Ü,.,~ 7, g [ /7 / I. , ß, g x. g? Q. D. Roy. ' kpa ck Dr. Patrick F. Scanlon. v\ A. \ Q; APPROVED: ) '3.) )J/ = V.I?Dr. W- ^[; I, Il E/ August PDF

Description
v\ A. \ ; cology and Physiology of a Black Bear (Ursus americnnus) Population in Great Dismal Swamp and Reproductive Physiology in the Captive Female Black Bear by ric Charles Hellgren Dissertation submitted

Please download to get full document.

View again

of 213
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Information
Category:

Leadership & Management

Publish on:

Views: 6 | Pages: 213

Extension: PDF | Download: 0

Share
Transcript
v\ A. \ ; cology and Physiology of a Black Bear (Ursus americnnus) Population in Great Dismal Swamp and Reproductive Physiology in the Captive Female Black Bear by ric Charles Hellgren Dissertation submitted to the Faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY I in Fisheries and Wildlife Sciences APPROVD:,.rx, i W- ^[; I, Il / ) '3.) )J/ = V.I?Dr. Mic ael R. Vaughan, Chairman Ä 1 fl r ur A, ß, g x g?. D. Roy. ' kpa ck Dr. Patrick F. Scanlon [V /7 / I ' Dr. Dean F. Stauifer / Ü,.,~ 7, g [ \ /l /k.,;. - Dr. Francis C. äxazdauskas, August 1988 Blacksburg, Virginia cology and Physiology of a Black Bear (Ursus americanus) Population in Great Dismal Swamp and Reproductive Physiology in the Captive Female Black Bear. by ric Charles Hellgren Dr. Michael R. Vaughan, Chairman Fisheries and Wildlife Sciences (ABSTRACT) cology and physiology of black bears in Great Dismal Swamp (GDS) ational Wildlife Refuge and surrounding area, a forested wetland in eastern Virginia and northeastern orth Carolina, were studied from April 1984 to March A total of 101 bears (71M, 30F) were captured 10 times. Males dominated the capture sample (_Ij 0.001), but age did not differ between sexes ( = 0.74). Mean (:hs) age was 4.i 0.3 years. Litter size ( =.1; = 1), modal age at primiparity (4 years), and interbirth interval (slightly greater than years) were indicative of n good-quality habitat. stimated annual adult survival rates were 0.84 for females and 0.58 for males. Causes of mortality included legal (outside the Refuge) and illegal harvest, vehicle collisions, depredation permit kills, research, and predation. Population density for the study area was estirnatcd by techniques at bears/kmz, corresponding to -377 bears for the 555 kmz study area. Demographie data suggested a stable and productive population. Three major levels of diet quality were observed in terms of crude iiber, fat, and protein. Spring diets were high in protein but moderate in crude liber, while fall diets were low in crude protein and high in ether extract. Condition indices and several blood characteristics (e.g. total protein, albumin, HCT, hemoglobin, and RBC) were at peaks in spring and late fall and at a low during summer. Serum creatinine concentrations also varied seasonally (P 0.001), with a peak during denning and high levels in spring and late fall, perhaps resulting from transition from and to hibernation. A urea/creatinine (U/C) ratio 510 was not a good indicator of the hibemating state, as 39 of 10 (3.5%) trapped, active bears had U/C ratios 510. Creatinine and total protein were the best indicators of the hibernating state. Albumin, HCT, hemoglobin, and RBC were the best indicators of condition during active stages, as indicated by signiiicant (P 0.1) correlations of condition indices and blood variables. ine blood variables varied with age (P 0.1). Multivariate analysis of variance and discriminant function analysis using blood variables failed to reject the hypothesis that bears cycled through 4 metabolic stages throughout the year. Results showed that metabolic shifts were tied to concomitant seasonal changes in diet quality, diet composition, and body condition, but also may have an endogenous component. Habitat and range use dynamics were described by radiotracking of 4 female and male bears. Median annual range size estimates were 79.1 km: for males (= 10), 33.1 km: for subadult h females (_= 7), and 1.4 km: for adult females (lji_= 11). Preferred (P 0.05) habitats on an annual basis were pocosins and mesic areas for females and gum-cypress and maple-coniferous stands for males. Seasonally, pocosin, gum-cypress, mesic, and disturbed areas were important for females. Bear distribution analysis indicated that roads were preferred (P 0.05) during all seasons except early fall, when bears made fall excursions to feeding areas far from Swarnp roads and close to the study area boundary. Range overlap was extensive for both sexes, although it appeared that females maintained exclusive ranges during spring and early summer. Denning ecology was described by monitoring 35 bears (F, 9M). Five bears (M, 3F) remained active throughout the winter. Den types included 14 elaborate ground nests, 11 excavated ground cavities, ground-level tree cavities, 1 above-ground-level tree cavity, and l den in a stump. Females with cubs denned earlier, (P 0.0) emerged later (_lf 0.001), and dermed longer ( 0.001; days vs days) than all other bear groups. Dry den sites did not appear to be limited. Present population management (protection from hunting and no public vehicular access) should be continued in the Refirge. The small effective population size ( = ) in GDS indicated the need for study of dispersal and genetics in the GDS and other southeastem wetland populations to determine the degree of isolation and extent of genetic variability. Maintenance and enhanoement of pocosins, mature gum, oak, and disturbed habitats would benelit black bears in i southeastem wetlands by providing a wide variety of natural foods throughout the year. Large den trees may not be necessary for successful denning and reproduction in certain southeastem wetlands because bears can use dense cover and microelevational factors to overwinter. Black bear conservation strategies in the Southeast are a critical need due to increasing habitat fragmentation. Six adult female black bears were maintained in captivity in Virginia from August 1987 to April Serum samples, as well as data on body weight and rectal temperatures, were collected from each bear at approximately 10-day intervals from 5 September to 30 March. Four of the six bears hibemated, not feeding for periods of 5 to 11 days ( = 94 d). Rectal temperature declined in both active and hibernating bears during winter, but to a greater extent (P = 0.013) in hibemators. Average weight loss during hibernation represented 7.9% of peak body weight. Mean serum n urea/creatinine (U/C) ratios were similar between physiological groups during the prehibemation phase. However, U/C ratios differed ( 0.05) after the onset of hibemation. Concentrations of total serum protein, serum urea nitrogen, and serum creatinine were similarly atfected by significant time-group interactions ( 0.01). Alkaline phosphatase, phosphorus, sodium, and chloride changed signiiicantly ( 0.05) during the course of the experiment, without regard to physiological group. U/C ratio was a good indicator of the hibemating state, but the sensitivity of serum urea levels to diet suggests careful use of U/C ratio as a field index. Serum progesterone (P) concentrations slowly increased from to 5 ng/ml during October and ovember, then increased -.5 fold 58 i 5 days before parturition in bears that produced cubs. After the implantation peak, P declined, reaching undetectable levels 1- days postpartum. Similar P profiles were observed in 3 of 4 bears that did not produce any observed cubs. P also was assayed in 38 active wild black bears to relate to reproductive status in the den. Changes in serum estradio1 17ß concentrations during gestation also were proliled. The occurrence of pseudopregnancy or early embryonic mortality in bears with elevated serum progesterone concentrations is discussed. Table of Contents ITRODUCTIO... 1 STUDY ARA...A... CHAPTR I: POPULATIO DYAMICS... II U MATRIALS AD MTHODS... 1 Trapping and Handling... 1 Data Analysis RSULTS Sex Ratio and Age Structure..., Reproduction Survival Rates and Mortality Factors Population Size and Stability... DISCUSSIO... 3 LITRATUR CITD... 3 CHAPTR : SASOAL PATTRS I UTRITIO AD PHYSIOLOGY Table of Contents v MATRIALS AD MTHODS Trapping and Handling Food Habits and Blood Analysis RSULTS AD DISCUSSIO Food Habits and Diet uality Condition Indices Serum Chemistry and Hematology Handling effects Age effects... 5 Seasonal eifects Correlation of Blood Characteristics with Condition Indices... 3 Test of Metabolic Stage Hypothesis... 3 cological and Management Implications LITRATUR CITD CHAPTR 3: HOM RAG DYAMICS AD HABITAT US MATRIALS AD MTHODS Trapping and Handling Telemetry Data Collection and Analysis RSULTS..., Home Range Size Home Range Overlap...l Seasonal Habitat Use Spring Summer arly Fall Late Fall...;..., Habitat Use of Individual Bears Table of Contentsvi Bear Distribution Relative to Roads Relative to Study Area Boundary Relative to Surrounding Agricultural Areas DISCUSSIO Management lmplications LITRATUR CITD CHAPTR 4: DIG COLOGY MATRIALS AD MTHODS... 1 Trapping and Handling... 1 Denning and Winter Activity... 1 Management Implications LITRATUR CITD CHAPTR 5: MAAGMT OVRVIW A CHAPTR : PHYSIOLOGY OF GSTATIO AD HIBRATIO MATRIALS AD MTHODS Maintenance and Handling Serum Analyses Statistical Analysis RSULTS DISCUSSIO LITRATUR CITD APPDICS 185 Table of Contents vii Appendix Table 1. Reproductive information on female black bears at first capture in Great Dismal Swamp, Appendix Table. Life table information for captured black bears in Great Dismal Swamp, Virginia orth Carolina, Appendix Table 3. Black bear population estimates ( se) for Great Dismal Swamp, Virginia-orth Carolina, Appendix Table 4. Frequency and aggregate percentage of all food items identified in 533 black l bear scats collected within and surrounding Great Dismal Swamp ational Wildlife Refuge, Virginia-orth Carolina, Appendix Table 5. utrient composition of spring food items of black bears in Great Dismal Swamp....V 191 Appendix Table. utrient composition of early summer food items of black bears in Great Dismal Swamp Appendix Table 7. utrient composition of late summer food items of black bears in Great Dismal Swamp Appendix Table 8. utrient composition of early fall food items of black bears in Great Dismal Swamp Appendix Table 9. utrient composition of late fall food items of black bears in Great Dismal Swamp Appendix Table 10. utrient composition of winter food items of black bears in Great Dismal Swamp Key to nutritive quality references Appendix Table 11. Serum electrolyte and mineral concentrations (mean S) of female black bears in Great Dismal Swamp as affected by age and season Appendix Table 1. Serum electrolyte and mineral concentrations (mean S) of male black bears in Great Dismal Swamp as alfected by age and season Appendix Table 13. Selected serum chernistries (mean S) of female black bears in Great. Dismal Swamp as affected by age and season Table of Contentsviii Appendix Table 14. Selected serum chemistries (mean A: S) of male black bears in Great Dismal Swamp as affected by age and season Appendix Table 15. Red blood cell characteristics (mean A: S) of female black bears in Great Dismal Swamp as aifected by age and season. See text for explanation of abbreviations... 0 Appendix Table 1. Red blood cell characteristics (mean A: S) of male black bears in Great Dismal Swamp as affected by age and season. See text for explanation of abbreviations Appendix Table 17. itrogenous serum characteristics (mean A: S) of female black bears in Great Dismal Swamp as atfected by age and season. See text for explanation of abbreviations. 04 Appendix Table 18. itrogenous serum characteristics (mean t S) of male black bears in Great Dismal Swamp as alfected by age and season. See text for explanation of abbreviations. 05 Appendix Table 19. Concentrations of serum chemical and hematologic characteristics in black bears from Great Dismal Swamp not tested for age and season variation Appendix Table 0. Blood characteristics (mean A: S) as intluenced by time during handling of black bears in Great Dismal Swamp Appendix Table 1. Correlation coeiiicients (r) between blood characteristics, body weight, and condition indices in black bears from Great Dismal Swamp. See text for explanation of abbreviations Appendix Table. Correlation coeüicients (r) between blood characteristics, body weight (kg), and condition index among sex and age groups in black bears from Great Dismal Swamp. See text for abbreviations Appendix Table 3. Monitoring periods and location samples for female black bears in Great Dismal Swamp, Virginia-orth Carolina in Appendix Table 4. Monitoring periods and location samples for male black bears in Great Dismal Swamp, Virginia-orth Carolina in Appendix Table 5. Habitat use vs. habitat availability for female black bears in Great Dismal Swamp, Virginia-orth Carolina, Appendix Table. Habitat use vs. habitat availability for male black bears in Great Dismal Swamp, Virginia-orth Carolina, Table er Contentsix . Appendix Table 7. Growth of black bear cubs born in captivity at Virginia Polytechnic Institute and State University, February Appendix Table 8. Mean (S) concentrations of serum chemistries during fall and winter for hibernating ( = 4) and active ( = ) adult female black bears. Sampling intervals were 10-1 days apart.... Appendix Table 9. Morphometric characteristics of male black bears in Great Dismal Swamp, Virginia-orth Carolina. umbers in parentheses represent sample size. Values in mm unless otherwise noted Appendix Table 30. Morphometric characteristics of female black bears in Great Dismal Swamp, Virginia-orth Carolina. umbers in parentheses represent sample size. Values in mm unless otherwise noted Appendix Table 31. Canine characteristics (mm) of male black bears in Great Dismal Swamp, Virginia-orth Carolina. umbers in parentheses represent sample size.... Appendix Table 3. Canine characteristics (mm) of female black bears in Great Dismal Swamp, Virginia-orth Carolina. umbers in parentheses represent sample size Appendix Table 33. Distribution of female black bear radiolocations compared to distribution of random points for distance to roads and distance to the study area, Great Dismal Swamp, Virginia~orth Carolina, l Appendix Table 34. Distribution of radiolocations of female black bears captured south of Lake Drummond compared to distribution of random points for distance to roads and distance to the study area, Great Dismal Swamp Appendix Table 35. Rectal temperatures (mean :1: S) of black bears in Great Dismal Swamp, Virginia-orth Carolina, VITA Table of Contents X List of Tables Table 1. Litter size of black bears in Great Dismal Swamp, Virginia-orth Carolina, Table. Annual survival rates of black bears in Great Dismal Swamp, Virginia-orth Carolina as estimated by radiotelemetry (Trent and Rongstad 1974) Table 3. Bemographic characteristics of southeastem wetland black bear populations Table Table Table Table 4. Frequency and aggregate percentage of food items identiiied in 533 black bear scats collected within Great Dismal Swamp, Virginia orth Carolina, utritive quality of composite seasonal diets of black bears in Great Dismal Swamp, Virginia-orth Carolina, Weight and physical condition ratios (PCR)(mea.n :1: S) of male black bears in Great Dismal Swamp, Virgir1ia-orth Carolina ( ), as affected by age and season Weight and physical condition ratios (PCR)(mean i S) of female black bears in Great Dismal Swamp, Virginia-orth Carolina ( ), as affected by age and season Table 8. Blood characteristics (mean :1: S) alfected (P 0.05) by time during handling of black bears in Great Dismal Swamp, Virginia-orth Carolina, Table 9. Blood characteristics (mean :1: S) of black bears in Great Dismal Swamp, Virginia orth Carolina, , affected by age (P 0.1). See text for explanation of abbreviations Table 10. Blood characteristics (mean :1: S) of black bears in Great Dismal Swamp, Virginia orth Carolina ( ), as alfected by season (P 0.1). See text for explanation of abbreviations Table 11. Signilicant (P 0.1) correlation coeilicients (r) between blood characteristics, body weight (kg), and condition index among age groups for female black bears from Great Dismal Swamp, See text for abbreviations. Table 1. Signilicant (P 0.1) correlation coefiicients (r) between blood charactenstics, body weight(kg), and condition index an1ong age groups for male black bears from Great Dismal Swamp. See text for abbreviations.... List of Tables xi Table 13. Classification functions to separate metabolic stages among black bears in Great Dismal Swamp, Virginia-orth Carolina, Table 14. Correlations of blood variables with the canonical functions derived from classifying black bears into metabolic status groups Table 15. Habitat categories developed from vegetation cover map of Great Dismal Swamp, Virginia orth Carolina (Garnmon and Carter 1979) for black bear habitat use/availability analysis Table 1. Total and seasonal home range size (km) of solitary adult adult females, females with cubs, subadult fernales, and male black bears in Great Dismal Swamp, Virginia-orth Carolina in Table 17. Seasonal habitat use vs. habitat availability for black bears in Great Dismal Swamp, Virginia-orth Carolina, Table 18. Yearly habitat use of female black bears with 15 radiolocations compared to habitat availability within their convex polygon home range, Great Dismal Swamp, Virginia orth Carolina, Table 19. Mean distances of female black bears from the study area boundary and roads in Great Dismal Swamp, Virginia-orth Carolina, Table 0. Mean distances of female black bears captured south of Lake Drummond from the study area boundary and roads in Great Dismal Swamp, Virginia-orth Carolina, Table 1. Denning chronology of black bears in Great Dismal Swamp, Virginia and orth Carolina during Table. Characteristics of ground dens used by black bears in the Great Dismal Swamp, Virginia and orth Carolina during (meanzl: se) Table 3. Recovery of added unlabeled progesterone from male black bear serum assayed against human serum prepared standards q Table 4. Recovery of added unlabeled estradiol-17ß from male black bear serum assayed against human serum prepared standards Table 5. Characteristics of adult female black bears held in captivity at VPISU, September 1987 to April Table. Mean (S) concentrations of serum chernistries from September to March for hibernating ( = 4) and active ( = ) adult female black bears significantly (P 0.1) affected by time Table 7. Mean concentrations of serum characteristics not affected by physiological state or sampling interval in adult female black bears held in captivity at VPISU, September March Table 8. Mean serum concentrations of progesterone (ng/ml) and estradiol-17ß (pg/ml) in wild female black bears from Great Dismal Swamp, Virginia- orth Carolina, List of Tables xii List of Illustrations Figure Figure Figure Figure Figure Figure Figure Figure Figure l. Location of Great Dismal Swamp (GDS) in Virginia and orth Carolina. Study area (555 kmz) is outlined by heavy border. GDS ational Wildlife Refuge is hatched portion..... Distribution of roads, ditches, and railroads in Great Dismal Swamp (GDS),Virginia-orth Carolina Age-frequency distribution (by sex) of black bears captured in Great Dismal Swamp, Virgin.ia orth Carolina during Seasonal variation in major components of black bear diets in Great Dismal Swamp during Canonical variates from discrirninant function analysis grouping female (top) and male (bottom) metabolic state using blood characteristics. ach symbol represents one individual Convex polygon home ranges for 18 females monitored for 8 months in Great Dismal Swamp, Virginia-orth Carolina during Convex polygon home ranges for 10 males monitored for months in Great Dismal Swamp, Virginia-orth Carolina during Convex polygon home ranges for females monitored during spring (emergence to 15 June) in Great Dismal Swamp, Va C during Mean % nonoverlapping range = 70.3% Convex polygon home ranges for females monitored during early summer (1 June to 31 July) in Great Dismal Swamp, Va-C during Mean % nonoverlapping range = 70.8% Figure 10. Convex polygon home ranges for females monitored during late summer (1 Aug to 15 Sept) in Great Dismal Swamp, Va-C during Mean % nonoverlapping range = 54.0% Figure ll. Convex polygon home ranges for female
Related Search
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks
SAVE OUR EARTH

We need your sign to support Project to invent "SMART AND CONTROLLABLE REFLECTIVE BALLOONS" to cover the Sun and Save Our Earth.

More details...

Sign Now!

We are very appreciated for your Prompt Action!

x