Answering key bumble bee conservation questions by studying discovered wild nests: A Bombus affinis case study

The nesting ecology of wild bumble bees is not well resolved, but
information learned from discovered nests can be of great conservation
value. Data collected at nests on foraging patterns, caste-specific
behavior, and health (e.g., pathogens) is invaluable for understanding
bumble bee behavior and ecology, but difficult to decipher solely from
foraging observations away from the nest. Wild nests are often found
opportunistically, and due to a lack of standardized guidance on data
collection, the information collected alongside nest discoveries is often
idiosyncratic. Here we provide a framework for data collection when nests
are discovered to ensure the data are as complete as possible and
comparable across studies. To meet these goals, we provide an action plan
which includes key conservation questions and methodological guidelines
both for in-situ data collection and post season nest excavation. This
plan is ordered by increasing complexity of data collection methods and
includes suggestions on how to report findings. To illustrate our
framework, we provide an example with recently discovered Bombus affinis
(rusty patched bumble bee) nests. Through observations at B. affinis
nests, we discovered novel patterns of activity, including changing
activity levels over time, the timing of male and gyne production,
variable timing in nest senescence, and  associations of nests
with past rodent activity. Post-senescence nest excavation allows the
estimation of colony size and caste numbers, pest incidence, and provides
an opportunity to examine nest material for stressors (e.g., pesticides).
Although individual nest discoveries may be of limited value in forwarding
conservation strategies, and it may not be feasible for all teams to
collect all data types at all discovered nests, the aggregate collections
of many similar datasets can be of critical importance for species of
conservation concern.