Journal of the Southeastern Association of Fish and Wildlife Agencies

A swamp rabbit life history study was conducted in Alabama during 1960-1967. Of 438 swamp rabbits taken by hunters on Wheeler National Waterfowl Refuge in northern Alabama during February, 205 (46 percent) were males. In a sample of 64 others collected statewide throughout the year, 29 (45.3 percent) were males. Late winter weights are presented for 322 swamp rabbits examined in north Alabama. Based on implantation sites or corpora lutea counts, the mean size of 95 first swamp rabbit litters of the season was 2.863. The mean size of 17 second litters of the year was 3.176. No significant differences were found between the size of litters from different latitudes or within different litter sequences. The onset of the swamp rabbit breeding season is well defined in northern Alabama, usually starting in mid-February, and slightly preceding the onset of the cottontail breeding season.

An analysis was made of 1132.5 square feet of forest litter collected during the late winter in a bottomland hardwood forest area of the Mississippi Delta. A seed cleaner and a Trier sampler were used to separate food items from litter trash and derive a quantitative estimate. Food available to the turkey averaged 135 Ibs. per acre. Sugarberry seeds made up one-half of the entire amount. The next two most abundant items found were insect galls, 22.5 Ibs., and grape, 19.6 Ibs. The food items most commonly found in analysis of wild turkey crops and droppings were those usually appearing in the least quantity in the litter analysis. Pecan, animal matter, spice bush, and wild grape were the food items most frequently eaten by the wild turkey. The main purpose of this study was to determine the quantity of food available for the wild turkey (Meleagris gallopavo silvestris) prior to the nesting season in a bottomland hardwood area in the Mississippi Delta.

Band recovery locations of Canada geese (Branta canadensis) banded in Florida are discussed in regard to ,the Canada goose decline in Florida and other southeastern states. Flock inventories of traditional wintering areas in the South and newly-established mid-continent wintering sites are reported. Limited data indicate refuges with grain farming located along migration routes have intercepted Canada geese enroute to their ancestral wintering areas. The resulting problems are stressed. * * * * * The U. S. Fish and Wildlife Service's 1967 winter waterfowl survey reports the highest Canada goose population in history (Gottschalk 1967). For nearly a half century, most goose concentrations have consistently increased, but certain wintering flocks in the South have dwindled. Only remnant flocks remain along the Atlantic and Gulf coasts from South Carolina to Texas. If this decline continues, these flocks will probably perish by 1975.

The widespread use of road counts in estimating population trends emphasizes the need for information on factors influencing animal behavior patterns. The present study, conducted on the Atomic Energy Commission Savannah River Plant in South Carolina, attempted .to relate the atmospheric variables of Temperature, Relative Humidity, Vapor Pressure Deficit, and Barometric Pressure to numbers of rabbits (Sylvilagus floridanus) seen during morning and evening activity peaks along a specially selected 30-mile route. The route was driven twice in each 24-hour period from July 31 to September 4, 1964. Sling psychrometer readings were taken at five permanent points along the route each time it was counted and the averages converted to the appropriate variables by use of the U. S. Department of Commerce Psychrometric Table No. 235. Barometric pressure was obtained at the beginning of each peak activity period from the U. S. Department of Commerce Weather Bureau at Augusta, Georgia.

A ten-year study of the reaction and adaptability of the introduced Aoudad sheep (Ammotragus lervia) in the Palo Duro Canyon of Texas was begun in the winter of 1957-58. At that time, forty-two sheep from the McKnight Ranch, Picacho, New Mexico, were released into the halfmillion acre Palo Duro Canyon. The exotic sheep were introduced into the canyon to fill a separate ecological niche and to share the vast reaches of the canyon, noncompetitively, with native mule deer. The aoudad, a hardy big game animal, was to become a real challenge to sportsmen in the rugged terrain of the Palo Duro Canyon. The first six years of the study were spent in trying to determine an adequate census technique, habitat preference, reproduction, and sheep movement studies. In the seventh year after the aoudad sheep release, an adequate population was thought to be present in order to have a limited experimental hunt.

A new hypnotic agent which is especially potent in birds was tested on free-feeding wild turkeys (Meleagris gallopavo) in Florida by oral administration on baits. One hundred thirteen were narcotized sufficiently to be captured. At the optimum dosage (4 grams of powdered drug per cup of bait) the first evidences of narcosis were noted almost immediately and some turkeys were captured within 3 minutes after beginning to feed. Narcosis wore off after 8 hours even in the more heavily drugged individuals. Mortality from overdosage was less than 3 per cent at optimum dosage levels. The new drug is clearly superior in narcotic qualities to alpha-chloralose but it is so distasteful to turkeys that they often refused to eat it.

Secobarbital sodium, methohexital sodium, methoxymol, and alphachloralose were used in field experiments to capture mourning doves (Zena1:dura macroura) in Florida during 1966 and the spring or 1967. A total of 240 doves was caught. The four drugs are compared and the best dosage for each is given. Methoxymol proved superior to the others.

Since January 1965 approximately one hundred feral swine (Sus scrota) have been captured with alpha-chloralose on whole corn at bait Bites intended for wild turkeys (Meleagris gallopavo). A series of experiments on penned feral and domestic hogs was conducted to determine minimum and maximum dosages of alpha-chloralo~e and preferred baits for the safe capture of free-ranging hogs. A method to capture feral hogs with alpha-chloralose applied to baits is described. During the past several years feral hogs have become increasingly more important as game animals in Florida, especially on public hunting areas. This has led to increased emphasis on trapping them from refuges and areas where they are not wanted, for rele~.~e in public hunting areas. Hogs are well known as pests in many situations and this problem has become more acute in agricultural areas and some national forests and parks recently.

The radioactive isotope, 65Zn was fed and injected into rabbits, opossums, foxes, and bobcats. When injected, 65Zn was detectable in feces from these animals for over a year after injection. The radioactive zinc present in the fecal pellets is also very stable to weathering. The injection of 65Zn is an excellent technique for long-term marking of feces in censusing, home range, and migration studies. Public health dangers, although largely imaginary, seriously limit the use of this technique and are discussed.

Thirty-six immature alligators (Alligator mississippensis) collected from a canal in the Everglades were examined for information on summer food preferences. A snail (Pomacea paludosa) comprised 65.8 percent by volume of the stomach contents. Invertebrates accounted for 98.0 percent by volume of the total stomach contents.

Establishment was not attained during a six-year intensive investigation into the factors influencing survival of liberated pen-reared Reeve's pheasants in Kentucky. During the tenure of the study, 6,815 juvenile and 859 adult Reeve's were liberated in a varie~ of habitat composition at seven pre-selected release areas. The sex ratIo of release stock was 93 cocks per 100 hens. To enhance field identification, all liberated pheasants were marked with plastic neck tags and metal leg bands. The total recorded mortality was less than two percent of the number released. Approximately thirty percent of the known fatalities was attributed to predation. Avian and fox predation accounted for most of predatory fatalities. Ten broods averaging almost ten chicks per brood were reported. Some evidence was found to indicate a "drumming" display by adult male Reeve's may be associated with reproduction.

Laboratory studies to determine the effect of striped bass egg sedimentation were conducted and a mean hatch of 35.7 percent was recorded for eggs placed on coarse sand while eggs placed on plastic had an average hatch of 36.4 percent. In comparison, the average hatch on silt-sand was 13.1 percent and 3.2 percent on silt-clay-sand substrate. None of the eggs deposited on a muck-detritus substrate hatched. Further egg studies indicated that the percent hatch improved with the period of time eggs were suspended prior to sedimentation. Preliminary observations concerning white bass egg development and notes useful in approximating the time of ovulation are presented. Larvae from the striped bass female X white bass male cross are compared with larvae resulting from the reciprocal cross (white bass female X striped bass male).

Striped bass, Roccus saxatilis (Walbaum), have been reported along the Gulf Coast from Florida to eastern Louisiana. This fish has been found in all major river systems along the Mississippi Gulf Coast from the Pascagoula River west to the Tangipahoa River. The striped bass population in the west Pascagoula River supports a small sports fishery and it is the only one that consistently yields fish from year to year. The Pascagoula fish range in size up to 32 pounds in weight. In the last two years striped bass from 7 to 28 pounds have been taken in February and early March and many of the larger fish contained roe. The population level in the other rivers appears to be too low to maintain a sports fishery.

Data gathered at the Weldon Striped Bass Hatchery, Weldon, North Carolina, during the years 1960-1967 indicated that the optimum spawning temperature range for striped bass in the Roanoke River was between 62" F. and 67" F. The minimum recorded temperature at which spawning has occurred was 55" F. and the maximum was 71· F. Preliminary bioassays conducted at the hatchery during the 1967 spawning season substantiated this optimum temperature range, and further revealed that at temperatures of 74" F. to 80· F., the percent hatch dropped from 80 to 60 and the frequency of dead and malformed fry increased from 48 percent to 100 percent. At these higher temperatures, none of the fry, normal nor malformed, survived for more than 70 hours after hatching. Eggs incubated and hatched, and fry held, in water at 70" F., evidenced no mortality for 76 hours following hatch. The bioassays also revealed that at water temperature ranging from 60· F.

During the spring of 1967, 240,000 striped bass and striped bass X white bass hybrid fry were stocked in four one-acre dirt ponds. Each pond received 30,000 striped bass and 30,000 hybrids. At the end of a 71-day period, approximately 23,187 were harvested in three ponds, 12.88 percent of ,the original number. A total kill occurred in the fourth pond one week prior to harvest. Results indicate the hybrid having faster growth and higher survival rates.

Commercial catch statistics for brown shrimp (Penaeus aztecus Ives) from a restricted area along the Texas coast were examined by using the virtual population technique. The sum of all catches from a single year class was used as a minimum estimate of population size at the time of recruitment. The conversion of catches from pounds to numbers also made possible maximum estimates of the exploitation rate for all periods after recruitment. Monthly catches of shrimp of each size group were compared for the years 1961-66, and weights were converted to value by using the mean price per pound for each size group for the period. Comparisons of the percentage of a year class harvested at each size with the percentage of the gross value contributed by each size group may aid in making decisions concerning the management of shrimp stocks.

Analog computation and simulation involves the use of an electronic computer in which scaled voltages represent physical variables. This computer solves differential equations to simulate time related systems. Simulation of Von Bertalanffy's equation representing growth in length or weight is a simple procedure. Change of constant values enables a rapid adaptation and fit to a given set of growth data. A check on age analysis by using length-weight plots may be possible with this computer. An example of its use in analysis of striped bass growth is given.

Pink or spotted (Penaeus duorarum) , brown (P. aztecus) , and white (P. setiferus) shrimp, marked with biological stains and fluorescent pigments, were released in nursery areas tributary to the Core Sound and Lower Cape Fear River estuaries in Nor·th Carolina to obtain information concerning population dynamics including movement and migration patterns. A combined total of 26,989 pink, brown, and white shrimp was marked and released from April to October, 1966. Of these, 1,671 or 6.2% were returned. The combined average interval between release and recapture was 17.5 days, and the average distance traveled was 0.5 miles per day. Data indicated that size distribution "levels of equilibrium" were reached in individual nursery areas, whereby the size frequency modes increased to characteristic levels and subsequently remained at these levels during the study of each species. With few exceptions, all "inside" movement was toward waters of higher salinity.