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Lab of Dr. Butch Weckerly



some kind of pig
Floyd (Butch)
Weckerly, Ph.D.
Professor of Biology
Phone: 512-245-3353
Fax: 512-245-8713

a picure of a lot of pigs


Mailing Address:
Department of Biology
Texas State University
601 University Drive
San Marcos, TX 78666



My research examines individual and population response to environmental heterogeneity. Most of my work has been with vertebrate species, primarily large herbivores. Many of the studies I conduct provide information useful to conserving and managing populations, communities and ecosystems.

  • Duarte, A., F. W. Weckerly, M. Schaub, and J. S. Hatfield. 2016. Estimating golden-cheeked warbler immigration: implications for the spatial scale of conservation. Animal Conservation 19:65-74. [pdf]
  • Duarte, A., J. S. Hatfield, J. D. Nichols, T. M. Swannack, M. R. J. Forstner, M. C. Green, and F. W. Weckerly. 2016. Simulating range-wide population and breeding habitat dynamics for an endangered woodland warbler in the face of uncertainty. Ecological Modeling 320:52-61(International) [pdf]
  • Weaver, S. P., T. R. Simpson, J. T. Baccus, and F. W. Weckerly. 2015. Baseline population estimates and microclimate data for newly established overwintering Brazilian free-tailed bat colonies in central Texas. Southwestern Naturalist 60:151-157. (Regional) [pdf]
  • Kolbe, N. R., and F. W. Weckerly. 2015. Home-range overlap of Roosevelt elk herds in the Bald Hills of Redwood National Park. California Fish and Game 101:208-217. (Regional) [pdf]
  • Aiken, M. R. E., D. M. Wolcott, A. Duarte, R. S. Luna, H. D. Starns, and F. W. Weckerly. 2015. Use of rumen-reticulum fill to examine nutrient transfer and factors influencing food intake in white-tailed deer. Canadian Journal of Zoology 93:439-445. (International) [pdf]
  • Wolcott, D. M., R. L. Reich, and F. W. Weckerly. 2015. Biological and environmental influences on parturition date and birth mass of a seasonal breeder. PLOS One 10(4): e0124431(International) [pdf]
  • Thalmann, J. C., R. T. Bowyer, K. A. Aho, F. W. Weckerly, and D. R. McCullough. 2015. Antler and body size in black-tailed deer: an analysis of cohort effects. Ecological Advances 2015:Article ID 156041. [pdf]
  • Starns, H. D., F. W. Weckerly, A. D. Duarte, and M. A. Ricca. 2015. Vegetation changes associated with a population irruption by Roosevelt elk. Ecology and Evolution 5:109-120. [pdf]
  • Wolcott, D. M., J. L. Asmus, and F. W. Weckerly.  2014. Overcoming cohort effects in a Mediterranean ecosystem: the role of density and precipitation on southern mule deer body mass. Journal of Wildlife Management 79: 1335-1342[pdf]
  • Duarte, A., J. E. Hines, J. D. Nichols, J. S. Hatfield, and F. W. Weckerly. 2014. Age-specific survival of male Golden-cheeked Warblers on the Fort Hood Military Reservation. Avian Conservation and Ecology 9:a4. [pdf]
  • Aiken, M. R. E., A. Duarte, R. S. Luna, D. M. Wolcott, and F. W. Weckerly. 2014. Daytime declines in rumen-reticulum fill of male white-tailed deer (Odocoileus virginianus) from south Texas. Canadian Journal of Zoology 92:637-642. [pdf]
  • Starns, H. D., A. Duarte, M. A. Ricca, and F. W. Weckerly. 2014. Climatic and density influences on recruitment in an irruptive population of Roosevelt elk. Journal of Mammalogy 95:925-932. [pdf]
  • Duarte, A., R. S. Luna, H. S. Starns, and F. W. Weckerly. 2014. Intraspecific scaling of rumen-reticulum fill might depend on dietary fiber. American Midland Naturalist 172:330-338. [pdf]
  •  Ricca, M. A., Van Vuren, D. F. W. Weckerly, K. Miles, and J. Williams. 2014. Irruptive dynamics of introduced caribou on Adak Island, Alaska: an evaluation of Riney-Caughley model predictions. Ecoshere 5:a94 (24 p). [pdf]
  • Weckerly, F. W., and M. A. Ricca. 2014. Aggression and coexistence in female caribou. Arctic 67:189-195. [pdf]
  • Parra, C. A., A. Duarte, R. S. Luna, D. M. Wolcott, and F. W. Weckerly. 2014. Body weight, age, and reproductive influences on liver weight of white-tailed deer. Canadian Journal of Zoology 92: 273-278. [pdf]
  • Duarte, A., J. L. R. Jensen, J. S. Hatfield, and F. W. Weckerly. 2013. Spatiotemporal variation in range-wide golden-cheeked warbler breeding habitat. Ecosphere 4:Article 152. [pdf]
  • Warren, C. C., J. A. Veech, F. W. Weckerly, L. O’Donnell, and J. R. Ott. 2013. Detection heterogeneity and abundance estimation in populations of golden-cheeked warblers (Setophaga chrysoparia). The Auk 130: 677-688. [pdf]
  • Luna, R. L., A. Duarte, and F. W. Weckerly.  2013. Influence of body size on dietary nutrition of white-tailed deer Odocoileus virginianus. Journal of Fish and Wildlife Management 4:53-62. [pdf]
  • Luna, R. S., and F. W. Weckerly. 2013. Variation across years in rumen-reticulum capacity and digesta load in white-tailed deer (Odocoileus virginianus). Southeastern Naturalist 12:283-296. [pdf]
  • Street, G. M., F. W. Weckerly, and S. Schwinning. 2013. Modeling forage mediated aggregation in a gregarious ruminant. Oikos 122:929-937. [pdf]
  • Weckerly, F. W.  2013.  Conspecific body weight, food intake, and rumination time affect food processing and forage behavior.  Journal of Mammalogy 94:120-126.b [pdf]
  • Luna, R. S., A. Duarte, and F. W. Weckerly. 2012. Rumen-reticulum characteristics, scaling relationships and ontogeny in white-tailed deer (Odocoileus virginianus). Canadian Journal of Zoology 91:1351-1358. [pdf]
  • Hatfield, J. S., Duarte, A., and F. W. Weckerly.  2012. Shifting foundations and metrics for recovery.  Wildlife Society Bulletin 36:415-422[pdf]
  • Ricca, M. A., F. W. Weckerly, and A. Duarte.  2012.  Range expansion of nonindigenous caribou in the Aleutian archipelago of Alaska.  Biological Invasions 14:1779-1784. [pdf]
  • Weckerly F. W.  2012.  Cave cricket exit counts: environmental influences and length of surveys.  Journal of Cave and Karst Studies 74:1-6. [pdf]
  • Hunt, J. W., F. W. Weckerly, and J. R. Ott.  2012.  Reliability of occupancy and binomial mixture models for estimating abundance of golden-cheeked warblers (Dendroica chyrsoparia).  The Auk 129:105-114. [pdf]
  • Weaver, S. P., and F. W. Weckerly. 2011.  Sex ratio estimates of Roosevelt elk using counts and Bowden’s estimator.  California Fish and Game 97:130-137. [pdf]
  • Duarte, A., F. W. Weckerly, and D. R. McCullough. 2011.  Does rumen-reticulum capacity correlate with body size or age?  European Journal of Wildlife Research 57:1131-1136. [pdf]
  • Asmus, J. L., and F. W. Weckerly. 2011. Evaluating the Precision of Cementum Annuli Analysis for Aging Mule Deer from Southern California. Journal of Wildlife Management 75:1194-1199. [pdf]
  • Duarte, A., F. W. Weckerly, and D. R. McCullough. 2011. Does rumen-reticulum capacity correlate with body size or age? European Journal of Wildlife Research 57:1131-1136. [pdf]
  • Robinson, S. E., and F. W. Weckerly. 2010. Forage selection and grouping by male and female scimitar-horned oryx in the Llano Uplift region of Texas. Southwestern Naturalist 55:510-516. [pdf]
  • Weaver, S. P., and F. W. Weckerly. 2011. Sex ratio estimates of Roosevelt elk using counts and Bowden’s estimator. California Fish and Game 97:130-137. [pdf]
  • Weckerly, F. W., and J. A. Foster.  2010.  Blind count surveys of white-tailed deer and population estimates using Bowden’s estimators.  Journal of Wildlife Management 74:1367-1377. [pdf]
  • Faas, C. J., and F. W. Weckerly.  2010.  Habitat interference by axis deer on white-tailed deer.  Journal of Wildlife Management 74:698-706. [pdf]
  • Gaston, M. A., A. Fujii, F. W. Weckerly, and M. R. J. Forstner.  2010.  Potential component Allee effects and their impact on wetland management in the conservation of endangered anurans. PLOS One 5(4):e10102. [pdf]
  • Weckerly, F. W. 2010.  Allometric scaling of rumen-reticulum capacity in white-tailed deer Odocoileus virginianus.  Journal of Zoology ( London) 280:41-48. [pdf]
  • Ferguson , A. W., N. A. Currit, and F. W. Weckerly.  2009.  Isometric Scaling in Home Range Size of Male and Female Bobcats (Lynx rufus).  Canadian Journal of Zoology 87:1052-1060. [pdf]
  • Watson, C. A., F. W. Weckerly, J. S. Hatfield, C. C. Farquhar, and P. S. Williamson.  2008.  Presence – Nonpresence surveys of golden-cheeked warblers: detection, occupancy, and survey effort.  Animal Conservation 12:484-492. [pdf]
  • Krejca, J. K., and B. Weckerly.  2008.  Detection probabilities of Karst invertebrates.  Proceedings of the Cave and Karst Management Symposium 18:283-289. [pdf]
  • Ferguson, A. W., F. W. Weckerly, J. T. Baccus, and M. R. J. Forstner. 2008.  Evaluation of Predator Attendance at Pitfall Traps in Texas.  Southwestern Naturalist 53:450-457. [pdf]
  • Jones, R. L., F. W. Weckerly, and D. R. McCullough. 2008. Influence of age and sex on dressed–whole weight relationships in a California black-tailed deer population. California Fish and Game 94:137-142. [pdf]
  • Shelton, S. L., and F. W. Weckerly. 2007. Inconsistencies in historical geographic range maps: the gray wolf as example. California Fish and Game 93:224-227. [pdf]
  • Richardson, K. E., and F. W. Weckerly. 2007. Intersexual social behavior of urban white-tailed deer and its evolutionary implications. Canadian Journal of Zoology 85:759-766 [pdf]
  • Ramzinski, D. M., and F. W. Weckerly. 2007. Scaling relationships between body weight and fermentation gut capacity in Axis deer. Journal of Mammalogy 88:415-420. [pdf]
  • Weckerly, F. W. 2007. Constant proportionality in the female segment of a Roosevelt elk population. Journal of Wildlife Management 71:773-777 [pdf]
  • Longoria, M. P., and F. W. Weckerly. 2007. Estimating detection probabilities from sign of Collared Peccary. Journal of Wildlife Management 71:652-655. [pdf]
  • Jackson, J. T., F. W. Weckerly, T. M. Swannack, and M. R. J. Forstner. 2006. Inferring absence of Houston Toads given imperfect detection probabilities. Journal of Wildlife Management 70:1461-1463. [pdf]
  • Weckerly, F. W., M. L. Kennedy, and S. Stephenson. 2006. Hunter effort-harvest size relationships among hunt types of white-tailed deer. Wildlife Society Bulletin 33:1303-1311.
  • Keifer, S. J., and F. W. Weckerly. 2005. Population density and body weight influences on home range size of feral hogs. California Fish and Game 91:136-142
  • Weckerly, F. W. 2005. Grass and supplemental patch selection in a population of Roosevelt elk. Journal of Mammalogy 86:630-638.
  • Weckerly, F. W., K. A. McFarland, M. A. Ricca and K. P. Meyer. 2004. Cropping rates, social affinity and sexual segregation in Roosevelt elk when population density changes. American Midland Naturalist 152:386-399.
  • Small, M. F., R. Rosales, J. T. Baccus, F. W. Weckerly, D. N. Phalen and J. A. Roberson. 2004. A comparison of effects of radiotransmitter attachment techniques on captive white-winged doves. Wildlife Society Bulletin 32:627-637. 
  • Weckerly, F. W. 2004. Movement of male and female black-tailed deer foraging on acorns. Northwestern Naturalist 85:16-19. 
  • Weckerly, F. W., V. C. Bleich, C. B. Chetkiewicz, and M. A. Ricca. 2003. Body weight and rumen-reticulum capacity in tule elk and mule deer. Journal of Mammalogy 84:659-664. 
  • Weckerly, F. W., Ricca, M. A., and K. P. Meyer. 2001. Sexual Segregation in Roosevelt Elk: Cropping Rates and Aggression in Mixed-sex Groups. 82:825-835. 
  • Weckerly, F. W. 2001. Are large male Roosevelt elk less social because of aggression? Journal of Mammalogy 82:414-421. 
  • Weckerly, F. W., and M. A. Ricca. 2000. Using the presence of sign to measure habitats used by Roosevelt elk. Wildlife Society Bulletin 28:146-153. 
  • Weckerly, F. W. 1999. Social bonding and aggression in fiale Roosevelt elk. Canadian Journal of Zoology 77:1379-1384. 
  • Weckerly, F. W. 1998. Sexual segregation and competition in Roosevelt elk (Cervus elaphus roosevelti ). Northwestern Naturalist 79:113-118.
  • Weckerly, F. W., and K. E. Kovacs. 1998. Using military helicopters to survey elk in north coastal California. California Fish and Game 84:44-47.
  • Weckerly, F. W. 1998. Sexual size dimorphism: influence of mass and mating systi in the most dimorphic mammals. Journal of Mammalogy 79:33-52.
  • Weckerly, F. W. 1996. Roosevelt elk along the Prairie Creek drainage: an evaluation of estimating abundance and herd composition. California Fish and Game 82:175-181. 
  • Ricca , M. A., F. W. Weckerly, and R. D. Silitsch. 1996. The effects of soil moisture and tiperature on overwinter survival of Curculio larvae (Coleoptera:Curculionidae). The American Midland Naturalist 136:203-206. 
  • Main , M. M., F. W. Weckerly, and V. C. Bleich. 1996. Sexual segregation in ungulates: new directions for research. Journal of Mammalogy 77:449-461.
  • Weckerly, F. W. 1994. Selective feeding behavior of black-tailed deer: forage quality or abundance? Journal of Mammalogy 75:705-713.
  • Massey, B. N., F. W. Weckerly, C. E. Vaughn, and D. R. McCullough. 1994. Correlations between fecal N and diet composition in free-ranging black-tailed deer. The Southwestern Naturalist 39:165-170.
  • McCullough, D. R., F. W. Weckerly, P. I. Garcia, and R. R. Evett. 1994. Sources of inaccuracy of deer herd composition counts. Journal of Wildlife Managient 58:319-329.
  • Weckerly, F. W. 1993. Intersexual resource partitioning in black-tailed deer: a test of the body size hypothesis. Journal of Wildlife Managient 57:475-494.
  • Weckerly, F. W. 1992. Territoriality in North American Odocoileus: a call for a common definition. Wildlife Society Bulletin 20:228-231.
  • Weckerly, F. W., and M. L. Kennedy. 1992. Examining hypotheses about feeding strategies of white-tailed deer. Canadian Journal of Zoology 70:432-439.
  • Kennedy, M. L., J. P. Nelson, Jr., F. W. Weckerly, D. W. Sugg, and J. C. Stroh. 1991. An assessment of selected forest factors and lake level in raccoon managient. Wildlife Society Bulletin 19:151-154.
  • Weckerly, F. W., and J. P. Nelson, Jr. 1990. Age and sex differences of white-tailed deer diet composition, quality, and calcium in Tennessee. Journal of Wildlife Managient 54:532-538.
  • Weckerly, F. W., K. E. Nicholson, and R. D. Semlitsch. 1989. Experimental test of discrimination of insect infested and noninfested acorns by squirrels. American Midland Naturalist 122:412-415.
  • Weckerly, F. W., D. W. Sugg, and R. D. Semlitsch. 1989. Germination success of acorns (Quercus): insect predation and tannins. Canadian Journal of Forest Research 19:811-815.
  • Weckerly, F. W. 1989. Plasticity in length of hindgut segments of white-tailed deer. Canadian Journal of Zoology 67:189-193.
  • Weckerly, F. W., A. L. Gennaro, and T. L. Best. 1988. Description of a new rock pocket mouse, Chaetodipus intermedius, from New Mexico lava fields. The Southwestern Naturalist 33:100-102.
  • Weckerly, F. W., P. L. Leberg, and M. L. Kennedy. 1987. Density estimates of the Virginia Opossum (Marsupialia:Didelphidae) in western Tennessee. Tennessee Acadiy of Science 62:108-110.
  • Weckerly, F. W., P. L. Leberg, and R. A. Van Den Bussche. 1987. Variation of weight and chest girth in white-tailed deer. Journal of Wildlife Managient 51:334-337.
  • Pfaffenberger , G. S., F. W. Weckerly, and T. L. Best. 1986. Male pseudohermaphroditism in a population of kangaroo rats, Dipodomys ordii. Southwestern Naturalist 30:124-125.
  • Weckerly, F. W., and T. L. Best. 1985. Morphological variation among rock pocket mice, Chaetodipus intermedius, from New Mexico lava fields. Southwestern Naturalist 30:491-501.


Dissertations Directed

  • Wolcott, Daniel. M. 2015. Biological and environmental influences on developmental variation of ungulates in variable environments.
  • Duarte, Adam. 2015. Population dynamics and habitat conservation for the golden-cheeked warbler (Setophaga chrysoparia). [Co-chaired Dr. Jeff Hatfield, Patuxent Wildlife Research Center]
  • Luna, Ryan. S. 2013. Body size, rumen-reticulum functions and dietary nutrition of white-tailed deer.


  • Peterson, Leah M.2016. Social Factors during foraging bouts influence sexual segregation in Roosevelt elk.
  • Kolbe,Nicholas R.2016. Density-dependent not-independent factors influence Roosevelt elk recruitment in the Bald Hills of Redwood National Park.
  • Bhaskar, Gayatri. 2015. Rumen-reticulum and liver mass relationships in white-tailed deer ( Odocoileus virginianus ) differ between females and males.
  • Aiken, Meredith, R. E. 2014. Variation in rumen-reticulum fill in white-tailed deer (Odocoileus virginianus).
  • Starns, Heath, D. Spring 2014. Influence of a population irruption by Roosevelt elk on a vegetation index.
  • Parra, Claire, A. Fall 2012. Body weight and age influences on liver weight in white-tailed deer (Odocoileus virginianus): implications for reproductive effort.
  • Warren, Christopher C. (Co-chair Jim Ott) Fall 2011.  Singing behavior leads to detection bias in a territorial songbird. 
  • Duarte, Adam.  Spring 2011.  Dynamics of rumen-reticulum capacity and fill in white-tailed deer (Odocoileus virginianus).
  • Jonker, Amber L.  Fall 2010. Modeling the relationship between estimates of local occupancy and local abundance in avian species.
  • Hunt, Jason W.  (Co-chair Jim Ott) Summer 2010.  Estimating occupancy and abundance of golden-cheeked warblers (Dendroica chrysoparia) in central Texas. 
  •  Street, Garrett M.  Spring 2010.  Forage abundance as the impetus for large ruminant aggregation: a modeling approach. 
  • Faas, Clinton J.  Summer 2008.   Habitat interference by exotic axis deer (Axis axis) on native white-tailed deer (Odocoileus virginianus) in Texas. 
  • Robinson, Sarah E.  Summer 2008.  Forage selection and grouping patterns of male and female scimitar-horned oryx (Oryx dammah) on Mason Mountain Wildlife Area, Mason, Texas. 
  • Myrick, Katherine. (Co-chair Jeff Hatfield).  Spring 2008.  Plant species and vertebrate species richness in National Parks in the Eastern United States. 
  • Watson, Cynthia, A. (Co-chair Paula Williamson).  Summer 2006.  Estimating detection probabilities of Golden-cheeked Warblers. 
  • Richardson, Katherine.  Summer 2006.  Sexual segregation in urban white-tailed deer: social incompatibility or predation risk? 
  • Ramzinski, Dawn.  Spring 2006.  Scaling relationship between body weight and gut capacity in Axis deer (Cervus axis). 
  • Francis, Deena R.  Spring 2005.  Influence of opening weekend and weather on white-tailed deer harvests at Milan Army Ammunition Plant, Tennessee. 
  • Longoria, Meredith P.  Fall 2004.  Using motion-triggered cameras to estimate habitat use by Collared Peccaries.