Wildlife Monographs最新文献

{"title":"Evaluation of Factors Potentially Influencing a Desert Bighorn Sheep Population","authors":"TED McKINNEY, THORRY W. SMITH, JAMES C. DeVOS Jr.","doi":"10.2193/0084-0173(2006)164[1:EOFPIA]2.0.CO;2","DOIUrl":"https://doi.org/10.2193/0084-0173(2006)164[1:EOFPIA]2.0.CO;2","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <h3> ABSTRACT</h3>\u0000 \u0000 <p>We studied a desert bighorn sheep (<i>Ovis canadensis</i>) population in the Mazatzal Mountains (primary study area) in central Arizona and population indices on reference areas between 1989 and 2003. We evaluated disease exposure and nutritional status of desert bighorn sheep, vegetation parameters, predator diets, and mountain lion (<i>Puma concolor</i>) harvest and abundance (1999–2003) and mountain lion predation (1995–2003) as factors potentially affecting desert bighorn sheep and population parameters. We measured rainfall monthly, monitored demography and relative abundance of desert bighorn sheep using aerial surveys, captured and placed radio collars on desert bighorn sheep, and collected samples of blood, parasites, and other pathogenic agents from captured animals. We measured mineral content, relative use, and structural composition of vegetation and determined diets of desert bighorn sheep adults and lambs, dietary intakes of nitrogen (FN), 2,6-diaminopimelic acid (FDAPA), neutral detergent fiber, and minerals using fecal analyses. We incorporated mountain lion reductions as an experimental element, monitored harvest, and used track surveys as an index of relative abundance of the predator and monitored radio-collared desert bighorn sheep to determine mortalities and causes of death. We determined diets of bobcats (<i>Lynx rufus</i>), coyotes (<i>Canis latrans</i>), and mountain lions using fecal analyses. Drought conditions occurred during summer (July-September) and winter (November-April) during 4 and 3 years, respectively, between 1999 and 2003. Annual surveys indicated that the Mazatzal Mountains population declined during drought between 1994 and 1997, experienced low growth and lamb production coincident with above-normal rainfall in 1998 and drought in 1999, and exhibited higher growth, production, and productivity during 2000–2003 despite persistent drought conditions during this period. We observed no clinical symptoms of disease in radio-collared desert bighorn sheep, and hematological and other evidence of exposure to disease agents was unremarkable. Population indices on the primary study and reference areas were positively correlated with winter (November-April) rainfall. We found no evidence of forage overutilization on the primary study area. Rainfall on Mazatzal Mountains was associated with differences in primary production, particularly of forbs, forage mineral concentrations, and diets, nutritional status, and demographic attributes of desert bighorn sheep between 1999 and 2003. Higher winter rainfall was associated with higher forb growth, and higher rainfall was associated with higher concentrations of P and Se but lower levels of Fe in browse; higher concentrations of Ca, P, and Zn in forbs; and higher levels of P, Se, and Zn in grasses. Narrower mean Ca:P ratios of browse and forbs were associated with hi","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"164 1","pages":"1-36"},"PeriodicalIF":4.4,"publicationDate":"2010-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2193/0084-0173(2006)164[1:EOFPIA]2.0.CO;2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6235260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aspects of the Thermal Ecology of Bobwhites in North Texas","authors":"FRED S. GUTHERY, ALEXANDR R. RYBAK, SAMUEL D. FUHLENDORF, TIM L. HILLER, STEVEN G. SMITH, WILLIAM H. PUCKETT JR., ROBERT A. BAKER","doi":"10.2193/0084-0173(2004)159[1:AOTTEO]2.0.CO;2","DOIUrl":"https://doi.org/10.2193/0084-0173(2004)159[1:AOTTEO]2.0.CO;2","url":null,"abstract":"<p><b>Abstract: </b> We studied the thermal ecology of northern bobwhites (<i>Colinus virginianus</i>) to better understand the role of temperature in the field behavior of these birds. We obtained descriptive data on thermal aspects of the landscape; bobwhite selection for Normalized Difference Vegetation Index (NDVI; vegetation biomass) classes and cover associations relative to their thermal properties; and thermal conditions at nests, mid-day coverts, and roosts. We collected data on a 796-ha area in the Texas Rolling Plains during May 2000-July 2003 using satellite imagery, black-bulb temperature probes, mortality- and temperature-sensing radiotransmitters, and continuous-recording video cameras for nest observations. Linear models of black-bulb temperature (<i>T</i><sub>bb</sub>) as a function of air temperature (<i>T</i><sub>a</sub>) at a base weather station explained 42–70% of the variation in <i>T</i><sub>bb</sub> in 10 NDVI classes during daylight and 78% during night in summer (all NDVI classes; Jul 2001). During February 2002, <i>T</i><sub>a</sub> explained 38–92% of the variation during day and 89% of the variation at night. The linear models provided a means of qualitatively assessing thermal space on the landscape as <i>T</i><sub>a</sub> changed and of predicting <i>T</i><sub>bb</sub> in NDVI classes. At <i>T</i><sub>a</sub> = 42 °C, 100% of the 796-ha landscape under study had predicted <i>T</i><sub>bb</sub> > 39 °C, the approximate threshold leading to hyperthermia in bobwhites. Based on 9,287 radiolocations of 217 bobwhites, bobwhites selected for all NDVI classes in mixed-shrub cover (sand plum, [<i>Prunus angustifolia</i>]; fragrant sumac, [<i>Rhus aromatica</i>]) on an annual and seasonal basis. If <i>T</i><sub>a</sub> was <35 °C, the approximate upper critical temperature, the operative temperature (<i>T</i><sub>e</sub>) experienced by bobwhites exceeded <i>T</i><sub>a</sub> in 699 of 818 simultaneous readings (<i>n</i> = 24 bobwhites with thermal transmitters) and the difference between <i>T</i><sub>e</sub> and <i>T</i><sub>a</sub> increased as air temperature declined. Data from video cameras indicated thermal stress (i.e., gular flutter) in 25 of 26 incubating bobwhites. Gular flutter began at an average <i>T</i><sub>a</sub> of 30.4 ± 0.2 ±C SE (<i>n</i> = 158) and total bouts of gular flutter averaged 87 minutes/bird/day after 16 June. Data from thermal radiotransmitters indicated 91.3 ± 6.1% of incubating adults were in thermal stress at <i>T</i><sub>a</sub> > 35 °C. Temperature of nest contents averaged about 30 °C and incubating bobwhites appeared to protect nest contents more rigorously from hyperthermia than from hypothermia. Mid-day covert selection (NDVI 6, mixed-shrub cover; <i>n</i> = 58) during summer reduced bobwhite exposure to <i>T</i><sub>bb</sub> > 39 °C by an average of 1,600.7 heating-degree minutes in comparison with random points (<i>n</i> = 58) during 1200–1600 hours. The roosting disc ap","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"159 1","pages":"1-36"},"PeriodicalIF":4.4,"publicationDate":"2010-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2193/0084-0173(2004)159[1:AOTTEO]2.0.CO;2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6207310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pathogens, Nutritional Deficiency, and Climate Influences on a Declining Moose Population","authors":"DENNIS L. MURRAY, ERIC W. COX, WARREN B. BALLARD, HEATHER A. WHITLAW, MARK S. LENARZ, THOMAS W. CUSTER, TERRI BARNETT, TODD K. FULLER","doi":"10.2193/0084-0173(2006)166[1:PNDACI]2.0.CO;2","DOIUrl":"https://doi.org/10.2193/0084-0173(2006)166[1:PNDACI]2.0.CO;2","url":null,"abstract":"Abstract Several potential proximate causes may be implicated in a recent (post-1984) decline in moose (Alces alces andersoni) numbers at their southern range periphery in northwest Minnesota, USA. These causes include deleterious effects of infectious pathogens, some of which are associated with white-tailed deer (Odocoileus virginianus), negative effects of climate change, increased food competition with deer or moose, legal or illegal hunting, and increased predation by gray wolves (Canis lupus) and black bears (Ursus americanus). Long-standing factors that may have contributed to the moose decline include those typically associated with marginal habitat such as nutritional deficiencies. We examined survival and productivity among radiocollared (n = 152) adult female and juvenile moose in northwest Minnesota during 1995–2000, and assessed cause of death and pathology through carcass necropsy of radiocollared and non-radiocollared animals. Aerial moose surveys suggested that hunting was an unlikely source of the numerical decline because the level of harvest was relatively low (i.e., approx. 15% / 2 yr) and the population usually grew in years following a hunt. The majority of moose mortalities (up to 87% of radiocollared moose [n = 76] and up to 65% of non-radiocollared moose [n = 84]) were proximally related to pathology associated with parasites and infectious disease. Liver fluke (Fascioloides magna) infections apparently constituted the greatest single source of mortality and caused significant pathology in the liver, thoracic and peritoneal cavities, pericardial sac, and lungs. Mortality due to meningeal worm (Parelaphostrongylus tenuis) was less prevalent and was manifested through characteristic neurological disease. Several mortalities apparently were associated with unidentified infectious disease, probably acting in close association with malnutrition. Bone-marrow fat was lower for moose dying of natural causes than those dying of anthropogenic factors or accidents, implying that acute malnutrition contributed to moose mortality. Blood profiles from live-captured animals indicated that those dying in the subsequent 18 months were chronically malnourished. Relative to other populations, average annual survival rates for adult females (0.79 [0.74–0.84; 95% CI]) and yearlings (0.64 [0.48–0.86]) were low, whereas those for calves (0.66 [0.53–081]) were high. Pregnancy (48%) and twinning (19%) rates were among the lowest reported for moose, with reproductive senescence among females being apparent as early as 8 years. Pregnancy status was related to indices of acute (i.e., bone-marrow fat) and chronic (i.e., blood condition indices) malnutrition. Opportunistic carcass recovery indicated that there likely were few prime-aged males (>5 yr old) in the population. Analysis of protein content in moose browse and fecal samples indicated that food quality was probably adequate to support moose over winter, but the higher fecal protein among anim","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"166 1","pages":"1-30"},"PeriodicalIF":4.4,"publicationDate":"2010-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2193/0084-0173(2006)166[1:PNDACI]2.0.CO;2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6207312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SURVIVAL, MOVEMENTS, AND HARVEST OF EASTERN PRAIRIE POPULATION CANADA GEESE","authors":"SUSAN E. SHEAFFER, DONALD H. RUSCH, DALE D. HUMBURG, JEFFERY S. LAWRENCE, GUY G. ZENNER, MURRAY M. GILLESPIE, F. DALE CASWELL, STEVE WILDS, SCOTT C. YAICH","doi":"10.2193/0084-0173(2004)156[1:SMAHOE]2.0.CO;2","DOIUrl":"https://doi.org/10.2193/0084-0173(2004)156[1:SMAHOE]2.0.CO;2","url":null,"abstract":"<p><b>Abstract: </b> The Eastern Prairie Population (EPP) of Canada geese (<i>Branta canadensis interior</i>) nests in the Hudson Bay lowlands of Manitoba and migrates through south-central Manitoba, western Minnesota, and Iowa, with a wintering terminus primarily in Missouri, Arkansas, and southern Illinois. The southern range of the EPP historically extended through Arkansas and along coastal southwestern Louisiana and Texas. However, during the 1950s and 1960s a progressive northern shift in wintering distribution occurred as numbers of geese wintering in Louisiana and Arkansas declined while numbers wintering in Missouri increased. Continued temporal and geographic shifts in fall and winter distributions were suspected during the 1980s when numbers of wintering Canada geese increased in Minnesota and declined in Missouri. However, concurrent increases in numbers of Mississippi Valley Population (MVP; <i>B. c. interior</i>) and Mississippi Flyway Giant Population (MFGP; <i>B. c. maxima</i>) Canada geese in portions of the winter range shared with EPP geese confounded interpretations of winter population and harvest surveys. During 1984-93, researchers conducted a cooperative banding and observation effort to improve information on survival rates, harvest rates, and winter distributions of EPP Canada geese. Consistent harvest regulations within 3-year periods during 1984-93, combined with extensive observations of marked geese, allowed for an integrative analysis of survival and movements of this population relative to changes in harvest pressure. We used observations, recaptures, and hunter recoveries of marked geese to provide information on survival, harvest, and movements of the EPP that is needed for long-term management of this population.</p><p>Annual survival rates of neck-banded adult geese averaged (x ± SE) 0.707 ± 0.019 during 1984-86, 0.651 ± 0.022 during 1987-89 when harvest seasons were restricted, and 0.595 ± 0.028 during 1990-93 when harvest seasons were liberalized. Annual survival rates for neck-banded adults were lower versus leg-banded adults during 1987-89 and 1990-93 (<i>P</i> ≤ 0.05). Mean survival of neck-banded adults during the harvest seasons in 1987-89 was lower than the mean rate in the harvest seasons of 1984-86, primarily due to a low survival estimate in 1989. Survival averaged 0.918 ± 0.0129 during the 1987 and 1988 harvest seasons but declined to 0.665 ± 0.051 during 1989. Restrictions in harvest correlated with a decrease in direct recovery rates and an increase in survival rates of neck-banded adults during the 1987 and 1988 harvest seasons, but not in 1989. Higher recovery rates in 1989-92 suggested that increased harvest mortality contributed to lower survival of adult geese. However, mortality rates during the 1989-92 harvest seasons increased at a greater proportion than increases in direct recovery rates, suggesting that factors other than harvest could have significantly impacted fall mortality rates of","PeriodicalId":235,"journal":{"name":"Wildlife Monographs","volume":"156 1","pages":"1-54"},"PeriodicalIF":4.4,"publicationDate":"2010-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2193/0084-0173(2004)156[1:SMAHOE]2.0.CO;2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6235258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}