Condensed Tannins' Effect on White-Tailed Deer Forage Digestibility in Mississippi

Abstract: Condensed tannins (CT) can reduce digestibility of forages for white-tailed deer (Odocoileus virginianus), potentially confounding estimates of diet quality and nutritional carrying capacity. We collected 143 spring and 142 summer samples of 8 important deer forage species from 22 properties in Mississippi, USA, and tested for CT content using a modified butanol-HCl assay. Three species (partridge pea [Chamaecrista fasciculata], southern dewberry [Rubus trivialis], and roundleaf greenbrier [Smilax rotundifolia]) contained CT, ranging from 0.11% to 6.46% dry weight. Summer CT concentration was greater than in spring for 2 species. We ranked soil samples from least to most fertile using 8 chemical characteristics and found a positive correlation between fertility and CT concentration for 1 species and no correlation for 2 species. We tested effects of CT concentration on in vitro dry matter disappearance (IVDMD) and in vitro protein digestibility using samples of partridge pea and roundleaf greenbrier and rumen fluid from 3 free-ranging deer. Average IVDMD was reduced 1.9% for each 1% increase in CT concentration. In vitro protein digestibility was reduced 2.5% for each 1% increase in CT concentration. Assuming that our methods reflect the effects of CT on in vivo digestibility, maximum loss of available crude protein (CP) in our samples was 3.0 g/100 g dry-weight forage, and only 13 of the 112 CT-containing forage samples (12%) would have decreased available CP by >1 g/100 g dry-weight forage. Deer consuming equal portions of sampled forages would lose <1% of dietary CP to CT. Comparisons of foraging area quality using crude protein estimates should be unaffected by CT under reasonable restrictions of similar habitat types, soil fertility, and time. Given the ability of deer to forage selectively and the abundance of alternative forages in Mississippi, the potential for CT to substantially affect spring or summer diet quality of deer appears minimal.     

Activity patterns of Queensland fruit flies (Bactrocera tryoni) are affected by both mass‐rearing and sterilization

Mass‐reared sterile tephritid flies released in sterile insect technique (SIT) programmes exhibit behaviour, physiology and longevity that often differ from their wild counterparts. In the present study, video recordings of flies in laboratory cages are used to determine whether the sequential processes of mass‐rearing and sterilization (using gamma radiation) that are integral to SIT affect general activity patterns of male and female Queensland fruit flies Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) (‘Q‐flies'). Compared with wild flies, mass‐reared flies exhibit a marked reduction in overall activity, and further reduction is found after sterilization. In terms of the frequency of activities, both fertile and sterile mass‐reared Q‐flies fly less often and exhibit more bouts of inactivity and grooming than wild Q‐flies. In addition, in terms of the duration of activities, fertile and sterile mass‐reared Q‐flies spend less time flying and more time walking, grooming and being inactive than wild Q‐flies. Although fertile and sterile mass‐reared flies are similar in other regards, sterile mass‐reared flies spend more time being inactive than fertile mass‐reared flies. These findings raise new questions about how changes in behaviour and activity levels may influence the performance of mass‐reared sterile Q‐flies in the field, as well as the physiological and metabolic processes that are involved. The frequency and duration of inactivity could provide a simple but powerful and biologically relevant test for quality in mass‐rearing and SIT programs.     

Using Video Surveillance to Estimate Wildlife Use of a Highway Underpass

ABSTRACT Roads pose many threats to wildlife including wildlife-vehicle collisions, which are a danger to humans as well as wildlife. Bridges built with provisions for wildlife can function as important corridors for wildlife passage. We used video surveillance to record wildlife passage under a bridge near Durham, North Carolina, USA, to determine whether it functioned as a wildlife underpass. This is particularly important for white-tailed deer (Odocoileus virginianus) because forests associated with the bridge created a corridor between 2 natural areas. We calculated detection probabilities and estimated the number of crossings as observed crossings divided by detection probability. We observed 126 crossings by >10 species of mammals. Detection probability was 42%; therefore, an estimated 299 wildlife crossings occurred. We observed 75 deer: 17 deer approached the underpass and retreated. We estimated sighting 40% of deer crossings and 92% of deer approaches. Thus, an estimated 185 deer crossings and 18 approaches occurred. As an index of road mortality, we conducted weekly surveys of vehicle-killed animals on a 1.8-km section containing the underpass. We discovered only 5 incidences of animals killed by vehicles. The size and design of the bridge promoted wildlife use of the underpass, providing landscape connectivity between habitats on opposite sides of the highway and likely increasing motorist safety. Thus, bridges in the appropriate landscape context and with a design conducive to wildlife use, can function as a corridor to reduce the effects of fragmentation.     

Evaluation of different models to describe egg and pupal development of Xyleborus fornicatus Eichh, （Coleoptera： Scolytidae）, the shot-hole borer of tea in Sri Lanka

Development data of eggs and pupae ofXyleborusfornicatus Eichh. （Coleoptera： Scolytidae）, the shot-hole borer of tea in Sri Lanka, at constant temperatures were used to evaluate a linear and seven nonlinear models for insect development. Model evaluation was based on fit to data （residual sum of squares and coefficient of determination or coefficient of nonlinear regression）, number of measurable parameters, the biological value of the fitted coefficients and accuracy in the estimation of thresholds. Of the nonlinear models, the Lactin model fitted experimental data well and along with the linear model, can be used to describe the temperature-dependent development of this species.     

Cryptic variation and the tragedy of unrecognized taxa: the case of international trade in the spiny turtle Heosemys spinosa (Testudines: Geoemydidae)

Loss of habitat and human exploitation have driven many turtle species to the brink of extinction, particularly in many parts of southern Asia. The spiny turtle (Heosemys spinosa) is a terrestrial species distributed throughout the Sundaland region of South‐East Asia. Despite international legislative protection, H. spinosa continues to be illegally collected for the food and traditional medicine markets of China. Given its widespread distribution, taxonomists have reasonably questioned whether H. spinosa truly represents a single evolutionary lineage or multiple undiagnosed species. Recently, a large and illegal shipment of rare, wild‐caught H. spinosa was confiscated in Hong Kong, China, and the turtles were eventually distributed to several zoos and academic collections. Based on analyses of these individuals, along with additional individuals from the pet trade and museum collections, we found concordant genetic and phenotypic variation, indicating that two distinct types of H. spinosa exist in this collection of turtles. Further characterization of this variation will require field surveys and the collection of additional morphological and genetic data from specimens of known geographic provenance. However, our data indicate that this highly exploited, endangered species may contain additional cryptic taxa, and emphasize the critical need for systematic evaluation of species before unrecognized variation is lost forever. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 811–824.     

Effects of Dichloroisoproterenol on Macromolecular Synthesis and Differentiation in Tetrahymena vorax

ABSTRACT. The effect of dichloroisoproterenol on macrostomal cell formation in Tetrahymena vorax was examined and the drug was found to be 50% inhibitory at a concentration of 88 μM. Cellular uptake and incorporation of a variety of radiolabelled precursors was monitored in the presence of dichloroisoproterenol. The results demonstrate a strong, concentration-dependent inhibitory effect on RNA and protein biosynthesis, with a lesser inhibition observed for lipid biosynthesis. These data indicate that dichloroisoproterenol's reported effects on vacuole formation and processing in Tetrahymena are nonspecific with regard to phagocytic processes, but result from a general suppression of macromolecular synthesis.     

A preliminary assessment of the conservation status of Cypripedium species in the wild

The conservation of few plants produces such an emotive response as that of hardy slipper orchids of the genus Cypripedium. The genus, comprising 45 species and two varieties, is holarctic in distribution with the centre of diversity in China. Much is known about the status of some species and their populations in Europe and North America, but little information is available on the Asiatic and Mexican species. Most cypripediums are showy orchids and are well represented in herbaria, allowing an estimate of the present distribution, frequency and conservation status of the known species to be made. The authors conclude that having considered the number of herbarium specimens, nearly half of the genus may be considered threatened and in need of some legal protection if the plants are to survive in the wild. They identify a need to examine the conservation status of the taxa in in this genus more closely, and outline two important conservation tools that may help efforts to this end: the IUCN Red List Categories and Criteria for the Amendment of the Appendices of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora).     

The abundance,distribution and structural characteristics of tree‐holes in Nothofagus forest,New Zealand

Tree‐holes provide an important microhabitat that is used for feeding, roosting and breeding by numerous species around the world. Yet despite their ecological importance for many of New Zealand's endangered species, few studies have investigated the abundance or distribution of tree‐holes in native forests. We used complementary ground and climbed tree surveys to determine the abundance, distribution and characteristics of tree‐holes in undisturbed Nothofagus forest in the Lewis Pass, New Zealand. We found that hole‐bearing trees were surprisingly abundant compared with many other studies, including Australian Eucalyptus species and American beech. In fact, we estimated as many as 3906 tree‐holes per hectare, of which 963 holes per hectare were potentially large enough to provide roost sites for hole‐nesting bats in New Zealand, while only eight holes per hectare were potentially suitable for specialist hole‐nesting birds. This was of great interest as primary cavity‐excavating animals are absent from New Zealand forests, compared with North America and Australia. Moreover, tree‐hole formation in New Zealand is likely to be dominated by abiotic processes, such as branch breakage from windstorms and snow damage. As has been found in many other studies, tree‐holes were not uniformly distributed throughout the forest. Tree‐holes were significantly more abundant on the least abundant tree species, Nothofagus fusca, than on either N. menziesii or N. solandri. In addition to tree species, tree size was also an important factor influencing the structural characteristics of tree‐holes and their abundance in this forest. Moreover, these trends were not fully evident without climbed tree surveys. Our results revealed that ground‐based surveys consistently underestimated the number of tree‐holes present on Nothofagus trees, and illustrate the importance of using climbed inspections where possible in tree‐hole surveys. We compare our results with other studies overseas and discuss how these are linked to the biotic and abiotic processes involved in tree‐hole formation. We consider the potential implications of our findings for New Zealand's hole‐dwelling fauna and how stand dynamics and past and future forest management practices will influence the structural characteristics of tree‐holes and their abundance in remnant forest throughout New Zealand.     

White-Tailed Deer Foraging Habitat in Intensively Established Loblolly Pine Plantations

ABSTRACT Stand establishment techniques involving multiple herbicide applications are commonly used on industrial pine (Pinus spp.) plantations, raising concern over potential effects on white-tailed deer (Odocoileus virginianus) forage production. We tested effects of stand establishment intensity on deer forage in 1–5-year-old loblolly pine (Pinus taeda) plantations (n = 4) in the East Gulf Coastal Plain of Mississippi using forage biomass and 4 measures of nutritional carrying capacity that reflected crude protein or digestible energy requirements for body maintenance and lactation. We also assessed whether forage biomass combined with a deer use rating effectively indexed nutritional carrying capacity. Treatments were combinations of mechanical site preparation, chemical site preparation (CSP), and herbaceous weed control (HWC). Total forage biomass and forage biomass of grasses and forbs were reduced by broadcast HWC. Forage biomass of vines was reduced both by CSP and by multiple broadcast HWC applications. Maintenance-level carrying capacity estimates were reduced by broadcast HWC; lactation-level estimates were higher in moderate-intensity treatments. We believe the inherently low fertility of this region makes high-quality forage production a more important management priority than increasing forage quantity. Chemical or chemical and mechanical site preparation combined with banded HWC provided the best option for providing both forage quality and quantity in open-canopied, intensively managed pine plantations. Biomass-based indices may be suitable for indexing protein-based maintenance-level carrying capacity in this region, but our results indicated they were not useful for indexing other carrying capacity estimates.