Tuesday, January 17, 2012

Of Cactus Flowers and Fruit

The flowers of chollas, prickly pears, saguaros, queen of the night and barrel cacti are strikingly beautiful but delicate and very short lived. If an individual bud opens in the early morning or even at night the flower will begin to wilt by noon with raising temperatures or even as soon as it is pollinated. If it lasts till nightfall it will most likely not open again the next day. There are cacti which go through their whole annual blooming cycle within one night and a short morning like the night blooming cereus, but most species produce enough successive flowers to keep the bloom going for a week or more. It doesn't matter how long it lasts: the bloom of the Sonoran desert cacti is a beautiful spectacle that we celebrate every year. It is also a reliable fiest: the succulent cacti are able to faithfully produce flowers even in drought years when the showy and celebrated annuals of the desert like poppies, lupines and Owl Clovers have to skip the year.

Santa Rita Prickly Pear: Only a few of these pears will ripen.
At least some rain is necessary for the cacti to follow the bloom with the more costly production of fruit. If it doesn't rain enough for too long even the fertilized flowers will just shrivel up and fall off. But in years of at least average rainfall the fruit of our desert cacti are not only at least as beautiful as the flowers but many also last much longer.

Saguaro Cactus
Carnegiea gigantea - Saguaro Cactus
After the bloom in June, Saguaro fruit grow very quickly. They stay plain green on the outside. But as soon as they are ripe in late June they burst open to form a bright red star that advertises the sweet pulp and thousands of tiny seeds to birds and insects.

StellaTucker (Tohono O'odam) harvests Saguaro fruit by pushing them down with a 12 foot pole made from Saguaro ribs
Generations of Tohono O'odam have collected the fruit to brew ceremonial wine. Midsummer dances of this tribe are a plea for good, life spending monsoon rains. By the time the storms arrive, Saguaro fruit are usually gone from the cacti and the seeds distributed by everybody who enjoyed the sweet snacks.


Mammillaria grahami - Arizona Fishhook Cactus
Pretty much exactly 8 days after each summer rainstorm all our tiny Mammillarias wear crowns of pink flowers. Shortly later they produce small red-pepper-like seedpods. Just the right size to be carried away whole by Trashers, Cactus Wrens, Squirrels and even ambitious Harvester Ants.

Night-blooming Cereus

Peniocereus gregii - Arizona Night-blooming Cereus
The beautiful Queen of the Desert Night chooses a warm night in June or July to open its flowers and fill the desert with its sweet heavy fragrance. Mysteriously, all plants in a certain area appear to be synchronized, while other groups, at only about ten miles distance, follow their own internal signal. Temperature, moon phase or humidity seem of little importance, or their interaction is so complex that I don't understand their impact. Anyway, every year I scout for new plants in the desert around our place during this spectacular night. This cactus is thin-branched and much less succulent than others. Instead, it has a big underground bulb to support it during drought years. Some plants dry up completely and rest for years before they thrive out and bloom again.
Elongate big fruit develop from the pollinated flowers. This year the Pima County gardener asked me for seeds, so I covered a fruit with a paper bag. While the woodpeckers made holes into the other fruits and harvested the seed pulp in mid September,  the protected one kept growing until I lost patience in late October.

Prickly Pear

Opuntia engelmanii - Engelman's Prickly Pear
Desert Tortoise Photo by Doris Evans
Prickly pear Cacti bloom in late March and their fruit grow and ripen up to the end of summer. In good years a big Engleman's Opuntia can produce many pounds of purplish plum-sized 'pears'. They sit in tight decorative rows on the pads until in late September finally Gila Woodpeckers, Fig Beetles, ants and bees dig into the juicy flesh. Fruit that fall off are gobbled up by Desert Tortoises and Havelinas. Our neighbor boils prickly pear juice and jam, mustard and salza in big purple stained pots. With the harvest of the prickly pears, the bounty of summer is mostly gone.

Barrel Cactus

Ferocactus wislizeni - Arizona Barrel Cactus
Cacti that produce their fruit later in the year tend to hold onto them throughout the winter months. A bright yellow crown of fruit on often shoulder-high barrel cacti is a great sight when all other desert colors are rather drab. The fruit are nestled among formidable hooked thorns. Only the most daring squirrels and woodpeckers break some of them loose before their time.

Barrel Cactus seedlings 
The cactus is holding on for a good reason: The seeds, though ripe, will not germinate when it isn't warm enough. We spread seeds last year in December on moist sand in a container on the window sill, and they were just sitting there through the winter to finally produce little cacti at exactly the same time as some other seeds that we put out in March. The March seeds germinated after three weeks in the sand box.

Cholla Cacti

Cylindropuntia spinosior – Cane or Walkingstick Cholla
Cane Cholla fruit also stay on the plant during the winter months. Their bright yellow color stands out against the clear blue sky. Winter visitors often insist that they saw blooming cacti on their hikes in December.

Chain Fruit Cholla - Opuntia fulgida
The Chain-Fruit Cholla drives holding on to its fruit to the extreme. It simply never lets go, so after every blooming season more fruit are added to the ones already hanging on the branches, forming long, dangling chains. I have to cut one open: I doubt that there are seeds inside. Instead, those green fleshy members increase the photosynthesis-surface of the cactus just like leaves would. This cactus is one of the jumping chollas, and spreads its offspring by enlisting animals and people to carry broken-off pieces into new territory (zoochory). This vegetative propagation produces clones of the originals, rather than new plants. 

Christmas Cholla - Cylindropuntia leptocaulis

I like the fruit of the dainty Christmas Cholla best. Unassuming but pretty little star flowers appear in late summer, and the fruit cling to the thin green branches like red holiday decorations just around Christmas. They are juicy and sweet like strawberries. Of course, they don't last too long when they are ripe.

Tuesday, January 10, 2012

Water and Song Birds at Sweetwater Wetlands in January 2012

On January 7 2012, I joined the Sweetwater excursion of the local Audubon Society led by Janine Spencer. Thank you Janine it was a delightful morning! It was cold and sunny, so the light was beautiful but the contrasts were a bit harsh.

A Solitary Sandpiper poked through the mud, just one individual, but he turned up several times very close to the trail and the bridge, so I even got a video.

Hundreds of ducks, mostly Northern Shovelers were asleep along the banks or just waking up to preen themselves. The photo above is meant as a little puzzle. Can you find a pair of American Wigeons, Northern Pintails, a Ring-neck, and a female Mallard?

 This shot of a subtly patterned Gadwall is on of my favorites. I just read a quotation from an old-time hunter who called it ' just a gray duck, nearly to be ashamed of, far inferior to a Mallard' To each his own!

We also saw Ruddies, some Pied-billed Grebes (above), a Moorhen and of course many American Coots. A Sora Rail could be heard but not seen.

Sliders were basking - it got soon quite warm. I felt in my down west, carrying two cameras and binoculars.  At this time there seemed to be sufficient thermal up-drift for the local Harris Hawks to make an appearance.

I finally got a shot of one of the rats that scurry in the salt bushes. I had to consult Rich Hoyer's blog for the species id: It's an Arizona Cotton Rat (Sigmodon arizonae).

Scores of small song birds around the little pond right at the parking lot. Yellow-rumped Warblers were the most lively and numerous ones, and hard to photograph.

A group of beautiful Lawrence's Goldfinches shows up year after year. They posed nicely, but not quite close enough for my little camera.

On the ground, a Song Sparrow and a very uncooperative Abert's Towhee. But he is a character resident for Sweetwater, so his shot has to be here, no matter how blurry.

 White-crowned Sparrow females were confusing until easily recognizable males joined them. They are familiar from the feeders at home where they show up every winter in good numbers 

Photo by Muriel Neddermeyer (cropped)
A Marsh Wren entertained us with his constant chatter, but he was hard to spot and nearly impossible to photograph, so I had to borrow this photo.

As it got warmer, gnats and other insects swarmed over the water. Black and Says Phoebe (or is this a female Vermillion?) were competing for the best perches from which to start their short, fluttering forays over the creek.

After consulting Rich Hoyer for Ids, and with Robyn Waayer's input, I'm now confident to add some more of the little gray, green, and brown guys that make birding so challenging and interesting.

 A female gnat-catcher, but from this angle and with this light it's impossible to tell whether it's a Black-tailed or a Blue-gray. I think there wasn't much gray on the tail, though.

The Chestnut-sided Warbler that everybody wanted to see.  Check out Susan Beebe's excellent photo here also from Sweetwater.

A cute Orange-crowned Warbler was pruning the cat tails. Was he feeding on seeds or bugs that were hiding in there? A couple of Common Yellow Throats teased me for half an hour while they invaded the territory of a ver upset Marsh Wren. I got lots of blurred action shots. 

 My photos are taken with a 150 mm zoom lens on my Olympus SLR and with my little SP-800UZ Olympus (30 x optical zoom). I wasn't carrying a tripod around, so if there was no bridge rail or tree trunk to stabilize my aim tI was just shooting freehandedly. While these images are just good enough to document a sighting and help with ids, I'm nearly ashamed showing them here, especially in comparison with Susan's and Muriel's excellent photos. Maybe I should invest into a better camera for bird photos, but my main focus will be on insects again soon. Spring is coming early this year in the desert, the Fairy Dusters are already blooming.

Sunday, January 8, 2012


Here are just some images that I put together for a proposal. I'll let them speak for themselves

Saturday, January 7, 2012

A new Backyard Dove

Here is a strange addition to our backyard fauna: I think it is a leucistic Eurasian Collared Dove. Last year one lonely Eurasians moved in and tried to make friends with resident Mourning Doves. Now there are three including this very light one. The question is now whether it's a fawn-colored variant of the Eurasian Collared, a leucistic bird (which might be the same thing) or a very light Ringed Turtle Dove (domestic variety).  Since it is the same size as the other Eurasians I believe it's one of them.

Native Mourning Dove  left,  normal-colored Eurasion Collared Dove in the middle and our light-colored new one on the right
 Interestingly the Eurasian Collared doves were just expanding their range from eastern Europe to Germany when I was a kid. In the eighties they were already our most common doves in Western Germany. Here in the US they were introduced in Florida and are spreading rapidly west. I've seen them for years at Sweetwater.

Mourning Dove nest in our potting shed
The Collared doves will certainly be competitors of the Mourning Doves. But the locals have enormous breeding success, raising clutch after clutch all year round in every possible niche, flower pot, top of a cactus, awning, shelf....