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Full-Text Articles in Animal Sciences
The Population Dynamics Of Two Rodents In Two Coastal Marshes In Virginia, Robert K. Rose, John A. March
The Population Dynamics Of Two Rodents In Two Coastal Marshes In Virginia, Robert K. Rose, John A. March
Virginia Journal of Science
The communities of small mammals were evaluated for 13 months with capture-mark-recapture methods in two Spartina-Juncus marshes of the Atlantic coast in Northampton County, Virginia. Small mammals were trapped for three days each month using live traps placed on floats on two study grids. Two rodents were numerically dominant (~90% of small mammals) there: marsh rice rat, Oryzomys palustris, and meadow vole, Microtus pennsylvanicus. Monthly estimates of population density were greater for rice rats (peak: 45/ha) than for those of meadow voles (peak: 30/ha). Survival rates were generally low, especially for rice rats, indicating highly vagile populations. Both …
A Staging Sequence And Analysis Of Growth In Postovipositional Embryos Of Lamprophis Fulignosus, Angela Renee Vogel Rivera
A Staging Sequence And Analysis Of Growth In Postovipositional Embryos Of Lamprophis Fulignosus, Angela Renee Vogel Rivera
Biological Sciences Theses & Dissertations
The brown house snake, Lamprophis fuliginosus, is a small, oviparous snake found throughout much of Africa. This lamprophiine colubrid reproduces rapidly; captive females can lay clutches every three to four months for a sustained period. Thus, L. fuliginosus is an excellent model for developmental studies requiring large numbers of embryos. In addition, the embryos of oviparous species are more suitable for some procedures than are those of viviparous forms. The most widely used system for staging embryonic snakes was developed for the common gartersnake, Thamnophis sirtalis, a viviparous natricine colubrid (Zehr, 1962). Based on the examination of 135 …
The Annual Reproductive Cycle Of Oryzomys Palustris In A Virginia Tidal Marsh, Erin A. Dreelin
The Annual Reproductive Cycle Of Oryzomys Palustris In A Virginia Tidal Marsh, Erin A. Dreelin
Biological Sciences Theses & Dissertations
The objectives of my study were to determine when the marsh rice rat (Oryzomys palustris) begins and ends reproduction during the year, if there are seasonal changes in litter size, and the weight at which sexual maturity is reached. Monthly samples of rice rats were trapped from May 1995 to May 1996 in Northampton County, Virginia. Rice rats were trapped with Fitch live traps, euthanized in the field, and brought to the lab for necropsy. Data from two other studies of rice rats in Northampton County were also examined. Potential breeders did not reproduce with equal intensity throughout the …
Evaluation Of The Gross Anatomy Seasonal Changes Function And Histology Of The Perineal Gland In The Hispid Cotton Rat, Sigmodon Hispidus, Julie Anne Winchell
Evaluation Of The Gross Anatomy Seasonal Changes Function And Histology Of The Perineal Gland In The Hispid Cotton Rat, Sigmodon Hispidus, Julie Anne Winchell
Biological Sciences Theses & Dissertations
The perinea! gland in the hispid cotton rat, Sigmodon hispidus, is a seasonally cyclic, subcutaneously located organ which is associated with the reproductive system. On gross dissection, the gland possesses a strong attachment to the penis with only loose fascia! connections to the rectum and surrounding muscle and skin. Histologic exam confirms this connection to the reproductive tract and shows the organ to be a compound tubuloacinar gland with a projection leading into the penis. The cyclic hypertrophy and regression of the gland closely parallels that of the testes and seminal vesicles indicating that this cyclicity may be under …
An Analysis Of External Features As Predictors Of Reproductive Status In Small Mammals, Kenneth Wayne Mccravy
An Analysis Of External Features As Predictors Of Reproductive Status In Small Mammals, Kenneth Wayne Mccravy
Biological Sciences Theses & Dissertations
Reproductive status in specimens of nine populations of seven species of small mammals was evaluated by examining the external reproductive features of nipple size, condition of the pubic symphysis, and vaginal condition and, in males, testis position. Usefulness of these external features in predicting true monthly breeding rates was evaluated by comparing predictions of breeding rates with true rates based on necropsy. Accuracy of predictions of reproductive status of individuals based on single external features and combinations of external features and body measurements was then analyzed at a finer level by comparing those predictions with results of necropsy of the …