applications, 30(7), e02158
Development of remote sensing indicators for mapping episodic die-off of an invasive annual grass (Bromus tectorum) from the Landsat archive. Weisberg, P. J., Dilts, T., Baughman, O., Meyer, S., Leger, E. A., Van Gunst, J., Cleeves, L. 2017, Ecological Indicators, 79, 173-181.
Multi-scale connectivity and graph theory highlight critical areas for conservation under climate change. Dilts, T., Weisberg, P., Leitner, P., Matocq, M., Inman, R., Nussear, K., Esque, T. 2016, Ecological Applications, 26, 1223-1237
Impacts of climate change and renewable energy development on habitat of an endemic squirrel Xerospermophilus mohavensis in the Mojave Desert, USA. Inman, R., Esque, T., Nussear, K., Matocq, M., Leitner, P., Weisberg, P., Dilts, T. 2016, Biological Conservation, 200, 112-121
Functionally relevant climate variables for arid lands: using climatic water deficit modeling to predict distribution of desert shrub vegetation. Dilts, T., Weisberg, P. J., Dencker, C. M., Chambers, J. C. 2015, Journal of Biogeography, 42(10), 1986 - 1997.
Predicting wildfire occurrence distribution with spatial point process models and its uncertainty assessment: a case study in the Lake Tahoe Basin, USA. Yang, J., Weisberg, P. J., Dilts, T., Loudermilk, L., Scheller, R., Stanton, A., Skinner, C. 2015, International Journal of Wildland Fire, 24, 380 - 390.
Fire modulates climate change response of simulated aspen distribution across topoclimatic gradients in a semi-arid montane landscape. Yang, J., Weisberg, P. J., Shinneman, D. J., Dilts, T., Earnst, S. L., Scheller, R. M. (2015). 2015, Landscape Ecology, 30(6), 1055 - 1073.
Guild-specific responses of avian species richness to LiDAR-derived habitat heterogeneity. Weisberg, P. J., Dilts, T., Becker, M. E., Young, J. S., Wong-Kone, D. C., Newton, W. E., Ammon, E. C. 2014, Acta Oecologica, 59, 72-83.
Direct and indirect effects of irrigated agriculture on land cover change in an arid lands watershed. Dilts, T.E., Yang, J., Weisberg, P.J., Olson, T.J., Turner, P.L., and Condon, L.A. 2012, Annals of the Association of American Geographers, 102(3): 531-548.
Longitudinal- and transverse- scale environmental influences on riparian vegetation across multiple levels of ecological organization. Yang, J., T.E. Dilts, L.A. Condon, P.L. Turner, Weisberg, P.J. 2011, Landscape Ecology, 26(3): 381-395.
The Landscape Similarity Toolbox: new tools for optimizing the location of control sites in experimental studies.

Large-scale manipulative experiments are critically important for linking ecological theory with land management at a relevant spatial scale. Statistically powerful inferential approaches such as the before-after-control-impact design involve pairing a small number of treatment sites with control sites of analogous ecological structure and landscape context. Pairing treatment and control sites that are as analogous as possible is an important step to ensuring that differences are due to a treatment effect. The Landscape Similarity Toolbox provides tools for optimizing the location of potential control sites based upon the spatial characteristics of the treatment site.


Dilts, T., Yang, J., Weisberg, P. J. 2010, Ecography
Longitudinal- and Transverse-scale Environmental influences on riparian vegetation across multiple levels of ecological organization. Yang, J., Dilts, T., Condon, L. A., Turner, P. L., Weisberg, P. J. 2010, Landscape Ecology. 26 (3) 381-395
A weights-of-evidence model for mapping the probability of fire occurrence in Lincoln County, Nevada. Dilts, T., Sibold, J. S., Biondi, F. 2009, Annals of the Association of American Geographers, 99(4), 712-727.
Lay or Popular Publications
Mapping riparian vegetation with LiDAR data: Predicting plant community distribution using height above river and flood height. Dilts, T., Yang, J., Weisberg, P. J. 2010, Redlands, California: ArcUser
Presentations
Landscape Genetics of the Pygmy Rabbit (Brachylagus idahoensis) across the Sagebrush Sea of the Great Basin. M Matocq, TE Dilts, E Larrucea, P Weisberg, M Crowell, KT Shoemaker 2019, American Fisheries Society & The Wildlife Society