Sunday, May 13, 2018

Roadrunner's Coming of Age

Roadrunners are bold, active birds. At times also very vocal, from a mechanical clicking sound that is repeated rapidly to a strange moaning sound that I could not attribute to any known bird or animal when I first heard it.

Young Roadrunner -note the short tail - chasing a lizard. This one easily escaped.
Roadrunners are THE caricature-characters of the desert Southwest. Together with the trickster coyote they are known to children around the world. And I must say, watching the real bird, with all its velociraptor fierceness, is much more interesting and even amusing than all those cartoons. Immediately after my arrival in the southwest, I experienced them as skilled, opportunistic predators who didn't refuse a juicy bug, grabbed tadpoles out of my aquarium, did not spare the occasional song bird, but also did not back off from a rattlesnake.

Photo by Doris Evans
This fierceness increases exponentially when a hungry brood is waiting. 
 My friend Doris Evans documented how even little chicks devoured whole lizards that the parents delivered to a nest in her yard. Compare that to the little bits of meat that mother hawk carefully feeds her chicks! Doris was lucky to have the nest so close to her window that she missed no details of the nursery. Over the years I watched two nests in Sabino Canyon, but from a safe distance: What was going on there was surprisingly quiet and secretive. Here at home, we see and hear all the preliminaries for nesting and breeding, like the gift-giving from male to female and the haunting, moaning cries that seem to claim a territory, but then it gets eerily quiet: the Roadrunner parents are not betraying the location of their nest and vulnerable young-ones by a lot of obvious activity. The nest is out in the open, if concealed by a prickly cholla cactus, and roadrunner chicks are born featherless and blind, so it takes a while for them to reach fledgling status.


But when the chicks are finally out of the nest, they soon carry on with the  typical boldness of their species.  First they mostly follow their parents around to noisily demand their lunch, but soon they begin to bother everything that's smaller than they and check it out for prey-value. They explore every place that could hide any morsels, including the inside of my parked car and my friend's computer desk. I have seen them watch the tail of my cat with the worst of intentions, and a friend who was hunting bugs for scientific, not culinary reasons, found them following him around, hoping for a hand-out?  The ones in Sabino Canyon seem to quickly learn the schedule of the tourist tram. I saw bits of hamburger tossed to them, which is of course absolutely wrong. Don't do it.

So my latest painting is about the hunger of the dragon brood. It sold as soon as I put it up on Facebook.

Wednesday, April 25, 2018

April in Cochise County

No bugs at all on Prickly Poppies, But maybe there's a painting in this?
 I had to drive to Hereford Arizona to discuss the color settings for the printing of tiles of my watercolors. So of course I took the opportunity to check how spring is progressing in the Huachucas. Clearly, it's very dry. Besides oaks, not much is blooming except close to paved roads where run-off nourishes at least a few prickly poppies and New Mexico Thistles.

A male Collops and some Nemognatha on the thistle heads
 Pat Sullivan's garden in Ramsay Canyon always offers something special, because he keeps planting all kinds of native blooming plants and some that are not quite native but just irresistible to bugs.  Of course he also waters them regularly.


On little flee bane flowers, we found baradine weevils that maybe Charlie O'Brian can identify ... there were so many of those that the yellow disk of some flowers was black with them.


Osmia sp.
Daleas were buzzing with green metallic bees that might be genus Osmia, but I'm waiting for confirmation. I'm proud of the accidental in-flight-shot! The captured specimen got contaminated with moth scales before it was photographed. Terrible stuff! I don't even collect any moths!

The nicest surprise was a little black, red banded Leaf Beetle, Lema balteata. Years ago Eric Eaton photographed  a mating pair in Catalina, also in a garden. Since then I've been searching for these elusive guys that look deceptively similar to our common Lema trabeata. On Kitt Peak, I thought I saw one on white blooming solanaceae, but it immediately disappeared.  I went back several times, and then the plants fell victim to gardening crews tending to the observatory. But maybe what I saw was just L. trabeata after all. The beetles in Pat's garden, 2 that I found and 3 in his collection, seem to prefer a sunflower with very narrow leaves (need to ask for the sp). They weren't close to any solanaceae at all.

Carr House
I drove up Carr Canyon and found it dryer than Ramsay. Very dusty along the road, so even the fresh oak leaves yielded nothing. At Carr House, I managed to get away from the road and things looked up.

Narnia sp. on Cholla fruit
 Three species of oaks were leafing out. Most hosted nearly no insects that I could find, but the ones that did offered many different species.


A clearing planted with young oaks and Alligator Junipers
 It seems to me that oaks, even of the same species, may contain very different levels of their main defense,  tannic acid. So some trees are just much more vulnerable than others and I have learned to look for those.

Leaf Beetles on young oaks: Pachybrachis haematodes, Octotoma marginicollis,  Xenochalepus ater, Pentispa suturalis
Brachys cephalicus
 There were several different Leaf Beetle species and a Brachys,  a leaf mining Buprestid. So not all Metallic Wood-boring Beetles are real borers . I think I'll use the European term "Jewel Beetle' instead


The nymphs of membracid Treehoppers, probably Cyrtolobus sp., would have been very well  camouflaged among the leaf buds of the oaks, but were given away by the dark shapes of ants that were hanging all over them.

Crematogaster sp. attending to a molting Cyrtolobus sp. nymph
 There were at least 2 species of ants in attendance, Honey-pot Ants and Acrobat Ants. In one case they seemed to assist in the molting of a nymph like a pair of concerned midwives.


So much productivity had of course attracted a number of predators, from still in-pupa Lady Bugs, to strangely elongate Robber Flies,   Leptogastrinae,  to jumping spiders and Little dark beetles, all of them in pairs, and shaped like melyridae.  
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Friday, April 20, 2018

Encounter - a watercolor painting


Young Gray Fox exploring. I watched him when I was camped at Madera Canyon - in the morning he went about his business quite unconcerned, doing his toilet from stretching, yawning, scratching and preening to well, everything... but he was petrified when the Tarantula walked by. To pounce or not to pounce?

The Gray Fox (Urocyon cinereoargenteus) is widespread throughout North and Central America. In the eastern US the Gray Fox seems to be loosing territory to the dominant Red Fox (Vulpes vulpes). In Arizona Gray Foxes are holding their own, together with their smaller cousins, the Kit Foxes. Red Foxes are only found in the north eastern corner of the state. 
Gray Foxes are small agile canines that can even climb trees. Their diet consists mainly of rabbits, rodents, birds, reptiles and fruit, but in dry western areas like Utah's canyon land and the southwestern deserts,  arthropods are the main component of a rather omnivorous menu. He could probably tackle the tarantula but in this case, the young hunter just stood back and watched.


I know gray foxes occur in the open desert, but I imagine that they appreciate some cool canyons and lusher vegetation more. So I gave that to my guy when I tried to make the light source more obvious and enhance the contrast to give the painting more interest. Did it work?

Tuesday, April 17, 2018

Centris Bees and White Ratanay in the Tucson Mountains


Krameria grayi – White Ratany is a grayish inconspicuous desert bush that grows in the lower elevation of the Tucson Mountains  Even when it's blooming, they are not very showy, though the single flowers and later the heart shaped seed pods are very pretty and intricate.


But right now, during their blooming season the bushes draw attention not through their looks but by the noise coming from them. Loud, deep buzzing, very sonorous, very different from the higher sound of Honey Bees.


Big Centris bees are coming and going, sometimes hovering with a strange wiggling motion, sometimes landing in the sand nearby - seemingly just resting.



These New World bees range with 250 species from Kansas to Argentina, and here around the Tucson Mountains I have found at least 3 species. Females of these bees possess adaptations for carrying floral oils rather than (or in addition to) pollen or nectar. According to Wikipedia, they visit mainly plants of the family Malpighiaceae to collect oil, but also Plantaginaceae, Calceolariaceae, Krameriaceae and others. Yesterday, they were definitely concentrating on that one blooming Kramericea, the Ratanay.


Some also visited Janusia, Fam. Malpighiaceae. I did not know the family of this strange vine, but obviously I can rely on the good senses of the bees and in this case Wikipedia (I think I know who is the careful editor of these bee entries).

The Centris bees  completely ignored a desert lavender bush in direct proximity. These flowers were later in the day extremely popular, but with honey bees.


Centris Subgenus Paracentris, Oil-Diggers and Desert-Diggers, Female, could be C. cockerelli or atripes

I have watched Centris pallida  dig tunnels and nesting chambers into loose sand and J. Alcock describes the same for another sympatrically occurring Sonoran Desert Centris, C. rhodopus. So I expect this Centris bee to behave similarly
I asked Entomologist and pollination expert Doug Yanega how the oil is used in the nest to rear the larvae. Here is his answer:

'The nest cells are vertical and they have a lining that prevents the oil seeping into the soil, and the bees just scrape off the liquid (which is rather viscous) into the cell.
Once they have a good pool, they float an egg on top and seal it. There are numerous bee genera that do this worldwide, but in the US I think only Macropis and Centris, IIRC.


P.S. Today I found this C. cockerelli  on our neighbor's hybrid (Desert Museum) Palo Verde. There is no sign of C. pallida yet, but most of the foothills paloverdes are not blooming yet around Picture Rocks. I just learned from Doug Yanega that there are no oils in Parkinsonia - just nectar that the bees need to feed themselves. I guessed that already because I often see male Centris on those flowers.

As for the species identification of the Rantanay Centris: One suggestion was C. caesalpinia, but they have red eyes, which mine did not.  Not C. rhodofus because they have red eyes and legs. Mine look like C. cockerelli, except that those should have yellow faces, and mine have a reddish orange clypeus. But:
 John Ascher When all else fails, consult the literature! Turns out that there is a western form in CA and AZ of C. cockerelli with a reddish yellow clypeus and an eastern form form in TX with a white to yellowish clypeus intergrading in NM. I had forgotten about this. So C. cockerelli is likely correct. Sorry for the confusion. At least we learned something (if nothing else, to consult the literature rather then rely on memory!)
 So: western form of Centris cockerelli!

Friday, April 13, 2018

Brown Canyon Hike, Buenos Aires National Wildlife Refuge

For Brown Canyon (you can still join in) on Saturday the 14th of April 2018, we will meet at 7:30 at the intersection of Ajo Way and Hw 286. At 7:40 sharp, we will go south on HW 286 to the turn-off into the preserve (right turn) around mile marker 20, meeting there at 8 am. . The guide will greet us and give a short talk, then take us into the preserve. Bring $5 cash for the guide! There are restrooms at beginning and end of the hike. Bring lots of water and a light lunch!
As the weather cooled down nicely, we are expecting a great, easy hike. Landscape, birds, bats, and bugs will not disappoint.


Brown Canyon is part of the Buenos Aires National Wildlife Refuge and only accessible as a group with a guide.

Tuesday, April 10, 2018

Ancylandrena Mining Bees in our back yard

Updated repost from 2014
 Our house is built on sand. It sits on a little mesa (elevation) consisting of soil that was excavated to put in the basement. Over the years I found out that we share this site with many sand loving, digging insects, tarantulas and scorpions. And please don't think that that is a problem. Some of these guys may even keep out others that we would like less.

The little dark parasitic bee, waiting close to the nest entrance
 Yesterday I was reading at the bedroom window when I noticed a dark little bee zigzagging and descending repeatedly out of sight under the window. Time to investigate.
When I got outside, she was resting on a flat rock. In the soil around it were several small, round holes about 5 mm in diameter. Another bee buzzed closer, circled, landed next to one of the holes and slipped inside.

A mining bee exiting the nest entrance
 This bee was larger, plumper, and lighter than the little observer. It stayed in the hole for a long time. While I was watching, two more bees arrived and crawled in. for over 10 min no bees left as far as I could see. Then the smaller bee flew up, circled shortly and also crawled into the hole. Several other bees of the bigger kind entered 5 other holes, all in an area of less than a square meter.  Eventually bees also exited the hole that I was watching, but too fast to get any good pictures. Peak activity seemed to be around 10 to 11 am.
Today I came better prepared. For example, I found a way to sit instead of crouching over the hole for what turned out to be long waiting times. So I got some video of the larger bees that clearly shows that several bees are using the same entrance and are under ground simultaneously. Incidentally, the little bee was inside during that time as well. This time I trapped her and three exiting larger bees to get a closer look. I had an idea by now that I was dealing with mining bees and a clepto-parasite, but I found that I didn't have these guys in my photo collection yet.

Ancylandrena sp. Doug Yanega det.
 Indoors, I put each bee into a white ceramic bowl and covered it with a clear plastic container. It took a while for them to calm down. If they had been beetles, they would have experienced a short cool-down in the fridge by now, but bees just don't look right when they are cold. So instead, I got the chance to take a few quick photos, some OK, some blurred and some out of focus, of each bee before she took off for the window. No harm done, they were easily coaxed back into the container.
John Ascher commented on BugGuide:
The expected species is A. larreae if creosote bush is blooming nearby (lots of it!)
The yellowish tan thoracic hairs are consistent with that species.
She should have a conspicuous yellow blister at e base of the mandible.

Hexepeolus rhodogyne, Doug Yanega det.
In the close-ups, the parasitic bee looked somewhat beat-up. Maybe her life as an uninvited guest was not quite as easy as it seems. But her visits in the nest, concurrent with those of several 'owners' did not seem to create any disturbance.

Several of my Flickr and facebook connections are bee specialists, so I posted the photos there and on BugGuide.

From Doug Yanega came the response:  "The latter is Hexepeolus rhodogyne, and it is a cleptoparasite in nests of Ancylandrena (the first bee). It wasn't until the 1990's that the host-parasite association of these taxa was confirmed, as I recall. The genus Hexepeolus contains only that one species".

John Ascher added a link to the 1994 paper: Biologies of the bee genera Ancylandrena (Andrenidae, Andreninae) and Hexepeolus (Apidae, Nomadinae) : and phylogenetic relationships of Ancylandrena based on its mature larva (Hymenoptera, Apoidea). American Museum novitates ; no. 3108

It turned out that BugGuide had an image of a mounted specimen of the parasite, but only an empty, prepared, page for the host. So I was able to fill in both with white backgound-life-close-ups and action in situ shots:

BugGuide Info Page

As for the species id, in Discover Life I found a description of a rare Tucson specialty, A. rozeni, but it would be difficult to identify it without comparative material:  A. rozeni - This is a rare species with records restricted to Arizona, specifically known from the Tuscon area - The male appears closest to that of A. larreae though slightly smaller, has a shorter clypeus, has shorter antennae, has smaller light markings in the paraocular area, is less densely pitted anteriorly on the scutum, hairs sparser in the anterior of the scutum, and has a greater proportion of dark hair on the upper areas of the head - The female appears most similar to that of A. timberlakei, although it may be differentiated by the presence of some degree of a tan or yellowish brown mound on the base of the mandible, a greater proportion of dark hairs in the upper areas of the head, the fact that all hairs anterior to the middle of the tegulae are white, and that there is a greater proportion of light-colored hairs on the scopa (2)
 Anyway, I preserved a specimen.

So to summarize, Ancylandrena is a mining bee. In spring males and females emerge from underground cells. They mate, and the females dig nest burrows in sandy soil. Mining bees collect pollen in the long hairs of the tibial scopa of the hind legs. (They do not  have a 'pollen basket' like honey bees and bumble bees). They construct small cells containing a ball of pollen mixed with nectar, upon which an egg is laid, before each cell is sealed. Although not social, several individuals seem to be sharing at least a nest entrance (Solitary, communal ground-nesting). As many insects do, they provide provisions for their offspring, but they are not around to guard the larvae while these are growing up. Clepto-parasites like the one I observed commonly make use of this arrangement to raise their own brood. Many of these clepto-parasites, like this one, are in the subfamily Nomadinae (Cuckoo Bees). They usually lack the hairs that are used by their relatives to collect and transport pollen. There are a number of strategies to get parasitic eggs into a provisioned nest. In this case the cleptoparasitic bee just followed the host bees to get her eggs into the brood chambers before they were closed. In Rozen's study several eggs of Hexepeolus rhodogyne were attached to the inner wall of the brood chambers while the larger egg of the host bee was sitting on the pollen ball. This explains why Hexepeolus was around for several days entering the same nest repeatedly: she had to access the chambers that were just in the right stage of construction.

PS: I was busy at an art show for three days, but when I checked again on Monday, 3/24/2014 there were still Ancylandrenas entering the same nest. I also found another nest about 60 meters south on a berm planted with cacti and creosote bushes.

Update April 2018: In the following years  I did not see these bees nesting again. But my observation and photos made it into a great new bee book 'The Bees in Your Backyard' by J S Wilson and O M Carril Princeton University Press 2016.

 
 In April 2018, on our neighbors' potted Aloe, I found a group of sleeping males most likely of the Ancylandrena species Ancylandrena rozeni. Id by John Ascher from my photos.
These guys lack the brown hair of the ones I photographed in 2014 and are silver-grey all over. No yellow blister under the mandibles.

Saturday, March 31, 2018

Will the Harris Hawks of Sandario Rd in Picture Rocks become homeless?

Watching a pair of Harris hawks at a tree that has hosted their family for years, maybe decades, made me wonder about the symbiosis between an endemic hawk and an imported tree.
Aleppo Pines were brought  to Arizona desert cities from Lebanon and Syria as landscaping trees. Most were planted 30 to 50 years ago. Although they were not really adapted to our typical rain pattern of monsoon showers in summer and soft. but productive rains in winter, they thrived for decades and outgrew in many cases their allotted space. Low slung ranch houses under towering, monstrous pine trees were a strange, but typical look for Tucson neighborhoods when I arrived here in the early nineteen nineties.

But nowadays, those trees are becoming rare. We lost a few on our own property: they became pale, nearly straw colored, produced a couple of panic crops of cones, and died. It made us sad and left us feeling guilty - thinking that we did not care for them properly.
Then there was a diagnosis: Aleppo Pine Blight.
 There was a lot of guessing as to the cause of this disease. Bark Beetles and 'nearly invisible' mites were blamed. I stripped the bark of our tree corpses: no tell-tale sign of bark beetle infestation at all. Anyway, those bugs like mountain air, not desert heat ... but still, bugs usually get the blame.

Bark beetle infestations leave typical tracks under the bark of trees killed by the beetles. They were not present in dying Aleppo pines.
By far not all plant diseases are caused by organisms (bugs). Disease may occur because moisture is not available to tissues; consequently, they malfunction or die as a result. Insect infestation may sometimes be exasperating the problems but they are usually secondary to climactic stresses. No insect infestation was found in most dead pine trees in Tucson. 
Excessive evapotranspiration occurs when soils are dry and sustained winds  blow at extremely low relative humidity. The high water loss from needles cannot be replaced by adequate water uptake from the soil. Climate change has increased these stresses over the last decade, so now even old, established trees are succumbing all over Tucson. Another factor: irrigation over decades might have leached nutrients from the desert soil and caused an increase in salts, while an ever increasing layer of caliche that further inhibits healthy root growth and water uptake. Temperature extremes are also increasing lately - maybe exceeding tolerance thresholds of the Mediterranean Pines.
But even if the huge pines were aesthetically uncool and also, while healthy, a burden on our limited water resources, they had a positive side: Harris Hawks loved them as nesting trees. 
Harris Hawks are superbly adapted to the Sonoran Desert in many ways. I am pretty certain that it was the pressure of this hard environment that made them evolve into the only social species of hawks: the resident, territorial pair allows several younger hawks to live close by. The hawks hunt as a group, share the kill, and the young 'satellites' help the main couple to raise its young. So an obvious advantage for the resident couple. From the viewpoint of the younger hawks, this altruism is a little hard to understand because genetic tests showed that the hawks are not usually related. So no kinship selection here. But, the entire group can take down larger prey than a single hawk could slay. This may be advantageous as so many small prey animals are night active here. Considering that about 50% of fledgling hawks usually die from starvation within their first year, communal living may give more time for the young guys to become strong adults.  Furthermore,  the younger birds are probably in an excellent position to take over territory if something happens to the owners.   
Free Flight Hawk Group of the Arizona Desert Museum
 Harris Hawks,  because they hunt cooperatively, can afford to be smaller than our other successfully free roosting desert birds of prey, Red-tails, Caracaras, and Great Horned Owls. (Kestrels breed in cavities, Gray, Black and Zonetail stay in riparian or mountain forests, Cooper's adapted well to human neighborhoods with trees).

Who knows who built this nest? GHO do not do it themselves
 But Harris Hawks share their habitat directly with their great arch enemy: the Great Horned Owl.  The owls hunt and slay birds up to the size of Harris Hawks, they rob hawk nestlings and they love to take over established nest sites like the classical Harris Hawk nest in the sturdy bowl of sheltering Saguaro arms. 
A different site, also now owned by the GH owls. Both Picture Rocks, west of the Tucson Mountains
 So Harris Hawks around Tucson may have really benefited from the prevalence of huge, dense Aleppo Pines - I knew at least half a dozen nests that successfully produced fledglings year after year.  I also know of successful owl attacks on some of these nests, but at least in one case, the hawks were back a year later. Maybe the dense pine branches give enough of an advantage to the smaller, maneuverable hawk over the large owl. 
Dead Pines along Sandario Road, still hosting an active nest
 Since we lived in Picture Rocks I saw Harris Hawks around, but although I found Red-tail, Screech and GH Owl, Cooper's, and Kestrel nests, I never found a Harris Hawk nest around here. But I always saw them flying, carrying branches or food,  into two huge pine trees at Sandario Rd. There had to be a nest! But it remained completely shrouded by those dark tree crowns. 
Sadly, this spring the needles are falling, the trees are nearly bare. There is a nest though, and the hawks have not quite given up on it. 
 Today I saw the female sitting on the rim of the nest. - freely silhouetted against the sky. Then she flew down, landed on a power line post, the male joined her and they mated. So the hawks are optimistic, life will go on, even in a dead tree.