Sedinger J.S.,University of Nevada, Reno |
White G.C.,Colorado State University |
Espinosa S.,100 Valley Road |
Partee E.T.,15 East 4th Street |
Braun C.E.,Grouse Inc.
Journal of Wildlife Management | Year: 2010
We used band-recovery data from 2 populations of greater sage-grouse (Centrocercus urophasianus), one in Colorado, USA, and another in Nevada, USA, to examine the relationship between harvest rates and annual survival. We used a Seber parameterization to estimate parameters for both populations. We estimated the process correlation between reporting rate and annual survival using Markov chain Monte Carlo methods implemented in Program MARK. If hunting mortality is additive to other mortality factors, then the process correlation between reporting and survival rates will be negative. Annual survival estimates for adult and juvenile greater sage-grouse in Nevada were 0.42 ± 0.07 (x ̄ ± SE) for both age classes, whereas estimates of reporting rate were 0.15 ± 0.02 and 0.16 ± 0.03 for the 2 age classes, respectively. For Colorado, average reporting rates were 0.14 ± 0.016, 0.14 ± 0.010, 0.19 ± 0.014, and 0.18 ± 0.014 for adult females, adult males, juvenile females, and juvenile males, respectively. Corresponding mean annual survival estimates were 0.59 ± 0.01, 0.37 ± 0.03, 0.78 ± 0.01, and 0.64 ± 0.03. Estimated process correlation between logit-transformed reporting and survival rates for greater sage-grouse in Colorado was ρ 0.68 ± 0.26, whereas that for Nevada was ρ 0.04 ± 0.58. We found no support for an additive effect of harvest on survival in either population, although the Nevada study likely had low power. This finding will assist mangers in establishing harvest regulations and otherwise managing greater sage-grouse populations. © The Wildlife Society.
Braun C.E.,Grouse Inc. |
Williams S.O.,University of New Mexico
Western Birds | Year: 2015
We reviewed the literature and observations of the occurrence and status of the White-tailed Ptarmigan (Lagopus leucura) in New Mexico. Historical reports were infrequent, likely because of an inadequate system for recording observations from the public, although by 1928 biologists had a good understanding of the distribution and status of the species in the state. By 1980, ptarmigan persisted in small numbers in the northern portion of the New Mexico range but were uncommon or absent in the southern portion of the range, prompting a transplant of White-tailed Ptarmigan from Colorado into the southern area in 1981. Following that successful transplant, observations initially increased and subsequently continued at a relatively low level with most reports coming from the southern portion but including others from throughout the historical range. White-tailed Ptarmigan are localized in suitable habitats, but their abundance in New Mexico may be affected by the decreasing size of alpine snowfields in summer, grazing in areas dominated by willow (Salix spp.), and the shift to a warmer and drier climate.
Braun C.E.,Grouse Inc. |
Tomlinson R.E.,U.S. Fish and Wildlife Service
Southwestern Naturalist | Year: 2015
We calculated hatching dates for 2,479 immature mourning doves (Zenaida macroura) captured and banded in a suburban area of Tucson, Arizona, during 2000-2012. Hatching commenced in February and continued into late September. Frequency of hatching peaked during 21-31 May and gradually declined to the end of September. Mourning doves in the Tucson area have hatching distribution similar to those of populations in other parts of the United States. Our data show no measurable differences in length of the mourning dove breeding season among varied locations throughout the United States over a 70-year period.
Kaler R.S.A.,Kansas State University |
Ebbert S.E.,U.S. Fish and Wildlife Service |
Braun C.E.,Grouse Inc. |
Sandercock B.K.,Kansas State University
Wilson Journal of Ornithology | Year: 2010
We report results of a 4-year translocation effort to reestablish a breeding population of Evermann's Rock Ptarmigan (Lagopus muta evermanni) in the Near Islands group of the western Aleutian Archipelago. Habitat restoration was completed by eradication of introduced foxes from Agattu Island by 1979. We captured and moved 75 ptarmigan from Attu Island to Agattu Island during 2003-2006, and monitored 29 radio-marked females in the last 2 years of the study. We compared the demography of newly translocated birds (n = 13) with resident birds established from translocations in previous years (n = 16). Mortality risk was increased by translocation and 15% of females died within 2 weeks of release at Agattu Island. All surviving females attempted to nest but initiated clutches 8 days later in the breeding season and laid 1.5 fewer eggs per clutch than resident females. Probability of nest survival (x̄ ± SE) was good for both translocated (0.72 ± 0.17) and resident females (0.50 ± 0.16), and renests were rare. Probability of brood survival was higher among translocated (0.85 ± 0.14) than resident females (0.25 ± 0.12), partly as a result of inclement weather in 2006. Fecundity, estimated as female fledglings per breeding female, was relatively low for both translocated (0.9 ± 0.3) and resident females (0.3 ± 0.2). No mortalities occurred among radio-marked female ptarmigan during the 10-week breeding season, and the probability of annual survival for females in 2005-2006 was between 0.38 and 0.75. Translocations were successful because females survived, successfully nested, and recruited offspring during the establishment stage. Post-release monitoring provided useful demographic data in this study and should be a key component of translocation programs for wildlife restoration. Future population surveys and additional translocations may be required to ensure long-term viability of the reintroduced population of ptarmigan at Agattu Island. © 2010 by the Wilson Ornithological Society.
Wann G.T.,Colorado State University |
Aldridge C.L.,Colorado State University |
Aldridge C.L.,U.S. Geological Survey |
Braun C.E.,Grouse Inc.
Population Ecology | Year: 2014
Long-term datasets for high-elevation species are rare, and considerable uncertainty exists in understanding how high-elevation populations have responded to recent climate warming. We present estimates of demographic vital rates from a 43-year population study of white-tailed ptarmigan (Lagopus leucura), a species endemic to alpine habitats in western North America. We used capture-recapture models to estimate annual rates of apparent survival, population growth, and recruitment for breeding-age ptarmigan, and we fit winter weather covariates to models in an attempt to explain annual variation. There were no trends in survival over the study period but there was strong support for age and sex effects. The average rate of annual growth suggests a relatively stable breeding-age population ((formula presented) = 1.036), but there was considerable variation between years for both population growth and recruitment rates. Winter weather covariates only explained a small amount of variation in female survival and were not an important predictor of male survival. Cumulative winter precipitation was found to have a quadratic effect on female survival, with survival being highest during years of average precipitation. Cumulative winter precipitation was positively correlated with population growth and recruitment rates, although this covariate only explained a small amount of annual variation in these rates and there was considerable uncertainty among the models tested. Our results provide evidence for an alpine-endemic population that has not experienced extirpation or drastic declines. However, more information is needed to understand risks and vulnerabilities of warming effects on juveniles as our analysis was confined to determination of vital rates for breeding-age birds. © 2014, The Society of Population Ecology and Springer Japan (outside the USA).