4th August 2009

A very windy, but mainly bright day.  I met up with Dave Jones of RSPB in the morning, and we looked at Achscrabster quarry.  The site didn’t let us down, and it was nice to have an independent witness to one of my Great Yellow sightings.  We had a quick look at Broubster Leans, where RSPB have a ‘Birds & Bees’ crop, Phacelia providing the main pollen and nectar interest.  A White-tailed Bumblebee worker had ‘blue balloons’ on its legs – presumably Phacelia pollen collected to the pollen baskets.  Harebell pollen is also rather light blue and two of the Broken-belteds elsewhere had collected this.  We saw a few bees (including Northern White-tailed and Heath Bumblebee queens) before the rain came on, and Dave had to meet up with colleagues at Dunnet Head – a new information post there has just opened up, and made page 4 of the Press and Journal!

 

I decided to test the quarry hypothesis again, and headed to Stonegun south of Castletown.  Unbelievably, the first bumblebee I saw was a Great Yellow, this time on Lesser Knapweed.  A sheltered patch of Marsh Woundwort had abundant Garden Bumblebees and another Great Yellow worker, this one carrying pollen.  Are they in the quarries because they are sheltered, flower-rich, provide nest-sites, or a combination of all three.  Dave had mentioned that Kidney Vetch, an important spring forage plant for queens, would probably do well in a quarry and it didn’t take long to find a clump, albeit now gone to seed.

 

Further south, I ran out of quarries, but a good roadside patch of Marsh Woundwort did provide another Great Yellow worker another 4km SE of the quarry.  At the border with the next 10km square, a field of flowering red clover caught my eye.  This could draw in a Great Yellow, and it could be the most southerly recent record.  I met the farmer, a young chap who was very interested and helpful, and I walked the edge of the field slowly.  The wind was a real problem, but I’m fairly sure there was a Great Yellow flying away from me.  I needed 100% confirmation, so can’t claim it.  The wind is due to drop, and move round to the south, so I may have another chance – but the crop will be cut for hay this week!