Journal of the Southeastern Association of Fish and Wildlife Agencies

Although the Delmarva fox squirrel was once distributed through southeastern Pennsylvania, Delaware, the Eastern Shore of Maryland, and two counties in Virginia, it now occurs only in portions of four Eastern Shore counties in Maryland. This study has shown that the Delmarva squirrel prefers forest habitat areas with an open understory. This trait has also been demonstrated for other subspecies of fox squirrels. It is postulated that lumbering and development have been major determinants in reducing the numbers of the Delmarva fox squirrel.

Nightlight counts and daytime observations were utilized in the Great Smoky Mountains National Park to measure the effects of hemorrhagic disease on a high density white-tailed deer (Odocolieus virginianus) population. Deer utilization of 1,846 acres of pasture in the Cades Cove area appeared to be greatest during February, 1971. Following the availability of spring browse, the number of deer utilizing the pastures stabilized at approximately one deer per ten acres until the die-off. During the period of mortality (August through October) utilization of pastures by deer decreased by 84 percent. This decrease in utilization closely corresponds with percent mortality observed under experimental infection with the epizootic hemorrhagic disease virus in deer. Utilization of pastures nine, twelve and twenty-four months post-dieoff was similar to pre-dieoff use.

Twig growth of young browse plants growing in the open was several times greater than that of plants beneath pine trees. The difference was most pronounced when plants were youngest. Most twig growth was within reach of deer (below 5 feet) until plants were 5 or 6 years old, but the proportion decreased with age for tall shrubs and small trees. Although twigs constitute only a small fraction of the browse consumed by deer (Harlow and Hooper 1972), twig length is a good indication oftotal browse yields (Schuster 1965). This paper presents data on the length of annual twig growth for young browse plants growing in the open and beneath a canopy of pine trees in east Texas.

Day and night float counts for wood duck (Aix sponsa) broods were conducted on a 10.8 kilometer segment of the Holston River during the spring of 1973. Nighttime float counts were made using two boats, one down each side of the stream. Hand-held airplane landing lights were used to search the water's edge for roosting broods. Daytime float counts were made the morning following each night census on the same segment of river as the night census. The night and day methods were compared. Eight float counts during the day and eight during the night were completed. The mean number of broods seen at night was 29.5 (2.7 broods per kilometer). The mean number of broods seen during the day was 7.3 (0.7 broods per kilometer). There was a statistically significant difference between the day and night float techniques. The night counts were much more accurate and precise than the highly variable day counts. More than four times as many broods were seen at night as were seen during the day.

During the fall of 1971 and 1972, the first successful efforts were made to capture and band white-fronted geese on their wintering grounds. Careful observations of feeding behavior were instrumental in developing rocket net techniques that would work with these extremely wary birds. Nets were strategically located in ryegrass fields where geese naturally fed and could be concentrated with judicious scattering of fice. A total of 290 geese have been banded.

Canada goose nests were manualIy transferred from normal ground position into a metal tub. Nesting success for transferred geese was 68.5 percent. Three years average hatchability of disturbed eggs was 62.0 percent while that of undisturbed eggs was 67.5 percent.

Wild-trapped sandhill cranes (Grus canadensis pratensis) captured and moved to habitat occupied by cranes 152 miles away did not return "home" and were seen near the release site up to 20 months later. The frequency that the translocated birds were seen near the release site indicated that dispersal had been minimal and that restocking in suitable habitat might be done with relatively few wild-trapped cranes. Dispersal behavior is an Important factor m restockmg success with wildtrapped animals and determines the minimum number of individual animals required. To measure dispersal behavior in sandhill cranes in anticipation of future restocking efforts, we trapped and moved cranes from high population areas to other occupied crane habitat. We thank M. J. Fogarty and D. W. Peterson for help in capturing some of the cranes.

Bobwhite nesting success data was collected during a five year (1967-71) study on an area with a high population density (2 + quail/acre) and a three year (1969-71) study on an area with an "average" density (4 acres/ quail). Despite the differences in population density and the intensity of habitat management, the season nesting success on both areas averaged approximately the same, 17.5 percent on the high density area (based on 1,412 nests studied) and 20.8 percent on the "average" density area (based on 313 nests studied.

Farm ponds and community lakes continue to attract a large number of fishermen. The manageability of these waters for increased fish production offers opportunities for substantial gains in terms of benefits to fishermen from management input costs. Intensive culture of channel catfish, tilapia and mirror carp can provide sport fishing opportunities, especially where fishing pressure is intense. Almost a ton of channel catfish per acre has been harvested by sport fishermen from intensively managed ponds. Problems associated with intensive culture are nutrition, disease, and the diminished aesthetics of fishing an intensively managed pond. Present management practices for bass-bluegill ponds are adequate, but intense study of optimum rates of exploitation and fertilization should provide for more efficient techniques. Strategy and tactics for the future should consider energy flow patterns in fish communities.

Despite continued deterioration and outright destruction of many streams Missourians still have a notable and diverse stream resource. Nearly 9,900 miles of permanent streams and 8,200 miles of intermittent streams with permanent pools remain. Positive stream management practices and activities in Missouri include water quality surveillance and control, access site acquisistion and development, stocking for put-and-take trout fishing, National Scenic Riverways designation, commercial fishing on some larger rivers, and continuing research projects. Three examples of application of research to stream resource problems are discussed. The first is an evaluation of gigging for rough fishes. On Big Piney River, it was shown that giggers had catch rates up to 22 times higher than hook and- line anglers. The harvest by gig, expressed as pounds per acre, nearly equaled the average annual harvest by anglers.

There are about 500 reservoirs (larger than 500 acres), totaling 4.3 million acres, in the 14 States of the Southern Division. Angling demand is predicted to double on Southern waters by the year 2000, and most of the increase is expected to be satisfied by man-made lakes. Southern reservoirs are typically below average in basic fertility, but long growing seasons foster high annual production rates, resulting in above average sport fish yield potentials. The steady accumulation of reservoir environmental and biological data during the past quarter century has greatly increased our ability to predict standing crops and angler harvests and to devise management practices based on production potentials. Production is primarily controlled by available nutrients, basin morphometry, water exchange rate, climatic cycles, eutrophication rate, and species composition.

This summary and discussion covers four papers on current fishery management problems and programs in small ponds and community lakes, reservoirs, streams, and coastal and estuarine environments. Problems are classified in four major categories: economic, political, social, and biological. Biological problems are subdivided as either environmental (physical-chemical) or biotic. In discussing the goals and objectives of fishery management, a distinction is made between the terms harvest, catch and yield, and the goals of maximum sustained harvest and optimum sustained yield. Discussion of management of largemouth bass populations in reservoirs develops the hypothesis that bass biomass may amount to only one half to one sixth of the potential sustained carrying capacity in some waters. Calculations are made to project changes in biomass, production, catch and harvest that may result from the application of various protected-length regulations.

Claytor Lake, Virginia, an 1820 ha main stem hydroelectric reservoir, was studied for one year to determine the effect of water discharge on reservoir phytoplankton. Number/liter, areal units/liter, average cell size, and chlorophyll a content were used as measures of photoplankton abundance. Rate of water discharge had an adverse effect on reservoir phytoplankton during spring and summer. Although increased rate of water discharge caused increased phytoplankton loss, the adverse effect of rate of water discharge on reservoir phytoplankton populations was probably at least partially due to additional discharge of nutrients. The inverse relationship between rate of water discharge and reservoir phytoplankton populations decreased in the uplake direction.

An investigation of the effects of increased sodium chloride concentrations on striped bass fry survival was conducted at the Auburn University Fisheries Research Unit from April 8 to July 7, 1972. The mean survival of fry in ponds with increased sodium chloride concentrations was 7.65% as opposed to 1.70% in six control ponds. The survival in all ponds was highly variable, ranging from 0.33 to 39.50% in increased sodium chloride ponds and from 0.00 to 9.58% in control ponds.