The mountains that rise above the Great Basin are full of surprises. They have been recognized for a long time as sky islands. Often when I make my way up their slopes, I find species of insects and birds that I did not expect to see.
Bumblebee Spring surprised me in this way last week. It is a moist spot on an otherwise dry slope to the west of Kanarraville (Utah). Saying that it occurs in the Basin and Range province is only barely true. It is within inches of the Mojave Desert (to the south) and the Colorado Plateau (to the east). And rising to the southwest is the Pine Valley Mountains.
Our small team of bee enthusiasts spent three afternoons following feral honeybees and bumble bees in the area looking for nesting sites. We believe that by better understanding where our bees live, we can better understand the ecological relationships that are important to maintain the health of these wild places.
Our first observation (made within minutes of parking the vehicle) was a very large bumblebee. She was over 25 mm long with a prominent black spot on her back between the wings. I recognized her at once as a Nevada Bumble Bee (Bombus nevadensis). This was a bit of a surprise because of the elevation. We were at 7,400 feet above sea level and this bumble bee is supposed to remain below 7,200 feet.
Given our location, the sighting is reasonable. Bumble bees are northern insects. They are adapted to cold climates (at least in the winter) and one typically sees them commonly occurring in lowlands when in the north (at least north of Cedar City). Of course there are exceptions, especially as one takes elevation into account. I mean that northern species can occur in southern areas by moving up in elevation.
What was also surprising was that the bees were feeding aggressively on the lovely bright yellow mountain goldenbanner (Thermopsis montana). Some people call this plant false lupin because of how the pea-like flowers cluster along the stem like lupins. This was a little unexpected because it is not considered a primary foodplant of the Nevada Bumble Bee.
The bumble bees and flowers were abundant. Warblers and vireos were making all kinds of pleasant sounds in the canopies of Gambel oak. In this little forgotten corner of the West, they are trees even though throughout Utah they are called scrub oaks because of their shrub-like appearance and their habit of forming dense thickets.
Here they form a forest by an intermittent spring and provide shade for a lovely flora and a diverse collection of pollinators. It is one more lovely spot hidden away (and nearly invisible) to the thousands of busy travelers staring at the blacktop in cruise control just a few miles away.
