Monthly Archives: May 2014

Winners and losers of land use intensification

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We have a new paper out showing which pollinators are more affected by land use intensification and which can cope with it quite well in New Zealand. There is a clear agreement that we should move beyond general species richness patterns, and understand each species specific response. Probably is not surprising that e.g., the invasive Bombus terrestris is doing great while bees in the native genus Leioproctus are struggling with land use intensification. However, most pollinator studies are still mainly based on richness and abundance metrics (Winfree et al 2011). That’s why we really wanted to see not only compositional changes, but also functional changes. At the end, identifying the traits of the winners and losers was the most interesting part of the paper.

As usually happens to me, I entered this article on the analysis phase, which means I can not tell you how cool is NZ, because I’ve never been there. However, I can tell you that the stats cover a lot of ground (may be too much and we lose a bit of focus?) and try to make a good use of functional diversity metrics (see here the code used to separate FD and richness effects) and species identity sensitivity to land use intensification.

Marking bees with glow-in-the-dark powder

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Lab notebook style post to keep record of pilot experiments I run. We used one day this spring to see if we can track what bumblebee queens are doing. We captured queens and applied a colored powder to them. The idea is to see if we can find the powder in flowers after that, to see where and what they visit.

Lessons learned:

  • Capturing queens is time-consuming. 12 queens – 6 hours.
  • Marking them is super easy. Only a tiny bit of powder in the vial is enough. Inside the vial bees buzz and cover themselves completely.
  • First tests with too much powder were bad (bees too covered, see photo below)
  • We used glowing in the dark powder (sold in 8 colors in amazon) in case it helps spot it later with a UV light (also very cheap at amazon).
  • Very few flowers are open at this stage of the year, so we targeted a few Salix at different distances from the marking area along a power line corridor, and look for powder in Salix flowers after 6 hours.
  • We recovered a single flower with powder, but was in a Salix 500m down the corridor (not bad)
  • Not convinced on this technique for queens, but may work better for workers, when you can mark 100’s of bees.

As always we only had bad phone cameras, here is a photo of the first trial with way too much powder used. This bee was seen 1 h. after the release flying happily.Bee_glow