Page 7 - Bumblebee Conservation Trust Buzzword Magazine July 2020
P. 7

2019 BeeWalk  The Brown-banded carder bee (Bombus   Unfortunately, June itself was cold


                                             and wet, poor conditions for foraging
      humilis) showed a bit of a decline from
 the results  2018 – it really does seem to like hot   bumblebees. Spring nests were
      weather – but this was counterbalanced
                                             finished off, and species took a hit as
                                             elderly workers died off and could not
      by the species continuing to spread
      northwards. A highlight of the 2019    be replaced. The average number of
      BeeWalk training days was finding the   bumblebees seen per kilometre of
      species at a new site – Croome Park,   transect walked almost halved, from
      in Worcestershire – and it’s fantastic to   30 in June to 17 in July.
      see this rare species recolonising its   Fortunately, the rest of the summer
      former range.                          was warm as well as wet, and flowers
      Overall, however, 2019 was just an OK   bloomed. Late-emerging bumblebees
      year for bumblebees in general. The    were able to recover slightly, although
      warm spring saw most species reach     the two common late-flying species
      above-average numbers between          – Common carder bee (Bombus
 Photo: Brown-banded carder bee
 (Bombus humilis) by Dave Clark  March and June. Early-emerging   pascuorum) and Garden bumblebee
      species did particularly well, with the   (Bombus hortorum) – both ended up
      Early bumblebee (Bombus pratorum),     having poor years overall.

 By Dr Richard Comont,   warm summers, and all three did well   Tree bumblebee (Bombus hypnorum)
      and Buff-tailed bumblebee (Bombus
 Science Manager  during 2019.    terrestris) reaching noticeably high
 The Shrill carder bee in particular had   numbers and having some of their best
 2019 was the biggest year yet for   its best year since BeeWalk began. This   years since monitoring began.
 BeeWalk, our bumblebee abundance   is likely to be due in no small part to the
 survey. Across Britain, almost 500 people   land management changes advised by
 walked transects at 587 different sites,   the Making a Buzz for the Coast and Back
 an increase of 38 over the year before.   from the Brink Shrill carder bee recovery
 They submitted nearly 31,000 records   project teams, with very high numbers of
 and counted more than 97,000 individual   the bumblebee recorded on some Kent
 bees. Thanks to their help, we’re able to   sites.
 track the fortunes of our bumblebees in
 near real time.

 The real positive story coming out of 2019
 was the recovery of some of our rarest
 bumblebees. Three species – the Shrill       Photo: BeeWalkers at Milton
 carder bee (Bombus sylvarum), Brown-         Creek by Lauren Kennedy
 banded carder bee (Bombus humilis)
 and the Ruderal bumblebee (Bombus            To read the latest BeeWalk
 ruderatus) – are Continental species at   The abundance trend of all bumblebees recorded   Report 2020, visit
 heart, and reach their northern range   on BeeWalk transects between 2010 and 2019,
 edge in Britain.  All three seem to be   including individuals not identified to caste or   bumblebeeconservation.
 responding positively to the combination   to species. This is shown as the mean number of   org/publications/
     bumblebees counted per kilometre walked each year
 of targeted conservation work and recent   (red line). The grey cloud is a measure of the annual
     variation around this average (standard deviation).
 Photo: A BeeWalk in progress in
 6  Kent by Nikki Gammans                                                      7
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