Sixth Particleboard Symposium held at Washington State University

Wood Science and Technology -     

Causes of mortality at nests of ground-nesting birds in the Upper Waitaki Basin, South Island, New Zealand: a 5-year video study

We used video cameras over 5 years to quantify causes of mortality at 172 nests of three species of ground-nesting birds that nest on braided riverbeds of the Upper Waitaki Basin, South Island, New Zealand. The species were banded dotterels Charadrius bicinctus (n=114), black stilts Himantopus novaezelandiae (n=23), and black-fronted terns Sterna albostriata (n=35). Of 77 recorded lethal events (excluding four desertions caused by us), 66 involved deaths of only eggs, and 11 involved deaths of adults and/or chicks, and/or eggs. The main predators were cats Felis catus, hedgehogs Erinaceus europaeus, and ferrets Mustela furo, which were responsible for 43, 20, and 18% of lethal events, respectively. Cats were the only predator species to take adult birds. We recorded only two avian predations: a harrier Circus approximans took a chick and a hatching egg from one nest, and an Australian magpie Gymnorhina tibicen ate chicks at one nest. Other causes of mortality were incubating adult birds, floods, and sheep Ovis aries. Each accounted for <4% of lethal events. Ninety percent of visits (151 of 168) by predators or potential predators happened between sunset and sunrise. We found no evidence that video cameras or infra-red lighting influenced predation rates during 2 years of testing for such effects.     

Effects of littoral habitat complexity and sunfish composition on fish production

Carey MP, Maloney KO, Chipps SR, Wahl DH. Effects of littoral habitat complexity and sunfish composition on fish production. Ecology of Freshwater Fish 2010: 19: 466–476. © 2010 John Wiley & Sons A/S Abstract – Habitat complexity is a key driver of food web dynamics because physical structure dictates resource availability to a community. Changes in fish diversity can also alter trophic interactions and energy pathways in food webs. Few studies have examined the direct, indirect, and interactive effects of biodiversity and habitat complexity on fish production. We explored the effects of habitat complexity (simulated vegetation), sunfish diversity (intra‐ vs. inter‐specific sunfish), and their interaction using a mesocosm experiment. Total fish production was examined across two levels of habitat complexity (low: 161 strands m^?2 and high: 714 strands m^?2) and two sunfish diversity treatments: bluegill only (Lepomis macrochirus) and bluegill, redear sunfish (Lepomis microlophus), and green sunfish (Lepomis cyanellus) combination. We also measured changes in total phosphorus, phytoplankton, periphyton, and invertebrates to explain patterns in fish production. Bluegill and total fish production were unaffected by the sunfish treatments. Habitat complexity had a large influence on food web structure by shifting primary productivity from pelagic to a more littoral pathway in the high habitat treatments. Periphyton was higher with dense vegetation, leading to reductions in total phosphorus, phytoplankton, cladoceran abundance and fish biomass. In tanks with low vegetation, bluegill exhibited increased growth. Habitat complexity can alter energy flow through food webs ultimately influencing higher trophic levels. The lack of an effect of sunfish diversity on fish production does not imply that conserving biodiversity is unimportant; rather, we suggest that understanding the context in which biodiversity is important to food web dynamics is critical to conservation planning.     

Alpacas fed calcium propionate seem to moderate their energy intake

Alpacas have evolved digestive and metabolic adaptations that enable them to survive in environments where the available feed varies in nutritional quality. Alpacas are thought to derive glucose from the deamination of amino acids in the liver, rather than via the conversion of propionate like true ruminants. Because fibre growth is dependent on the availability of absorbed amino acids, alpacas using amino acids as a source of energy should leave less amino acids available for fibre growth. If alpacas were to obtain glucose from a source of propionate, such as calcium propionate, the dependence on amino acids would be reduced leaving more available for fibre growth. Calcium propionate was added to the ration fed to 32 alpaca wethers, and fibre production was measured to monitor important fibre attributes in response to calcium propionate. Although the diets supplemented with calcium propionate should have provided more energy than the diets without calcium propionate, the metabolisable energy intake of all animals was similar (p = 0.278). It seems that rather than sparing amino acids, the alpacas regulated their energy intake and refused to consume the additional energy offered as calcium propionate. Consequently, they produced less fibre, and the diameter of their fibre was smaller than those alpacas that were not fed calcium propionate. It seems that alpacas rely on their digestive and metabolic adaptations to efficiently obtain and conserve energy for their survival.     

Modulation of hurricane activity in the gulf of mexico by the madden-julian oscillation

The Madden-Julian oscillation (MJO) is a large-scale episodic modulation of tropical winds and precipitation that travels eastward from Asia to America, with a characteristic repeat time of 30 to 60 days. Here it is shown that when MJO wind anomalies in the lower troposphere of the eastern Pacific are westerly, Gulf of Mexico and western Caribbean hurricane genesis is four times more likely than when the MJO winds are easterly. Accurate predictions of the MJO may lead to improved long-range forecasts of tropical cyclone activity.     

Towards Ethically Improved Animal Experimentation in the Study of Animal Reproduction

The ethics of animal-based research is a continuing area of debate, but ethical research protocols do not prevent scientific progress. In this paper, we argue that our current knowledge of the factors that affect reproductive processes provides researchers with a solid foundation upon which they can conduct more ethical research and simultaneously produce data of higher quality. We support this argument by showing how a deep understanding of the genetics, nutrition and temperament of our experimental animals can improve compliance with two of the '3 Rs', reduction and refinement, simply by offering better control over the variance in our experimental model. The outcome is a better experimental design, on both ethical and scientific grounds.