Systematic diet studies of Mexican gray wolves (Canis lupus baileyi) were not conducted before wo... more Systematic diet studies of Mexican gray wolves (Canis lupus baileyi) were not conducted before wolves were extirpated by the late 1960s from the southwestern United States. We collected carnivore scats (n ¼ 1,682) from the Apache and Gila national forests in Arizona and New Mexico, USA, from April 1998 through October 2001 and identified scats to species using traditional field methods, of which 251 were identified as Mexican wolf scats. We found the diet consisted of large-sized food items (92.8% percent frequency of occurrence [PFO]), primarily elk (Cervus elaphus) adults (36.6% PFO) and calves (36.2% PFO). Biomass calculations indicated that Mexican wolves consumed 414 kg of prey as represented by the scats, with elk representing 76.7% of the biomass. When comparing PFO with percent biomass, PFO calculations may have underrepresented larger food items and percent biomass may have overrepresented smaller food items. We compared the diet composition of Mexican wolf scats (n ¼ 251) to the diets reported in previous North American gray wolf (C. lupus) studies (n ¼ 7). The high proportion of elk in Mexican wolf diets in our study area may reflect the low-density, early colonizing stage of the wolf population and elk probably being the most numerous ungulate in our study area. Our results suggested that free-ranging Mexican wolves consumed a higher proportion of large-sized prey than other North American gray wolves. Our results provide baseline diet information for a newly reestablished wolf population.
Several aspects of the ecology of coyotes (Canis latrans) have been studied in cities (i.e., diet... more Several aspects of the ecology of coyotes (Canis latrans) have been studied in cities (i.e., diet, use and selection of habitat, movements), but additional knowledge will assist persons that are responsible for management of urban predators. We studied coyotes in central Tucson, Pima Co., Arizona, during November 2005-November 2006. Our objectives were to monitor radiocollared coyotes to determine size of home range, to ascertain use of habitat based on land-use categories and movements, and to describe a den of urban coyotes. Average size of home range calculated using the 95% fixed-kernel method was 26.8 6 5.1 SE km 2 for resident coyotes. Overall, land categories used most often were washes, medium-density residential areas, and low-density residential areas. Movements were ,520 m/h within land-use categories used most often during day and night (i.e., medium-density residential areas and washes) and .800 m/h in areas that were used most during the night (i.e., highdensity residential and commercial areas). Coyotes were able to meet their life-history requirements in central Tucson likely due to available resources and a diversity of land-use categories, especially washes.
We compared bed sites selected by desert mule deer (Odocoileus hemionus eremicus) to nearby rando... more We compared bed sites selected by desert mule deer (Odocoileus hemionus eremicus) to nearby random sites to assess bed site features. Thermal cover of bed sites (i.e., vegetation-75 cm high that provided shade for a deer) was highest in summer (X = 43.7% + 4.1 SE) compared to spring (29.7% + 4.4), winter (33.5% ? 3.1), and autumn (39.8% + 4.0); however, selection for bed sites with thermal cover that differed most from that available randomly was highest in spring (X difference between bed and random sites = 14.8% + 5.2) compared to summer (8.3% ? 4.1), winter (6.6% + 3.5), and autumn (8.6% ? 3.5). Thermal cover is likely important as a contribution to thermoregulation, escape cover, protection of fawns, and fawn survival. RESUMEN-Comparamos los echaderos seleccionados por el venado bura (Odocoileus hemionus eremicus) a sitios cercanos al azar para determinar las caracteristicas de los echaderos. La cubierta termal de los echaderos (o sea, vegetaci6n >75 cm de altura que provey6 sombra para el venado) fue mas alta en el verano (X = 43.7% + 4.1 SE), comparado con la primavera (27.9% ? 4.4), invierno (33.5% + 3.1), y otono (39.8% + 4.0). Sin embargo, la selecci6n de echaderos con cubierta termal que difiri6 mas que lo disponible al azar fue mas alta en la primavera (Xdiferencia entre echaderos y sitios al azar = 14.8% + 5.2) comparada con el verano (8.3% ? 4.1), invierno (6.6% ? 3.5), y otono (8.6% + 3.5). La cubierta termal es quizas importante como una contri-buci6n a la termorregulaci6n, cubierta de escape, protecci6n de ciervos, y supervivencia de ciervos.
... Wildlife Society Bulletin 22:94100.. Conover, MR 1997. Monetary and intangible valuation ofd... more ... Wildlife Society Bulletin 22:94100.. Conover, MR 1997. Monetary and intangible valuation ofdeer in the United States. Wildlife Society Bulletin 25:298305.. Conover, MR 1998. Perceptions of American agricultural producers about wildlife on their farms and ranches. ...
Vigilant behavior in wild ungulates is critical to guard against predation. However, few studies ... more Vigilant behavior in wild ungulates is critical to guard against predation. However, few studies have examined vigilant behavior in domesticated ungulates. Considering the expansion of large predator populations, understanding vigilant behavior and factors that influence it will help with the management of livestock. We observed adult female cattle (Bos taurus L.) in open-range conditions where large predators (wolves [Canis lupus L.] and mountain lions [Puma concolor (L.).]) were common threats during summers of 2005 and 2006 in eastern Arizona. This study was designed to determine 1) to what extent cattle exhibit vigilant behavior compared to published data on wild ungulates, 2) whether predation events influence vigilance rates of cattle, and 3) whether social and environmental factors affect vigilance of cattle. Cattle exhibited vigilant behavior (3% 6 0.19%) during peak foraging periods, but at a lower rate than wild ungulates. Cows with calves were more than twice as vigilant (4.5% 6 0.46%) as those without calves (2.0% 6 0.27%). Single cattle and groups of two to five exhibited higher vigilance rates (4.2% 6 0.79%) than groups of six to 20 (2.5% 6 0.32%) and groups of . 20 (3.0% 6 0.41%). Cattle in groups of . 20 increased vigilance as visual obstruction increased. Mother cows whose calves were preyed upon (n 5 5) exhibited a 3% to 48% increase in vigilance within 3 d after their calves were killed; this rate returned to near baseline levels after 10 d. Conversely, mother cows reduced foraging after their calves were killed from 88.5% 6 1.69% to 43.5% 6 11.4%; foraging rate also returned to near baseline levels after 10 d. Cattle exhibit vigilance at lower levels compared to wild ungulates, but this behavior appears to be at least partially an antipredatory behavior. Our findings provide support that predators can influence cattle behavior.
We captured 10 free-ranging desert mule deer (Odocoileus hemionus crooki) (five males and five fe... more We captured 10 free-ranging desert mule deer (Odocoileus hemionus crooki) (five males and five females) by net-gun from a helicopter and immobilized them with xylazine hydrochloride (HCI) (100 mg) and ketamine HC1 (300 to 400 mg) injected intramuscularly. Arousal and ambulation times were 13.9 ± 4.2 and 14.3 ± 4.2 mm in eight deer injected intravenously with tolazoline HC1 (3.0
The health of coyotes (Canis latrans) in urban areas has not been studied. Our objectives were to... more The health of coyotes (Canis latrans) in urban areas has not been studied. Our objectives were to assess the health of coyotes in Tucson (Arizona, USA) by determining the prevalence of antibodies to selected pathogens, estimating survival rates, and identifying sources of mortality. We drew blood from 22 coyotes to evaluate the prevalence of heartworm (Dirofilaria immitis) antigens, and antibodies
Stable isotope analysis of diet has become a common tool in conservation research. However, the m... more Stable isotope analysis of diet has become a common tool in conservation research. However, the multiple sources of uncertainty inherent in this analysis framework involve consequences that have not been thoroughly addressed. Uncertainty arises from the choice of trophic discrimination factors, and for Bayesian stable isotope mixing models (SIMMs), the specification of prior information; the combined effect of these aspects has not been explicitly tested. We used a captive feeding study of gray wolves (Canis lupus) to determine the first experimentally-derived trophic discrimination factors of C and N for this large carnivore of broad conservation interest. Using the estimated diet in our controlled system and data from a published study on wild wolves and their prey in Montana, USA, we then investigated the simultaneous effect of discrimination factors and prior information on diet reconstruction with Bayesian SIMMs. Discrimination factors for gray wolves and their prey were 1.97‰ for δ 13 C and 3.04‰ for δ 15 N. Specifying wolf discrimination factors, as opposed to the commonly used red fox (Vulpes vulpes) factors, made little practical difference to estimates of wolf diet, but prior information had a strong effect on bias, precision, and accuracy of posterior estimates. Without specifying prior information in our Bayesian SIMM, it was not possible to produce SIMM posteriors statistically similar to the estimated diet in our controlled study or the diet of wild wolves. Our study demonstrates the critical effect of prior information on estimates of animal diets using Bayesian SIMMs, and suggests species-specific trophic discrimination factors are of secondary importance. When using stable isotope analysis to inform conservation decisions researchers should understand the limits of their data. It may PLOS ONE | Proportional contributions to diet (Estimated; Mean and SD) were estimated by bootstrapping the number of each prey (and the range of possible masses from the literature) fed to each wolf. Proportional contributions (SIMM; Mean and SD) represent posterior density distributions of Bayesian stable isotope (δ 13 C and δ 15 N) mixing models formulated with various priors (from non-informative to minimum informative prior) and discrimination factors (i.e., red fox
The United States Air Force (USAF) uses part of Sonoran pronghorn (Antilocapra americana sonorien... more The United States Air Force (USAF) uses part of Sonoran pronghorn (Antilocapra americana sonoriensis) habitat for bombing exercises (i.e., Barry M. Goldwater Air Force Range [BMGR], southwest AZ, USA) that could be detrimental to the endangered subspecies. To minimize injury or death to Sonoran pronghorn, the USAF and United States Fish and Wildlife Service developed a monitoring protocol that would eliminate live ordnance delivery in the vicinity of pronghorn. From 1998 to 2003, we searched for pronghorn on or near military targets prior to ordnance delivery. If we observed pronghorn within 5 km of a target, the target was closed for 24 hours. We monitored bombing ranges on BMGR and closed .5,000 targets for .1,000 days due to military activity. To our knowledge, no pronghorn were killed or injured. We recommend that the monitoring program continue as long as military activity occurs in pronghorn habitat. (JOURNAL OF WILDLIFE MANAGEMENT 71 :
An infectious keratoconjunctivitis (IKC) epizootic in bighorn sheep (Ovis cana- densis) occurred ... more An infectious keratoconjunctivitis (IKC) epizootic in bighorn sheep (Ovis cana- densis) occurred in the Silver Bell Mountains, Arizona, USA, from 1 December 2003 to 31 March 2004. We used standard culture meth- ods and polymerase chain reaction (PCR) amplification of the 16S rRNA gene to test for the causative agents of IKC and other diseases reported to be associated with
Desert bighorn sheep (Ovis canadensis mexicana) are an important component of the biodiversity in... more Desert bighorn sheep (Ovis canadensis mexicana) are an important component of the biodiversity in the Pusch Ridge Wilderness (PRW) , Santa Catalina Mountains, Arizona. The population has decreased from approximately <20 in 1926 to in 1994 and their distribution is limited to < 50 km2 in the PRW. The population decline has been attributed to human activities including the development
Associations among causes of species endangerment in the United States reflect the integration of... more Associations among causes of species endangerment in the United States reflect the integration of economic sectors, supporting the theory and evidence that economic growth proceeds at the competitive exclusion of nonhuman species in the aggregate.
Systematic diet studies of Mexican gray wolves (Canis lupus baileyi) were not conducted before wo... more Systematic diet studies of Mexican gray wolves (Canis lupus baileyi) were not conducted before wolves were extirpated by the late 1960s from the southwestern United States. We collected carnivore scats (n ¼ 1,682) from the Apache and Gila national forests in Arizona and New Mexico, USA, from April 1998 through October 2001 and identified scats to species using traditional field methods, of which 251 were identified as Mexican wolf scats. We found the diet consisted of large-sized food items (92.8% percent frequency of occurrence [PFO]), primarily elk (Cervus elaphus) adults (36.6% PFO) and calves (36.2% PFO). Biomass calculations indicated that Mexican wolves consumed 414 kg of prey as represented by the scats, with elk representing 76.7% of the biomass. When comparing PFO with percent biomass, PFO calculations may have underrepresented larger food items and percent biomass may have overrepresented smaller food items. We compared the diet composition of Mexican wolf scats (n ¼ 251) to the diets reported in previous North American gray wolf (C. lupus) studies (n ¼ 7). The high proportion of elk in Mexican wolf diets in our study area may reflect the low-density, early colonizing stage of the wolf population and elk probably being the most numerous ungulate in our study area. Our results suggested that free-ranging Mexican wolves consumed a higher proportion of large-sized prey than other North American gray wolves. Our results provide baseline diet information for a newly reestablished wolf population.
Several aspects of the ecology of coyotes (Canis latrans) have been studied in cities (i.e., diet... more Several aspects of the ecology of coyotes (Canis latrans) have been studied in cities (i.e., diet, use and selection of habitat, movements), but additional knowledge will assist persons that are responsible for management of urban predators. We studied coyotes in central Tucson, Pima Co., Arizona, during November 2005-November 2006. Our objectives were to monitor radiocollared coyotes to determine size of home range, to ascertain use of habitat based on land-use categories and movements, and to describe a den of urban coyotes. Average size of home range calculated using the 95% fixed-kernel method was 26.8 6 5.1 SE km 2 for resident coyotes. Overall, land categories used most often were washes, medium-density residential areas, and low-density residential areas. Movements were ,520 m/h within land-use categories used most often during day and night (i.e., medium-density residential areas and washes) and .800 m/h in areas that were used most during the night (i.e., highdensity residential and commercial areas). Coyotes were able to meet their life-history requirements in central Tucson likely due to available resources and a diversity of land-use categories, especially washes.
We compared bed sites selected by desert mule deer (Odocoileus hemionus eremicus) to nearby rando... more We compared bed sites selected by desert mule deer (Odocoileus hemionus eremicus) to nearby random sites to assess bed site features. Thermal cover of bed sites (i.e., vegetation-75 cm high that provided shade for a deer) was highest in summer (X = 43.7% + 4.1 SE) compared to spring (29.7% + 4.4), winter (33.5% ? 3.1), and autumn (39.8% + 4.0); however, selection for bed sites with thermal cover that differed most from that available randomly was highest in spring (X difference between bed and random sites = 14.8% + 5.2) compared to summer (8.3% ? 4.1), winter (6.6% + 3.5), and autumn (8.6% ? 3.5). Thermal cover is likely important as a contribution to thermoregulation, escape cover, protection of fawns, and fawn survival. RESUMEN-Comparamos los echaderos seleccionados por el venado bura (Odocoileus hemionus eremicus) a sitios cercanos al azar para determinar las caracteristicas de los echaderos. La cubierta termal de los echaderos (o sea, vegetaci6n >75 cm de altura que provey6 sombra para el venado) fue mas alta en el verano (X = 43.7% + 4.1 SE), comparado con la primavera (27.9% ? 4.4), invierno (33.5% + 3.1), y otono (39.8% + 4.0). Sin embargo, la selecci6n de echaderos con cubierta termal que difiri6 mas que lo disponible al azar fue mas alta en la primavera (Xdiferencia entre echaderos y sitios al azar = 14.8% + 5.2) comparada con el verano (8.3% ? 4.1), invierno (6.6% ? 3.5), y otono (8.6% + 3.5). La cubierta termal es quizas importante como una contri-buci6n a la termorregulaci6n, cubierta de escape, protecci6n de ciervos, y supervivencia de ciervos.
... Wildlife Society Bulletin 22:94100.. Conover, MR 1997. Monetary and intangible valuation ofd... more ... Wildlife Society Bulletin 22:94100.. Conover, MR 1997. Monetary and intangible valuation ofdeer in the United States. Wildlife Society Bulletin 25:298305.. Conover, MR 1998. Perceptions of American agricultural producers about wildlife on their farms and ranches. ...
Vigilant behavior in wild ungulates is critical to guard against predation. However, few studies ... more Vigilant behavior in wild ungulates is critical to guard against predation. However, few studies have examined vigilant behavior in domesticated ungulates. Considering the expansion of large predator populations, understanding vigilant behavior and factors that influence it will help with the management of livestock. We observed adult female cattle (Bos taurus L.) in open-range conditions where large predators (wolves [Canis lupus L.] and mountain lions [Puma concolor (L.).]) were common threats during summers of 2005 and 2006 in eastern Arizona. This study was designed to determine 1) to what extent cattle exhibit vigilant behavior compared to published data on wild ungulates, 2) whether predation events influence vigilance rates of cattle, and 3) whether social and environmental factors affect vigilance of cattle. Cattle exhibited vigilant behavior (3% 6 0.19%) during peak foraging periods, but at a lower rate than wild ungulates. Cows with calves were more than twice as vigilant (4.5% 6 0.46%) as those without calves (2.0% 6 0.27%). Single cattle and groups of two to five exhibited higher vigilance rates (4.2% 6 0.79%) than groups of six to 20 (2.5% 6 0.32%) and groups of . 20 (3.0% 6 0.41%). Cattle in groups of . 20 increased vigilance as visual obstruction increased. Mother cows whose calves were preyed upon (n 5 5) exhibited a 3% to 48% increase in vigilance within 3 d after their calves were killed; this rate returned to near baseline levels after 10 d. Conversely, mother cows reduced foraging after their calves were killed from 88.5% 6 1.69% to 43.5% 6 11.4%; foraging rate also returned to near baseline levels after 10 d. Cattle exhibit vigilance at lower levels compared to wild ungulates, but this behavior appears to be at least partially an antipredatory behavior. Our findings provide support that predators can influence cattle behavior.
We captured 10 free-ranging desert mule deer (Odocoileus hemionus crooki) (five males and five fe... more We captured 10 free-ranging desert mule deer (Odocoileus hemionus crooki) (five males and five females) by net-gun from a helicopter and immobilized them with xylazine hydrochloride (HCI) (100 mg) and ketamine HC1 (300 to 400 mg) injected intramuscularly. Arousal and ambulation times were 13.9 ± 4.2 and 14.3 ± 4.2 mm in eight deer injected intravenously with tolazoline HC1 (3.0
The health of coyotes (Canis latrans) in urban areas has not been studied. Our objectives were to... more The health of coyotes (Canis latrans) in urban areas has not been studied. Our objectives were to assess the health of coyotes in Tucson (Arizona, USA) by determining the prevalence of antibodies to selected pathogens, estimating survival rates, and identifying sources of mortality. We drew blood from 22 coyotes to evaluate the prevalence of heartworm (Dirofilaria immitis) antigens, and antibodies
Stable isotope analysis of diet has become a common tool in conservation research. However, the m... more Stable isotope analysis of diet has become a common tool in conservation research. However, the multiple sources of uncertainty inherent in this analysis framework involve consequences that have not been thoroughly addressed. Uncertainty arises from the choice of trophic discrimination factors, and for Bayesian stable isotope mixing models (SIMMs), the specification of prior information; the combined effect of these aspects has not been explicitly tested. We used a captive feeding study of gray wolves (Canis lupus) to determine the first experimentally-derived trophic discrimination factors of C and N for this large carnivore of broad conservation interest. Using the estimated diet in our controlled system and data from a published study on wild wolves and their prey in Montana, USA, we then investigated the simultaneous effect of discrimination factors and prior information on diet reconstruction with Bayesian SIMMs. Discrimination factors for gray wolves and their prey were 1.97‰ for δ 13 C and 3.04‰ for δ 15 N. Specifying wolf discrimination factors, as opposed to the commonly used red fox (Vulpes vulpes) factors, made little practical difference to estimates of wolf diet, but prior information had a strong effect on bias, precision, and accuracy of posterior estimates. Without specifying prior information in our Bayesian SIMM, it was not possible to produce SIMM posteriors statistically similar to the estimated diet in our controlled study or the diet of wild wolves. Our study demonstrates the critical effect of prior information on estimates of animal diets using Bayesian SIMMs, and suggests species-specific trophic discrimination factors are of secondary importance. When using stable isotope analysis to inform conservation decisions researchers should understand the limits of their data. It may PLOS ONE | Proportional contributions to diet (Estimated; Mean and SD) were estimated by bootstrapping the number of each prey (and the range of possible masses from the literature) fed to each wolf. Proportional contributions (SIMM; Mean and SD) represent posterior density distributions of Bayesian stable isotope (δ 13 C and δ 15 N) mixing models formulated with various priors (from non-informative to minimum informative prior) and discrimination factors (i.e., red fox
The United States Air Force (USAF) uses part of Sonoran pronghorn (Antilocapra americana sonorien... more The United States Air Force (USAF) uses part of Sonoran pronghorn (Antilocapra americana sonoriensis) habitat for bombing exercises (i.e., Barry M. Goldwater Air Force Range [BMGR], southwest AZ, USA) that could be detrimental to the endangered subspecies. To minimize injury or death to Sonoran pronghorn, the USAF and United States Fish and Wildlife Service developed a monitoring protocol that would eliminate live ordnance delivery in the vicinity of pronghorn. From 1998 to 2003, we searched for pronghorn on or near military targets prior to ordnance delivery. If we observed pronghorn within 5 km of a target, the target was closed for 24 hours. We monitored bombing ranges on BMGR and closed .5,000 targets for .1,000 days due to military activity. To our knowledge, no pronghorn were killed or injured. We recommend that the monitoring program continue as long as military activity occurs in pronghorn habitat. (JOURNAL OF WILDLIFE MANAGEMENT 71 :
An infectious keratoconjunctivitis (IKC) epizootic in bighorn sheep (Ovis cana- densis) occurred ... more An infectious keratoconjunctivitis (IKC) epizootic in bighorn sheep (Ovis cana- densis) occurred in the Silver Bell Mountains, Arizona, USA, from 1 December 2003 to 31 March 2004. We used standard culture meth- ods and polymerase chain reaction (PCR) amplification of the 16S rRNA gene to test for the causative agents of IKC and other diseases reported to be associated with
Desert bighorn sheep (Ovis canadensis mexicana) are an important component of the biodiversity in... more Desert bighorn sheep (Ovis canadensis mexicana) are an important component of the biodiversity in the Pusch Ridge Wilderness (PRW) , Santa Catalina Mountains, Arizona. The population has decreased from approximately <20 in 1926 to in 1994 and their distribution is limited to < 50 km2 in the PRW. The population decline has been attributed to human activities including the development
Associations among causes of species endangerment in the United States reflect the integration of... more Associations among causes of species endangerment in the United States reflect the integration of economic sectors, supporting the theory and evidence that economic growth proceeds at the competitive exclusion of nonhuman species in the aggregate.
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