Demographics, morphometrics, and reproductive characteristics of Eastern cottontails (Sylvilagus floridanus) in Mississippi.Eastern cottontails Noun 1. eastern cottontail - widely distributed in United States except northwest and far west regions Sylvilagus floridanus cottontail, cottontail rabbit, wood rabbit - common small rabbit of North America having greyish or brownish fur and a tail with a (Sylvilagus floridanus Noun 1. Sylvilagus floridanus - widely distributed in United States except northwest and far west regions eastern cottontail cottontail, cottontail rabbit, wood rabbit - common small rabbit of North America having greyish or brownish fur and a tail with a ; hereafter In the future. The term hereafter is always used to indicate a future time—to the exclusion of both the past and present—in legal documents, statutes, and other similar papers. referred to as cottontail cottontail a wild rabbit, Sylvilagus spp. ) are an important game animal in the United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area. . During the 1997-98, 1998-99, and 1999-2000 harvest seasons, we characterized sex and age ratios, reproductive status, body mass, and hind foot length of harvested cottontails on Trim Cane Wildlife Management Area, Mississippi within 2 harvest regimes to better understand their population demographics and morphometrics Generally, morphometrics (from the Greek: "morph," meaning shape or form, and "metron”, meaning measurement) comprises methods of extracting measurements from shapes. In most cases applied to biological topics in the widest sense. . The area was partitioned into 2 sections with short (October-January) or long harvest regime (October-February) assigned to half of each section. Cottontail sex and age ratios did not differ among years. In February 19% of cottontails were pregnant. Most cottontails were conceived from March-June (81%) and young were born from April-July (80%). We did not detect a difference in body mass or hindfoot length between the sexes for cottontails; however, we did detect differences for body mass and hindfoot length between ages. During our study, harvest within February appeared to have little effect on cottontails. Ninety-three percent of the states within the geographic range of the cottontail allow harvest during February. Currently, there is a paucity pau·ci·ty n. 1. Smallness of number; fewness. 2. Scarcity; dearth: a paucity of natural resources. of information on the effects of harvest on cottontails and their population status. Therefore, we recommend other states with cottontails more aggressively investigate effects of harvest on their population status. ********** Eastern cottontails (Sylvilagus floridanus; hereafter referred to as cottontail) are an important game animal in the United States (Chapman et al., 1982). Over the past several decades, cottontail habitat has deteriorated leading to declines in many areas within their geographic range (Chapman et al., 1982). Barkalow (1962) suggested cottontails in northern latitudes produce larger litters and cottontails in southern latitudes produce smaller litters, but may produce more litters annually. In Alabama, Hill (1965) observed some cottontails breeding as early as the first week in January, but usually the breeding season Breeding season is the most suitable season usually with favorable conditions and abundant food and water when wild animals and birds (wildlife) have naturally evolved to breed to achieve the best reproductive success. started in late February and continued through September (Chapman et al., 1980). In Illinois, Lord (1963) documented lower survival rate of cottontails born early in the reproductive season. In Illinois (Lord, 1963) and Ohio (Negus ne·gus n. A beverage of wine, hot water, lemon juice, sugar, and nutmeg. [After Francis Negus (died 1732), English army officer.] Noun 1. , 1959; Stevens, 1962), a high incidence (27-50%) of breeding by juvenile cottontails was reported. However, Pelton (1968) only observed 3% of juvenile cottontails breeding in Georgia. Considering the importance of cottontails, its variable productivity, and the general belief in its decline in some areas it is of utmost importance for the investigation into their population dynamics Population dynamics is the study of marginal and long-term changes in the numbers, individual weights and age composition of individuals in one or several populations, and biological and environmental processes influencing those changes. . Probably the best data with less bias than surveys on rabbit parameters is from hunter bag checks (Chapman et al., 1982). Terrel (1972) commented that wildlife agencies would not be able to collect pertinent data from trapping because of the cost and labor it consumes in relation to amount of data collected. Therefore, it appears that population demographics and morphometrics can be easily and unbiasedly collected from hunter bag checks. Population demographics and morphometrics are important indicators of population changes. Petrides (1951) reported the importance of sex and age ratios in providing valuable indications of population characteristics. Therefore, our objective was to collect age ratio, sex ratio, reproductive status, body mass, and hind foot lengths from mandatory hunter bag checks and examine them by harvest regime across years to better understand these population demographics and morphometrics from harvested cottontails. STUDY AREA AND METHODS Trim Cane Wildlife Management Area (TCWMA) was located approximately 10 km north of Starkville in Oktibbeha County, Mississippi Oktibbeha County is a county located in the U.S. state of Mississippi. As of 2000, the population was 42,902. Its county seat is Starkville6. Oktibbeha is a Native American word meaning either bloody water (because of a battle fought on the banks) or possibly icy creek. . Trim Cane Wildlife Management Area consisted of 320 hectares converted from hardwood bottomland forest to agricultural fields during the early 1970s and was farmed until 1986 (Taylor, 1996). The area naturally succeeded into primarily oldfield and hedgerow hedgerow Fence or boundary formed by a dense row of shrubs or low trees. Hedgerows enclose or separate fields, protect the soil from wind erosion, and serve to keep cattle and other livestock enclosed. habitats. We examined cottontail population demographics, morphometrics, and reproductive characteristics on TCWMA during the 1997-98, 1998-99, and 1999-2000 harvest seasons. Prior to the 1997-98 harvest season, cottontails had not been harvested for >8 y. The area was partitioned into 2 sections based on soil moisture, with 1 of 2 harvest regimes (short and long harvest regime) assigned randomly to half of each section. Hunters harvested cottontails from the Saturday nearest to October 15th until the end of January in the short harvest regime, whereas hunters harvested cottontails from the Saturday nearest to October 15th until the end of February in the long harvest regime. The Mississippi Department of Wildlife, Fisheries fisheries. From earliest times and in practically all countries, fisheries have been of industrial and commercial importance. In the large N Atlantic fishing grounds off Newfoundland and Labrador, for example, European and North American fishing fleets have long and Parks selected weekends to hunt, selected hunters by lottery, and limited number of hunters and bag limit because of the small size of TCWMA. There were 3, 2-d weekend (Saturday and Sunday) hunts in November and 2, 2-d weekend hunts in October, December, January, and February. Two hunting parties were drawn for each weekend hunt and each party consisted of [less than or equal to]3 hunters, with each party limited to a harvest of 6 cottontails/d, and each party assigned to a harvest regime. Annually, equal effort (hours) was applied within each hunting regime from October-January. We observed the hunts, which facilitated faster cottontail processing and the ability to precisely determine number of hours hunted in each particular harvest regime. We recorded sex, body mass, and hind foot length for each harvested cottontail. Additionally, we noted if a male's testes testes or testicles Male reproductive organs (see reproductive system). Humans have two oval-shaped testes 1.5–2 in. (4–5 cm) long that produce sperm and androgens (mainly testosterone), contained in a sac (scrotum) behind the penis. were regressed or descended, and if females were anestrous an·es·trous adj. 1. Not exhibiting estrus. 2. Of or relating to anestrus. or pregnant. We collected eyes from all cottontails and reproduced extracts from females and placed them in 10% formalin formalin /for·ma·lin/ (for´mah-lin) formaldehyde solution. for·ma·lin n. An aqueous solution of formaldehyde that is 37 percent by weight. . We soaked eyes in formalin for 2 weeks, then extracted lenses and oven dried them at 80[degrees]C for 7 d, and weighed them to the nearest 0.0001 g (Hill, 1966; Lord, 1963). We used the cottontail eye lens weight table computed by Hill (1966) to age cottontails (number of days). If age was [greater than or equal to]365 d, we classified the rabbit as adult. We back-dated harvested juvenile cottontails to determine month of conception and birth (Hill, 1966). We predicted age based on morphometrics using logistic regression In statistics, logistic regression is a regression model for binomially distributed response/dependent variables. It is useful for modeling the probability of an event occurring as a function of other factors. models developed by Bond et al. (2000) for cottontails with damaged eyes due to harvest (n = 29, 18%). Bond et al. (2000) were able to accurately predict age of cottontails (79%) using body weight and hind foot length together in logistic regression equations. We investigated changes in population structure by comparing age and sex ratios among years. Since cottontails were not harvested for 8 years prior to implementation of experimental harvest, we assumed temporal (year-to-year) changes in population structure (age and sex ratios) were attributed to effects of harvest. If we detected an effect, we tested each treatment individually to determine if the effect was attributable to either treatment. We tested for differences in population structure among years using a Mantel-Haenszel chi-square (Stokes et al., 1995). We tested for differences in body mass and hindfoot length between ages and sexes using a two-way analysis of variance on treatment and year. RESULTS AND DISCUSSION Hunters harvested 165 cottontails during 244 h of hunting. Cottontail harvest rate (harvest/hr) typically increased from October to February. Over 3 y, cottontail harvest rate ranged from 0.22-0.74 for the short harvest regime and 0.55-1.02 for the long harvest regime. Most cottontails were harvested in January (n = 60) and February (n = 62), whereas fewer cottontails were harvested in October (n = 2), November (n = 21), and December (n = 20). Cottontail sex ratios (1997-98 = 46% females, 1998-99 = 51%, and 1999-2000 = 39%; [[chi square chi square (kī), n a nonparametric statistic used with discrete data in the form of frequency count (nominal data) or percentages or proportions that can be reduced to frequencies. ].sub.2] = 0.035, P = 0.556) did not differ among years within harvest regime and was similar to previously documented proportions from 48% (Wisconsin; Elder and Sowls, 1942) to 55% (western Maryland; Chapman et al., 1977). Age ratios (1997-98 = 64% juveniles, 1998 - 99 = 68%, and 1999-2000 = 73%; [[chi square].sub.2] = 0.69, P = 0.407) also did not differ among years. Past documented range of juvenile cottontails in the bag was 59% (Missouri; Wight wight 1 n. Obsolete A living being; a creature. [Middle English, from Old English wiht; see wekti- in Indo-European roots. , 1959) to 83% (Michigan; McCabe, 1981); therefore our cottontail age ratios fall well within the previously reported range of cottontail age ratios. [FIGURE 1 OMITTED] Cottontails exhibited little evidence of breeding activity (pregnant: October-January = 0%; testes descended: October-November = 0%, December = 8%, and January 27%) prior to February (pregnant = 19%; testes descended = 94%). Our results agree with studies conducted in New York New York, state, United States New York, Middle Atlantic state of the United States. It is bordered by Vermont, Massachusetts, Connecticut, and the Atlantic Ocean (E), New Jersey and Pennsylvania (S), Lakes Erie and Ontario and the Canadian province of (Chapman et al., 1980) and Maryland (Chapman et al., 1977). However, studies in Alabama (Barkalow, 1962) and Oregon (Trethewey and Verts, 1971) observed cottontails pregnant in January; whereas, in Connecticut (Dalke, 1942) and Wisconsin (Rongstad, 1966) cottontails were not observed pregnant until March. However, cottontails were observed pregnant year round in Texas (Bothma and Teer, 1977). Hill (1966) suggested that onset of breeding is variable between populations and even variable yearly within the same population. Temperature, severe weather, availability of succulent succulent (sŭk`yələnt), any fleshy plant that belongs to one of many diverse families, among them species of cactus, aloe, stonecrop, houseleek, agave, and yucca. vegetation, and rainfall have all been suggested as primary factors for initiation of breeding in cottontails (Ecke, 1955; Wight and Conaway, 1961; Hill, 1966; Bothma and Teer, 1977). Average cottontail litter size was 2.8 (n = 5, SE = 0.37, range 2-4) and less than previously reported, likely because only visible pregnancies were observed. The previous range of mean litter sizes for cottontails was 3.1 in Georgia (Pelton and Jenkins, 1971) to 5.6 in Illinois (Ecke, 1955). We were able to estimate month of conception and birth for juvenile cottontails (n = 82) harvested. Most harvested juvenile cottontails were conceived during March-June (81%, n = 66), whereas few were conceived during January-February (13%, n = 11) and July-August (6%, n = 5; Figure 1). Most harvested juvenile cottontails were born from April-July (80%, n = 65), whereas few were born from February-March (14%, n = 12) and August-September (6%, n = 5; Figure 1). Age and sex did not interact to affect body mass ([F.sub.1,144] = 0.18, P = 0.676) or hindfoot length ([F.sub.1,144] = 0.01, P = 0.781) for cottontails. We did not detect a difference in body mass (male: 1110 g, SE = 15.1; female: 1122 g, SE = 17.0; [F.sub.1,144] = 0.11, P = 0.742) between the sexes. The mean body mass we observed for adult male ([bar.x] = 1246 g) and female ([bar.x] = 1260 g) cottontails were greater for males but comparable for females reported in Maryland (males [bar.x] = 1134 g, females [bar.x] = 1244 g; Chapman and Morgan, 1973) and comparable for males and less than females reported in Michigan (males [bar.x] = 1299 g, females [bar.x] = 1441 g; Haugen, 1942). We did detect differences for body mass (adult: 1253 g, SE = 11.8; juvenile: 1050 g, SE = 10.7; [F.sub.1,144] = 128.04, P < 0.001) between ages. We observed mean body mass of juvenile male ([bar.x] = 1052 g) and female ([bar.x] = 1047 g) cottontails, which was comparable to Michigan (males [bar.x] = 1073 g, females [bar.x] = 1121 g; Haugen, 1942) and Virginia (male [bar.x] = 1066 g, females [bar.x] = 1037 g; Llewellyn and Handley, 1945). We did not detect a difference in hindfoot length (male: 91 mm, SE = 0.4; female: 91 mm, SE = 0.5; [F.sub.1,144] = 0.08, P = 0.781) between the sexes, however we did between ages (adult: 93 mm, SE = 0.5; juvenile: 90 mm, SE = 0.4; [F.sub.1,144] = 20.50, P < 0.001). We observed mean hind foot lengths of 93 mm (adult males and females) and 90 mm (juvenile males and females) for cottontails which were slightly less than the overall mean of 95.4 mm (90-105 mm) reported by Chapman and Morgan (1973) in Maryland, but within ranges reported for Virginia (83-110 mm; Llewellyn and Handley, 1945) and across the cottontail's geographic range (87-104; Nelson, 1909). In conclusion, our study should add important information on cottontail demographics, morphometircs, and reproductive data from a harvested population across years. Currently, most (93%, 37/40) states within the cottontail's range allow harvest after January. Therefore, in most states harvest occurs during a portion of the breeding season. However, cottontails are highly productive producing 3-7 litters annually and average 3-5 young/litter (Chapman et al., 1980). We observed few harvested cottontails pregnant in February (19.4%) and observed few juvenile cottontails in the harvest born in February (1.2%). Considering our reduced bag limit our results are conservative. During our study, harvest within February appeared to have little effect on cottontails. Most states within the geographic range of the cottontail allow harvest during February. Currently, there is a paucity of information on the effects of harvest on cottontails and their population status. Therefore, we recommend other states with cottontails more aggressively investigate effects of harvest on their population status. ACKNOWLEDGMENTS We thank all of the hunters, graduate students, S. Baker, P. Reynolds, D. Holt, and Mississippi Department of Wildlife, Fisheries and Parks conservation officers for their cooperation during this study. We also would like to thank all agencies that provided us with harvest season data. We thank R. Rockhold along with 2 anonymous reviewers who provided valuable comments on this manuscript. We also would like to thank L. M. Conner and D. Wood for their comments on earlier drafts of this manuscript. This project was funded by the Mississippi Department of Wildlife, Fisheries and Parks with a special small game research contract. This study was conducted under the authorization of Mississippi State University Mississippi State University, at Mississippi State, near Starkville; land-grant and state supported; coeducational; chartered 1878 as an agricultural and mechanical college, opened 1880. From 1932 to 1958 it was known as Mississippi State College. Institute of Animal Care and Use Committee Protocol Number 97-022. We thank the Delaware Agricultural Experiment Station The examples and perspective in this article or section may not represent a worldwide view of the subject. Please [ improve this article] or discuss the issue on the talk page. , Department of Entomology entomology, study of insects, an arthropod class that comprises about 900,000 known species, representing about three fourths of all the classified animal species. and Wildlife Ecology in the College of Agricultural and Natural Resources at the University of Delaware [3] The student body at the University of Delaware is largely an undergraduate population. Delaware students have a great deal of access to work and internship opportunities. for support during the analysis and writing phase of publication. LITERATURE CITED Barkalow, F.S., Jr. 1962. Latitude related to reproduction in the cottontail rabbit cottontail rabbit, animal of the order Lagomorpha, which includes the hares and rabbits, except for the domestic, or European, rabbit, which is in a separate species. . J. Wildl. Manage. 26:32-37. Bond, B.T., J.L. Bowman, B.D. Leopold, L.W. Burger, Jr., and K.D. Godwin. 2000. Delineating age and species of harvested cottontail and swamp rabbits. Proc. Annu. Conf. Southeast. Assoc. Fish and Wildl. Agencies 54:330-336. Bothma, J. du P., and J.G. Teer. 1977. Reproduction and productivity in South Texas cottontail rabbits. Mammalia 41:253-281. Chapman, J.A., A.L. Harman, and D.E. Samuel. 1977. Reproductive and physiological cycles in the cottontail complex in western Maryland and nearby West Virginia West Virginia, E central state of the United States. It is bordered by Pennsylvania and Maryland (N), Virginia (E and S), and Kentucky and, across the Ohio R., Ohio (W). Facts and Figures Area, 24,181 sq mi (62,629 sq km). Pop. . Wildl. Monograph 56:1-54. Chapman, J.A., J.G. Hockman, and M.M. Ojeda. 1980. Sylvilagus floridanus. Mammal. Sp. 136:1-8. Chapman, J.A., J.G. Hockman, and W.R. Edwards. 1982. Cottontails. Pages 83-123 in J.A. Chapman and G.A. Feldhamer, eds. Wild Mammal of North America North America, third largest continent (1990 est. pop. 365,000,000), c.9,400,000 sq mi (24,346,000 sq km), the northern of the two continents of the Western Hemisphere. : Biology, Management, and Economics. John Hopkins University Press. Baltimore, MD. Chapman, J.A., and R.P. Morgan. 1973. Systematic status of the cottontail complex in western Maryland and nearby West Virginia. Wildl. Monograph 36:1-54. Dalke, P.D. 1942. The cottontail rabbits in Connecticut. Bull. Conn. Geolological Natur. Hist. Surv. 65:1-97. Ecke, D.H. 1955. The reproductive cycle reproductive cycle n. The cycle of physiological changes that begins with conception and extends through gestation and parturition. of the Mearns cottontail in Illinois. Am. Midl. Nat. 53:294-311. Elder, W.H., and L.K. Sowls. 1942. Body weight and sex ratio of cottontail rabbits. J. Wildl. Manage. 6:203-207. Haugen, A.O. 1942. Life history studies of the cottontail rabbit in southwestern Michigan. Am. Midl. Nat. 28:204-244. Hill, E.P. 1965. Some effects of weather on cottontail reproduction in Alabama. Proc. Annu. Conf. Southeast. Assoc. Game and Fish Comm See comms. . 19:48-57. Hill, E.P. 1966. A cottontail rabbit lens growth curve from Alabama. Proc. Annu. Conf. Southeast. Assoc. Game and Fish Comm 20:50-56. Llewellyn, L.M., and C.O. Handley. 1945. The cottontail rabbits of Virginia. J. Mammal. 26:379-390. Lord, R.D., Jr. 1963. The cottontail rabbit in Illinois. Illinois Department of Conservation and Illinois Natural History Survery, Southern Illinois University Press Southern Illinois University Press (or SIU Press), founded in 1956, is a publisher and part of Southern Illinois University. External link
McCabe, R.A. 1981. The cottontail rabbit hunted for recreation and control. Proc. World Lagomorph Conf. 1:899-906. Negus, N.C. 1959. Breeding of subadult cottontail rabbits in Ohio. J. Wildl. Manage. 23:451-452. Nelson, E.W. 1909. The rabbits of North America. N. Am. Fauna 29:1-314. Pelton, M.R. 1968. A contribution to the biology and management of the cottontail rabbits (Sylvilagus floridanus mallarus) in Georgia. PhD. Dissertation, University of Georgia Organization The President of the University of Georgia (as of 2007, Michael F. Adams) is the head administrator and is appointed and overseen by the Georgia Board of Regents. , Athens. 160 pp. Pelton, M.R., and J.H. Jenkins. 1971. Productivity of Georgia cottontails. Proc. Annu. Conf. Southeast. Assoc. Game and Fish Comm. 25:261-268. Petrides, G.A. 1951. The determination of sex and age ratios in the cottontail rabbit. Am. Midl. Nat. 46:312-336. Rongstad, O.J. 1966. Biology of penned cottontail rabbits. J. Wildl. Manage. 30:312-319. Stevens, V.C. 1962. Regional variations in productivity and reproductive physiology of the cottontail in Ohio. Trans. N. Am. Wildl. Nat. Resour. Conf. 27:243-253. Stokes, M.E., C.S. Davis, and G.G. Koch. 1995. Categorical data categorical data data relating to category such as qualitative data, e.g. dog, cat, female. It may be nominal when a name is used, e.g. location, breed, or ordinal when a range of categories is used, e.g. calf, yearling, cow. analysis using the SAS system (1) Originally called the "Statistical Analysis System," it is an integrated set of data management and decision support tools from SAS that runs on platforms from PCs to mainframes. . SAS Institute SAS Institute Inc., headquartered in Cary, North Carolina, USA, has been a major producer of software since it was founded in 1976 by Anthony Barr, James Goodnight, John Sall and Jane Helwig. , Cary, North Carolina Cary is the second largest municipality in Wake County, North Carolina and the third largest municipality in The Triangle (North Carolina) behind Raleigh and Durham. It is the seventh largest municipality in North Carolina. . 648pp. Taylor, J.D. II. 1996. Northern bobwhite bobwhite, common name for an American henlike bird of the family Phasianidae, which also includes the pheasant and the partridge. The eastern bobwhite quail (Colinus virginianus) is about 10 in. (25 cm) long. habitat use and reproductive success Reproductive success is defined as the passing of genes onto the next generation in a way that they too can pass those genes on. In practice, this is often a tally of the number of offspring produced by an individual. in managed oldfield habitats in Mississippi. MS Thesis. Mississippi State University, Mississippi State. 103 pp. Terrel, T.L. 1972. The swamp rabbit (Sylvilagus aquaticus) in Indiana. Am. Midl. Nat. 57:283-295. Trethewey, D.E., and B.J. Verts. 1971. Reproduction in eastern cottontail rabbits in western Oregon This article is about the region of Western Oregon. For the University, see Western Oregon University. Western Oregon is a geographical term that is generally taken to apply to the portion of the state of Oregon that is west of the Cascade Range. . Am. Midl. Nat. 56:463-476. Wight, H.M. 1959. Eleven years of rabbit population data in Missouri. J. Wildl. Manage. 23:34-39. Wight, H.M., and C.H. Conaway. 1961. Weather influences on the onset of breeding in Missouri cottontails. J. Wildl. Manage. 25:87-89. Bobby T. Bond (1), Jacob L. Bowman (2), Bruce D. Leopold (3), L. Wes Burger, Jr. (3), K. David The Reverend Dr. K. David[1][2] was a Pastor, a New Testament Scholar, a Bible Translator and an able Administrator. He was a member in the Society for Biblical Studies in India (SBSI) Godwin (3), and Corey M. Class (3) (1) Georgia Department of Natural Resources The Georgia Department of Natural Resources is an administrative agency of the U.S. state of Georgia. The agency is charged with the responsibility of regulating hunting, fishing, boating, and non-game plants and animals. The agency is headed by a commissioner. , Wildlife Resources Division. Fort Valley, GA 31030; (2) Delaware Agricultural Experiment Station, University of Delaware, Newark, DE 19717-1303; and (3) Department of Wildlife and Fisheries, Mississippi State University, Mississippi State, MS 39762 (1) Corresponding Author. 1014 Martin Luther King Blvd., Bobby_Bond@dnr.state.ga.us. |
|
||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion