Journal of the Southeastern Association of Fish and Wildlife Agencies

Mitochondrial DNA (mtDNA) markers were used to distinguish 2 Morone hybrid reciprocal crosses, palmetto bass (Morone saxatilis female x M. chrysops male) and sunshine bass (M. chrysops female x M. saxatilis male), in Lake Seminole and the Apalachicola River, Florida. Individual sunshine bass survived to age 6 and weighed up to 5.9 kg, representing the oldest and largest specimens of this hybrid cross collected from a wild natural system. Hybrids moved downstream >125 km, through 2 dams, to the Apalachicola River. Palmetto bass demonstrated a greater tendency than sunshine bass to emigrate from Lake Seminole to the Apalachicola River. Movement differences are discussed and related to inheritance of maternal spawning traits which may effect hybrid fisheries within or below reservoirs.

Although threadfin shad (Dorosoma petenense) have been widely introduced as forage fish, little is known about their natural history in tropical reservoirs. Gonadosomatic index (GSI) analysis of threadfin shad from Lucchetti Reservoir, Puerto Rico, indicated that most spawning occurred from January to June and again in October, but some spawning occurred year-round, except from mid-August to mid-September. Aging of sagittal otoliths indicated that total length (TL) increased with age (r2 = 0.36). Maximum length was 86 mm TL (N = 2,002) and maximum age was 141 days (N = 124). Hatch date distribution corroborated GSI data regarding spawning periodicity. Diet analysis indicated that detritus and insects were the primary foods. Inconsistencies in threadfin shad dynamics among reservoirs suggest that system-level approaches should be employed in predator-prey management when threadfin shad comprise an important part of the prey base.

The feeding dynamics of juvenile largemouth bass (Micropterus salmoides) were studied from March 1992 to December 1994 in Lucchetti Reservoir, Puerto Rico. Early piscivory by juvenile bass was aided by constant, but qualitatively variable, availability of fish prey items including threadfin shad (Dorosoma petenense), mozambique tilapia (Tilapia mossambica), redbreast tilapia (T. rendalli), and bluegills (Lepomis macrochirus). Threadfin shad was the primary food item for juvenile bass, supplemented by bluegills and tilapias when abundant. Insectivory was high in situations of low fish prey abundance and was accompanied by an increased occurrence of empty stomachs. Two temporal sub-cohorts (early and late) showed different food utilization. Insect consumption by early-hatched bass in Lucchetti Reservoir was consistently higher than for late-hatched bass; piscivory was lower for early-hatched bass than for late-hatched bass.

The validity of otolith ageing in Puerto Rico was examined using known-age largemouth bass (Micropterus salmoides) in Lucchetti Reservoir. Age-0 largemouth bass were tagged with binary-coded wire microtags and stocked into the reservoir on 6 separate events between April 1992 and May 1996. Fish were collected throughout the study at ages 1-3 and otoliths and microtags were removed from tagged bass. Of 36 age-1 and older tagged bass recovered, 50% had no discernible otolith rings (read as age 0). Observed ages of all otoliths agreed with true ages only 14% of the time, and often differed by 2 years. Thus, we concluded that observed opaque bands were not annuli and this ageing technique is invalid for tropical largemouth bass. Length-at-age keys and length-frequency distributions were developed as alternative techniques for age determination, and these methods proved effective for Lucchetti Reservoir.

Daily angler logs were used to obtain lengths of 696 angler-caught largemouth bass (Micropterus salmoides) during January-May 1993 from Farm 13 Reservoir, Florida (2,600 ha), where a no-harvest rule was in effect. Sixty-three percent of these fish were caught by 2 fishing guides (and their clients) and 37% were caught by 19 other parties of anglers that fished without a guide. Angler-caught largemouth bass ranged from 254 to 648 mm total length (TL) with modal peaks at 381- and 457-mm length groups. By extrapolating angler log data into the catch estimate from an ongoing creel survey, we estimated 96 trophy largemouth bass (>635 mm) were caught by anglers from December 1992 through May 1993. Seventy percent of the largemouth bass were caught with live bait (golden shiners, Notemigonus chrysoleucas). Anglers fishing with golden shiners tended to catch larger bass than anglers using artificial lures.

Angler exploitation of largemouth bass (Micropterus salmoides) on the Conway and Winter Park chains of lakes, was evaluated using reward tags. An estimated 57% and 56% of the largemouth bass in the Conway and Winter Park chains, respectively, were caught by anglers during a 1-year period from 1991 to 1992. Annual exploitation rates were adjusted for tagging mortality and tag loss by 13% and 50%, respectively, for small Hallprint dart tags and 18% and 7%, respectively, for large Hallprint dart tags. Angler non-reporting of tagged fish was assigned a value of 20% based on a previous study. Since anglers on both chains voluntarily released a high percentage (72%) of the tagged largemouth bass they caught, annual exploitation rates (u) were 17% on the Conway chain of lakes and 16% on the Winter Park chain of lakes. Total annual mortality estimates (A) for largemouth bass during the study were 52% for the Conway chain and 50% for the Winter Park chain.

The relation between catch and effort is examined in the context of recreational fisheries. The concept of limited entry as a means of increasing angler catch rates is developed, empirical data demonstrating the catch-effort relationship are presented and ramifications of limited entry in fisheries management are discussed. Limited entry may have a place in the future of freshwater fisheries management.

Briery Creek Lake was stocked with both the Florida and northern subspecies of largemouth bass (Micropterus salmoides floridanus and M. s. salmoides, respectively) at a ratio of 3 Florida to 1 northern bass following impoundment in 1986. Progeny of these stockings in the 1989 and 1990 year classes were sampled in October as age-0 and again the following May and electrophoretically assayed to assign phenotypes for comparison of overwinter survival, first-year growth, and relative weight. Subspecies as well as intergrade (F1 and Fx) phenotypes were present in both year classes. First-generation hybrids dominated the 1989 cohort, but Fx and F1 bass were equally prominent in the 1990 year class. Approximately 50% of examined alleles were of Florida bass origin in both year classes. Differential overwinter mortality occurred among phenotypes in both year classes, with the percentage of the Florida subspecies declining by two-thirds while intergrade bass proportionally increased.

Changes in substrate and rainbow trout (Oncorhynchus mykiss) catch rates in Howard Creek, a southern Blue Ridge escarpment stream were evaluated before and during sedimentation resulting from construction of a pumped-storage hydroelectric project. As substrate quality declined from road and dam construction, both y-o-y and adult rainbow trout catch rates declined. The decline in y-o-y catch rates preceded the decline of adult catch rates. The substrate component best correlated (r= —0.96 and —0.88) with declining y-o-y and adult rainbow trout catch rates was the very fine sand fraction. Accumulation of fine sediments in Howard Creek impacted spawning success of rainbow trout and lack of recruitment resulted in declining adult rainbow trout catch rates.

Discharge of selenium (Se)-contaminated water into Belews Lake, North Carolina, resulted in a significant decline in fish diversity and biomass. However, fish populations in this cooling reservoir slowly recovered during a 10-year period from this contamination once Se inputs into the lake ceased. During this period, Se concentrations in skeletal muscle of fish declined, number of taxa increased from 7 to 22, and estimated fish biomass increased from 5.67 to 79.66 kg/ha.

We used infrared-triggered cameras to estimate white-tailed deer population size. The camera estimate simplifies analysis of photographs obtained from these cameras and provides an estimate similar to that generated using the models with program CAPTURE. Four surveys of an enclosed property in northeastern Mississippi generated counts of 16, 31, 40, and 14 antlered white-tailed deer using the camera estimate at different camera densities and at different time periods. Indentifying individuals by antler characteristics and analyzing the data using program CAPTURE estimated the population of bucks for the same 4 surveys of the same property to be 13 (95%CI= 12-27), 30 (95% CI = 20-169), 22 (95% CI = 21-41), and 11 (95% CI = 8-27) respectively. All camera estimates fell within the 95% confidence interval for program CAPTURE when models correcting for heterogeneity of capture and bias due to time and behavior were employed.

We evaluated wildlife responses on a small-scale study to determine possible forest management alternatives for large-scale application on Wildlife Management Areas (WMAs). Pellet-group counts of white-tailed deer (Odocoileus virginianus), elk (Cervus elaphus), and eastern cottontails (Sylvilaqus floridanus), and cervid frequency of browse use were used to determine use of oak-pine sites subjected to an array of management prescriptions including timber harvest, prescribed fire, and traditional food plots. We found that sites subjected to timber harvest were used to a greater extent than unharvested sites. Use of food plots was similar to harvested and burned sites for elk and deer but not for cottontails. Use of burned treatments was unrelated to burn frequency. Pellet-group counts and browse utilization frequency measured different aspects of habitat use and thereby treatment use.

Density-dependent population models likely are inappropriate for whitetailed deer (Odocoileus virginianus texanus) in southern Texas due to variable precipitation. We used a tame-deer technique to estimate carrying capacity and correlated results with precipitation and forage biomass. Carrying capacity estimates using digestible energy (DE) consumed by 12 deer were determined using 2 treatments (supplemented and non-supplemented) during 7 trials. Deer were placed in 14 0.33-ha randomly-located enclosures between May 1990 and May 1991. Mean estimates were 0.62 deer/ha/year (SE = 0.27) for non-supplemented enclosures and 1.00 deer/ha/year (SE = 0.57) for supplemented enclosures. Low estimates occurred during summer and high estimates occurred during spring. Precipitation (cm) and forage biomass (kg/ha) were estimated for each trial.

We recorded plant community characteristics in an 18-year-old, white-tailed deer (Odocoileus virginianus) exclosure in the Lower Coastal Plain of Mississippi during summer 1996. The 0.4-ha exclosure was constructed in 1977 within upland pine (Pinus spp.) forest of the Leaf River Wildlife Management Area in Perry County, Mississippi. Surveys at the time of exclosure construction revealed that similar plant cover and species richness existed inside and outside of the exclosure. Surveys were conducted during 1996 along 8 37-m transects located inside and outside the exclosure. Forest canopy did not differ between exclosure and control sites. Exclosure habitat supported 59 plant species and unprotected control sites contained 43 plant species. Density and coverage of midstory vegetation were greater (/• < 0.0001) in exclosed sites than control sites.

We describe a new, non-destructive procedure for visually estimating forage biomass based on volumetric cover. The accuracy of this procedure was tested against actual dry biomass by clipping and weighing 41 plots of wax myrtle (Myrica cerifera). Visual estimates of forage biomass were significantly related (P ≤ 0.001) to actual biomass determine by clipping (r2 = 0.925; y = 16.36 + 2.52 X, where y = dry biomass and X = volumetric cover). We developed this procedure to apply 3 white-tailed deer (Odocoileus virginianus) habitat suitability index (HSI) models to a suburban development. The 3 traditional HSI models evaluated did not include several variables unique to developed areas that could affect deer habitat quality. Therefore, the models may need to be modified before they can be applicable in developed areas.

Recent declines in deer densities in some areas of Eglin Air Force Base (AFB), Florida, have prompted concerns regarding the impact of coyote (Canis latrans) predation. We determined the food habits of coyotes from analysis of 166 scats collected on Eglin AFB from November 1994 to October 1996. We compared the frequency of white-tailed deer (Odocoileus virginianus) remains found in scats collected in high- and low-deer density areas during the deer fawning season to evaluate impacts of coyotes on white-tailed deer. Important coyote foods (by frequency of occurrence) were shrub/vine fruit (80%), beetles (55%), persimmon (27%), and deer (15%). Deer occurred most often (29%) during the fawning season. There was no difference in the frequency of deer remains found in scats collected in high- and low-deer density areas. The dominance of soft mast in the diet illustrates the important role that soft mast can play in the diet of coyotes.

Traditionally, reducing game-bird nest depredation has involved lethal means of predator control. We evaluated a non-lethal alternative, conditioned taste aversion (CTA), in Tom Green County, Texas. Simulated nests were constructed and baited with 3 eggs injected with lithium chloride, an aversive chemical. Simulated nests were constructed along the perimeter of a 40-ha pasture. A 21-day treatment phase was conducted with depredated nests being rebaited daily with treated eggs. A 28-day posttreatment phase involved establishing 24 non-treated nests in both the treated pasture and a control pasture. The study was replicated over 2 sites: the Management, Instruction, and Research Center (MIRC) and Stone Ranch (SR). There was no difference in nest survival between treatment and control pastures at MIRC (F = 5.0; 1, 3 df; P = 0.1). At SR, nest survival was higher in the treated pasture (F = 11.64; 1, 3 dfi P = 0.03).

Detailed knowledge of a species' biology and ecology is required before sitespecific management programs can be implemented. Therefore, we examined seasonal changes in food habits, nutritional status, and reproduction in a sample of 54 feral hogs (Sits scrofa) collected over a 2-year period from Cumberland Island National Seashore, Georgia. Seasonal variations in food habits probably were related to changes in food availability. Differences in seasonal rainfall patterns between years appeared to be related to dietary changes. No significant seasonal changes in body mass, fat indices, or crude protein in stomach contents were evident, which indicated that hogs on this subtropical island may not undergo pronounced seasonal variations in nutritional status.

Existing landcover maps offer an inexpensive opportunity to conduct largescale habitat assessments for black bears (Ursus americanus), but because cover classes used in these maps may have been developed without consideration for bears, inferring bear food and cover distribution from these maps may be difficult. We evaluated the information content of a habitat map that we constructed using National Wetlands Inventory (NWI) data for a composite home range of 21 radio-tagged adult black bears in coastal Louisiana. Habitat types having potentially different food and cover resources for bears and recognizable from NWI data were deciduous broadleaf forest, bald cypress forest, mixed deciduous broadleaf and bald cypress forest, scrub-shrub wetlands, brackish and fresh marsh, deciduous broadleaf forest spoil, upland hardwood forest, and agriculture. We compared measurements taken from 113 plots in 77 stands distributed among 7 habitat types.

We studied use of a new, less expensive design of wildlife crossing to determine the acceptance of the structure by wildlife. We documented wildlife use of 2 precast concrete wildlife crossings from 27 March 1995 to 30 June 1996 on State Road (SR) 29 in southwest Florida. Two additional crossings of a different design were monitored on Interstate (I)-75 for comparison. Over 1,000 photographs were taken of >20 species of wildlife, domestic animals, and humans using those 4 wildlife crossings. The SR 29 structures were utilized by Florida panthers (Felis concolor coryi), black bears (Ursus americanus), bobcats (Felis rufus), white-tailed deer (Odocoileus virginianus), raccoons (Procyon lotor), and 17 other species. Panther use of the 1-75 wildlife crossings increased over time. The new design of wildlife crossing on SR 29 allowed safe passage of many species of wildlife, including panthers.

We evaluated a habitat suitability (HSI) model developed for mallards (Anas platyrhynchos) wintering in the Lower Mississippi Valley by comparing mallard densities obtained from aerial surveys with habitat suitability indices derived from satellite imagery for 25, 256-km2 sampling units. Regression models that related mallard densities to habitat suitability indices accounted for only 29% of the variability in the data and the 95% confidence interval of predicted mallard densities included zero for most habitat suitability indices evaluated. Thus, we conclude that the published HSI model is a poor predictor of wintering mallard density in the Lower Mississippi Valley. We suggest model revision to allow users to remotely obtain model inputs for habitat characteristics at landscape scales. Further, we suggest the model be revised to consider yearly variation in habitat and flood conditions that better reflect the ability of an area to support wintering mallards.

An understanding of the mechanisms by which northern bobwhite (Colinus virginianus) populations respond to old-field habitat management is important to evaluate efficacy of these practices. We examined reproductive strategies and success of 114 radio-marked bobwhite on a managed wildlife area in east-central Mississippi during 1994—1996. Fifteen female and 5 male bobwhite incubated 23 nests. Male-incubated nests, female-incubated first nests, and female-incubated renests contributed 21.7%, 65.2%, and 13.0% to total nesting effort, respectively. Female-incubated first nests and male-incubated nests each accounted for 44% of successful nests. Of birds alive on 15 April (40 female and 74 male), 37.5% of females and 6.8% of males attempted ≥1 nest, whereas 12.5% of females and 5.4% of males were successful. Female nest initiation peaked in mid-May prior to the onset of male nesting.

We estimated interval (Dec-Feb) recovery and survival rates of marked northern bobwhites (Colinus virginianus) to determine effects of radiomarking and supplemental feeding on the Packsaddle Wildlife Management Area (WMA) in western Oklahoma from 1991 to 1996. We also estimated unretrieved harvest (crippling loss) reported by hunters and compared it to unretrieved harvest of radiomarked bobwhites to determined accuracy of hunter information. We banded 308 and radiomarked 296 bobwhites. Interval survival and recovery rates were estimated using the computer program MARK. Recovery rates of banded bobwhites (0.39) differed (χ2 = 5.03, P = 0.03) from radiomarked bobwhites (0.30). Estimated interval survival rates differed (χ2 = 42.1, P < 0.01) between banded (0.19) and radiomarked bobwhites (0.56). In our study, radiomarking bobwhites had an apparent positive influence on survival.

Call counts for a number of gamebirds (e.g., northern bobwhite [Colinus virginianus] and wild turkey [Meleagris gallopavo]) have been used to index population levels and trends and to document species presence or absence. Call counts for wild turkeys have been used for these purposes, but gobbling activity has not been related quantitatively to population size, reproduction, weather, male age structure, or hunting variables. Consequently, we examined these factors as they affected gobbling activity on Tallahala Wildlife Management Area, Bienville National Forest, in central Mississippi, from 1984 to 1995. Using multiple linear regression, we determined that within-year gobbling activity was related to hunter effort, days into call count period, wind velocity, year, and dewpoint. Among years, gobbling activity was related to hunter effort and hunter success.

A persistent shortcoming of wild turkey (Meleagris gallopavo) management programs is the inconsistency in survey techniques. One approach to standardize turkey population monitoring is to use cameras and infrared sensors. The 7 primary assumptions associated with using cameras and infrared sensors to monitor turkey populations can be grouped into those pertaining to baiting and those associated with sampling design. Because none of these assumptions have been tested, our objective is to outline an experimental design appropriate for determining which theoretical assumptions are practically valid. We recommend that testing these assumptions be a priority for additional research on using camera and infrared sensors for monitoring wild turkey population(s).