Honey bees are important pollinators of agricultural crops. Since 2006, US beekeepers have experienced high annual honey bee colony losses, which may be attributed to multiple abiotic and biotic factors, including pathogens. However, the relative importance of these factors has not been fully elucidated. To identify the most prevalent pathogens and investigate the relationship between colony strength and health, we assessed pathogen occurrence, prevalence, and abundance in Western US honey bee colonies involved in almond pollination. The most prevalent pathogens were Black queen cell virus (BQCV), Lake Sinai virus 2 (LSV2), Sacbrood virus (SBV), Nosema ceranae, and trypanosomatids. Our results indicated that pathogen prevalence and abundance were associated with both sampling date and beekeeping operation, that prevalence was highest in honey bee samples obtained immediately after almond pollination, and that weak colonies had a greater mean pathogen prevalence than strong colonies.Electronic supplementary materialThe online version of this article (doi:10.1007/s13592-015-0395-5) contains supplementary material, which is available to authorized users.

Recent epidemics of mountain pine beetles (Dendroctonus ponderosae) have fundamentally altered forests of the Intermountain West, impacting management decisions related to fire, logging, and wildlife conservation. We evaluated how a recent mountain pine beetle epidemic influenced the site occupancy of 39 avian species in forests dominated by ponderosa pine (Pinus ponderosa) on the Helena National Forest, Montana. Point count data were collected during the avian breeding seasons (May–July) of 2003–2006 (pre‐epidemic) and 2009–2011 (during‐epidemic). We used a community‐level Bayesian hierarchical model accounting for imperfect detection to obtain occupancy estimates for all detected forest birds. Our model for site occupancy included the annual presence of mountain pine beetles, the proportion of ponderosa pine at sites, the interaction between the two, and a random effect of year. We observed changes in occurrence over the study period for 23 of 39 species, including shifts toward and away from beetle‐killed ponderosa pine. Community turnover increased during the epidemic and then returned quickly to pre‐epidemic levels. Our results illustrate the myriad habitat preferences of the small landbird community and suggest that a mosaic of disturbed conifer, intact live conifer, and adjacent aspen forests will be critical for the persistence of populations of native avifauna in the Intermountain West.