27 de marzo de 2022

*Anthophora* fight

It's been another interesting week of observing the Anthophora pacifica and all the other life hanging out in their neighborhood.

The females are busily digging new nest holes, dotting the aggregation with piles of excavated dirt.

The bumble bee queens have been coming out, too, and occasionally hanging out at the Anthophora aggregation. The Anthophora mostly ignore them, though I've seen males butt them occasionally. This one poked around for a while, actually entering multiple and backing out of holes. Scouting for a site to found a colony?

A weird fungus or slime mold popped up at a couple of the holes:

And the coolest of all, a fight between females. First I caught one driving the other away from a hole. It seemed like the bee on the outside was trying to angle her abdomen in, perhaps to sting(?) but most of the action was mandible-to-mandible.
A few minutes later, after I grabbed a better camera, their grappling took them out of the hole:
What were they fighting over? There are tons on holes right there, so surely it's not just the real estate. Maybe it was an attempt at conspecific kleptoparasitism?

The fights between males that I've seen either are a flying one ramming/butting one that's resting or are a straight-up aerial dogfight. Quite a different style from this.

Ingresado el 27 de marzo de 2022 por eebee eebee | 3 comentarios | Deja un comentario

17 de marzo de 2022

Update on the *Anthophora* aggregation

This year the Anthophora aggregation has again been putting on a beautiful show. I saw bees emerge on days when it still seemed impossibly cold, when the nominal temperature from the weather app was 37 degrees F (though their nest site, on a south-facing slope, could easily have been ten degrees warmer.)

By Feb 26, there were already 78 holes. Almost all the bees I saw emerging were males.

The males tend to sunbathe photogenically.

I love how they groom themselves and stick out their tongues as they come out for the first time.

One bee seemed to be having great difficulty cleaning some gooey gunk off his tongue:
I wonder what was going on there!

I observed a couple of the earliest-emerging males appearing to actually dig holes themselves. Those days were quite cold, so could it have been a matter of "whoops, the air is not as warm as the temp of the dirt would have led me to believe, gotta get back underground?" Or maybe they were digging for females, though I haven't observed that behavior again after those first, coldest days?

I saw one pair of early females that appeared to have be being pushed out by a male-- odd, because I thought males usually ended up closest to the nest entrance. Maybe not always, or not with this species?

At least one of those pushed-out females really seemed like a new emergence, with matted hair. She appeared to struggle after getting out of the nest, making it to a plant at first but then flailing and falling bit by bit down the slope until she finally dug into some dirt and seemed to hunker down. A couple of days later--still before I seen other females--I found a dead female bee a few inches away from there. Perhaps she was sick or deformed?

I also wondered if perhaps she was just pushed out before she was ready. But I believe these overwinter as adults, so that doesn't make a ton of sense to me. But then again, the females do emerge later than the males, both in the season and during the day. Yesterday it was cold/foggy/sprinkling most of the morning, and when the sun peeked out I got out with my camera. The males started coming out right away:

And it was a half-hour later, once things had warmed up more, that the females started to come out:

They look so bedraggled as they emerge!

One great pleasure coming from all this is that two of my Washington Native Bee Society (website, iNat page) friends came and took photos-- my first time spending time with them in person, since WaNBS started during the pandemic and has only met virtually. Friend #1 also took some video, which I'm excited to someday see. These were great learning experiences for me, as both friends have much more bee and photography knowledge than I do.

Though we've long suspected this is an aggregation of A. pacifica based on John Ascher's suggestions, I wasn't sure of the level of certainty. WaNBS friend #2 properly keyed out a male and a female, and those were indeed A. pacifica. He also figured out that they were heavily visiting a neighbor's heather, likely using it as a primary nectar source, and that they strongly preferred one of the six cultivars at that site.

They also visit the periwinkles in my yard.

On March 12, I counted 133 holes. Presumably most holes have produced multiple bees, so that's a pretty substantial population. Based on (their relative lack of) observations elsewhere in town, WaNBS friend #2 thinks this Anthophora population is quite local, with my yard as the main nest site and a radius of perhaps a few blocks of foraging range. This year I've seen nests in south-facing neighbor's yards, as well; I'm very curious to see how this plays out in the longer term. I wonder if we'll ever get a big enough population, connected enough to others, to attract some Melecta, an Anthophora cuckoo with an observation on iNat as close as Pierce County.

Some more remaining mysteries:

Some of the males seem to have tuft of reddish hair around their frons, which I don't remember from last year:

I'm still surprised by how often I see the males in nest holes. They just hang out in them, peering out with their cute yellow-plated faces while they wait for it to warm up in the morning. I think they spend the night in holes, though without having marked individuals I guess it's possible that newly emerged males are just coming out every day. But I definitely see them fly in as well. Could they also be seeking females? Do they ever mate in nests?

I'm also curious and puzzled about the males' behavior around females. Sometimes the males are buzzing and patrolling around like crazy over the aggregation site, tussling with each other occasionally, but seem completely oblivious to the female newly emerging a couple of feet away. That's a far cry from the description in The Bees in Your Backyard of Anthophora males forming a ball of 20 or 30 bees trying to get to a female. Maybe that doesn't happen with this species? I have only very occasionally seen mating, and never with good photos:

Now I'm settling in for the next part of the Anthophora season: watching the females dig nest holes! I wonder how often they re-use old nest holes vs. digging new ones?

Ingresado el 17 de marzo de 2022 por eebee eebee | 0 comentarios | Deja un comentario

11 de febrero de 2022

*Anthophora* are back!

I spotted a zippy little male in a sunny spot in my yard. I also spotted three Anthophora-sized nest holes right where I had an aggregation last year. The temp was 50 degrees Fahrenheit.

Ingresado el 11 de febrero de 2022 por eebee eebee | 1 observación | 2 comentarios | Deja un comentario

22 de abril de 2021

Groups of small black beelike insects darting around above Anthophora aggregations

In the last couple of days, there have been large groups of small, black bees or wasps darting around above a couple of areas of Anthophora aggregation. They'd occasionally duck into a small hole or a large Anthophora hole, but always seemed to come out very fast. (This is besides than the Nomada and Sphecodes poking around, and the Anthophora females coming and going.) They had some SERIOUS mandibles going on.

They were fast and hard to photograph, but with fast shutter speed and a LOT of discarded shots, I got some that are conceivably identifiable. A few of the better ones are linked here.

Looks like ONE submarginal cell?! (Frustratingly, it isn't working to link this one in and have the photo show up below, so you just have to click the link.)

A couple more with wing veins visible:

One that shows the crazy mandibles:

Just a nice overall view:

Ingresado el 22 de abril de 2021 por eebee eebee | 4 observaciones | 2 comentarios | Deja un comentario

02 de marzo de 2021

Anthophora nest aggregation in my yard!

I knew I had some good ground-nesting bee habitat when I found the Halictus rubicundus aggregation in my yard last summer, and I had been excited to see whether they came back this year. But I didn't expect Anthophora! I only see one previous record of them in King County on Discover Life, and only three previous records in King County on iNat. But I spotted one a couple of houses down on Feb 9, then another on Feb 26, both days in the 40s Fahrenheit. Yesterday was the first sunny, 50s-temp day of the year, and it was like an Anthophora explosion! I saw many on a walk within a few-blocks radius of my house. When I got home, I spotted one entering a nest hole in my yard, digging a bit, then pushing dirt out. I waited with my camera, and it slowly, slowly poked its head and then its thorax out, staring at me. There were many others buzzing around, and I spotted >30 nest holes, many of them being actively entered or excavated by Anthophora.

Ingresado el 02 de marzo de 2021 por eebee eebee | 11 observaciones | 18 comentarios | Deja un comentario