Wildlife Research Wildlife Research Society
Ecology, management and conservation in natural and modified habitats
RESEARCH ARTICLE

The effect of research activities and winter precipitation on voiding behaviour of Agassiz’s desert tortoises (Gopherus agassizii)

Mickey Agha A , Mason O. Murphy B , Jeffrey E. Lovich C , Joshua R. Ennen D , Christian R. Oldham A , Kathie Meyer E , Curtis Bjurlin F , Meaghan Austin C , Sheila Madrak G , Caleb Loughran H , Laura Tennant C and Steven J. Price A I
+ Author Affiliations
- Author Affiliations

A Department of Forestry, University of Kentucky, Lexington, KY 40546-0073, USA.

B Department of Biology, University of Kentucky, Lexington, KY 40546-0225, USA.

C US Geological Survey, Southwest Biological Science Center, MS-9394, Flagstaff, AZ 86001, USA.

D Tennessee Aquarium Conservation Institute, 201 Chestnut St, Chattanooga, TN 37402, USA.

E 19233 Stratford Way, Apple Valley, CA 92308, USA.

F Stantec Consulting, 2617 Chamberlain Avenue, Madison, WI 53705, USA.

G Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4614, USA.

H Central Washington University, Department of Biological Sciences, Ellensburg, WA 98926, USA.

I Corresponding author. Email: steven.price@uky.edu

Wildlife Research 41(8) 641-649 https://doi.org/10.1071/WR14196
Submitted: 26 June 2014  Accepted: 27 January 2015   Published: 14 April 2015

Abstract

Context: There is little information available on how research activities might cause stress responses in wildlife, especially responses of threatened species such as the desert tortoise (Gopherus agassizii).

Aims: The present study aims to detect behavioural effects of researcher handling and winter precipitation on a natural population of desert tortoises in the desert of Southwestern United States, over the period 1997 to 2014, through extensive assessments of capture events during multiple research studies, and capture–mark–recapture survivorship analysis.

Methods: Juvenile and adult desert tortoises were repeatedly handled with consistent methodology across 18 years during 10 study seasons. Using a generalised linear mixed-effects model, we assessed the effects of both research manipulation and abiotic conditions on probability of voiding. Additionally, we used a Cormack–Jolly–Seber model to assess the effects of winter precipitation and voiding on long-term apparent survivorship.

Key results: Of 1008 total capture events, voiding was recorded on 83 (8.2%) occasions in 42 different individuals. Our top models indicated that increases in handling time led to significantly higher probabilities of voiding for juveniles, females and males. Similarly, increases in precipitation resulted in significantly higher probabilities of voiding for juveniles and females, but not for males. Tortoise capture frequency was negatively correlated with voiding occurrence. Cormack–Jolly–Seber models demonstrated a weak effect of winter precipitation on survivorship, but a negligible effect for both voiding behaviour and sex.

Conclusions: Handling-induced voiding by desert tortoises may occur during common research activities and years of above average winter precipitation. Increased likelihood of voiding in individuals with relatively low numbers of recaptures suggested that tortoises may have perceived researchers initially as predators, and therefore voided as a defensive strategy. Voiding does not appear to impact long-term survivorship in desert tortoises at this site.

Implications: This study has demonstrated that common handling practices on desert tortoise may cause voiding behaviour. These results suggest that in order to minimise undesirable behavioural responses in studied desert tortoise populations, defined procedures or protocols must be followed by the investigators to reduce contact period to the extent feasible.

Additional keywords: conservation, research manipulation, Sonoran Desert, survival, wildlife handling.


References

Agha, M., Lovich, J. E., Ennen, J. R., and Wilcox, E. (2013). Nest-guarding by female Agassiz’s desert tortoise (Gopherus agassizii) at a wind-energy facility near Palm Springs, California. The Southwestern Naturalist 58, 254–257.
Nest-guarding by female Agassiz’s desert tortoise (Gopherus agassizii) at a wind-energy facility near Palm Springs, California.CrossRef |

Arnold, T. W. (2010). Uninformative parameters and model selection using Akaike’s Information Criterion. The Journal of Wildlife Management 74, 1175–1178.

Averill-Murray, R. C. (1998). Effects on growth and survival of tortoises voiding their bladders during handling. In ‘Proceedings of the Desert Tortoise Council Symposium 1998–1999’. (Ed. B. Bartholomew.) pp. 99–100. (The Desert Tortoise Council: Wrightwood, CA.)

Averill-Murray, R. C. (2002). Effects on survival of desert tortoises (Gopherus agassizii) urinating during handling. Chelonian Conservation and Biology 4, 430–435.

Bates, D., Maechler, M., and Bolker, B. (2012). Package ‘lme4’: Linear mixed-effects models using S4 classes. Available at http://cran.r-project.org/web/packages/ lme4/lme4.pdf. Archived by Website at http://www.webcitation.org/6G9cwvmOB on 15 April 2013.

Beatley, J. C. (1974). Phenological events and their environmental triggers in Mojave Desert ecosystems. Ecology 55, 856–863.
Phenological events and their environmental triggers in Mojave Desert ecosystems.CrossRef |

Berry, K. H., and Christopher, M. M. (2001). Guidelines for the field evaluation of desert tortoise health and disease. Journal of Wildlife Diseases 37, 427–450.
Guidelines for the field evaluation of desert tortoise health and disease.CrossRef | 1:STN:280:DC%2BD3MvlvVWgug%3D%3D&md5=5bd61522c70f248b9bec823e45e36bacCAS | 11504217PubMed |

Berry, K. H., Spangenberg, E. K., Homer, B. L., and Jacobson, E. R. (2002). Deaths of desert tortoises following periods of drought and research manipulation. Chelonian Conservation and Biology 4, 436–448.

Bjurlin, C. D., and Bissonette, J. A. (2004). Survival during early life stages of the desert tortoise (Gopherus agassizii) in the south-central Mojave Desert. Journal of Herpetology 38, 527–535.
Survival during early life stages of the desert tortoise (Gopherus agassizii) in the south-central Mojave Desert.CrossRef |

Bowers, J. E. (2005). El Niño and displays of spring-flowering annuals in the Mojave and Sonoran Deserts. The Journal of the Torrey Botanical Society 132, 38–49.
El Niño and displays of spring-flowering annuals in the Mojave and Sonoran Deserts.CrossRef |

Bulova, S. J. (1994). Patterns of burrow use by desert tortoises: gender differences and seasonal trends. Herpetological Monograph 8, 133–143.
Patterns of burrow use by desert tortoises: gender differences and seasonal trends.CrossRef |

Burnham, K. P., and Anderson, D. R. (1998). ‘Model Selection and Inference: A Practical Information – Theoretic Approach.’ (Springer-Verlag: New York.)

Burnham, K. P., and Anderson, D. R. (2002). ‘Model Selection and Multimodel Inference: A Practical Information-Theoretic Approach.’ 2nd edn. (Springer-Verlag: New York.)

Cabanac, M., and Aizawa, S. (2000). Fever and tachycardia in a bird (Gallus domesticus) after simple handling. Physiology & Behavior 69, 541–545.
Fever and tachycardia in a bird (Gallus domesticus) after simple handling.CrossRef | 1:CAS:528:DC%2BD3cXltVGqtbo%3D&md5=8518e4c6dd73647ec1d69d5ad1aaaf46CAS |

Cabanac, M., and Bernieri, C. (2000). Behavioural rise in body temperature and tachycardia by handling of a turtle (Clemmys insculpta). Behavioural Processes 49, 61–68.
Behavioural rise in body temperature and tachycardia by handling of a turtle (Clemmys insculpta).CrossRef | 10794915PubMed |

Cabezas, S., Blas, J., Marchant, T. A., and Moreno, S. (2007). Physiological stress levels predict survival probabilities in wild rabbits. Hormones and Behavior 51, 313–320.
Physiological stress levels predict survival probabilities in wild rabbits.CrossRef | 1:CAS:528:DC%2BD2sXis1OksLc%3D&md5=804314a75cd023e3544790c661a7cb7eCAS | 17258747PubMed |

Cash, W. B., Holberton, R. L., and Knight, S. S. (1997). Corticosterone secretion in response to capture and handling in free-living red-eared slider turtles. General and Comparative Endocrinology 108, 427–433.
Corticosterone secretion in response to capture and handling in free-living red-eared slider turtles.CrossRef | 1:CAS:528:DyaK1cXhvFCl&md5=71e26362eca1a64fdb165faaf36d19f5CAS | 9405119PubMed |

Cayan, D. R., Das, T., Pierce, D. W., Barnett, T. P., Tyree, M., and Gershunov, A. (2010). Future dryness in the southwest US and the hydrology of the early 21st century drought. Proceedings of the National Academy of Sciences of the United States of America 107, 21271–21276.
Future dryness in the southwest US and the hydrology of the early 21st century drought.CrossRef | 1:CAS:528:DC%2BC3cXhs1Wis7nE&md5=3a7a3701851382a44865532fcb51bb27CAS | 21149687PubMed |

Clinchy, M., Krebs, C. J., and Jarman, P. J. (2001). Dispersal sinks and handling effects: interpreting the role of immigration in common brushtail possum populations. Journal of Animal Ecology 70, 515–526.
Dispersal sinks and handling effects: interpreting the role of immigration in common brushtail possum populations.CrossRef |

Crawley, M. J. (2013). ‘The R book.’ 2nd edn. (Wiley: Chichester.)

Crump, M. L., and Scott, N. J., Jr (1994). Visual encounter surveys. In ‘Measuring and Monitoring Biological Diversity: Standard Methods for Amphibians’. (Ed. W. R. Heyer, M. A. Donnelly, R. W. McDiarmid, L. C. Hayek and M. S. Foster.) pp. 84–92. (Smithsonian Institution: Washington, DC.)

Dickens, M. J., Delehanty, D. J., and Romero, L. M. (2009). Stress and translocation: alterations in the stress physiology of translocated birds. Proceedings of the Royal Society of London. Series B, Biological Sciences 276, 2051–2056.
Stress and translocation: alterations in the stress physiology of translocated birds.CrossRef |

Drake, K. K., Nussear, K. E., Esque, T. C., Barber, A. M., Vittum, K. M., Medica, P. A., Tracy, C. R., and Hunter, K. W. (2012). Does translocation influence physiological stress in the desert tortoise? Animal Conservation 15, 560–570.
Does translocation influence physiological stress in the desert tortoise?CrossRef |

Ennen, J. R., Meyer, K., and Lovich, J. E. (2012). Female Agassiz’s desert tortoise activity at a wind energy facility in southern California: The influence of an El Niño event. Natural Science 4, 30–37.
Female Agassiz’s desert tortoise activity at a wind energy facility in southern California: The influence of an El Niño event.CrossRef |

Ernst, C. H., and Lovich, J. E. (E.d.) (2009). ‘Turtles of the United States and Canada.’ 2nd edn. (Johns Hopkins Press: Baltimore.)

Gregory, L. F., Gross, T. S., Bolten, A. B., Bjorndal, K. A., and Guilette, L. J. (1996). Plasma corticosterone concentrations associated with acute captivity stress in wild loggerhead sea turtles (Caretta caretta). General and Comparative Endocrinology 104, 312–320.
Plasma corticosterone concentrations associated with acute captivity stress in wild loggerhead sea turtles (Caretta caretta).CrossRef | 1:CAS:528:DyaK28Xntlejt7g%3D&md5=f014cc918ad25df96af86dc0c8f0f64eCAS | 8954764PubMed |

Henen, B. T. (1997). Seasonal and annual energy budgets of female desert tortoises (Gopherus agassizii). Ecology 78, 283–296.
Seasonal and annual energy budgets of female desert tortoises (Gopherus agassizii).CrossRef |

Henen, B. T. (2002a). Energy and water balance, diet, and reproduction of female desert tortoises (Gopherus agassizii). Chelonian Conservation and Biology 4, 319–329.

Henen, B. T. (2002b). Reproductive effort and reproductive nutrition of female desert tortoises: essential field methods. Integrative and Comparative Biology 42, 43–50.
Reproductive effort and reproductive nutrition of female desert tortoises: essential field methods.CrossRef | 21708693PubMed |

Henen, B. T., Peterson, C. C., Wallis, I. R., Berry, K. H., and Nagy, K. A. (1998). Effects of climatic variation on field metabolism and water relations of desert tortoises. Oecologia 117, 365–373.
Effects of climatic variation on field metabolism and water relations of desert tortoises.CrossRef |

Hinton, T. G., Fledderman, P., Lovich, J., Congdon, J., and Gibbons, J. W. (1997). Radiographic determination of fecundity: Is the technique safe for developing turtle embryos? Chelonian Conservation and Biology 2, 409–414.

Holding, M. L., Frazier, J. A., Dorr, S. W., Henningsen, S. N., Moore, I. T., and Taylor, E. N. (2014). Physiological and behavioral effects of repeated handling and short-distance translocations on free-ranging Northern Pacific rattlesnakes (Crotalus oreganus oreganus). Journal of Herpetology 48, 233–239.
Physiological and behavioral effects of repeated handling and short-distance translocations on free-ranging Northern Pacific rattlesnakes (Crotalus oreganus oreganus).CrossRef |

Hutchison, V. H., Vinegar, A., and Kosh, R. J. (1966). Critical thermal maxima in turtles. Herpetologica 22, 32–41.

Jacobson, E. R., Weinstein, M., Berry, K., Hardenbrook, B., Tomlinson, C., and Freitas, D. (1993). Problems with using weight versus carapace length relationships to assess tortoise health. The Veterinary Record 132, 222–223.
Problems with using weight versus carapace length relationships to assess tortoise health.CrossRef | 1:STN:280:DyaK3s7pvVanug%3D%3D&md5=d8f523215031abab79d8f6f65ded8f61CAS | 8451815PubMed |

Kahn, P. F., Guyer, C., and Mendonca, M. T. (2007). Handling, blood sampling, and temporary captivity do not affect plasma corticosterone or movement patterns of gopher tortoises (Gopherus polyphemus). Copeia 2007, 614–621.
Handling, blood sampling, and temporary captivity do not affect plasma corticosterone or movement patterns of gopher tortoises (Gopherus polyphemus).CrossRef |

Kenagy, G. J., and Place, N. J. (2000). Seasonal changes in plasma glucocorticosteroids of free-living female yellow-pine chipmunks: effects of reproduction and capture and handling. General and Comparative Endocrinology 117, 189–199.
Seasonal changes in plasma glucocorticosteroids of free-living female yellow-pine chipmunks: effects of reproduction and capture and handling.CrossRef | 1:CAS:528:DC%2BD3cXkvVKltQ%3D%3D&md5=6bc8b1e0f0fc325dd6025f186d0a9c26CAS | 10642441PubMed |

Loehr, V. J., Henen, B. T., and Hofmeyr, M. D. (2011). Reproductive responses to rainfall in the Namaqualand speckled tortoise. Copeia 2011, 278–284.
Reproductive responses to rainfall in the Namaqualand speckled tortoise.CrossRef |

Longshore, K. M., Jaeger, J. R., and Sappington, J. M. (2003). Desert tortoise (Gopherus agassizii) survival at two eastern Mojave Desert sites: death by short-term drought? Journal of Herpetology 37, 169–177.
Desert tortoise (Gopherus agassizii) survival at two eastern Mojave Desert sites: death by short-term drought?CrossRef |

Lovich, J. E., and Daniels, R. (2000). Environmental characteristics of desert tortoise (Gopherus agassizii) burrow locations in an altered industrial landscape. Chelonian Conservation and Biology 3, 714–721.

Lovich, J. E., and Ennen, J. R. (2013). Assessing the state of knowledge of utility-scale wind energy development and operation on non-volant terrestrial and marine wildlife. Applied Energy 103, 52–60.
Assessing the state of knowledge of utility-scale wind energy development and operation on non-volant terrestrial and marine wildlife.CrossRef |

Lovich, J. E., Medica, P., Avery, H., Meyer, K., Bowser, G., and Brown, A. (1999). Studies of reproductive output of the desert tortoise at Joshua Tree National Park, the Mojave National Preserve, and comparative sites. Park Science 19, 22–24.

Lovich, J. E., Ennen, J. R., Madrak, S., Meyer, K., Loughran, C., Bjurlin, C., Arundel, T., Turner, W., Jones, C., and Groenendaal, G. M. (2011a). Effects of wind energy production on growth, demography and survivorship of a desert tortoise (Gopherus agassizii) population in southern California with comparisons to natural populations. Herpetological Conservation and Biology 6, 161–174.

Lovich, J. E., Ennen, J. R., Madrak, S. V., Loughran, C. L., Meyer, K. P., Arundel, T. R., and Bjurlin, C. D. (2011b). Long-term post-fire effects on spatial ecology and reproductive output of female Agassiz’s desert tortoises (Gopherus agassizii) at a wind energy facility near Palm Springs, California, USA. Fire Ecology 7, 75–87.
Long-term post-fire effects on spatial ecology and reproductive output of female Agassiz’s desert tortoises (Gopherus agassizii) at a wind energy facility near Palm Springs, California, USA.CrossRef |

Lovich, J. E., Agha, M., Meulblok, M., Meyer, K., Ennen, J., Loughran, C., Madrak, S. V., and Bjurlin, C. (2012). Climatic variation affects clutch phenology in Agassiz’s desert tortoise (Gopherus agassizii). Endangered Species Research 19, 63–74.
Climatic variation affects clutch phenology in Agassiz’s desert tortoise (Gopherus agassizii).CrossRef |

Lovich, J. E., Yackulic, C. B., Freilich, J., Agha, M., Meulblok, M., Meyer, K. P., Arundel, T. R., Hansen, J., Vamstad, M. S., and Root, S. A. (2014). Climatic variation and tortoise survival: has a desert species met its match? Biological Conservation 169, 214–224.
Climatic variation and tortoise survival: has a desert species met its match?CrossRef |

Lynn, S. E., Prince, L. E., and Phillips, M. M. (2010). A single exposure to an acute stressor has lasting consequences for the hypothalamo-pituitary-adrenal response to stress in free-living birds. General and Comparative Endocrinology 165, 337–344.
A single exposure to an acute stressor has lasting consequences for the hypothalamo-pituitary-adrenal response to stress in free-living birds.CrossRef | 1:CAS:528:DC%2BD1MXhsVKht7rN&md5=1d9fc9e76195f2c915d9b571968cec32CAS | 19682993PubMed |

MacDonald, G. M. (2010). Water, climate change, and sustainability in the southwest. Proceedings of the National Academy of Sciences of the United States of America 107, 21256–21262.
Water, climate change, and sustainability in the southwest.CrossRef | 1:CAS:528:DC%2BC3cXhs1Wis7nK&md5=6079d271122a1118c3c5bbe7818b9f49CAS | 21149704PubMed |

Mazeaud, M. M., Mazeaud, F., and Donaldson, E. M. (1977). Primary and secondary effects of stress in fish: some new data with a general review. Transactions of the American Fisheries Society 106, 201–212.
Primary and secondary effects of stress in fish: some new data with a general review.CrossRef | 1:CAS:528:DyaE2sXlsV2jt7w%3D&md5=05e7aadb5e61e8e551dac0c1360d029cCAS |

McLuckie, A. M., Lamb, T., Schwalbe, C. R., and McCord, R. D. (1999). Genetic and morphometric assessment of an unusual tortoise (Gopherus agassizii) population in the Black Mountains of Arizona. Journal of Herpetology 33, 36–44.
Genetic and morphometric assessment of an unusual tortoise (Gopherus agassizii) population in the Black Mountains of Arizona.CrossRef |

Medica, P. A., Bury, R. B., and Luckenbach, R. A. (1980). Drinking and construction of water catchments by the desert tortoise, Gopherus agassizii, in the Mojave Desert. Herpetologica 36, 301–304.

Medica, P. A., Lyons, C. L., and Turner, F. B. (1986). “Tapping”: a technique for capturing tortoises. Herpetological Review 17, 15–16.

Minnich, J. E. (1977). Adaptive responses in the water and electrolyte budgets of native and captive desert tortoises, Gopherus agassizii, to chronic drought. Proceedings of the Desert Tortoise Council Symposium 1977, 102–129.

Morafka, D. J., and Berry, K. H. (2002). Is Gopherus agassizii a desert-adapted tortoise, or an exaptive opportunist? Implications for tortoise conservation. Chelonian Conservation and Biology 4, 263–287.

Nagy, K. A., and Medica, P. A. (1986). Physiological ecology of desert tortoises in southern Nevada. Herpetologica 42, 73–92.

Noy-Meir, I. (1973). Desert ecosystems: environment and producers. Annual Review of Ecology and Systematics 4, 25–51.
Desert ecosystems: environment and producers.CrossRef |

Ott, J. A., Mendonc, M. T., Guyer, A. C., and Michener, W. K. (2000). Seasonal changes in sex and adrenal steroid hormones of gopher tortoises (Gopherus polyphemus). General and Comparative Endocrinology 117, 299–312.
Seasonal changes in sex and adrenal steroid hormones of gopher tortoises (Gopherus polyphemus).CrossRef | 1:CAS:528:DC%2BD3cXkvVKktA%3D%3D&md5=925f7cff88a4d6cc745a454fb580da15CAS | 10642451PubMed |

Patterson, R. (1971). The role of urination in egg predator defense in the desert tortoise (Gopherus agassizii). Herpetologica 27, 197–199.

Peterson, C. C. (1994). Different rates and causes of high mortality in two populations of the threatened desert tortoise (Gopherus agassizii). Biological Conservation 70, 101–108.
Different rates and causes of high mortality in two populations of the threatened desert tortoise (Gopherus agassizii).CrossRef |

Peterson, C. C. (1996a). Ecological energetics of the desert tortoise (Gopherus agassizii): effects of rainfall and drought. Ecology 77, 1831–1844.
Ecological energetics of the desert tortoise (Gopherus agassizii): effects of rainfall and drought.CrossRef |

Peterson, C. C. (1996b). Anhomeostasis: seasonal water and solute relations in two populations of the desert tortoise (Gopherus agassizii) during chronic drought. Physiological Zoology 69, 1324–1358.

Pike, D. A., Dinsmore, A., Crabill, T., Smith, R. B., and Seigel, R. A. (2005). Short-term effects of handling and permanently marking gopher tortoises (Gopherus polyphemus) on recapture rates and behavior. Applied Herpetology 2, 139–147.
Short-term effects of handling and permanently marking gopher tortoises (Gopherus polyphemus) on recapture rates and behavior.CrossRef |

R Development Core Team (2013). R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna. ISBN3–900051–07–0. http://www.R-project.org.

Romero, L. M., and Reed, J. M. (2005). Collecting baseline corticosterone samples in the field: is under 3 min good enough. Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology 140, 73–79.
Collecting baseline corticosterone samples in the field: is under 3 min good enough.CrossRef |

Seager, R., and Vecchi, G. A. (2010). Greenhouse warming and the 21st century hydroclimate of southwestern North America. Proceedings of the National Academy of Sciences of the United States of America 107, 21277–21282.
Greenhouse warming and the 21st century hydroclimate of southwestern North America.CrossRef | 1:CAS:528:DC%2BC3cXhs1Wis7nF&md5=fd00aca41c8a686d7337f9aad1d4b5a9CAS | 21149692PubMed |

Seager, R., Ting, M., Held, I., Kushnir, Y., Lu, J., Vecchi, G., Huang, H. P., Harnik, N., Leetmaa, A., Lau, N. C., Li, C., Velez, J., and Naik, N. (2007). Model projections of an imminent transition to a more arid climate in southwestern North America. Science 316, 1181–1184.
Model projections of an imminent transition to a more arid climate in southwestern North America.CrossRef | 1:CAS:528:DC%2BD2sXls1Kisb8%3D&md5=91029d1891914d6d1c4d1d761ed823a6CAS | 17412920PubMed |

Sigismondi, L. A., and Weber, L. J. (1988). Changes in response time of juvenile Chinook salmon exposed to multiple acute handling stresses. Transactions of the American Fisheries Society 117, 196–201.
Changes in response time of juvenile Chinook salmon exposed to multiple acute handling stresses.CrossRef |

Turner, F. B., Medica, P. A., and Lyons, C. L. (1984). Reproduction and survival of the desert tortoise (Scaptochelys agassizii) in Ivanpah Valley, California. Copeia 1984, 811–820.
Reproduction and survival of the desert tortoise (Scaptochelys agassizii) in Ivanpah Valley, California.CrossRef |

US Fish and Wildlife Service (1990). Endangered and threatened wildlife and plants: determination of threatened status for the Mojave population of the desert tortoise. Federal Register 55, 12178–12191.

US Fish and Wildlife Service (1994). Desert tortoise (Mojave population) Recovery Plan. US Fish and Wildlife Service. (USFWS: Portland, OR.)

US Fish and Wildlife Service (2011). Revised recovery plan for the Mojave population of the desert tortoise (Gopherus agassizii). US Fish and Wildlife Service, Pacific Southwest Region. (USFWS: Sacramento, CA.)

van Oers, K., and Carere, C. (2007). Long-term effects of repeated handling and bleeding in wild caught great tits Parus major. Journal fur Ornithologie 148, 185–190.
Long-term effects of repeated handling and bleeding in wild caught great tits Parus major.CrossRef |

White, G. C., and Burnham, K. P. (1999). Program MARK: survival estimation from populations of marked animals. Bird Study 46, 120–139.
Program MARK: survival estimation from populations of marked animals.CrossRef |

Wilson, D. S., Nagy, K. A., Tracy, C. R., Morafka, D. J., and Yates, R. A. (2001). Water balance in neonate and juvenile desert tortoises, Gopherus agassizii. Herpetological Monograph 15, 158–170.
Water balance in neonate and juvenile desert tortoises, Gopherus agassizii.CrossRef |

Wingfield, J. C., and Romero, L. M. (2001). The Endocrine System. In ‘Handbook of physiology’. (Ed. B. S. McEwen and H. M. Goodman.) pp. 211–234. (Oxford University Press: New York.)

Zimmerman, L. C., O’Connor, M. P., Bulova, S. J., Spotila, J. R., Kemp, S. J., and Salice, C. J. (1994). Thermal ecology of desert tortoises in the eastern Mojave Desert: seasonal patterns of operative and body temperatures, and microhabitat utilization. Herpetological Monograph 8, 45–59.
Thermal ecology of desert tortoises in the eastern Mojave Desert: seasonal patterns of operative and body temperatures, and microhabitat utilization.CrossRef |

Zylstra, E. R., Steidl, R. J., Jones, C. A., and Averill-Murray, R. C. (2013). Spatial and temporal variation in survival of a rare reptile: a 22-year study of Sonoran Desert tortoises. Oecologia 173, 107–116.
Spatial and temporal variation in survival of a rare reptile: a 22-year study of Sonoran Desert tortoises.CrossRef | 23011852PubMed |



Rent Article (via Deepdyve) Export Citation Cited By (1)