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15 February 2009

Greater Roadrunner

There are few birds associated with the southwest more than the roadrunner. Specifically, the roadrunner species in the US is the Greater Roadrunner - Geococcyx Californianus. The roadrunner is a large bird - it can reach nearly 2 feet from it's head to the tip of it's long tail feathers. It's probably most noted for it's ability run quickly - nearly 25 mph. This is likely an adaptation to aid it in hunting lizards and snakes.






Roadrunners are fascinating birds - aside form their size and unique shape and ability run, they have interesting hunting techniques. They have been documented to occasionally work in pairs to hunt rattlesnakes - one distracting the snake allowing the other to move in. They commonly kill their prey by repeatedly bashing the prey's heads on the ground or rocks.

The bird photographed above was spotted in the Santa Cruz Flats region in south central Arizona. This region (named for the normally dry Santa Cruz River), is bounded by Arizona City to the north, Marana to the south, and Picacho Peak to the east. The region primarily a flatland consisting of many farm plots (sod/turf, cotton, pecan groves, and others) and empty arid lots. this combination of natural habitat and the consistent water associated with the farm crops makes for an excellent location for many bird species. In fact, in a brief 90 minute survey of the region, 3 roadrunners were spotted among about 30 total bird species. With a little more time to focus on the seclusive species, it's likely another 5-10 species of sparrow and thrasher could have been identified.

07 February 2009

Twice-stabbed Lady Bird Beetle

While working on the yard I noticed an interesting 'lady bug' species on our Chilean Mesquite tree.




This species, called the Twice-Stabbed Lady Bird Beetle (or simply Lady Beetle...the "bird" part always seemed odd to me) was actually fairly prevalent on the tree, though hard to photograph because it never stayed still. There are three species of 'Twice-stabbed Lady Beetles', including Chilocoris Stigma, Chilocoris Cacti, and Olla v-nigrum. Compared to the well-known Lady Beetle species, these are quite a bit smaller, and apparently often go unnoticed.

These 'Lady Bugs' like to eat scale insects and also aphids, mites, and caterpillar eggs. I'm not sure exactly what on the Chilean Mesquite they were attracted to. In any event, this is at least the third species of lady beetles I've seen in the yard, and I can't say I've ever exactly been looking for them.

01 February 2009

Challenges of Macro

I've gotten interested in macro photos again in recent days, and have pulled out my Canon 100mm f/2.8 macro lens and put it to use. I'd forgotten how difficult macro shots are given the narrow depth of field. The ganzania picture is a good example:



If you click on it to see the full size image, you'll see the challenge. The center of the flower is very sharp, as was the goal of the shot. However, the petals are very blurry. If I'd wanted the petals to also be sharp, I'd need to stop down significantly - to the point of either not having adequate light to make the exposure, or requiring a higher ISO and thus grainy photo. Of course, I could/should use a tripod, but even then, at f/18 or higher you start to lose sharpness due to dispersion, so I'd need to add some extra light.

The iceplant flower (about 1" across in real life) below is another good example. I missed the focus just a little, and the result is the entire flower appears out of focus. Generally, the goal is to get the stamens and pistils in sharp focus since that is where the eye normally is drawn, and where the most contrast exists. But in this case I focused midway on the petal. The result: the center of the flower is out of focus, and the edge is out of focus.




The best thing to do is spend extra time with macros and use a tripod and add extra light. Reflectors help add natural light and fill shadows. I also use a macro ring flash on occasion, but it can cast an unnatural light on indoor macros (but it works great to fill shadows outside). And this is all the more important when you add extension tubes and attempt super-macro shots.