Wednesday, May 28, 2014

A Duett of Lesser Night Hawks

The temperature predictions for today were 106F. So we got up at 5:30 am to take the dogs for a walk. The sun was still behind the lonely Twin Peak, but the birds were awake. Gilded Flickers called from freshly opened Saguaro flowers, Western Kingbirds were watching from high spots, the Kestrel pair by the corral was noisily defending their nesting cavity in another Saguaro. Thrashers, Gila Woodpeckers and Cactus Wrens, of course.

When we came to the place where a Nighthawk had tried to mislead me with a broken-wing-display some nights before,  we heard the bird purr, saw it fly up from the ground, to be joined quickly by a second, bigger one, that had been sitting in a tree.

The first one flew slow, swooping loops and circles around the area, the second one followed so closely and moved in such synchronization that they seemed linked as one. This aerial ballet went on fore quite a while. One of the birds was purring continuously, the second one was making complicated, nasal-sounding calls.

The gular (throat) area of the larger pursuer - the male - was white and extended when he called. It's visible in the larger version of the image above.
All over lovely to watch but very hard to photograph against the grey morning sky. Incidentally, it stayed overcast all day and we never reached those record temps.  

Tuesday, May 27, 2014

Trying out a new policy towards rattlers

This one visited at breakfast on the patio today. The dogs raced at him, the Laika She-Wolf  just looked and quietly moved away. Frodo (coydog, bitten numerous times) stood close, but save, pointing. Bilbo ran around but stayed away. Cody, who should know better, barked and tried to get too close, so he ended up in time-out indoors. I hope he is not getting senile.

Packrat that was bitten by a rattler. The snake withdrew at first, then came back 5 min later and pulled it under the wood stack
We used to move all rattlers about a quarter of a mile away, only leaving a couple territorial old guys in their burrows. But they seem to be gone. Lately, we are so over-run with packrats that we are now opting to leave the rattlers be. This one is also a good active 'warner', even a hummingbird could set him off. So now he's curled up 10 feet from our table were the dogs are sleeping again and everything is peaceful so far. I looked him deeply between the eyes: he's a Diamondback.

On facebook, an interesting discussion about dog vaccination and treatment with antivenom developed. Of course I do not have any great answers, but at least some experience.
Here is one of the exchanges:

Terry D:
Your dogs all get the vaccine? First year I did for both mine.

Amy D:
I thought if your dog gets bitten it could die? That's why I started getting the anti venom shots. What is the truth about bites and dogs as a rule ? I know as a nurse at the hospital people get admitted right to Icu nowadays then down to the cardiac floor depending on age.

My opinion:
Generally, humans seem to be more sensitive than canines and cats. Wolfs and especially Coyotes probably had a long time to evolve with exposure to rattlers. Immunities do develop (evolutionary), as shown in prey species (Texas A&M). The validity of 'vaccine' has not been proven too well. 
My 5 dogs got bitten about 8 times in our 12 years here. The females and one male never, the oldest male once, the youngest, the coyote mix, 7 times. 

3 of our older dogs were also snake trained with electro-shock collars  and live snake exposure, but one of them was bitten right afterwards. 
The coydog was fed snakes by his mother in the den where he was born, I found the rattles.

We used antivenom once, iv overnight infusion of fluids twice, antibiotics several times (those snake teeth are full of germs). Anti venom after the bite may counter-act organ damage caused by the heamolytics of the snake venom. 
The coydog was treated after some bites, but not after others. He always had strong facial swelling, so none of the bites were dry-bites, but he always recovered after about 6 hours. Several times, he didn't even reduce his activity level and ept playing and eating, but was always very tender in the bite area. The last bite got him in the sponge of his nose and he wined. After that, he finally left the snakes alone, and he is a good, reliable 'snake-barker' now. But Amy mentioned age. And she is  right, that is a worrisome factor. My oldest male dog reliably stayed away after training, one bite and treatment (10 years ago) but he now seems to become forgetful and more grumpy...senile? All I can do is to keep him indoors during main snake activity, because I am afraid that a bite might be much worse for him now. 

It needs to be said that not all rattler venom is the same. Most individuals produce a 'cocktail' of venoms. There are heamolythic and neurotoxic components and the mix is evolutionary linked to the immunity that may have developed in prey species. So far, neurotoxins seem to be more prevalent in Mojave Rattlers than in Diamondbacks. The available antivenom blocks only haemolythic components. The neurotoxins, if present, would kill too quickly for any intervention anyway. Hence my attempt to correctly identify the snakes that are left in the immediate vicinity of the dogs.

There is the idea that younger snakes are more deadly than older ones because they have not yet learned to get the dose just right, so they inject always all their venom. I'm not so sure. I have seen big old rattlers bite a mouse which then just fell over and was dead. I watched a younger, smaller snake strike at a young packrat and the rat screamed (for minutes it seemed) before it finally died. The snake actually went into hiding and came back later to retrieve its prey.
 So the older snake must have administered a more potent bite. Of course, defensive bites may be different.     

Wednesday, May 21, 2014

Beetle Breeding

Two years ago, my young Japanese friends from New York came to collect some Hercules Beetles (Dynastes granti) that they wanted to breed. They got eggs, also a few larvae, but had no luck raising them. They complained that in the US, unlike Japan, there is no good breeding medium commercially available.

Strategus cessus
So last year I decided to start my own beetle farm, mainly to try out a recipe for a breeding medium that I got from a friend. It started with oal pellets for the barbeque and involved a lengthy fermentation process. I started early. Then everything was set up at the beginning of July and the only big dynastinae that were around that early were Strategus cessus from Madera Canyon. So I tried the method with them. The beetles not only produced eggs, but the eggs also hatched very quickly, by mid August. The larvae were voracious and grew quickly.

second instar larvae in September.
When I proudly posted baby pictures on facebook, I was told that these larvae had not been formally described. The species is more localized than the other Strategus species. It only occurs in Arizona, New Mexico and NW Mexico. Also, they lack the impressive horns that the males of most other Strategus species sport, so I guess collectors are much less fascinated with this species. Anyway, Brett Ratcliffe at the University of Nebraska was happy to write a scientific paper about them. So I sent him a few larvae to be preserved at different stages for description.

Pre-pupal S. cessus larva below and two still growing S. aloeus larva on top (December 2013)
My S. cessus larvae got rather big but around Thanksgiving they stopped feeding. Instead they became very agitated, one actually escaped from the container. They were obviously searching for a pupation spot. Or did they not want to stay in the old medium to pupate? Fungus gnats and worse, mites, were contaminating the containers by then, and I already knew that the pupae might be vulnerable to predation where the sturdy larvae had survived just fine.

Larva in the pupal chamber, photographed through the wall of the container

So I got clay, first from my mother-in-law's backyard, and when that didn't work, from Madera Canyon. Finally the larvae settled down and buried themselves deeply. Three of them stayed close to the transparent walls of the container so I could watch their progress. Except there was none. All winter long, and through March and most of April, the big larvae were just sitting in their pupal chambers, if that's what they were. Occasionally they turned over. They seemed to loose volume and became more opaque than before, but for months nothing else happened. I began to wonder if they might need a cold stimulus. Then, in April, I could see one pupae, but it soon darkened and died. Brett checked the ones he was keeping in Nebraska at this time, and they were dead as well. Still, one larva was holding out and one was hidden from sight.

S. cessus pupa lying on its back

On the 19th of May, the visible larva had changed. It was either dead or? I decided to dig it up. When I broke through the hard crust of the pupal chamber, I found a healthy, gold brown pupa and the empty last larval skin. This one will go to Brett to complete his collection of developmental stages.

eclosing beetle
When I dug out they other chamber, it contained a beetle that was just about to eclose, to break out of the pupal skin. Head, thorax and front legs were already black and shiny with hardened exoskeleton, and the front part of the pupal skin had come off. But the pupal skin which had become transparent and brittle, still covered everything else. The wings were still soft, white, uninflated and folded forward towards the underside (ventral). The abdomen was bigger than in an adult beetle, containing the fluids necessary to break open the pupal skin in back and inflate the wings.  
Insects are soft and vulnerable at this stage, so I carefully placed the beetle back on the clay. I assume he would need a rough surface to find traction for the now rather functional front legs to pull away from the rest of the pupal exuvium.

teneral beetel with pupal skin, exuvium
When I checked again a few hours later, the wings were properly folded back, the front ones (elytra) covering the membranous Hind-wings. They were still white and teneral, the abdomen still too big, but it already looked very much like an adult beetle.  

 For several hours the hardening and darkening process of the exoskeleton progressed. This what it looked like at 11 pm.

I the morning a perfectly hardened and dark beetle was trying to bury himself in the clay again.
I kept the containers with eggs and larvae in our basement in the water heater room, where it's dark and the temperature never changes dramatically.  I do not know where the beetles get their input about the seasons. I am raising 3 species now, and they all seem to have their own, species specific rhythms.  Strategus aloeus beetles, of the three-horned species, laid their eggs much later than their smaller relatives S. cessus. Then the larvae grew faster, buried into the depth of their containers and pupated. There was no great winter pause. Right now, in May, they are all resting as pupae.

Dynastes granti larva, much larger than the S. cessus larvae, with a darker head capsule and darker setae
 The Dynastes granti females laid eggs all the way till late November when the last of them died. The eggs then rested through the winter and the first viable larvae appeared in late January. Eggs that were laid late also hatched last. All Dynastes granti larvae are still feeding and growing.

I assume that in nature the freshly hatched S. cessus stay buried in their pupal chambers until the first strong monsoon rain wakes them up. I have seen mass emergencies during those early storms twice in Madera Canyon. The beetles mate then and their flight period does not last very long. 

Saturday, May 17, 2014

Snake encounters

Lots of snake activity today, but no good photos.
This morning my dogs reacted to a loud keening noise and stormed to the side of the yard where our fire wood is stacked. I heard the buzz of a retreating rattler and found a dying packrat. Cody and Frodo were so excited that I had to pull them away. I wanted to watch the rattler come back to its prey, but I got distracted until I heard Frodo bark again. I arrived to see the rat, pulled along by the snake, disappear under the wood pile. The snake, probably a Diamondback Rattler, had moved into the packrat's nest. The packrats themselves are very disruptive neighbors, so we will try to let the snake stay and hope nobody gets bitten except the rats.

Gopher Snake tracks

Crossing the dirt road to visit our neighbors, we found the tracks of a big Gopher Snake that had crawled into a squirrel hole. This snake must be huge and heavy judging from the deep undulating imprints. (Diamondbacks move in a much straighter line)

 In the late afternoon I took the dogs on a walk into the state land next to our property. This should have been the first 100F day of the season, but the sky was slightly overcast and it never got quite so hot. Zebra Tail Lizards were hiding under a thin layer of sand and kept jumping out right under the dogs noses. The dogs are getting old and experienced by now, and Cody has pretty much abandoned the chase. He used to be so intend that he'd jerk the leash from my hand and jump right over the creosote bushes. Young Jackrabbits were zigzagging between the shrubs, taking Laika and Frodo with them in break-neck pursuit.

Sidewinder Rattlesnake, Photo by the late Young Cage
Suddenly there was a quick motion in the sand, and both Cody and Bilbo tore towards it. I heard the buzz from a small rattle. A small, light colored snake was launching itself backwards, nearly flying over the sand. Only the head seemed to stand still, focusing slit-pupiled eyes on me. And there was a little horn over each eye - a Sidewinder, my very first! I got no photo because the dogs were misbehaving and getting much too close. They seemed to know that this was no Diamondback. The snake headed backwards straight to a hole in the ground and disappeared.
Picture Rocks is at the eastern border of the distribution of this sand-loving species. I know that they have been found in Red Rock and along the Santa Cruz River bed.
This is the 4th species of rattlers in our direct vicinity. Diamondbacks are the most common, followed by the occasional Mojave and so far a single Tiger Rattlesnake in our wash, and now this Sidewinder.

I have been watching more and more Desert Iguanas over the last years, while the numbers of Ornate Tree Lizards and Spiny Magisters seem to be declining sharply. It is a if the warming climate and the prolonged drought are pushing western species from the infamously hot Yuma Dunes deep into our area.

Friday, May 16, 2014

Backyard Black Light in May

At the beginning of the arid, hot pre-summer in the desert, our moths are small but intricately patterned

Graceful adult Antlions hang around, recently emerged from the pupal stage of pit-trap building, ant-eating doodle bugs that gave the group the name.

The Running Crab Spider is probably a harmless neighbor for the Darkling Beetle Eupsophulus castaneus. The beetles mate  is a tap dancer. He uses his whole body, not his feet, to produce a 'tatatptaptaptap' that can be heard several feet away.

Darkling Beetles of the genus Triorophus emerge covered in a waxy blue layer that wears of as they age.

A male Glowworm Beetle, Distremocephalus opaculus is winged and has feathered antennae, but no functional mouth parts. The larva-form females may, like the larvae, feed on millipedes. The Twirler Moths, Faculta inaequalis, may be  responsible for the tubular webs that I noticed a couple of weeks ago around the twigs of Palo Verde.

Checkered Beetle Enoclerus quadrisignatus

 Pseudopamera nitidulain the family of the Dirt-colored Seedbugs. Really? Dirt-colored?

Apatides fortis (Horned Powderpost Beetle). We leave dead trees lying around so all borers, cavity breeders (bees), macro-shredders and decomposers get their natural turn. Just before the dead wood finally falls victim to termite activity, there are still Bostrichids like Apatides emerging from their big, saw dust filled tunnels. Once I placed freshly wnd broken Palo Verde branches into a tight box to catch everything that emerged.  First I got buprestids and a few cerambycids. But up to three years after the wood was sealed in A. fortis still emerged. So the female had not oviposited  on very old dead wood. The development of the larvae just took so long.

Cyclocephala longula, Acoma sp. and Hybosorus illigeri
 On 5/16 the night was quite warm (daytime temps close to 100F) and it was slightly overcast. The summer scarabs began to appear, especially Acoma emerged in great numbers. Males only. I've never found a female. Hybosorus illigeri is a Scavenger Scarab Apparently introduced into the U.S. prior to the 1840's from Europe

I'm feeling watched; Ground mantis

Mediterranean Gecko
Sonoran Desert and Red-spotted Toads are faster at my black lights than I. They can live for more than 20 years. So they are probably old acquaintances from all those years of bug collecting at our garage wall.

Monday, May 12, 2014

The Red Tail Hawks have left the nest

Today, our morning walk began with a Harris Hawk on the telephone pole by our gate.

In the state land, the dark Red Tail female was perched on a blooming saguaro far east of her nest, but greeted us just as aggressively as always. Click here to follow this years brood from the beginning

Doesn't she look great with her wings spread wide and the morning sun behind her?

And now she's coming at me. Screeching constantly. Why?

That's why: one of the chicks is out there. Not quite a third of a mile from the nest, but he must have been flying to get this far. He seems to be the smaller of the two youngsters. The nest is empty, no idea where the other chick is, hopefully around somewhere.

Randy kept his distance from the hawks and gave Frodo and Laika another good brushing

A last look at the nest two days later: Mom is still scolding Cody and me, but the young ones are hidden somewhere, close by no doubt.

Saturday, May 10, 2014

Just some Backyard shots from May 2014

Foothills Paloverdes at our neighbors' palapa are in full bloom and buzzing with bees.

So are the saguaros flowers
 I am happy to report that there are at least as many native bees as honey bees. Here is a Diadasia sp. malejust arriving, several Perdita Bees and on the out side some kind of a wasp. As for pollination, I think birds are doing the best job here, as we don't seem to get any nectar bats.

Our Ironwood trees are loaded with flowers this year

Many different species of Chollas are spectacular and very colorful. But we've certainly had years with more flowers.

This night-blooming climber came as a seed from the desert museum. Between javelinas, packrats and bunnies, it never seems to reach climbing length here, but so far its circumference rivals that of the young mesquite tree it's leaning against.

Most of my potted Trichocereus cacti bloomed while I was in Mexico. But I got to see a few stragglers. Very pretty this year.

Quail couples are still showing up with very young chicks. Here the mother has to rebuff the advances of a bachelor male

This guy was trying to claim the area around the bird feeder as his territory.  A sisyphean task. He was panting heavily even though the temperatures had dropped to the seventies for some days.

Many quail chicks have out-grown the phase of tiny cuteness and are now big enough to have better chances of survival.

Lately javelinas found their way under the dog fence. Frodo and Bilbo sit meters away, restrained by their electric collars, and watch them munch at quail block and nursery cactus

When there isn't much left, some try to hog it all to themselves

This female Solfugid turned up right next to Randy who likes sitting  on the floor in the living room when we watch movies. She seemed to share our taste for old BBC stuff. It figures: at over 2 inches, she has to be an older lady.

 Ironwood and Saguaro in bloom: This year they overlap beautifully and the Foothills Palo Verdes are still contributing their subtle yellow glow. A beautiful spring