The State of Bee Monitoring in the United States: A Call to Refocus Away From Bowl Traps and Towards More Effective Methods

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Effective monitoring is necessary to provide robust detection of bee declines. In the United States and worldwide, bowl traps have been increasingly used to monitor native bees and purportedly detect declines. However, bowl traps have a suite of flaws that make them poorly equipped to monitor bees. We outline the drawbacks of bowl traps, as well as other passive sampling methods. We emphasize that current methods do not monitor changes in bee abundance. We then propose future approaches to improve bee monitoring efforts, which include improving our understanding of the efficacy and drawbacks of current methods, novel molecular methods, nest censusing, mark-recapture, sampling of focal plant taxa, and detection of range contractions. Overall, we hope to highlight deficiencies of the current state of bee monitoring, with an aim to stimulate research into the efficacy of existing methods and promote novel methods that provide meaningful data that can detect declines without squandering limited resources.

Related collections

Most cited references 63

Record: found
Abstract: found
Article: not found

Historical changes in northeastern US bee pollinators related to shared ecological traits.

I. Bartomeus, J. Ascher, J. Gibbs … (2013)

Pollinators such as bees are essential to the functioning of terrestrial ecosystems. However, despite concerns about a global pollinator crisis, long-term data on the status of bee species are limited. We present a long-term study of relative rates of change for an entire regional bee fauna in the northeastern United States, based on >30,000 museum records representing 438 species. Over a 140-y period, aggregate native species richness weakly decreased, but richness declines were significant only for the genus Bombus. Of 187 native species analyzed individually, only three declined steeply, all of these in the genus Bombus. However, there were large shifts in community composition, as indicated by 56% of species showing significant changes in relative abundance over time. Traits associated with a declining relative abundance include small dietary and phenological breadth and large body size. In addition, species with lower latitudinal range boundaries are increasing in relative abundance, a finding that may represent a response to climate change. We show that despite marked increases in human population density and large changes in anthropogenic land use, aggregate native species richness declines were modest outside of the genus Bombus. At the same time, we find that certain ecological traits are associated with declines in relative abundance. These results should help target conservation efforts focused on maintaining native bee abundance and diversity and therefore the important ecosystems services that they provide.

0 comments Cited 224 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Museum specimens reveal loss of pollen host plants as key factor driving wild bee decline in The Netherlands.

Jeroen Scheper, Menno Reemer, Ruud van Kats … (2014)

Evidence for declining populations of both wild and managed bees has raised concern about a potential global pollination crisis. Strategies to mitigate bee loss generally aim to enhance floral resources. However, we do not really know whether loss of preferred floral resources is the key driver of bee decline because accurate assessment of host plant preferences is difficult, particularly for species that have become rare. Here we examine whether population trends of wild bees in The Netherlands can be explained by trends in host plants, and how this relates to other factors such as climate change. We determined host plant preference of bee species using pollen loads on specimens in entomological collections that were collected before the onset of their decline, and used atlas data to quantify population trends of bee species and their host plants. We show that decline of preferred host plant species was one of two main factors associated with bee decline. Bee body size, the other main factor, was negatively related to population trend, which, because larger bee species have larger pollen requirements than smaller species, may also point toward food limitation as a key factor driving wild bee loss. Diet breadth and other potential factors such as length of flight period or climate change sensitivity were not important in explaining twentieth century bee population trends. These results highlight the species-specific nature of wild bee decline and indicate that mitigation strategies will only be effective if they target the specific host plants of declining species.