30 January 2011

Leafhoppers In Winter

Some hard freezes earlier in January put an end to much of the insect activity in my yard.  The only conspicuous inhabitants of the last few weeks are a few Dainty Sulphurs that still fly on the warm days, an occasional house fly, a lady bug or two, and a few bees on the warmest of days (though few flowers exist in our yard at the moment).

Regardless, I was in search of a Green Lacewing to complete a series based on the gravity-defying egg photo I posted a couple weeks ago.  I thought it would be a piece of cake to find one - but apparently the cold weather has had an impact on them too.

Instead, I located this fancy looking 1/8 inch bug on my orange tree:

Leafhopper on Orange Tree

This is a Leafhopper, so named because of its ability to 'hop' from leaf to leaf. These bugs are often considered pests, especially to food crops. 'Sharpshooters' are part of a sub-family of leafhoppers, with the Glassy-winged Sharpshooter the most infamous (especially to lovers of wine and grapes).

So many species exist that I may never know for sure what this one is, though it has been suggested it may be a Potato Leafhopper, Empoasca fabae.

27 January 2011

An Icon of the Southwest - the Cactus Wren

Common from Texas westward to Southern California, the Cactus Wren is truly an icon of the desert southwest.  Perhaps it doesn't rival the Roadrunner, tumbleweeds (which are actually invasive weeds from Russia), or rattlesnakes, but once you hear a Cactus Wren's buzzy call, it will be immediately familiar.

Many movie Westerns have Cactus Wrens subtly calling in the background.  And Arizona has even made it the State Bird.

This Cactus Wren was kind enough to pose on the tip of a Saguaro - perfect!
Cactus Wren on Saguaro
Cactus wrens are very unique as compared to other wrens.  They are much larger and much more gregarious.  They get their name form the fact that they usually build their nest within the fork of a cactus - including saguaros and chollas.

Cactus Wren

20 January 2011

Streak-backed Oriole

One of the perks of living in Arizona is the steady stream of rare birds that seem to show up all year. We get eastern vagrants, Asian strays, and the occasionally off-course neotropic bird.

One such example is the Streak-backed Oriole, Icterus pustulatus. The Streak-backed Oriole seems to make an appearance somewhere in Arizona about three out of 5 years. One showed up for a couple of seasons at the Gilbert Water Ranch and Riparian Preserve a few years ago, and this year as many as two were seen in the Yuma, AZ area.

Streak-backed Oriole
Streak-backed Oriole

The Streak-backed superficially may be confused with the Bullock's Oriole, but the most obivous difference is the lack of an eye-line on both the male and female Streak-backed.  Of course, the "streaked back" evident in the photos above is generally more pronounced as well, but first year Bullock's may also have some similar streaking.

17 January 2011

A Mexican General

When traveling the Arizona-Mexico border in late summer or early autumn, don't be surprised to stumble across a Mexican General.  Or perhaps 10,000 Mexican Generals!

Based on some of the outlandish stories in the media, often filled with sensationalism and hyperbole, you might expect me to be talking about members of the Mexican National Army.  However, I am actually talking about a large grasshopper, also called the Horse Lubber (Taeniopoda eques).  

The Horse Lubber does best after a good monsoon season (usually occurs in Southeastern Arizona from late June through mid-September), and can sometimes be seen in mass hordes crossing the high desert, usually in the vicinity of some wooded oak habitats.

Like most grasshoppers, it will eat many different plants, and occasionally other insects if presented with an opportunity.

13 January 2011

Snowy Egret

One of my favorite wintering birds in Arizona is the Snowy Egret (Egretta thula).  It seems to be a prototypical example of one of the topics I frequently blog about - the surprisingly vast array of animals that the desert supports.

Of course, the easiest places to spot Snowy Egrets are at man-made ponds and recharge basins.  But they also will show up as slow running washes, natural ponds and lakes, and other natural waterways.

Snowy Egret at Sunrise
Snowy Egret at Sunrise
At different times of the year Snowy Egrets can be found through most of the southern half of the USA, making it as far north as Idaho, Nebraska, and Massachusetts on a regular basis, but only regularly winters in California, Arizona, the Gulf Coast, and the southern Atlantic coast.

In general, it covers much of the same range as the larger Great Egret and the similar sized Cattle Egret, with the Great Egret's range being slightly larger, and the Cattle Egret's range slightly smaller.

Often, the Snowy Egret can be distinguished from Great Egrets by size alone - but if you do not have something of a known size to compare to, this can be difficult.  The best distinguishing feature is usually coloration - contrasting yellow and black on the lores and bill, and yellow feet.  In contrast, the Great Egret has gray/black feet and legs and much less black on the bill.

As for distinguishing from the Cattle Egret - once you've seen a Cattle Egret once this should be easy.  The short bill of the Cattle looks almost comical and disproportionate as compared to that of the Snowy Egret. 
Snowy Egret

Snowy Egret
The Snowy Egret's Feet Really Stand Out

Great Egret
Great Egret (for comparison)

09 January 2011

A One Millimeter Egg That Defies Gravity

This fall I started noticing little tiny green dots, attached by a minuscule thread, seemingly defying gravity. These dots were everywhere - on numerous plant species, generally attached to fairly sturdy portions of the plant.

After a bit of research, it turns out these are Green Lacewing (Chrysopa sp.) eggs.

There are many species of lacewings, and most lay eggs like this - attached to tiny threads, suspended upright. Some lay eggs in bundles, and some lay singular eggs in many places.

Green Lacewing Egg
Now, the above picture doesn't do justice to the size of this egg, so I decided to hold a ruler behind it so you could see that this egg really is just a millimeter.  To get such great magnification on the above photo, I used a 100mm macro lens and two extension tubes stacked (for better close focus).  Of course, my EM-140 ring flash provided the lighting.

Green Lacewing Egg with Ruler
Even then, the perspective isn't fully understood.  So I decided to take one more photo from about three feet away using the 100 mm lens (see below).  That is still quite close, but it begins to give you the perspective a bit better.

Next week I'll try to fiand an adult for my Macro subject.  They are very elegant, delicate bugs, and quite a beneficial bug to inhabit your garden.

Green Lacewing Egg with Ruler
Backed Out For Perspective

06 January 2011

Thousands of Snow Geese

Perhaps the most astonishing natural phenomenon I've ever seen is that of flocking Snow Geese.  Along the Central Flyway, a North/South corridor stretching from Saskatchewan and Manitoba southward through Nebraska, and down to Texas, it is not uncommon for flocks of 50000 Snow Geese to gather on lakes and resovoirs.

When I lived in Nebraska, one particularly warm late February day I decided to head to Branched Oak Lake, a State Recreation Area just west of Lincoln, NE.  I had no idea what I'd find, but I was hoping for some early migrants and perhaps some hawks or eagles in the wooded areas around the lake.

When I arrived and parked, I noticed what appeared to be a very large rocky dam in the middle of the lake.  How odd, I thought.

When I got out of my car I was immediately struck by a sound...something unfamiliar.  After about 2 seconds I realized those rocks were thousands of geese, and that sound was the aggregate of them all vocalizing.
Snow Geese Flock

As I watched in awe, I got my 300mm lens out and tried to capture the scene.  After a couple of shots I noticed a Bald Eagle take flight from across the lake.  That is all it took - the geese got spooked and took off.

Snow Geese Flock
My eyes saw the birds take flight, and it took a couple of seconds before my ears heard the jet-like sound of the thousands of birds take flight all at once.

In the photo above, note just how many geese remained on the lake even with the sky full of geese.  I can't even guess how many geese there were - 20,000?  More?  I can't wait until the day I get to witness such a spectacle again.

02 January 2011

Pipevine Swallowtail Lifecycle

Pipevine SwallowtailI had a previous post marveling at the beauty of the Pipevine Swallowtail (Battus philenor). Its black body with orange and blue spots, combined with its size, make for a striking sight.

While sorting through pictures from last summer, I realized I actually obtained photos of a good chunk of the Pipevine Swallowtail lifecycle.

Pipevine Swallowtail larvae feed almost exclusively on pipevines (thus the name), so where you see pipevine, you are bound to see caterpillars and chrysalis.  This was the case at Boyce Thompson Arboretum in late August.

Pipevine Swallowtail Caterpillar
At left is a Pipevine Swallowtail caterpillar chomping away at the last leaf on a small pipevine.  The pipevines near the paths at Boyce Thompson were all quite small - likely purposely cut back.  That didn't stop the caterpillars - of the two dozen or so pipevines, each had at least one caterpillar - some had two or even four.

And below is the chrysalis.  Unfortunately no egg photos this time!
Pipevine Swallowtail Chrysalis

01 January 2011

Atascosa Highlands CBC - Some of the Best Habitat in Arizona

I had the pleasure of volunteering for my first CBC - a Christmas Bird Count, on December 31, 2010. CBCs, for those unaware, are organized efforts around Christmas (anytime between mid December and early January) in which volunteers and experts perform a census of birds in pre-defined areas. These efforts are coordinated/associated with the National Audubon Society (though you need not be a member to participate).

The intent is to have a consistent measure of birds from year to year so that trends and status can be identified over time. CBCs are defined by a "circle" - a diameter of 15 miles. Circles are subdivided into regions, and ideally a team is assigned to each region every year.

This year I volunteered for the Atascosa Highlands CBC, located in some prime habitat just east of I-19 and along and north of the Mexico border in Arizona. This is some of the wildest land in Arizona, hilly, rocky, and mountainous. Few roads traverse the area, and many are rocky high-clearance vehicle only.

Southeast Arizona is world renowned for its biological diversity due to the confluence of two deserts, pine-oak forests, riparian "magnets", "sky islands", and proximity to Mexico. The Atascosa CBC takes advantage of this, and is centered in some less publicized but prime Arizona habitat. With elevations ranging from about 3500 to 6300 feet, it includes high desert, desert grassland, pine-oak, riparian, and lake habitat, among others. 

To give another idea of the remoteness and habitat, this is where the Jaguar Macho B was known to roam.  Macho B, one of the only known Jaguars in the USA, was famously captured and collared in early 2009, only to die a short time later amid controversy.

Of course, weather (that on the day of the count, and that of the past breeding seasons) play a major roll in what is seen year to year. This year was no exception. A pretty good monsoon season resulted in a good crop of berries on the junipers and hawthorns, and weather had been fairly mild. But the two days prior to the CBC a very cold and snowy storm system moved in.

The higher elevations of the CBC had a few inches of new snow, and the day of the count saw flurries and snow showers, and generally cold, cloudy conditions.

None-the-less, my partner for our CBC area (Dave Powell) and I were prepared and ready to do our best in the Jalisco and Apache Canyon areas.

Gray FlycatcherRight out of the gate we came across a nice loose/mixed flock of birds, including this Gray Flycatcher, Empidonax wrightii.

Empids can be notoriously difficult to identify.  In SE Arizona, very few species typically over winter, but Gray, Hammond's, and Dusky all do, and are all similar.  Without a lot of experience, simply looking at the visual features of these birds is generally inconclusive.  The differences are so minimal that you'd really need them side by side to see the difference.

Luckily, the Gray Flycatcher has an interesting diagnostic behavior - it wags its tail slowly similar to a Phoebe.  We ended up seeing several of these during the day, and that behavior is now burned in to my brain.  Unfortunately, none decided to pose for a close up photo.

Ash-throated Flycatcher
In that same group was a slightly more rare Ash-throated Flycatcher, Myiarchus cinerascens.  True to its secretive form, it generally stayed in the middle of the trees, obscured by branches and twigs.

However, it stayed around long enough to provide plenty of good views, if slightly obscured and brief.

And I say "true to form" based on what the field guides state - this was actually my first Ash-throated.

This handsome Black-throated Sparrow also made an appearance:
Black-throated Sparrows
Unfortunately, as I am learning my new camera I accidentally cranked the ISO up to 3200.  Apparently that dial that worked one way on my old camera has a different function on my new one!  I was able to salvage the photo with some noise reduction, but a bit of the finer feather detail was lost.  My Canyon Towhee photos, on the other hand, were not salvageable.

Weather and camera mishaps weren't the only hazards to contend with, as this thorny shrub shows:

Desert Thorns
Of course, thorns like that are easy to avoid - they stand out and are readily visible.  The tiny thorns of the mesquites and some of the low weeds are much harder to avoid.

Speaking of plants, this area was primarily mesquites, ash, and hawthorn.  Dave Powell, being a butterfly guru as well, pointed out quite a bit of Seep-willow, a good autumn butterfly magnet.

There were also scattered cacti, including Arizona pincussion, barrels, a small number of prickly pears, and chollas.  Areas had nice stands of Ocotillos, and there were also a few agaves, and some moderately impressive stands of yuccas - I think we ended up seeing three species.

There was some grassland, though much of the area is open for cattle grazing reducing the quality of that habitat.  The cattle seemed to keep a close eye on us.
Northern Cardinal

Anyway, this area near the cattle was full of berries (hawthorn, I think).  And where there are a lot of berries, there are often a lot of birds.  This maxim held true, and several mockingbirds and northern cardinals frequented the vicinity. 

And nearby we were able to draw in a pair of Red-tailed Hawks with some owl calls.  Only on inspection of the photo below did I notice that it appeared to have breakfast in its talons.

Was this Red-tailed the reason why we came up empty on Montezuma Quail?  Click on the photo for the full-size view.
Red-tailed Hawk
OK, Montezuma Quail are tough even in good years, so I won't solely blame this hawk.

We had a good share of Ladder-backed Woodpeckers, a handful of Red-naped Sapsuckers, and a few Northern Flickers (all red-shafted).  And this Flicker below held true to the pattern for this day of difficult to see birds.

Northern Flicker

At one point we scared up a couple of White-winged Doves.  Those familiar with Arizona know that those are very common summer birds, but can be very local and rare in the winter.  In fact, we were the only area of the Atascosa count to spot any this year. [Update: the count results indicate one other group did in infact see White-winged Dove as well.]

As we proceeded up and out of Jalisco Canyon, we searched a grassland for Cassins Sparrow.  No luck, but an Eastern Meadowlark was flushed, seemingly a bit out of place.

To this point we'd seen Black-throated, Black-chinned, White-crowned, Chipping, and Rufous-winged sparrows (I actually missed the Rufous-winged, but made up for that later...)  And finally we encountered a bird willing that stayed in the open long enough for a decent photo - a nice Vesper Sparrow.

Vesper Sparrow
Aside from Cattle, we didn't see much in the way of mammals in the count area.  Dave saw an Antelope Jackrabbit, we saw some dead Striped Skunks on the roads, and these cryptically hidden White-tailed Deer were spooked off:
White-tailed Deer
As I said before, I missed the Rufous-winged Sparrow earlier in the day, but as we were heading back to the car to end the day, I spotted some movement to the right.  Lucky for me, it turned out to be two more Rufous-winged Sparrows - my second new bird of the day.
Rufous-winged Sparrow
Drat - sticks in the way again and slightly off focus.

Anyway, this photo pretty much summed up the weather for the day...cloudy, stark, and a bit of snow.  The habitat seen here was fairly typical of our area up out of the canyons.  The canyons and there borders often had more dense vegetation and more variety (see the above deer photo).
Atascosa View

All told, we ended up with 30 species of birds in about 7.5 hours of work. Definitely not the most diverse or productive area, but it was a great experience and a lot of fun!