Monday, May 23, 2016

The Gallery Gang on Mount Lemmon

Our group may yet grow back to its old strength in numbers! And haven't we all grown in skills, knowledge, camera size, social media connectedness .. to mention only a few growth aspects.
Bill George (second from right) summed up some history that I had forgotten:  The Gallery Gang,  goes back a few years (just about a decade or so) to when our local newspaper, the Arizona Daily Star, had a Reader's Gallery where we could send in photos hoping to have them published in the newspaper. The Gallery Gang were all those selected by the newspaper as "Gallery All Stars"
Each of us had  a full page spread of our photos along with an interview and a bio. We came together after that and did some photo shoots, but as things happen in life we drifted apart - to finally reunite now.
For myself I should add that this interactive Star Gallery was the first step towards social media, including BugGuide and my blog. 

Rose-breasted Grosbeak by Doris Evans
Friday the 20th of May was sunny, cool at first but warming up quickly. I think we might have caught the very end of spring migration - I definitely saw some warblers that I could not identify, and Doris photographed a Rose-breasted Grosbeak that we others all missed and that was way west of its range.

Most birds, though, seemed to be on their home turf by now and busy building nests.  We had been tipped off that there would be a Buff-breasted Flycatcher at Rose Canyon, but we found instead a Cordilleran Flycatcher moving into one of the one ugly, out-of place structure, a huge container trailer that for some obscure reason was parked down there. Actually, Robert Bateman would probably see a beautiful painting in the contrast between the dainty, fluffy bird and the texture of the rusty convoluted entrails of the trailer.

Bill George says that birds aren't quite his 'thing in photography, but his group photo certainly speaks for his skills

Bird photography isn't quite my thing either, and I'm blaming my tools (of course). And the branches, and the dappled light ... and this pose: who can tell that this absolutely devoted singer is a Yellow-eyed Junco? But just click on the link!

Incinerator ridge (views of old mining sites from higher up may explain the name) yielded some elusive warblers, a number of Spotted Towhees and several pairs of Western Tanagers. Doris told me a trick to remember the name: the males sport the colors of a western sunset. Our target birds showed up, too, but later better and more.

Squirrel, Abert's or Arizona Grey? Cliff Chipmunk, Black-headed Grosbeak and Yellow-eyed Junco
At Summerhaven, a feeding station could have provided easy access to a number of critters - I saw our only Abert's squirrel (or tassel-eared squirrel) (Sciurus aberti) there, but not knowing  that we headed soon for the more natural setting of Marshall Gulch. The squirrel really  lacked any tassels. But I was told that they have to be mature to show obvious hair tufts on their ears (?).

Red-faced Warbler by Lois Manowitz
 At Marshall Gulch we headed straight for creek and willows. Actually splashed through the shallow water to get the sun behind us. The scene immediately came alive with chipmunks and birds that were feeding on soft willow leaves, catkins and the bugs that were themselves gnashing on nectar and honeydew. Soon we got great views of the beautiful  Red-faced Warbler that, more than anything,  had drawn us up the mountain. Getting good pictures in that dappled light was quite a different story.

The mournful flute song of Hermit Thrushes rung through the Ponderosa Pines and House Wrens interrupted their constant hunt for insects to belt out their sharp little songs.

A pair of Painted Redstarts chose a nesting site that did NOT meet with the groups approval. So exposed! So close to the road!

But the critters up here were in general not shy of humans. A Pocket Gopher peaked at us from his hole, then very decisively slammed it shut with some soil. But reemerged immediately closer to us. Disappeared again and popped up literally between my feet, where he became the center of attention and stayed.

I held out a stick and he grabbed it, got it stuck across his burrow entrance, corrected quickly and pulled it in. Checked whether it fir the subterranean design, found it wanting and tossed it out of yet another hole. The area was a veritable Swiss cheese. The gopher became our star entertainer of the afternoon.

He smiles at his easily amused fans

 I was of course also looking for insects. Like on my recent Sonora trip, Veined Ctenucha Moths were flying in numbers. House Wrens demonstrated that that their vivid coloration does not necessarily scare predators from eating them.

Arizona Sister by Ned Harris
Two-tailed Swallowtails sailed by and never landed, but Arizona Sisters posed beautifully on the tips of tree branches. They don't nectar on flowers, so that's where we usually see them

Left top and bottom Andrena milwaukeensis (Milwaukee Andrena), top right Megachile Subgenus Megachiloides or Xanthosarus, and buprestid beetle Anthaxia Subgenus Melanthaxia
On blooming Dogwood (one of the small and multi-flowered  species) I found bees that must be specialized on this high altitude habitat that is more similar to a Canadian forest more than an Arizona desert.

Stiletto Fly (house fly sized) and Bot Fly (monster sized)
Much more massive than even the bumble bee, a fly landed with an unmistakable drone: the biggest Bot Fly that I have ever seen.  Jeff Boettner, a friend and Bot Fly specialist, was quite excited about my find: 'This is Cuterebra atrox (male) and this species is known from over 200 males but only 7 females. Not sure why. The males are mostly singletons, so hard to know if these are leks or not? I think you have found this species before on rocks in fall. But there are museum specimens from AZ from June 10 thru Oct 7th- this would be the earliest. The other crazy thing about these guys is that the host mammal is still unknown. So I would love to get DNA from a sample of these.' OK, It'll go into the mail on Monday

In the afternoon Collins Cochran and spouse and Doris Evans and I took the service road to Oracle down the back side of the mountain.One of the reasons to get my new Subaru Forester was that I wanted to be able to do that. Landscape-wise the trip was worth it - beautiful vistas.

But it was so dry that we found few reasons to stop - no freshly green bushes to beat, no flowers to glean for insects - or maybe I was just to tired. Doris was revived by a Red Tail Hawk on the wires above, I stopped for a folk art piece or rather weird cultural statement and the towering flower stalks of yellow blooming agaves.

Wednesday, May 18, 2016

Still surprises in my backyard: the Longhorn Beetle Chrotoma dunniana

This week's theme in our Facebook group SW U.S. Arthropods was the beetle family Cerambycidae. Cami Cheatham Schlappy, a  group member, looked it up: the name is derived from  Greek mythology: When the shepherd musician Cerambus  told an insulting story about nymphs, they transformed him into a large wood-chewing beetle with horns. No freedom of expression in antiquity! Our southern neighbors, more familiar with cattle than sheep, call any longhorn beetle 'el torrito', little bull.

Brothylus gemmulatus
At high elevations, Robyn Waayers, who lives among oaks and pines above Julian in California, commonly finds Brothylus gemmulatus on her patio at this time of the year. In Arizona I had to drive up to Mount Lemmon (Catalina Mountains, Pima Co. AZ) to find my first one of this species.

Achryson surinamum, a typical low desert species
In the lower desert around Tucson, AZ, the black light on our garage wall attracts the same regulars each spring.
Those Ceramcycids that suddenly show up in numbers  may have eclosed from their pupae a while ago. They then stayed in the safety of the pupal chamber until some external signal woke them up. Only then did they make the final push out of their pupal chamber.

An adult  longhorn waiting in its pupal chamber in a split log on Mt Graham
 Depending on the species these chambers are situated more or less deeply inside dead or life wood. So  this timely emergence takes some preparation. The larva usually chews an exit hole from that chamber to the outside, because the adult beetle rarely has the mouth parts to do so. This exit stays then  plugged with wood pulp until flight time.
Some twig borers instead prepare a thinned out area within the twig where it will snap off  during a strong wind (we have plenty of that this year!) and set the beetle free.

Anelaphus piceum
 This very non-distinct brown fuzzy smallish bycid is one of the first to show up each year. When I posted my first photo on FB, Steven Lingafelter said: 'I think this is what I've been getting that I'm calling Anelaphus piceum. If you turn the specimen toward you and look down the elytra from the anterior perspective, the elytral pubescence is clearly divided by a few vague, less pubescent rows along the elytral costae, and that is distinctive for this otherwise monotonous species.'
So I looked through my photos: this one clearly shows those lines in the pubescence.

Chrotoma dunniana
 Just when I thought the black light at our garage wall would not bring in any more interesting stuff after about a decade of lighting very often in that same location, a surprise appeared on a warm mid-May night. It flew not quite to the light and began scrambling over the rocks under a Palo Verde Tree. Most experts agree that this longhorn is rarely collected. The only other one on are Mike Quinn's 2 Texas posts. 
Even Hovore and Giesbert wrote: A single adult of this rarely collected species was reared by us from the root crown of living snakewood, Condalia (prob. globosa var. pubescens).  Hovore, F.T. and E.F. Giesbert. 1976. Notes on the ecology and distribution of western Cerambycidae (Coleoptera). Coleopterists Bulletin, 30(4): 349-360. JSTOR
CA-TX / Baja Calif., Mexico
Chrotoma dunniana

Saturday, May 14, 2016

Dark Morph Red-tailed Hawk with the Gallery Gang

Because of a chain of sad events in our close family plus some serious wind damage to our house, I had no real drive to write blog posts lately. But life goes on and most of it is good. Like a visit of my photographer friends from the Gallery Gang plus artist friend Mary Lee who all came to see our famous 'Dark Female'. They all stopped by on May 6 early in the morning. A spectacular Red Tail Hawk has been raising her brood not far from our house for nearly 10 years now.

I checked the previous day - the chicks had grown quite a bit but were still sitting quietly high on top of the nest. Mom was vigilantly screaming from her favorite saguaro perch nearby.

But when the 'Gang' walked out early on Friday morning, the hawk chose an aerial display instead. My friends had exactly the right cameras for the occasion and the sound of so may rapid-fire motor drives sounded a little ominous.

From my friends' photos, I gained a completely new very personal view of  'our Dark Female' whom I've now watched for nearly 10 years.  Ned, who specializes in Raptor photography and has contributed his work to several books on that topic called her the most magnificent dark morph RT hawk that he has seen.

Ned and Tom with their heavy duty 'guns'
Tom and Lois in action. Doris' photo even brings the Tortollitas and Catalinas close

Her beauty was slightly marred by a broken tail feather. Incubation and rearing two fast growing chicks takes a lot out of a bird.

The kids are very close to fledgling now. We believe that this time, one of them has inherited mom's rare coloration. The one on the right is definitely much darker than its sibling. The left one shows already a pattern similar to that of the male (who never showed up during our visit).

Kestrels, Night Hawks and Desert Iguanas had also been high on everyone's wish list, but they all did not show themselves to my friends. Of course a day before our photo excursion and the very next morning when it was just me and the dogs, all of them posed very nicely.

The resident Kestrel pair has fledglings to guard, too. Their sississississi calls betray their location, but the young ones are already acrobatic flyers and can avoid most danger (as long as they stay away from the Chainfruit Chollas

Lesser Night Hawks are very active at dusk and dawn. Their purring sound can be heard from our patio and mated pairs glide close to the ground and loop through the ironwoods along the washes

This big Desert Iguana was around a day before and right after the visit of the photographers. They would have loved him! (Her?)

5 days after our group visit, the Dark Female had shifted the center of her attention about two thirds of a mile westwards. When Randy and I inspected the empty nest she still dutifully came over to screech, but soon flew back to where the chicks were probably resting from one of their first flights.

Around the nesting saguaro, big swatches of white wash on the ground still told the story of the fledged former occupants. In other years, I have seen RT hawk chicks come back to the nest to spend the night for a couple of weeks. The parents will still be around their keening offspring for a couple of months. It's a very stressful, hot and dry time in the desert. It will be a hard test for the survival skills of the young hawks. Some birds migrate to cooler mountains for the summer, but I have seen our Dark Female around at any time of the year. And next year hopefully at the nest again!

For the photos of the Hawk in flight and the close-ups of the chicks I thank Doris, Lois, Tom, and Ned!

Friday, April 29, 2016

Sexual dimorphism of Centris Bees

 For Arizona, this April morning  (4/26/2016) was rather cool and very windy. At 72 degrees Fahrenheit and gusts up to 40 mi per hour, the only insects flying seemed to be big, strong Centris bees visiting our Foothills Palo Verdes (Parkinsonia microphylla). The big bees were actually flying in wind so strong that it ripped one of our swamp coolers off its foundation.

At around 8 am, and just about 70 degrees Fahrenheit, many Centris Bees were actively collecting among the bright yellow flowers that are just beyond their prime by now. But equally many were still asleep, clinging to twigs with their tarsi, but even more firmly with their strong mandibles.

Most insects are ectotherm, meaning that their body temperature depends completely on environmental factors and fluctuates. They can only regulate it somewhat through their behavior. Birds and mammals produce and regulate their body temperature actively through endogenous mechanisms (shivering, panting, sweating, addipose tissue metabolism), which makes them endotherm (this is not to say that they do not use behavioral means of thermoregulation in addition).

But there are exceptions among insects. Big hairy bees and big active sphingid moths, as well as some big beetles and Robber Flies (my own observation) are able to elevate their body temperature using muscle activity that does not translate into movement or at least locomotion, just like their avian and mammalian counterparts who shiver to get warm.

Birds are highly effective thermoregulators, they can shiver and increase their insulation when it's cold
Birds and mammals maintain high body temperatures almost constantly. Times of  hibernation and nightly torpor phases in some few species are the exceptions.  In contrast,  facultatively endotherm insects are ectotherm most of the time. That saves a lot of energy. They actively increase their body temperature only when needed. Flight is a very demanding way of locomotion, and the flight musculature of most insects is only operational when warm enough. Maintaining this high temperature requires a great energy investment, especially in small organisms with a less than optimal body-mass-to-surface-area ratio. Note that all part-time endotherm insects are comparatively big and hairy, at least as insects go!

Promachus albifacies buzzing its wings to warm up before it can actually fly
 So even those big hairy bugs don't keep their temperature up constantly. B. Heinrich found that bumblebees only fly at cold environmental temperatures when their investment yields a  worthwhile return - meaning that they fly among nectar-rich flowers, but stop, rest and crawl if the available flowers are of minor quality. While the flying bumblebees maintained high body temperatures, body temperature of the crawling ones quickly fell to the level of the environmental temperature. And before they could fly again, they first had to warm up.

Male Centris pallida
So on this cool morning, the palo verde flowers, a little past their prime, were a still worthwhile investment to most of our bees, but not to all of them. And those who were not flying and active were still really cold and unresponsive.

female Centris pallida
There were sleeping females as well as  males, debunking the myth that females always sleep in their nest burrows. They may do so, often, because they often spend the sunset time digging (own observation). So when it gets dark and cold they just stay in the burrows. But they also camp out among the flowers when that's where nightfall catches them.

The sleeping bees do not warm up quickly. While it is usually difficult to get a close look at those constantly hovering Centris Bees, this is an opportunity to study them.

Male on theft, female on the right
Sexual dimorphism is in the details. While both sexes have big green eyes in this species, the area between the eyes is white in males. It looks like the reason is the much larger clypeus. This feature is shared with many bees,  and interestingly some male beetles also have more white in their faces.
The faces of the female bees are more fuzzy and grey.
Another difference: his eyes are bigger and more bulging. Male Centris bees are extremely eager suitors, to the point that they try to dig up their late-born sisters to mate with them. Much of that activity is pheromone driven. But often, the males also relentlessly pursue flying females. Those big bulging eyes - to better see her in three-dimensional space?

Centris bee digging her brood chamber
Only females build nests and collect provisions in form of pollen and flora oils, a specialty of Centris (and Epicharis), so only females show special adaptations for the transport of those substances. Their hind tibiae are covered with long, dark hairs densely covering the hind leg - the scopa. There are also long bristles arranged like a comb on the front legs. I often see Centris Bees hover and use their front legs in grooming motions - probably combing pollen and oils from all over the body and stuffing it into those hind-tibia brushes.  Maybe that comb of setae is also useful to dig in the loose sand?

Scopa of the hind leg and setae brush on the front legs of the female
The hairy tibia of Centris and Epicharis is considered the evolutionary precursor of the corbicula (pollen basket) of the apidae (orchid, honey, carpenter, bumblebees).

Corbicula, a bare concavity into which moist pollen is crammed, on the hind leg of a Honey Bee
 "The corbicula is a glabrous, concave baskets on the hind tibia of Apidae, and represents a key evolutionary innovation, allowing efficient transport of plant resins and large pollen/nectar loads and freeing the corbiculate clade from dependence on oil-offering flowers" (Martins AC et al., 2014)

Here is another look at the male Centris pallida - he does not have those brushes of long hairs on the hind tibiae.

Lastly, he also has no ovipositor and that means no stinger. I have handled individuals of both sexes when they were still too cold to fly and none tried to sting me, but I'm too careful to find out whether that is the rule for Centris Bees. They are certainly not as aggressive as social bees and wasps but the females probably can sting.

Literature quoted: The corbiculate bees arose from New World oil-collecting bees: implications for the origin of pollen baskets. Martins AC, Melo GA, Renner SS,Mol Phylogenet Evol. 2014 Nov;80:88-94. doi: 10.1016/j.ympev.2014.07.003. Epub 2014 Jul 15.