Tuesday, February 28, 2017

Animals in their habitat: Burrowing Owls

Animals in their habitat: 'Burrowing Owls'. These little long-legged owls are fun to watch and don't seem to mind posing for photos and sketches. They like to take over burrows of rodents or just irrigation pipes, so they can be found in the Avra Valley fields where Pima Cotton is grown (hence the uninspired background). But they are versatile and according to literature once lived in all open spaces of the Americas (not in the tundra, though, I'd guess). They are day active b...ut do most of their hunting at dawn and dusk. They perch and swoop or just jump and run after insects, lizards and small rodents, occasionally birds. Supposedly they bring cattle dung to their nest to attract dung beetles. But I know dung beetles: they like it fresh. So I doubt that interpretation of the behavior. Another behavior seems easier to understand: from inside their burrow, incubating females often make hissing and rattling noises very similar to that of a rattle snake. Rattlers also sleep in burrows. So the imitation seems like a good sound-based Batesian mimicry that might keep a badger or coyote from getting too inquisitory.

Monday, February 27, 2017

Animals in their habitat: Gamble's Quail

Gamble's Quail Family. This species lives in the creosote and Saguaro areas of the Sonoran Desert. We have Mearn's Quail in the south eastern canyons and Scaled Quail in the grasslands further east. February is a little early for chicks, but at last weekend's art show, prints and note cards of this image sold out very quickly. So humans are eagerly waiting for spring, The male quail are also getting all territorial and sit on their perches calling 'ChiCAgo!' for hours. During most of the year, quail live very socially in coveys - probably related groups of siblings from those large clutches. Quail mothers lay 10 to 18 eggs in a protected hollow under dense vegetation or in a suitable flower pot. Not much nesting material is used. The hen does not incubate before she is completely done, and at one egg per day, this takes a while. Dangers lurk: snakes, Gila monsters, Roadrunners, Ravens, Coyotes, all love to gobble up a whole clutch. But if it works out, all chicks hatch at the same time. They are extremely precocious, fully feathered and able to follow their parents after only a couple of hours. The group does not return to the nest. Both parents are vigilant guardians, and the kids stay together instinctively. The chicks not only grow amazingly fast, they can also fly long before they are fully grown. The breeding season is long: groups of chicks can be seen from late March to late August.

 Like many desert-dwelling species, Gambel’s Quail populations undergo a “boom-and-bust” cycle. A year with ample winter-spring rainfall that generates lots of green vegetation will yield larger clutches and an abundance of chicks. Dry winters mean less food and lower productivity. So this year, we are expecting huge rows of chicks to follow their parents around!

Thursday, February 23, 2017

Animals in their Habitat: Elegant Trogons

'Habitat' includes of course the geologic base (soil and profile), the resulting plant society, climate and geographic location. But the animal neighbors are as important. They are part of the food chain as prey or predator and, usually most importantly, compete for the same resources or provide them, like food and nesting cavities. In this painting after my very first observation of Elegant Trogons in Madera Canyon (1994), I posed them and their neighbors in a thicket of Sycamore branches, Ferns and Columbine flowers. So I considerably shrunk the distance between canopy and forest floor in my imaginary world.

I think back then, Trogons, who reach the northernmost point of their distribution in SE Arizona, only migrated north for the breeding season. Trogons are primarily occupants of tropical forests, but as omnivores, they are somewhat adaptable. They glean the brush for insects and they love the berries of the Madrone tree, but they do not refuse those of introduced Pyracantha shrubs. In spring, the pair raises 2 to 4 chicks in a tree cavity, and Sycamores seem to provide the most desirable ones. Nowadays Elegant Trogons can be seen year round in SE Arizona's canyons and riparian areas.

Monday, February 20, 2017

Animals in their Habitat: Coatimundis in Sycamore Canyon

A couple of weeks ago, I was lucky enough to watch a single Coati foraging under the bird feeders of Madera Canyon Lodge. That reminded me of a quite dreamlike experience from my very early days in Arizona. I was camping in Chiricahua National Monument with a group of friends. I woke up early and peaked out of my tent.. The young bright white sycamore trees were too thin to block the rays of the raising sun. While I was drowsily squinting, the trunks seemed to sway and move. But as soon as my eyes adjusted, I recognized that the moving things were actually the straight-upright tails of a gang of coatimundis. They hung around for a while, chattering and sniffing noisily under rocks and branches that they seemed to move with their little hands.
White-nosed Coatis, Nasua narica, are related to Racoons. Our Arizona coatis are the northernmost ambassadors of a genus that is widespread in central and south America. They are day-active omnivores with a taste for insects, lizards, roots, fruits, nuts and eggs. They are very fond of fruit, especially manzanita berries. Normally, they weigh from 10 to 25 pounds, but the ones at Madera Canyon look like they are quite a bit heavier.
Coatis mate in early spring. A litter of 4 to 6 young is born after a gestation period of about 11 weeks, usually in a den in a wooded canyon. Coatis usually stick together in groups of one half to two dozens, but lately a group of 40 was observed in Ramsey Canyon in the Huachucas. Although they seem to like woodland and creeks, they also sometimes appear in the backyards of Oro Valley and Tucson.

Sunday, February 19, 2017

Animals in their habitat: Acorn Woodpeckers in Madera Canyon

 Acorn Woodpeckers in Madera Canyon. The creek was running underground at the time, as it does during longer and longer periods each year now. When water is a limiting factor, artificial water sources become a big draw for wildlife.
Acorn Woodpeckers don't just look like clowns. As the only social woodpecker species (that I am aware of) they are given to a lot of very entertaining antics from the human point of view. And they are smart. I'm sure these two were discussing the idiot who had closed the valve so tightly
The old little drinking fountain at the Lodge fell victim to the parking lot extensions years ago. The dated Tucson-insider title was 'CAP' Water?' An engineer from Tucson Water bought the painting

Saturday, February 18, 2017

Desert Animals in their habitat: Backyard Hummingbirds

Costa's Hummers stay year round in our backyard and the males fiercly defend their territories, often in form of a particular feeder and pearch nearby. February is already mating time and nest-building time for the females. The male accompanies his flight display with a long, piercing whistle. In our backyard, Aloes introduced from South Africa are blooming. While they are mainly ignored by local insects, Hummingbirds, Orioles (and Honey Bees) are less fussy and enjoy the early nectar board.

 Anna's hummers are also in their nuptial best right now. Gorget and forehead are shimmering in metallic colors from purple to orange and green. depending on the light refraction.  Much of their mating song is produced while sitting on the highest point of a Mesquite tree. Anna's only lately became year-round residents of Arizona. Garden flowers, feeders and decorative water features enabled them to do so - one of the species that benefited from the transformation of pristine desert into suburbia.

Friday, February 17, 2017

Desert Animals in their habitat: Urban Doves

 Mourning Doves are so adaptable. They breed on top of sun exposed cacti in the pristine desert, but I also had a pair in the tiny patio area of my very first Tucson apartment. They raised their 2 chicks in a flower pot and afterwards started right over - up to 5 times a year. I called the painting originally ' Keeping an eye on the alien'. At the time my I was on a J -Visa and and frequent questioning by border patrol agents was still upsetting to me. But when I entered the painting in a show, it was rejected. Later it won an award in a different setting. Go figure. I had changed the title, but that may not have been the reason.
As an afterthought: Today, but not in the early nineties when I painted this, our local doves, Mourning and White-winged, really have to compete with alien invaders. The Eurasian Collared Doves are pushing them out of several prime nesting sites in our backyard as we speak.

Thursday, February 16, 2017

Desert animals in their habitat: The Owls of Sabino Canyon

To me, this is also a painting of wildlife in its habitat. If you can't see it, close your eyes and listen. There: the hooting call of Great Horned Owls. I have never hiked the area at dusk without hearing them calling to each other. In fact, a Native American friend who was often with me felt their presence so keenly that they made him uncomfortable (I did talk him out of it). Why is it that owl...s have such a bad reputation in many traditional cultures? When I was a kid in Germany, my mother thought that owls might have been drawn to windows that were illuminated at night and in the old times that often happened when someone lay sick or dying. So they were thought of as harbingers of death. Anyway - I'm glad we moved away from those superstitions and can enjoy our owl sightings now. Not all old traditions are to be cherished.

Wednesday, February 15, 2017

Painting of desert animals in their habitat: Racoons

 'At Night at Sabino Creek'. Often I just find the left-over shells of crayfish in the morning, but lots of five-fingered prints tell the story. The clear, cool water shows the gold-brown color of tannins from decaying oak leaves: this creek originates high in the Catalina mountains and can tell of snow melt and towering Ponderosa Pines, rare Arizona Cypress, Live oaks  and Aligator Juniper, and finally Saguaro Cactus and lush Cottonwoods. 

Paintings of Desert Animals in their habitat: Jack Rabbit

In an effort to brighten up social Media with art postings, I will regularly post some of my watercolor paintings here and on my Facebook page.  Hopefully they'll all have some appeal to the naturalists among us as well 

We ( Jack Rabbit and I) live in the Sonoran Desert. It's not bare like the Sahara, but not usually covered in grass, either. Except after really good summer monsoon storms. A carpet of little Cheat Grass plants covers the creosote flats. But the life cycle is short and soon they are producing awfully sticky seeds.  By then the grass itself is bleached and golden until the wind blows away every trace of it. The painting was mainly about this: the short golden grass in the sun. But the Jack rabbit was there and made a great center of interest for viewers who are less intrigued by temporary Cheat Grass lawns.

Friday, February 10, 2017

Santa Rita Mountains, February 2017

Yesterday morning I finished my 'Coyote Prowls' and then headed south for the Santa Rita Mountains. More about the painting in my watercolor blog.

After a rainy January, the weather has turned sunny and gorgeous. With all the early precipitation, we don't even have to feel bad about it. The mountains, covered in last years dead grasses reflected the sun like fields of gold, nicely set off by the blue shapes of Mount Whrightston  and Mount Baldy.

I could see snow on the higher elevations, but down in Box Canyon the temperature reached the high eighties. I met a naturalist friend and we looked for insects: He found interesting syrphids. The antennae of the males were shaped like bundles of feathers. Copestylum (Hiatomyia) plumosa? I got no photos, too bad. I hope to go back for them.

The creeks were gurgling with clear fresh water. No bugs except some Water Striders.  Bonewhite Sycamores rose ghostly in the early evening shade of the canyons.

Several dark butterflies were flying around: Mourning Cloaks, Bordered Patches and Pipevine Swallowtails. Does their dark coloration give them enough thermoregulatory advantage for an early start? 

 Already, Desert Broom was attracting scores of wasps.  These are potential queens of Paper Wasp species that overwintered, I assume. Like every year in spring, I'm confused - their coloration differs from that of the workers I'm used to seeing in summer and autumn.

 At Madera Canyon Lodge, a Coatimundi visited the bird-feeder area. He seemed well-fed, content and rather tame. Probably not a great situation, but I did enjoy watching him for a while. 

White-nosed Coatis in SE Arizona are the northernmost ambassadors of the south and central American genus Nasua (in German Nasenbaer). They are Racoon-related omnivores but more day-active than those (less hunting pressure, historically?. They feed on insects, lizards, roots, fruits, nuts and eggs. They are very fond of fruit, especially the manzanita berry, and obviosly don't dislike easy-picking bird seed.

  On the way home, the grasslands glowed even more and mountain shadows undulated. It's hard to decide which photo to choose.

P.S. In the meantime I found several Flickr posts of the little group of  Coaties at the Madera Canyon Lodge. I was quite dismayed to see how very obese at least one of the three regulars is.  Feeding wild animals is illegal in Arizona. But feeding birds is exempt from this law. In fact most birdlovers still believe that they are doing a commendable service to the birds. As a biologist the only value that I can see is that people might get interested and feel protective about more than just hummingbirds. Also,  for the lodge and several B and Bs in Madera Canyon the bird feeders are an intrinsic part of a lucrative business and beloved by so many visitors that it would probably be impossible to end this practice. But the feeding and overfeeding of the coaties is problematic. The feeders are alraedy positioned pretty much out of reach of even good climbers.  I hope there is a way (and I will raise the issue) to keep the spilled birdseed from reaching the ground.

Saturday, February 4, 2017

Dung Beetles - important for environment and agriculture

Scarab beetles are one of our largest and most divers beetle families. Most Arizonans are quite familiar with the day active Green Fig Beetle and smaller brown beetles of several  genera that tend to accumulate around porch lights and are often just called June Bugs.

Hercules Beetle larva

 Gardeners among us usually hate the white, c-shaped, fat grubs of scarabs that live in the ground and supposedly feed on the roots of your favorite plants. Some of them might in fact do that.

But most scarabs are decomposers, and therefore very important for gardening and agriculture. Their grubs feed on dead plant material that they digest with the help of bacterial symbionts in their widely extended guts. Hence the impression that they are fat. The strong mandibles of those often very large grubs are able to break down decaying wood and leaf matter, utilize amazing amounts of material,  and thus open it up to smaller decomposers, and finally fungi and bacteria. So eventually the nutrients will again be part of the garden soil and available for uptake by plants..

  Among scarabs, dung beetles have evolved to break down the feces of larger animals. The importance of this 'service' can hardly be overestimated.  Obviously, they are removing waste that would otherwise pose a serious health risk. For example, dung beetles help to remove harmful pathogens like E. coli from soil. But if you consider the amount of dung that  big herds of  grazing animals produce, you'll understand that the mere accumulation of this dung would eventually cover so much surface that the grasses that the herds a feeding on would be displaced by a rather sterile crust of dung.

Dung Beetles of the genus Phanaeus
Beetles in the genus Phanaeus are 'tunnelers'. They excavate tunnels beneath the very fresh dung pile and lower a portion of dung down into the ground below. There, the female will lay an egg in the brood ball and seal the chamber. The larval beetle will feed on the dung as it grows until metamorphosing into an adult and emerging.

Dung Beetles in the genus Canthon are America's typical dung rollers. With their shovel heads, they cut a spherical dung portion from the fresh pile. Most of this work is done by the male. The resource is limited, though fights between rivals happen often. A female joins a successful male, often sits on top of his prize as he rolls it in a rather straight line away from the competition. They bury the dung ball and in the underground chamber she lays an egg on it.

Although there is no longer a source in the US to buy dung beetles of any type, historically, the U.S. government sponsored dung beetle introduction programs. When the local dung beetle population did not seem to be able to handle the waste of Texas' huge Cattle herds, Digitonthophagus gazella (Gazelle Scarab) was brought in in the 1970. Of Indoafrican origin,  it is now perhaps the most widespread dung beetle in tropical and subtropical pastures. (Noriega et al. 2010).  Euoniticellus intermedius was brought to Texas from Africa. Thus dung beetles from traditional feeding grounds of big herds were introduced.  I do not know why dung beetles were not brought in from old buffalo grounds like the midwestern prairies, but instead from Eurasia and Africa. Maybe the introducers thought them more suitable for the Texas climate. The beetles proved invasive. They quickly spread throughout most of the southern U.S. 
Digitonthophagus gazella (Gazelle Scarab) and Euoniticellus intermedius, both introduced
 The introduced species are doing their job. They propagated so successfully that they are found all over Arizona by now. In fact, by now most larger dung beetles we find are of those two species. It is difficult to tell if this is harming the populations of endemic species that they compete with, but it is hard to imagine that they wouldn't. My impression is that the  two introduced species are generalists that can deal with nearly all types of soil, dung types, and exposure. They also find dung sources fast and at great distance and fly well enough to quickly move into new areas.  Where we live, for example, grazing is so poor that cattle may only be brought in every few years. Phanaeus and large Canthon species never show up, only all kinds of small Aphodines plus the two imported medium sized species depicted above.  Our endemic large Canthon imitator, the smaller Canthon indigaceus and the three Phanaeus species seem be more discriminating in their choice of habitat and not so fast at pioneering new spaces.