Journal of the Southeastern Association of Fish and Wildlife Agencies

Isoelectric focusing (IEF) and densitometric scanning were used to identify 6 species of catfish based on diagnostic bands and banding patterns produced by muscle proteins. Blue catfish (lctalurus furcatus), white catfish (Ictalurus catus), and flathead catfish (Pylodictis olivaris) each have diagnostic bands in pH 4-5 gels that allow positive species identification. IEF of channel catfish (Ictalurus punctatus) musculature in this pH range exhibits a polymorphic system. One of the bands is diagnostic for this species when present, allowing identification of 58% of the channel catfish tested. Channel catfish without this band, yellow bullhead catfish (lctalurus natalis), and black bullhead catfish (Ictalurus melas) are indistinguishable in the pH 4-5 range gels, but can be identified by banding patterns produced by IEF of proteins in pH 6-7 gels.

Increased management of wild catfish stocks is imminent due to their growing popularity with anglers and commercial exploitation. Length-categorization systems, like those used for largemouth bass (Micropterus salmoides), would improve catfish stock assessment and facilitate comparison of results among years, gears, samples, and populations. Flathead catfish (Pylodictis olivaris) from the Flint River, Georgia, collected by electrofishing and those caught by fishermen were assessed with Proportional Stock Density (PSD) and Relative Stock Density (RSD) indices. Population PSD was 72, suggesting a high quality fishery. Fishermen selected fish in the RSD Quality-Preferred and Preferred-Memorable length categories. Minimum length for size categories may be too low, and I submit alternate thresholds. Use of a standardized system is recommended for reporting results of catfish studies.

We conducted laboratory and field investigations to detennine the relative value of shads (Dorosoma spp.) and sunfishes (Lepomis spp.) as prey for largemouth bass (Micropterus salmoides). In the laboratory, we examined the energy content of gizzard shad (D. cepedianum) and bluegill (L. macrochirus) and digestibility by largemouth bass. Although the ratios of proximate components in the 2 prey species differed, total energy contents as calories per gram were equal. The rates at which gizzard shad and bluegill were digested were similar at feeding rates <1.5%-2.0% of largemouth bass body weight, but gizzard shad were digested increasingly faster than bluegill at progressively higher feeding rates: maximum rate of digestion occurred at about 5% of the largemouth bass body weight for gizzard shad, and about 3% for bluegill.

We measured effects of an increase in the largemouth bass minimum length limit from 254-mm to 406-mm and a decrease in the creel limit from 10 per day to 3 per day in Tradinghouse Creek Reservoir, Texas, from 1985 to 1987. Electrofishing and rotenone surveys were used to measure regulation effects on largemouth bass population and predator-prey parameters; angler surveys were used to determine effects on creel rates. After the regulation was implemented, the population structure shifted from one dominated by small, young individuals to one dominated by larger, older fish. Although relative weight among stock-quality and quality length groups declined, growth rates remained stable. Estimates of available prey remained below optimum levels. Angler catch rates increased 89%; harvest rates declined 70%.

The minimum legal size of largemouth bass (Micropterus salmoides) was increased from 305 to 406 mm in 1983 on West Point Reservoir to indirectly increase young-of-the-year recruitment by gizzard shad (Dorsoma cepedianum). Fish collections from 1982 through 1987 indicated that largemouth bass increased in abundance in response to the regulation change and their population structure shifted toward larger sizes. Concurrently, gizzard shad size distribution shifted downward. It appeared that the increased size limit for largemouth bass resulted in increased forage through increased gizzard shad recruitment. A survey of the sport fishery in 1984 and 1985 indicated effort and harvest similar to that before the regulation change.

Populations of largemouth bass (Micropterus salmoides) in Oklahoma reservoirs were sampled in 1986 and 1987 to determine the degree of introgression of Florida largemouth bass (M. s. floridanus), introduced over a 16-year period, into populations of native northern largemouth bass (M. s. salmoides). Florida subspecific alleles were present in 28 of 30 populations (93%) and were found in >50% of the fish from 8 (27%) reservoirs. Correlations with selected physical and biological parameters indicated that the percentage of bass with Florida alleles increased as the size of fish stocked increased and as cold weather and water level fluctuation decreased. Reservoirs in southern portions of the state with stable water levels that were stocked with fingerlings > 100 mm in length at rates > 25/ha for several consecutive years had the highest degrees of Florida allele introgression into existing bass populations.

Twenty-seven comparison tows were made between a 2-seam otter trawl with 6 loops of 13 link, 4.8-mm chain attached to the leadline (original net) and an identical trawl with additional chain loops attached every 25.4 cm across the entire leadline (heavily chained net) during June-August 1988 in tributaries of the Neuse River, N.C. Objectives were to determine the effect of the heavily chained net on the juvenile finfish, crab, and shrimp catch-per-unit-effort (CPUE) estimates and the feasibility of developing conversion factors to convert CPUE estimates from one net type to the other. The CPUE estimates were significantly higher (P ≤ 0.01) with the heavily chained net for juvenile Atlantic croaker (Micropogonias undulatus), southern flounder (Paralichthys lethostigma), and blue crab (Callinectes sapidus).

The effects of soak time and fish density on number and size of white crappie (Pomoxis annularis) caught with trap nets were investigated in Mississippi lakes. Catch/set (1-7 days) of large white crappie (≥200-mm total length) increased asymptotically with soak time, but that of small and medium fish (<130 and 130-199 mm, respectively) decreased after the first 2-3 days. Catch/day of all length groups of white crappie, increased sharply with soak time, peaked in 1-3 days, and decreased thereafter. These trends indicated that catch could be optimized if nets were run every 2-3 days, and that longer soak times could result in the underestimation of small and medium-size fish. Trap net samples taken within 0.4- to 2.4-ha lake enclosures prior to treatment with rotenone indicated that catch/effort in nets reflected absolute abundance of medium and large white crappie within these areas.

Fisheries personnel of the Arkansas Game and Fish Commission have developed a standardized system of collecting, analyzing, and reporting electrofishing and rotenone sample data. The system utilizes microcomputers and custom written Microsoft QuickBasic Version 4.0 programs and dBASE files to compile sample data, generate reports, and store information in a statewide database. This system provides fish managers with a quick method for processing data with in-depth analysis while relieving them of time consuming manual processing of sample data. Processing of data is performed by a centralized computer staff for storage in a statewide database that is easily accessed by non-programmers.

Larval fathead minnows (Pimephales promelas), <48 hours old, were exposed to water from the Apalachicola, Choctawhatchee, and Ochlockonee rivers in northern Florida during field toxicity tests in November 1985 and April 1986. The fish were exposed for 6 or 7 days in a flow-through system to control water; full-strength river water; and 50%, 25%, and 12.5% dilutions of river water. Mortality in full-strength Choctawhatchee River water was significantly higher (40% mortality) than in control water or in the 3 other dilutions of the river water (<15% mortality). Mortalities of fathead minnows in the different dilutions of the Apalachicola and Ochlockonee rivers did not differ significantly from those in the controls. Further study is needed to determine the cause of the toxicity of Choctawhatchee River water to larval fish.

Growth of introduced Stizostedion hybrids (S. vitreum x S. canadense) was examined from July 1983 to December 1985. Hybrids averaged 296 and 442 mm TL at ages 1 and 11. Condition factors (K) of hybrids increased with age, while relative weights (W,) were within the acceptable range (95-105) for all but 3 months of the first 2 years following introduction. Both condition indices decreased sharply during the spring and early summer. Reduced abundance of small shad due to winter mortality and altered predator-prey relationships during spring and early summer may seasonally impact condition of hybrid Stizostedion.

A telemetry study was conducted in the Apalachicola River/estuary, Florida, to determine migratory behavior of anadromous Gulf of Mexico sturgeon. Ultrasonic (remote and mobile units) and radio telemetry gears were used to assess movements of sturgeon in both fresh and saltwater. Transmitter-equipped fish (N = 10) began fall migration between 22 September and 19 October 1987, and averaged 4.6 days to descend 152 Ian to the lower Apalachicola River where freshwater "staging areas" were utilized for periods of 0-20 days prior to moving into brackish river water. Three sturgeon continuously monitored during river exit spent 8-12 hours in brackish river water, apparently osmoregulating before making nocturnal exits to Apalachicola Bay. Ultrasonic monitoring was largely unsuccessful, although 3 sturgeon were tracked into saltwater and monitored in Apalachicola Bay for up to 4 hours.

Food habits of sympatric and allopatric populations of adult brook trout (Salvelinus !ontinalis) and rainbow trout (Oncorhynchus mykiss) from 4 streams in the Great Smoky Mountains National Park were compared to determine if competition for food resources might explain the apparent exclusion of the former by the latter in Southern Appalachian streams. When diets of brook trout in sympatry with rainbow trout were compared with diets of brook trout in allopatry, there was little significant change in prey composition. Based on this information, exploitation competition for food resources does not seem to play a role in the invasion of rainbow trout into areas of Southern Appalachian streams occupied by brook trout.

We compared estimates of northern bobwhite (Colinus virginianus) density derived from line transect (LT) and capture-removal (CR) sampling with each other and with 2 independent indices of abundance (coveys flushed/party-hour of hunting and captures/l00 trap-sets). CR estimates were not correlated with either index (P ≥ 0.371), whereas LT estimates were correlated with captures/100 trap-sets (P = 0.009) and not with coveys/party-hour (P = 0.156). Although CR and LT estimates were not correlated (P = 0.288), the estimators gave similar (P > 0.05) estimates of density in each of 4 years of study, and estimates differed by <22% in 3 non-drought years.

Counts of whistling male northern bobwhites (Colinus virginianus) were conducted on standardized routes from 1981-86 at Fort Bragg Military Reservation, North Carolina. Harvest data were collected at check stations from 1967-86, and were used to monitor population fluctuations. A linear relationships (r2 = 0.89, P < 0.01) was observed between the mean number of quail heard per station and the subsequent fall harvest. The call index and hunter success also were related (r2 = 0.73, P < 0.03). A negative trend (b = -0.51, P < 0.001) in the mean number of calling males per station was recorded from 1981-86. Whistle-count surveys may provide a cost-effective method for predicting fall harvest levels for controlledaccess management areas.

A known population density was established for northern bobwhites (Colinus virginianus) on a lOO-ha pasture. Line transects were walked twice/day for 5 days to obtain a density estimate. Twelve density estimators using the linetransect data were compared to the known bobwhite density. On our study area, 6 estimators overestimated bobwhite density and 6 of them underestimated density. Because few coveys were flushed, individual transect replicates had to be pooled to provide estimates. This pooling of replicates did not enable us to calculate a mean density and specific variances for each estimator. Variances produced by a Jackknife method appeared to underestimate the true variances. During years of low bobwhite densities (which are common), use of line-transect methods may be inappropriate. Capture-recapture data, collected 1 week prior to running the line transects, underestimated quail density on the pasture.

We developed and evaluated 7 least-squares regression models to estimate body fat and protein reserves from external measurements of post-breeding male and female lesser prairie-chickens (Tympanuchus pallidicinctus). For males, protein was adequately modeled (R2 = 0.60), but attempts to model body fat were unsuccessful. For females useful fat (R2 = 0.92), log fat (R2 = 0.74), condition index (R2 = 0.58), and protein (R2 = 0.74) models were derived. These models can be used to compare post-breeding lesser prairie-chicken nutrient reserves among populations and habitats, without sacrificing the birds sampled.

Periodic observations from 1976 through 1989 on an unhunted whitetailed deer (Odocoileus virginianus) herd located in coastal South Carolina indicated that the population had likely incurred a major decline from a hemorrhagic disease (HD) outbreak, and another may be imminent. Weights of adult does were comparable to those of the hunted herd on the nearby Francis Marion National Forest. Conception rates were insensitive to the occurrence of HD or acorn mast failures. Among adult does collected in early February, femur marrow fat content was a better indicator of animal condition and the abundance of acorns during the previous fall than perirenal fat or serum cholesterol levels. Significant (P < 0.05) differences in blood urea nitrogen and albumin concentrations seemed to be negatively associated with prevalence of HD and positively associated with fall acorn abundance.

Ages of 76 known-age white-tailed deer (Odocoileus virginianus) were estimated by tooth wear and replacement (TWR) and by incisor cementum annuli (CA) determination. TWR and CA methods gave similar results (75% and 71% correct, respectively). However, accuracy was dependent on deer age, with TWR being more accurate than CA in age classes <3.5 years and CA being more accurate in age classes >3.5 years. Accuracy of 55 southeastern United States biologists in estimating age of 98 known-age deer jaws also was determined. Results indicated biologists were well-skilled in the TWR technique but generally underestimated actual age class >3.5 years. Using their mode response (N = 98), biologists correctly determined age for 71.4% of the jaws; however, when using their estimates given for all jaws (N = 5,390), 62.6% were aged correctly.

We evaluated how well observers in a helicopter classed male white-tailed deer (Odocoileus virginianus) into groups ≤3.5 or ≥4.5 years old. Resightings of individually marked anti previously aged deer on 2 southern Texas ranches were used for evaluation during repeated helicopter surveys from 1986 to 1988. Classifications of marked males were at least ≥90% correct on 11 of 14 flights on 1 ranch and 6 of 14 on the other. Although accuracy was acceptable on many flights, some flights gave inaccurate estimates (> 10% misclassified) of male composition. Because managers make only a single, annual helicopter flight, we recommend male classifications made during helicopter counts be used as trend data and be evaluated over a number of years. Managers should avoid using male composition data from individual flights in calculations of harvest rate for a particular age class.

We investigated 4 in vitro digestion procedures to estimate dry matter, energy, and apparent protein digestibilities of 2 southern Texas white-tailed deer (Odocoileus virginianus) forages. Standard 2-stage rumen inoculum technique consistently underestimated in vivo dry matter digestibility by 1% to 9%, but could be corrected to in vivo values by regression analyses (R2 = 0.89). This technique also predicted digestible energy (kcal/g) and digestible protein (g/100g feed) accurately (R2 = 0.84 and 0.71, respectively). Cellulase, pepsin, or multienzyme techniques did not predict dry matter, energy, or protein digestibility accurately or consistently.

We surveyed 611 rural landowners in the Arkansas Coastal Plain in 1987 to detennine perceptions of white-tailed deer (Odocoileus virginianus) damage to agricultural and forestry crops. Respondents (N = 231) owned an average of 148 ha, with the 2 greatest areas in row crops (98 ha), such as soybeans, cotton, and rice, and forests (38 ha). One-half (50%) of respondents had sustained deer damage, most (52%) of whom described it as minimal. Landowners who estimated financial losses from deer reported an average loss of $1,650: 61% lost <$1,000, and 1% lost >$10,000. Of those with damage, 23% said that damage was unreasonable and 46% had tried control. Respondents most often used scare devices, chemical repellents, and fences, but few respondents (<3%) felt that these devices worked. Most respondents (71%) wanted deer on their land, 15% wanted deer but they worried about damage, and 7% did not want deer.

An improvement cut that removed commercially low-quality trees from an unmanaged 20-ha, 60-year-old, mixed mesophytic forest in Kentucky reduced the availability of cavities, snags, and small seeds. Stand basal area was reduced from 21 to 17 m2/ha. The abundance of primary and secondary cavity-using birds, as well as neotropical, migrant songbirds, was not affected severely by the cut. Both winter and breeding populations of primary cavity-using birds, breeding great crested flycatchers (Myiarchus crinitus), tufted titmice (Parus hicolor), and Carolina wrens (Thryothorus ludovicianus) were unaffected for 3 years after the cutting. Winter abundance of tufted titmice decreased immediately after the cutting and remained low for at least 3 years. The abundance of breeding Carolina chickadees (Parus carolinensis) decreased for 2 years after the cutting. Of 25 migratory songbird species evaluated, only ovenbirds (Seiurus aurocapillus) decreased in number.

We documented red-cockaded woodpecker (Picoides borealis) occupation of cavity tree clusters on North Carolina study areas from 1980-88. Most occupied cavity tree clusters (93%) were used in consecutive years, but 6.8% were abandoned each year. Abandoned sites were captured or reoccupied at an annual rate of 8.7%, implying there is a 60% chance that an abandoned site will be reoccupied in a 10-year period. However, recently abandoned clusters were reoccupied at a much higher rate than long-abandoned clusters. Cluster occupation was dynamic with some being occupied, abandoned and reoccupied, or captured during our study. Cluster use by solitary males often was intermediate temporally between group occupation and abandonment. Habitat enhancement may improve reoccupation rates and could be an important short-term strategy to increase the number of social units of this endangered species.

We monitored 18 southern fox squirrels (Sciurus niger niger) by telemetry in coastal South Carolina to determine habitat use in relation to availability of habitat types within observed home-range areas. Fox squirrels used leaf nests primarily, although females preferred to nest in cavities during winter. Nests were concentrated in hardwoods with a preference for oak (Quercus spp.) and gum (Nyssa spp.) species with >20 cm DBH (diameter breast height). Fox squirrels preferred (P < 0.01) hardwood, mixed pine-hardwood, and pine with a hardwood midstory habitat types, and ecotone areas.