Wildlife markets are hotspots for illegal wildlife trade, with traders operating as a result of weak monitoring and law enforcement. Knowledge of species traded, sources, and routes used for transport is needed to identify illegal wildlife trade markets and intervene to stem trade. We conducted surveys in 13 wildlife markets across Bangladesh every month during January-December 2019 to assess the abundance and diversity of wildlife taxa traded and the factors driving this trade. Passeriformes, Columbiformes, Psittaciformes, Artiodactyla, Carnivora and Testudines were the most traded orders. Wildlife markets were also centres of trade for high-value species, including the tiger Panthera tigris, crocodile Crocodylus porosus and tortoises. In hill markets and peri-urban markets the most commonly sold species originated from nearby forests, whereas urban markets included both native species and exotic species sourced internationally. Market type, road links to the market, the presence of law enforcement agencies, proximity to a port and form of sale (live animals or byproducts) all significantly influenced what is being traded. Trade of mammals, reptiles, high-value wildlife species and threatened species was less common in markets proximal to law enforcement agencies. Markets close to seaports or airports were more likely to sell mammals, threatened species and high-value wildlife. Based on our results, we recommend a set of interventions to help reduce market-based wildlife trade in Bangladesh.

Substantial evidence exists that members of the US Congress vary in their lawmaking effectiveness. Less known, however, is whether constituents are sufficiently informed and inclined to hold their representatives accountable, based on their effectiveness. We conduct two separate survey experiments, informing some constituents about lawmakers' effectiveness and comparing their responses to those with the baseline level of information. We find that voters demonstrate little knowledge of their elected officials' lawmaking effectiveness. When presented with objective and credible information about lawmaking effectiveness, however, respondents express greater approval of more effective lawmakers. Effects are strongest among ideological moderates, but are even pronounced among partisans, who approve of effective representatives of the opposing party, and disapprove of ineffective representatives from their own party.

As chemical management options for weeds become increasingly limited due to selection for herbicide resistance, investigation of additional nonchemical tools becomes necessary. Harvest weed seed control (HWSC) is a methodology of weed management that targets and destroys weed seeds that are otherwise dispersed by harvesters following threshing. It is not known whether problem weeds in western Canada retain their seeds in sufficient quantities until harvest at a height suitable for collection. A study was conducted at three sites over 2 yr to determine whether retention and height criteria were met by wild oat, false cleavers, and volunteer canola. Wild oat consistently shed seeds early, but seed retention was variable, averaging 56% at the time of wheat swathing, with continued losses until direct harvest of wheat and fababean. The majority of retained seeds were >45 cm above ground level, suitable for collection. Cleavers seed retention was highly variable by site-year, but generally greater than wild oat. The majority of seed was retained >15 cm above ground level and would be considered collectable. Canola seed typically had >95% retention, with the majority of seed retained >15 cm above ground level. The suitability ranking of the species for management with HWSC was canola>cleavers>wild oat. Efficacy of HWSC systems in western Canada will depend on the target species and site- and year-specific environmental conditions.

Precise measurements of basal melting have been made at a series of 14 sites lying within a few kilometres of the grounding line of the Ronne Ice Shelf, Antarctica, where the ice thickness ranges from 1570 to 1940 m. The study was conducted over the course of 1 year and included a detailed survey of the horizontal deformation, as well as phase-sensitive radar measurements of the vertical displacement of both internal reflecting horizons and the ice-shelf base. Results from the surface survey show that the long-term viscous strain rate is modulated at tidal frequencies by (probably) elastic strains of order 10−5 per metre of tidal elevation. The radar measurements show a similar modulation of the long-term thinning/thickening of the ice shelf, with thickness oscillations up to a few centimetres in range. The long-term trends in ice thickness determined at points moving with the ice-shelf flow are consistent with a steady-state thickness profile. Vertical strain rates within the ice shelf were determined from the relative motion of internal reflectors. At two sites the observations were sufficient to discern the effect of tidal bending about a neutral surface 60% of the way down the ice column. Coincident measurements of horizontal and vertical strain imply a Poisson’s ratio of 0.5, and this combined with the asymmetric bending gives rise to the observed oscillations in thickness. At a number of sites the longterm viscous strain rates were found to be a linear function of depth. For an ice shelf this is an unexpected result. It can be attributed to the presence of significant vertical shear stresses set up close to the grounding line where the ice is still adjusting to flotation. Additional vertical motion arising from firn compaction was observed within the upper layers of the ice shelf. The additional motion was consistent with the assumption that firn density is a function only of the time since burial by steady surface accumulation. With both spatial and temporal fluctuations in the vertical strain rate accurately quantified it was possible to estimate the vertical motion of the ice-shelf base in response. Differences between the calculated and observed motion of the basal reflector arise because of basal melting. Derived melt rates at the 14 sites ranged from −0.11 ±0.31 to 2.51 ±0.10 m a−1, with a mean of 0. 85 m a−1 and a standard deviation of 0.69 m a−1, and showed no signs of significant sub-annual temporal variability. There was no obvious global correlation with either ice thickness or distance from the grounding line, although melt rates tended to decrease downstream along each of the flowlines studied. Previous estimates of basal melting in this region have been obtained indirectly from an assumption that the ice shelf is locally in equilibrium and have included a broad range of values. Only those at the lower end of the published range are consistent with the directly measured melt rates reported here.