DOI: 10.5061/dryad.70j22
title: Data from: The carry-over effects of pollen shortage decrease the survival of honeybee colonies in farmlands

description: Many studies have reported honeybee colony losses in human-dominated
 landscapes. While bee floral food resources have been drastically reduced
 over past decades in human-dominated landscapes, no field study has yet
 been undertaken to determine whether there is a carry-over effect between
 seasonal disruption in floral resource availability and high colony
 losses. We investigated if a decline in the harvest of pollen by honeybees
 in spring affected managed honeybee colony dynamics (brood size, adult
 population and honey reserves) and health (Varroa mite loads and colony
 survival) throughout the beekeeping season. A decline in pollen harvest
 was associated with a direct reduction in brood production, leading to a
 negative effect on the adult population size later in the season, and
 lower honey reserves before the onset of winter. Furthermore, the decline
 in pollen harvest negatively impacted the health of the colony, resulting
 in higher Varroa mite loads and higher seasonal and winter colony losses.
 Early-warning signs of these carry-over effects were identified, showing
 that preferential investment in honey reserves instead of brood production
 early in the season increased the decline in pollen harvest and its
 associated carry-over effects. Synthesis and applications. The results
 suggest that the decline in pollen harvest may have been overlooked as a
 cause of pollen shortage and associated bee colony losses. Strategies to
 avoid such losses in intensive farmland systems include (i) limiting or
 avoiding honey harvests in spring, (ii) monitoring colonies for
 early-warning signals of colony failure and (iii) increasing the amount of
 floral resources available through wise land-use management.
description: Data on bee colony
 dynamics and health used in this study "Requier et al. (2016) Pollen
 shortage negatively impacts bee colony survival. Journal of Applied
 Ecology"The data available came
 from part of ECOBEE, a long term ecological research program set up to
 monitor honeybee colonies in a context of real professional beekeeping
 practices in the Poitou-Charentes region in central western France
 (46°23’N, 0°41’W). Over five consecutive years, from 2008 to 2012, the
 colony dynamics were monitored by measuring three core colony traits: the
 amount of brood in the colony (termed brood size), adult population and
 honey reserves, bimonthly throughout the monitoring period. This dataset
 also include the Varroa mite load (assessing using a sticky board placed
 at the bottom of the hive brood chamber, and the seasonal and witner
 colony survival (the criteria for the seasonal survival and the
 overwintering survival of the colony were whether the colony remained
 operational for beekeeping activity during the season or after winter
 arousal, respectively). All the colonies came from an A. mellifera
 mellifera × caucasica strain and were managed in accordance with local
 professional beekeeping practices, without migration, with honey
 collections, systematic supplemental feeding with syrup when necessary,
 and systematic treatment against Varroa mites. (see Odoux et al. 2014 for
 more details). Complete details may be found in "Requier et al.
 (2016) The carry-over effects of pollen shortage decrease the survival of
 honeybee colonies in farmlands. Journal of Applied
 Ecology.Requier et al. 2016 JAE_Pollen
 shortage negatively impacts bee colony
 survival.zip