Julie A. Savidge, Professor
Department of Fish, Wildlife and Conservation Biology
&
Graduate Degree Program in Ecology
Colorado State University
Ft. Collins, CO 80523-1474

Office: (970) 491-6510
FAX: (970) 491-5091
Email: julie.savidge@.colostate.edu

Education:
B.S. in Zoology, Colorado State University, 1975
M.S. in Wildland Resource Science, University of California, Berkeley, 1977
Ph.D. in Biology, University of Illinois, 1986

My lab has worked with a variety of different taxa and in several different ecosystems, from Burrowing Owls in short-grass prairie to exotic rats in the US Virgin Islands. Past themes have included determinants of biodiversity, factors affecting habitat selection and/or reproductive success of sensitive species, and impacts and management of exotics. Much of my work has been conducted in the Mariana Islands, located in the Pacific, and has centered on various aspects of and ramifications from the Brown Treesnake introduction to Guam.

My early research identified exotic Brown Treesnakes as the cause of the drastic avian declines and extirpations on Guam. Since that time, and as part of a cooperative project with the USGS/Fort Collins Science Center, my lab has been involved with projects on the biology and control of this species on Guam, including behavior of juveniles, adult reproduction, variability of populations across Guam, and assessment of various control techniques. (Photo: Brown Treesnake by Bjorn Lardner)

Current research also focuses on maintaining and restoring birds in the Marianas. While Brown Treesnakes decimated most avian species, a small population of Micronesian Starlings remains on Anderson Air Force Base. We are studying the behavior of these cavity nesters, and aim to develop a predator-resistant nest structure to help expand their population and that could potentially be adapted for the endangered Micronesian Kingfisher, another cavity nester extirpated on Guam. As part of a collaborative effort to understand how seed dispersal has been disrupted on Guam by the loss of frugivores and how it might be restored, another project is investigating the role of native birds in seed dispersal on the island of Saipan, north of Guam. By studying habitat use, movements, and diet of important frugivores, we hope to gain information relevant to maintaining forests in the Marianas and for restoring this critical ecological service to Guam.
(Photo: Sali by Peter)

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Bjorn Lardner:

Postdoctoral Research Scientist –

Research: past research was mostly on growth, behavior and control of juvenile Brown Treesnakes. Current efforts focus on the snakes’ reproduction and mortality, and development of a population-dynamic computer program that can help guide, and indicate the outcome of, large-scale Brown Treesnake suppression efforts.

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Evan Rehm:

Postdoctoral Research Scientist –

Research: the ecological role of native birds in maintaining seed dispersal in Saipan, Mariana Islands, and their potential use in restoring seed dispersal to Guam (where almost all native birds have been lost due to the introduced brown treesnake).

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Kevin Brindock:

PhD Student-

Research: Endangered Mariana Swiftlets (Specifics TBD)

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Martin Kastner
Research Assistant in Avian Restoration –

Research: Study of Micronesian Starling nesting behavior on Guam and development of a predator-resistant nest site for Micronesian Starlings as a surrogate for the endangered Micronesian Kingfisher (currently only existing in captivity).

Completed Graduate Student Research

Desmond, M. J. 1991. Ecological aspects of burrowing owl nesting strategies in the Nebraska Panhandle. M.S. Thesis, University of Nebraska, Lincoln, NE.

King, J. W. 1991. Effects of the Conservation Reserve Program on selected wildlife populations in southeast Nebraska. M.S. Thesis, University of Nebraska, Lincoln, NE.

Cramer, T. A. 1993. Limnological and habitat influences on wetland bird communities in the Nebraska Sandhills. M.S. Thesis, University of Nebraska, Lincoln, NE.

Delisle, J. M. 1995. Avian use of fields enrolled in the Conservation Reserve Program in southeast Nebraska. M.S. Thesis, University of Nebraska, Lincoln, NE.

Desmond, M. J. 1997. Evolutionary history of the genus Speotyto: a genetic and morphological perspective. Ph.D. Dissertation, University of Nebraska, Lincoln, NE.

Ritter, M. W. 1997. Wetland habitat characteristics and wetland use by Mariana common moorhen on Guam. M.S. Thesis, University of Nebraska, Lincoln, NE.

Vercauteren, T. L. 1998. Local scale analysis of sandhill crane use of lowland grasslands along the Platte River, Nebraska. M.S. Thesis, University of Nebraska, Lincoln, NE.

Converse, S. J. 1999. Habitat use and effects of harvest on ornate box turtles (Terrapene ornata ornata). M.S. Thesis, University of Nebraska, Lincoln, NE.

Ekstein, R. T. 1999. Factors affecting burrowing owl distribution at multiple spatial scales. M.S. Thesis, University of Nebraska, Lincoln, NE.

Griebel, R. L. 2000. Ecological and physiological factors affecting nesting success of burrowing owls in Buffalo Gap National Grassland. M.S. Thesis, University of Nebraska, Lincoln, NE.

Gubanyi, J. A. 2001. Effects of high deer abundance on forests in Eastern Nebraska. Ph.D. Dissertation, University of Nebraska, Lincoln, NE.

Gragg, J. 2004. Manipulating rodent density to alter behavior of brown treesnakes. M.S. Thesis, Colorado State University, Ft. Collins, CO.

Jehle, G. 2004. Avian response to prescribed fire in the upland shrub/ponderosa pine system of Rocky Mountain National Park, Colorado. M.S. Thesis, Colorado State University, Ft. Collins, CO.

Boyarski V. L. 2005. Trappability and activity of juvenile brown treesnakes (Boiga irregularis) on Guam. M.S. Thesis, Colorado State University, Ft. Collins, CO.

Estelle, V. B. 2005. Assessing the potential of an introduced crab predator to affect migratory and wintering shorebirds. Ph.D. Dissertation, Colorado State University, Ft. Collins, CO. (co-advised with Dr. B. Noon)

Sachtleben, T. 2005. Predation and nest success of forest birds in native and non-native habitat on Saipan, Mariana Islands. M.S. Thesis, Colorado State University, Ft. Collins, CO.

Yackel Adams, A. A. 2005. Population demography of Lark Buntings: post-fledging survival, fecundity, and breeding decisions. Ph.D. Dissertation, Colorado State University, Ft. Collins, CO. (co-advised with Dr. S. Skagen)

Williamson, M. A. 2008. Vegetation and songbird community response to hydro-axe removal of big sagebrush and pinon-juniper. M.S. Thesis, Colorado State University, Ft. Collins, CO.

Mason, L. 2008. Scented guide ropes as a method to enhance brown treesnake (Boiga irregularis) trap capture success on Guam. M.S. Thesis, Colorado State University, Ft. Collins, CO.

Siers, S. R. 2015. Microgeographic and ontogenetic variability in the ecology of invasive Brown Treesnakes on Guam, and effects of roads on their landscape-scale movements. Ph.D. Dissertation, Colorado State University, Ft. Collins, CO. (co-advised with Dr. R. Reed)

Lardner, B., G. H. Rodda, A. A. Yackel Adams, J. A. Savidge, and R. N. Reed. 2015. Detection rates of geckos in visual encounter surveys: Turning confounding variables into useful knowledge. Journal of Herpetology, In press.

Lardner, B., J.A. Savidge, R.N. Reed, and G.H. Rodda. 2014. Movements and activity of juvenile brown treesnakes (Boiga irregularis). Copeia 2014:428-436.

Siers, S.R., J.A. Savidge, and R.N. Reed. 2014. Invasive brown treesnake movements at road edges indicate road crossing avoidance. Journal of Herpetology 48:500-505.

Lardner, B., R. N. Reed, A. A.Yackel Adams, M. J. Mazurek, T. J. Hinkle, P. M. Levasseur, M. S. Palmer, and J. A. Savidge. 2013. Selective predation by feral cats on a native skink on Guam. IRCF Reptiles & Amphibians 20:16-19.

Lardner, B., J. A. Savidge, R. N. Reed, and G. H. Rodda. 2013. A method for telemetry-based logging of animal activity. Herpetological Review, in press.

Lardner, B., A. A. Yackel Adams, J. A. Savidge, G. H. Rodda, R. N. Reed, and C. S. Clark. 2013. Effectiveness of bait tubes for Brown Treesnake control on Guam. Wildlife Society Bulletin 37:664-673.

Mathies, T., B. Levine, R. Engeman, and J. A. Savidge. 2013. Pheromonal control of the invasive brown treesnake: potency of female sexual attractiveness pheromone varies with ovarian state. International Journal of Pest Management 59:141-149.

Savidge, J. A., M. W. Hopken, G. W. Witmer, S. M. Jojola, J. J. Pierce, P. W. Burke, and A. J. Piaggio. 2012. Genetic evaluation of an attempted Rattus rattus eradication on Congo Cay, U.S. Virgin Islands, identifies importance of eradication units. Biological Invasions 14:2343-2354.

Lardner, B., J. A. Savidge, T. J. Hinkle, E. O. Wostl, S. R. Siers, R. N. Reed, and G. H. Rodda. 2011. Boiga irregularis(Brown Treesnake). Predation attempt by crab. Herpetological Review 42:434-435.

Lardner, B., J. A. Savidge, R. N. Reed, and G. H. Rodda. 2011. Boiga irregularis (Brown Treesnake). Predation attempt by praying mantis. Herpetological Review 42:435-436.

Mason, L. C., J. A. Savidge, G. H. Rodda, and A. A. Yackel Adams. 2011. Scented guide ropes as a method to enhance brown treesnake (Boiga irregularis) trap capture success on Guam. Journal of Herpetology 45:308-312.

Mathies, T., R. Scarpino, B. A. Levine, C. Clark, and J. A. Savidge. 2011. Excluding non-target species from Brown Treesnake, Boiga irregularis (Reptilia: Colubridae), bait stations: experimental tests of station design and placement. Pacific Science 65:41-57.

Savidge, J. A., J. W. Stanford, R. N. Reed, G. R. Haddock, and A. A. Yackel Adams. 2011. Canine detection of free-ranging brown treesnakes on Guam. New Zealand Journal of Ecology 35:174-181.

Christy, M. T., A. A. Yackel Adams, G. H. Rodda, J. A. Savidge, and C. L. Tyrrell. 2010. Modelling detection probabilities to evaluate management and control tools for an invasive species. Journal of Applied Ecology 47:106-113.

Lehman, R. N., J. A. Savidge, P. L. Kennedy, R. E. Harness. 2010. Raptor electrocution rates for a utility in the intermountain western United States. Journal of Wildlife Management 74(3):459-470.

Mathies, T., J. A. Cruz, V. A. Lance, and J. A. Savidge. 2010. Reproductive biology of male Brown Teesnakes (Boiga irregularis) on Guam. Journal of Herpetology 44:209-221.

Lardner, B., J. A. Savidge, G. H. Rodda, and R. N. Reed. 2009. Prey preferences and prey acceptance in juvenile Brown Treesnakes (Boiga irregularis). Herpetological Conservation and Biology 4:313-323.

Lardner, B., J. A. Savidge, G. H. Rodda, R. N. Reed, and A. A. Yackel Adams. 2009. The results of nocturnal visual surveys are influenced by lamp properties. Applied Herpetology 6:391-396.

Tyrrell, C. L., M. T. Christy, G. H. Rodda, A. R. Ellingson, A. A. Yackel Adams, J. A. Savidge, K. Dean-Bradley, and R. Bischof. 2009. Evaluation of trap capture in a geographically closed population of brown treesnakes on Guam. Journal of Applied Ecology 46:128-135.

Boyarski, V.L., J.A. Savidge, and G. H. Rodda. 2008. Brown treesnake (Boiga irregularis) trappability: Attributes of the snake, environment and trap. Applied Herpetology 5:47-61.

Gubanyi, J. A., J. A. Savidge, S. E. Hygnstrom, K. C. VerCauteren, and G. W. Garabrandt. 2008. Impact of deer density on vegetation in natural areas in southeastern Nebraska. Natural Areas Journal 28:121-129.

Rodda, G. H., K. Dean-Bradley, J. A. Savidge, M. T. Christy, and C. L. Tyrrell. 2008. Post-colonization reversal of selection pressure on dispersal behavior of the brown treesnake, Boiga irregularis, on Guam. South American Journal of Herpetology 3:123-134.

Boyarski, V. L., G. H. Rodda, and J. A. Savidge. 2007. Evaluation of harmonic radar for detecting locomotor activity. Journal of Wildlife Management 71:1704-1707.

Christy, M. T., C. S. Clark, D. E. Gee II, D. Vice, D. S. Vice, M. P. Warner, C. L. Tyrrell, G. H. Rodda, and J. A. Savidge. 2007. Recent records of alien anurans on the Pacific island of Guam. Pacific Science 61:469-484.

Christy, M. T., J. A. Savidge, R. Bischof, and G. H. Rodda. 2007. Can temperature be used as a tool for limiting brown treesnake invasion via transportation pathways? Pages 246-256 in Proceedings of the NWRC International Symposium: Managing Vertebrate Invasive Species, Ft. Collins, CO.

Christy, M. T., J. A. Savidge, and G. H. Rodda. 2007. Multiple pathways for invasion of anurans on a Pacific island. Biodiversity and Distributions 13:598-607.

Gragg, J. E., G. H. Rodda, J. A. Savidge, G. C. White, K. Dean-Bradley, and A. R. Ellingson. 2007. Response of brown treesnakes to reduction of their rodent prey. Journal of Wildlife Management 71:2311-2317.

Griebel, R. L. and J. A. Savidge. 2007. Factors influencing burrowing owl reproductive performance in unfragmented shortgrass prairie. Journal of Raptor Research 41:212-221.

Lardner, B., J. A. Savidge, and G. H. Rodda. 2007. Spotting cryptic animals in the dark: what light properties should a good headlamp have? Pages 234-245 in Proceedings of the NWRC International Symposium: Managing Vertebrate Invasive Species, Ft. Collins, CO.

Lehman, R. N., P. L. Kennedy, and J. A. Savidge. 2007. The state of the art in raptor electrocution research: a global review. Biological Conservation 136:159-174.

Rodda, G. H. and J. A. Savidge. 2007. Biology and impact of Pacific Islands invasive species: Boiga irregularis, the Brown Treesnake. Pacific Science 61:307-324.

Rodda, G. H., J. A. Savidge, C. L. Tyrrell, M. T. Christy, and A. E. Ellingson. 2007. Size bias in visual searches and trapping of brown treesnakes on Guam. Journal of Wildlife Management 71:656-661.

Savidge, J. A., F. J. Qualls, and G. H. Rodda. 2007. Reproductive biology of Brown Treesnakes, Boiga irregularis, during their colonization of Guam and in comparison to their native range. Pacific Science 61:187-195.

Yackel Adams, A. A., S. K. Skagen, and J. A. Savidge. 2007. Population-specific demographic estimates provide insights into declines of Lark Buntings (Calamospiza melanocorys). Auk 124:578-593.

Jehle, G., J. A. Savidge, and N. B. Kotliar. 2006. Green-tailed Towhee response to prescribed fire in mountain shrubland. Condor 108:634-646.

Sachtleben, T., J. L. Reidy, and J. A. Savidge. 2006. A description of the first Micronesian Honeyeater (Myzomela rubratra saffordi) nests found on Saipan, Northern Mariana Islands. Wilson Bulletin 118:309-315.

Yackel Adams, A. A., S. K. Skagen, and J. A. Savidge. 2006. Modeling post-fledging survival of lark buntings in response to ecological and biological factors. Ecology 87:178-188.

Converse, S. J., J. B. Iverson, and J. A. Savidge. 2005. Demographics of an ornate box turtle population experiencing minimal human-induced disturbances. Ecological Applications 15:2171-2179.

Jehle, G., A. A. Yackel Adams, J. A. Savidge, and S. K. Skagen. 2004. Nest survival estimation: a review of alternatives to the Mayfield Estimator. Condor 106:472-484.

Converse, S. J. and J. A. Savidge. 2003. Ambient temperature, activity, and microhabitat use by ornate box turtles (Terrapene ornata ornata). Journal of Herpetology 37:665-670.

Griebel, R. L. and J. A. Savidge. 2003. Factors related to body condition of nestling burrowing owls in Buffalo Gap National Grassland, South Dakota. Wilson Bulletin 115:121-124.

Converse, S. J., J. B. Iverson, and J. A. Savidge. 2002. Activity, reproduction and overwintering behavior of ornate box turtles (Terrapene ornata ornata) in the Nebraska Sandhills. American Midland Naturalist 148:416-422.

Desmond, M. J., T. J. Parsons, T. O. Powers, and J. Savidge. 2001. An initial examination of mitochondrial DNA structure in burrowing owl populations. Raptor Research 35:274-281.

Beck, R. E., Jr. and J. A. Savidge. 2000. The Mariana Crow. Pages 191-195 in R. Reading and B. Miller, editors. Endangered animals: conflicting issues. Greenwood Press, Westport, CN.

Desmond, M. J., J. A. Savidge, and K. M. Eskridge. 2000. Correlations between burrowing owl and black-tailed prairie dog declines: a 7-year analysis. Journal of Wildlife Management 64:1067-1075.

Desmond, M. J. and J. A. Savidge. 1999. Satellite burrow use by burrowing owl chicks and its influence on nest fate. Pages 128-130 in P. D. Vickery and J. R. Herkert, editors. Ecology and conservation of grassland birds of the western hemisphere. Studies in Avian Biology 19, Cooper Ornithological Society.

Ritter, M. and J. A. Savidge. 1999. A predictive model of wetland habitat use on Guam by endangered Mariana common moorhens. Condor 101:282-287.

Best, L., H. Campa, K. Kemp, R. Robel, M. Ryan, J. Savidge, H. Weeks, and S. Winterstein. 1997. Bird abundance and nesting in CRP fields and cropland in the Midwest: a regional approach. Wildlife Society Bulletin 25:864-877.

Best, L., H. Campa, K. Kemp, R. Robel, M. Ryan, J. Savidge, H. Weeks, and S. Winterstein. 1997. Avian abundance in CRP and crop fields during winter in the Midwest. American Midland Naturalist 139:311-324.

Delisle, J. and J. A. Savidge. 1997. Avian use and vegetation characteristics of Conservation Reserve Program fields. Journal Wildlife Management 61:318-325.

Delisle, J. and J. A. Savidge. 1996. Reproductive success of grasshopper sparrows in relation to edge. Prairie Naturalist 28:107-113.

Desmond, M. J. and J. A. Savidge. 1996. Factors influencing burrowing owl (Speotyto cunicularia) nest densities and numbers in western Nebraska. American Midland Naturalist 136:143-148.

Seibert, T., J. Sidle, and J. A. Savidge. 1996. Inexpensive aerial videography acquisition, analysis, and reproduction. Wetlands 16:245-250.

Desmond, M., J. Savidge, and T. Seibert. 1995. Spatial patterns of burrowing owl (Speotyto cunicularia) nests within black-tailed prairie dog (Cynomys ludovicianus) towns. Canadian Journal Zoology 73:1375-1379.

King, J. and J. Savidge. 1995. Effects of the Conservation Reserve Program on selected wildlife in southeast Nebraska. Wildlife Society Bulletin 23:377-385.

Savidge, J. A., L. Sileo, and L. M. Siegfried. 1992. Was disease involved in the decimation of Guam’s avifauna? Journal of Wildlife Diseases 28:206-214.

Savidge, J. A. 1991. Population characteristics of the introduced brown tree snake on Guam. Biotropica 23:294-300.

Seibert, T. and J. A. Savidge. 1991. Pollination and breeding biology of large-flowered bellwort, Uvularia grandiflora. Canadian Field Naturalist 105:392-394.

Griffin, C. R., C. M. King, J. A. Savidge, and F. and J. B. Cruz. 1989. Effects of introduced predators on island birds: contemporary case histories from the Pacific. Proc. XIX ICBP World Conference, Canada.

Savidge, J. A. 1988. Food habits of Boiga irregularis, an introduced predator on Guam. Journal of Herpetology 22:275-282.

Savidge, J. A. and T. F. Seibert. 1988. A camera device for monitoring avian nest predation at artificial nests. Journal Wildlife Management 52:291-294.

Fritts, T. H., N. J. Scott, Jr., and J. A. Savidge. 1987. Activity of the arboreal brown tree snake (Boiga irregularis) on Guam as determined by electrical outages. The SNAKE 19:51-58.

Savidge, J. A. 1987. Extinction of an island forest avifauna by an introduced snake. Ecology 68:660-668.

Savidge, J. A. 1987. The ecological and economic impacts of an introduced snake on Guam and its threat to other Pacific islands. PLES 3:29-34.

Savidge, J. A. 1984. Guam: paradise lost for wildlife. Biological Conservation 30:305-317.

Savidge, J. A. 1978. Wildlife in a herbicide-treated Jeffrey pine plantation in eastern California. Journal of Forestry 76:476-477.

Courses Taught

I teach FW 472, Issues in Animal Conservation and Management, every fall and FW 104 Wildlife Ecology & Conservation in spring.

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I do not currently have any openings. If this situation changes, I will post advertisements on this website as well as other outlets (e.g., Texas A&M Wildlife Job Board; Society for Conservation Biology; Ecolog).

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