Resource Availability Affects Seasonal Trajectories of Population-Level Learning.

AbstractEnvironmental effects on learning are well known, such as cognition that is mediated by nutritional consumption. Less known is how seasonally variable environments affect phenological trajectories of learning. Here, we test the hypothesis that nutritional availability affects seasonal trajectories of population-level learning in species with developmentally plastic cognition.

Climate change is associated with increased allocation to potential outcrossing in a common mixed mating species.

Premise: Although the balance between cross- and self-fertilization is driven by the environment, no long-term study has documented whether anthropogenic climate change is affecting reproductive strategy allocation in species with mixed mating systems. Here, we test whether the common blue violet (Viola sororia; Violaceae) has altered relative allocation to the production of potentially outcrossing flowers as the climate has changed throughout the 20th century.

Methods: Using herbarium records spanning from 1875 to 2015 from the central United States, we quantified production of obligately selfing cleistogamous (CL) flowers and potentially outcrossing chasmogamous (CH) flowers by V.

Bumble bees exhibit body size clines across an urban gradient despite low genetic differentiation.

Environmental heterogeneity resulting from human-modified landscapes can increase intraspecific trait variation. However, less known is whether such phenotypic variation is driven by plastic or adaptive responses to local environments. Here, we study five bumble bee (Apidae: Bombus) species across an urban gradient in the greater Saint Louis, Missouri region in the North American Midwest and ask: (1) Can urban environments induce intraspecific spatial structuring of body size, an ecologically consequential functional trait? And, if so, (2) is this body size structure the result of plasticity or adaptation? We additionally estimate genetic diversity, inbreeding, and colony density of these species-three factors that affect extinction risk.

Equivalent learning, but unequal participation: Male bumble bees learn comparably to females, but participate in cognitive assessments at lower rates.

Sex-specific cognitive abilities are well documented. These can occur when sexes engage in different ecological contexts. Less known is whether different ecological contexts can also drive sex-specific participation rates in behavioral tests.

Intraspecific Variation in Worker Body Size Makes North American Bumble Bees ( spp.) Less Susceptible to Decline.

Population declines have been documented in approximately one-third of bumble bee species. Certain drivers of these declines are known; however, less is known about the interspecific trait differences that make certain species more susceptible to decline. Two traits that have implications for responding to rapidly changed environments may be particularly consequential for bumble bee populations: intraspecific body size variation and brain size.