Characterization of six microsatellite loci in the African wild silk moth (Gonometa postica,Lasiocampidae)

Six microsatellite markers were developed for the African wild silk moth, Gonometa postica (Lasiocampidae), using an enrichment protocol. The total number of alleles ranged from three to 17 for a sample of 130 individuals across the distribution of the species. Observed levels of heterozygosity ranged from 0.17 to 0.78. Deviation from Hardy–Weinberg equilibrium detected in some loci is probably the result of large interannual population size fluctuations characteristic of this species. No evidence of linkage disequilibrium was detected among loci. These loci will be useful for the inference of demographic processes in a moth species that is of potential economic importance.     

Ten microsatellite loci for evolutionary research on Nesospiza buntings

We tested 19 loci originally developed for Vidua and Geospiza, of which six Vidua loci were polymorphic and furthermore, developed four microsatellite loci for Nesospiza buntings. Allelic variation ranged from two to 13 alleles, with heterozygosity from 0 to 0.82. Ascertainment bias was evident as increased allelic diversity of loci developed for Nesospiza, versus those developed for Vidua. Two loci showed linkage, and several, deviation from Hardy–Weinberg equilibrium. We suggest such deviations are through introduction of new alleles by introgression, or of the Wahlund effect. These loci will contribute to the understanding of speciation in Nesospiza buntings of the Tristan da Cunha islands.     

Effects of Local and Landscape Variables on Wetland Bird Habitat Use During Migration Through the Rainwater Basin

ABSTRACT Staging areas and migratory stopovers of wetland birds can function as geographic bottlenecks; common dependence among migratory wetland bird species on these sites has major implications for wetland conservation. Although 90% of playa wetlands in the Rainwater Basin (RWB) region of Nebraska, USA, have been destroyed, the area still provides essential stopover habitat for up to 10 million waterfowl each spring. Our objectives were to determine local (within wetland and immediate watershed) and landscape-scale factors influencing wetland bird abundance and species richness during spring migration at RWB playas. We surveyed 36–40 playas twice weekly in the RWB and observed approximately 1.6 million individual migratory wetland birds representing 72 species during spring migrations 2002–2004. We tested a priori hypotheses about whether local and landscape variables influenced overall species richness and abundance of geese, dabbling ducks, diving ducks, and shorebirds. Wetland area had a positive influence on goose abundance in all years, whereas percent emergent vegetation and hunting pressure had negative influences. Models predicting dabbling duck abundance differed among years; however, individual wetland area and area of semipermanent wetlands within 10 km of the study wetland consistently had a positive influence on dabbling duck abundance. Percent emergent vegetation also was a positive predictor of dabbling duck abundance in all years, indicating that wetlands with intermediate (50%) vegetation coverage have the greatest dabbling duck abundance. Shorebird abundance was positively influenced by wetland area and number of wetlands within 10 km and negatively influenced by water depth. Wetland area, water depth, and area of wetlands within 10 km were all equally important in models predicting overall species richness. Total species richness was positively influenced by wetland area and negatively influenced by water depth and area of semipermanent wetlands within 10 km. Avian species richness also was greatest in wetlands with intermediate vegetation coverage. Restoring playa hydrology should promote intermediate percent cover of emergent vegetation, which will increase use by dabbling ducks and shorebirds, and decrease snow goose (Chen caerulescens) use of these wetlands. We observed a reduction in dabbling duck abundance on wetlands open to spring snow goose hunting and recommend further investigation of the effects of this conservation order on nontarget species. Our results indicate that wildlife managers at migration stopover areas should conserve wetlands in complexes to meet the continuing and future habitat requirements of migratory birds, especially dabbling ducks, during spring migration.     

Testing the host‐finding ability of a monophagous caterpillar in the field

1. Relatively few studies of the host‐finding ability of specialised, phytophagous insects involve direct observations of individual insects moving among intact hosts and non‐hosts. Information from such studies can inform the design of restoration programmes for species of conservation concern. 2. The movement of caterpillars of the threatened Oregon silverspot butterfly, Speyeria zerene hippolyta (Edwards) (Lepidoptera: Nymphalidae) was studied in the field in cleared arenas with 10 cm radii. Caterpillars were placed in the centre, surrounded by three individuals of their host, Viola adunca, and three different non‐host individuals, separated by bare ground. In a second experiment, second instars were placed between a host and a non‐host, 3–6 cm away. Caterpillars were observed to determine if they walked to their host more often than expected by chance. 3. Caterpillars walked to vegetation significantly more often than expected by chance. They did not, however, reach their hosts more often than expected, based on plant availability. 4. It is concluded that S. z. hippolyta caterpillars can distinguish vegetation from bare ground from 10 cm away. There is no evidence that they can distinguish their host plant from other herbaceous species at distances of 3 cm.