Sierra Aconchi Expedition, Sonora, MEX, July 2013, a set on Flickr.We spent four days in the Sonoran backcountry with Sky Island Alliance's MABA Expedition team (Madrean Archipelago Biodiversity Assessment) cataloguing insects, mammals, herpetofauna, birds, and plants. After four days in the field we headed to the colonial town of Banamichi along the Rio Sonora and stayed a night at La Posada del Rio, a restored hacienda along the plaza. It was a great combination of rugged backcountry exploration, camping, work, and then fantastic cultural experiences before heading home.
Easter 2013 exploration - Willow Springs Ranch, AZ, a set on Flickr.A group of friends gathered in the Sonoran Desert over Easter weekend 2013 to celebrate a 40th birthday. The company, food, and chocolate cake were outstanding. The weather was perfect, and to our delight we also were surrounded by beautiful desert wildflowers, found a desert tortoise just emerging from its burrow, and climbed a hill to find a furious flurry of hundreds of spring butterflies "hilltopping."
Hilltopping is mate-locating behavior. Males compete for the best location on the highest hills, patrolling furiously, trying to find the few females amidst a sea of males. Theory is that the "top" males that can ascend the hill and hold the best territory make the best mates.
We observed black swallowtails, desert orange-tips, Sara orange-tips, possible Texas crescents, and perhaps 4 other species.
The experience was pure magic—our blood pressure plummeted and we sat, entranced, surrounded by an aerial dance, exclaiming with delight like children at a circus.
Enjoy a short video here:
Sonoran Desert spring butterfly hilltopping from ConserVentures on Vimeo.
The last week has seen a lot of wildlife drama at Ravenrock.
After a summer pretty much devoid of hummingbirds, two took up stations at our three feeders on Monday (a male black-chinned, and an immature Selasphorus—either a rufous or broad-tailed). On Wednesday two more had joined them, and on Friday morning four more, for a total of eight birds doing full-on battle all around the cottage. Most of them are very aggressive Selasphorus, with the black-chinned holding his own. These guys are so pumped up they even dive-bomb hapless butterflies, who get spun around in the hummer-jet-wash.
We put up a fourth feeder, and have gone from a consumption rate of about a cup a week (including Gila woodpeckers and nocturnal nectar-feeding bats) to two cups every 12 hours.
This morning early, while I was out doing some yard work, I heard a coyote yipping off to the west just below our hill, and caught movement down off the state road. Two, then three coyotes were dashing towards the house at full runs—normally they trot-walk. Then two more appeared, and it became clear these five were chasing a sixth coyote, who ran hell-for-leather straight up the hill and bulleted over our hill just behind our bird-feeding yard. The chasers stopped at the bottom of the hill. In the golden early morning light their pelts were gorgeous russet-and-brown, they were very stocky and healthy-looking coyotes. Seems like we've got two packs having a territory dispute perhaps, with our property in the middle of the contested ground.
Finally, it's not been quiet on the reptile front, either, though decidedly less dramatic. A lovely small desert tortoise kept me company at the clothesline on Wednesday, and also on our walk we passed this lovely horned lizard hunting ants just off the state road. He was so well-camoflaged we nearly stepped on him.
We frequently see dung beetles diligently working the cow droppings around Ravenrock. Earlier this spring we watched six beetles at one fresh cow patty, madly rolling up dung into perfect spheres and then surprisingly quickly pushing it away with their hind legs, usually two beetles to a ball.
But yesterday we found these two just outside the front door to our cottage—and were just enchanted.
Has anyone seen any like this before? To describe them as "adorable" seems antithetical to a dung-harvesting insect, but it's true!
Starting at dawn (when this audio was recorded), they have been singing non-stop all day every day, and when the moon was more full, well into the night.
We have counted sixteen distinct species (at least) that they are mimicking—greater peewee, lesser nighthawk, American kestrel, Cassin’s kingbird, cactus wren, and Gambel’s quail, to name a few.
While we need to confirm it, it seems that they actually do tend to sing time-appropriate songs. For example, one of them sings Cassin’s kingbird's mostly-dawn and -dusk call right at dawn or dusk.
Anyone else notice this same phenomenon?
Photo credit: USGS Patuxent Bird Identification InfoCenter, George Jameson
Update on July 21: one of the birds sang most of the night last night, with a near-new moon and cloud cover.
|Photograph by B.J. Bumgarner|
Asperatus clouds are so rare they managed to escape classification until 2009. Ominous and stormy as they appear, these clouds often break up rather quickly, without producing a storm. As with most other undulating cloud types, these clouds are formed when turbulent winds or colliding air masses whip up the bottoms of the cloud layer into fancy shapes and formations. More common in the plains of the United States (try Iowa), asperatus clouds are at their weird and swirly best during the morning or midday hours after a thunderstorm.
Photograph by B.J. Bumgarner
(via Trebaol of Arabia blog on Tumblr)
According to Wikipedia:
A solstice is an astronomical event that happens twice each year as the sun reaches its highest or lowest excursion relative to the celestial equator on the celestial sphere.
As a result, on the solstice the sun appears to have reached its highest or lowest annual altitude in the sky above the horizon at local solar noon. The word solstice is derived from the Latin sol (sun) and sistere (to stand still), because at the solstices, the sun stands still in declination; that is, the seasonal movement of the sun's path (as seen from Earth) comes to a stop before reversing direction. The solstices, together with the equinoxes, are connected with the seasons. In many cultures the solstices mark either the beginning or the midpoint of winter and summer.
The term solstice can also be used in a broader sense, as the date (day) when this occurs. The day of the solstice is either the longest day of the year (in summer) or the shortest day of the year (in winter) for any place outside of the tropics.Solstice is one of our favorite times of year—in the heart of the Sonoran Desert it's blazingly hot (106 today), incredibly dry (6% humidity), and often windy. But the black-throated sparrows are singing madly, the summer Anna's hummingbirds are arriving back from California, the nighthawks and elf owls are trilling and peeping all night long—and it means the rains are coming, the desert is ready, the anticipation is palpable.
First official day of summer monsoons in the Sonoran Desert (as seen through ocotillo plant). The traditional date for the start is a week away—June 24, or San Juan's Day.
What is a "monsoon?"Some say that's a misnomer, but according to the Arizona State University School of Geographical sciences, the "Arizona Monsoon" begins after a "prolonged (3 consecutive days or more) period of dew points averaging 55°F" or higher." More from ASU:
The Arizona Monsoon is a well-defined meteorological event (technically called a meteorological 'singularity') that occurs during the summer throughout the southwest portion of North America. During the winter time, the primary wind flow in Arizona is from the west or northwest—from California and Nevada. As we move into the summer, the winds shift to a southerly or southeasterly direction. Moisture streams northward from the Pacific Ocean and the Gulf of Mexico. This shift produces a radical change in moisture conditions statewide.
Such a change, together with daytime heating, is the key to the Arizona monsoon. This wind shift is the result of two meteorological changes:
- The movement northward from winter to summer of the huge upper air subtropical high pressure cells, specifically the so-called Bermuda High (H).
These two features combine to create strong southerly flow over Arizona. The southerly winds push moisture north-ward from Mexico. The exact source region for the moisture of the Arizona monsoon is unknown. Researchers have proposed the Gulf of Mexico and/or the Gulf of California as the source regions but conclusive evidence has so far been elusive.
- In addition, the intense heating of the desert creates rising air and surface low pressure (called a thermal low) in the Mohave (L).
|MyRadar iPhone app showing the monsoon action on June 16, 2012|
Here at Ravenrock, black-throated sparrows started singing right on cue as clouds build over the mountains.
- Posted using BlogPress from my iPhone
Anyone else feel fall this morning? In the desert, it is quiet, sneaky. It was nearly in the 60s this morning ~ cool for us! ~ and the sun is mellow golden, the air crisp, with a hint of something other than the 100+degrees days we've been having. Bird migration is underway, we have vultures gathering in large kettles, and orioles, grosbeaks, and hummingbirds moving through in larger numbers.
One of our favorite summer activities is to explore the beautiful ranchlands and wildlife refuge immediately south of Ravenrock—one of the best destinations being West Coast Tank, an enormous cattle pond that fills up (about 5 acres) every summer with the rains. We've had inches of rain, so we headed south to West Coast. But halfway there we had to turn around, because another flooded tank had totally backed up into the road:
We explored a new route around to the east, and discovered some lovely country and lots of little temporary creeks running from the Sierrita Mountains. The desert is bursting green, and the sky was lovely blue, the Baboquivari Mountains a vibrant purple-blue. Lots of new flowers and butterflies, including ghost brimstones and bright yellow giant sulphurs.
We had lunch at the Gadsden Coffee Company in Arivaca, then out to I-19 via Amado, where we saw this sign—rural church humor. Pretty funny.
With the summer rains come our cavalcade of tortoises. We've seen little ones and really big ones; this young guy, a medium-sized one, was ambling down the trail on our morning walk today (on males you can see the hook on the front of the plastron or belly plate, that is thought to be used during 'combat' with other males for territory; the plastron is also slightly dished, to facilitate mating).