The Appalachian Cooperative Grouse Research Project (ACGRP) was a multistate cooperative effort initiated in 1996 to investigate the apparent decline of ruffed grouse (Bonasa umbellus) and improve management throughout the central and southern Appalachian region (i.e., parts of Ohio, Pennsylvania, Rhode Island, Kentucky, West Virginia, Virginia, and North Carolina, USA). Researchers have offered several hypotheses to explain the low abundance of ruffed grouse in the region, including low availability of early‐successional forests due to changes in land use, additive harvest mortality, low productivity and recruitment, and nutritional stress. As part of the ACGRP, we investigated ruffed grouse population ecology. Our objectives were to estimate reproductive rates, estimate survival and cause‐specific mortality rates, examine if ruffed grouse harvest in the Appalachian region is compensatory, and estimate ruffed grouse finite population growth. We trapped >3,000 ruffed grouse in autumn (Sep‐Nov) and spring (Feb‐Mar) from 1996 to September 2002 on 12 study areas. We determined the age and gender of each bird and fitted them with necklace‐style radiotransmitters and released them at the trap site. We tracked ruffed grouse ≥2 times per week using handheld radiotelemetry equipment and gathered data on reproduction, recruitment, survival, and mortality. Ruffed grouse population dynamics in the Appalachian region differed from the central portion of the species' range (i.e., northern United States and Canada). Ruffed grouse in the Appalachian region had lower productivity and recruitment, but higher survival than reported for populations in the Great Lakes region and southern Canada. Population dynamics differed between oak (Quercus spp.)–hickory (Carya spp.) and mixed‐mesophytic forest associations within the southern and central Appalachian region. Productivity and recruitment were lower in oak‐hickory forests, but adult survival was higher than in mixed‐mesophytic forests. Furthermore, ruffed grouse productivity and recruitment were more strongly related to hard mast (i.e., acorn) production in oak‐hickory forests than in mixed‐mesophytic forests. The leading cause of ruffed grouse mortality was avian predation (44% of known mortalities). Harvest mortality accounted for 12% of all known mortalities and appeared to be compensatory. Population models indicated ruffed grouse populations in the Appalachian region are declining (%LD = 0.78–0.95), but differences in model estimates highlighted the need for improved understanding of annual productivity and recruitment. We posit ruffed grouse in the Appalachian region exhibit a clinal population structure characterized by changes in life‐history strategies. Changes in life history strategies are in response to gradual changes in forest structure, quality of food resources, snowfall and accumulation patterns, and predator communities. Management efforts should focus on creating a mosaic of forest stand ages across the landscape to intersperse habitat resources includi...
Several studies have demonstrated the negative effects of clearcutting on terrestrial plethodontid salamander populations. However, none has experimentally compared clearcutting with multiple alternative timber-harvest methods. Using a randomized, replicated design, we compared the short-term effects (1-4 years after harvest) of clearcutting to effects of leavetree, group selection, and two shelterwood cuts on terrestrial salamanders in the southern Appalachian Mountains of Virginia and West Virginia (U.S.A.). Treatment plots were 2 ha each. We also compared salamander age class (percent juvenile), fecundity (percentage of females carrying eggs and average number of eggs per gravid female), size of gravid females, and species composition and diversity between treatments with canopy removal ( cut ) and those without canopy removal ( uncut). All treatments with canopy removal had significantly fewer salamanders than the control treatment, but salamander abundances on alternative treatments with canopy removal did not differ significantly from salamander abundances on the clearcuts. There were no significant differences between cut and uncut treatments in the proportion of females that were gravid or in the average number of eggs in gravid females; however, gravid Plethodon cinereus females weighed more on the cut treatments and gravid Desmognathus ochrophaeus females weighed more on uncut treatments. There were no significant differences between cut and uncut treatments in the proportion of the sample that was juvenile, except in the largest species tested, P. glutinosus , which had a significantly higher proportion of juveniles in the uncut treatments. We conclude that initial declines in terrestrial plethodontid abundance caused by timber harvesting may be minimized across the landscape by concentrating high-intensity timber harvesting ( clearcutting ) in small areas ( a few hectares in size ). Efectos Iniciales de la Tala Rasa y de Prácticas Silvícolas Alternativas sobre la Abundancia de Salamandras TerrestresResumen: Varios estudios han demostrado los impactos negativos de la tala rasa sobre poblaciones de salamandras pletodóntidas terrestres. Sin embargo, ninguno ha comparado experimentalmente la tala rasa con múltiples métodos alternativos de cosecha de madera. Utilizando un diseño aleatorio, replicado, comparamos los efectos a corto plazo (1-4 años postcosecha) de la tala rasa con los efectos de prácticas silvícolas alternativas sobre salamandras terrestres en el sur de las montañas Apalaches en Virginia y Virginia del Oeste (E.U.A.). Las parcelas de tratamiento eran de 2 ha cada una. También comparamos la clase de edad de salamandras (porcentaje de juveniles), fecundidad (porcentaje de hembras con huevos y promedio de huevos por hembra grávida), tamaño de hembras grávidas y composición de especies y diversidad entre tratamientos con remoción de dosel (corte) y sin remoción de dosel (sin corte). Todos los tratamientos con remoción de dosel tuvieron un número significativamente menor de salamandras que el con...
Acorn tannins may affect food preferences and foraging strategies of squirrels through effects on acorn palatability and digestibility and squirrel physiology. Captive eastern gray squirrels (Sciurus carolinensis) were fed 100% red oak (Quercus rubra) or white oak (Quercus alba) acorn diets to determine effects on intake, digestion, and detoxification activity. Red oak acorns had higher phenol and tannin levels, which may explain the lower dry matter intakes and apparent protein digestibilities and the higher glucuronidation activities observed in squirrels. Although the white oak acorn diet had lower apparent protein digestibilities than the reference diet, it did not suppress dry matter intake for a prolonged period or stimulate glucuronidation. Negative physiological effects of a 100% red oak acorn diet suggest gray squirrels may require other foods to dilute tannin intake and provide additional nutrients. To distinguish the roles of different tannin types in the observed effects of acorn diets on squirrels, squirrels were fed rat chow containing no tannins, 4% or 8% tannic acid (hydrolyzable tannin), or 3% or 6% quebracho (condensed tannin). Apparent protein digestibilities were reduced by tannic acid and quebracho diets. Only the 8% tannic acid diet tended to increase glucuronidation. Specific effects of tannins may largely depend on tannin type, composition, and source and on other nutritional and physiological factors.
Blood samples were collected monthly from captive and wild adult (12 months old or older) male white-tailed deer (Odocoileus virginianus) over 1 year in southwest Virginia. Plasma was assayed for luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), and testosterone (T) using radioimmunoassays. LH and T levels for the captive and wild deer were essentially similar and followed a distinct annual cycle. LH concentrations (nanograms per millilitre) peaked earlier (October, captive, 4.5 ± 1.8 (mean ± standard error); September, wild, 3.3 ± 0.9) than T concentrations (nanograms per millilitre) (November, captive, 13.3 ± 2.7; November, wild, 23.7 ± 7.8) and dropped off sharply prior to, or concomitant with, T concentrations. LH and T levels were lowest during the late winter and spring. T concentrations were closely correlated with androgen levels (Mirarchi, R. E., P. F. Scanlon, R. L. Kirkpatrick, and C. B. Schreck. J. Wildl. Manage. 41: 178–183 (1977)) determined by competitive protein binding assay. Mean PRL and FSH concentrations in wild and captive deer also displayed seasonal variations. Prolactin concentrations (nanograms per millilitre) were highest in May (147.5 ± 0.0) and lowest in November while FSH levels (nanograms per millilitre) peaked in September (180.2 ± 22.4) and were lowest in March. Differences in hormone concentrations between deer and sheep, and the relationship between PRL and antler growth and FSH and spermatozoan production, are discussed.
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