Weasels and stoats are not welcome in New Zealand, although they live there.  But they’re not native, and as opportunistic and energetic predators they’re particularly dangerous for the few remaining species of indigenous birds, many of which are ground-nesters, having evolved on an island on which there are no native species of mammal except bats, and no snakes at all.

So we shouldn’t have enjoyed seeing a fierce European invader and eater of eggs and nestlings, but we watched this little stoat playing “kill the pine cone” around a heap of cut pine boughs at the edge of a pasture.  Its mock-predatory antics were so fast it defied being captured on camera, but when it stopped playing to check us out, E got a shot.

(Photo E. Shock)

Hen update with photo. The Stalwart Hen and her Nidlings (the Anna’s hummingbird and her nestlings in our backyard pinetree) are still hanging in there, despite a night of unseasonal wind and cool rain.  In this photo, the bottom side of the tip of one of the nidling’s beaks is just visible at the left edge of the nest, above a nearly horizontal pine needle.  From the upper window, I can see two nestlings clearly, but the window screen makes focusing a photo tough from there.  The two Nidlings have grown enough so that they fill the cup of the nest, and their little beaks stick upward over the edge.  Each day the beaks are getting longer and darker, but they’re still nowhere near final hummer-length.  Go Hen Go!

There’s a property of owls I call “Half-Dome Head.”  It’s a shape that’s noticeable in the profile of all owls, particularly the larger ones.  The Barred Owl to the right is exhibiting major Half-Dome Head.  If Half-Dome Head can be achieved when making owls in clay, the resulting effigies will be Especially Owly.

The name derives from the famous granitic dome formation, Half Dome, in Yosemite Valley, California, which bears an obvious resemblance to an owl’s head in profile.  The geologic Half Dome is forming largely by weathering: eons of sheet-exfoliation on the fragmented face of an exposed granodioritic batholith gave it the shape we see today.  (Appropriately, one of the most Half-Dome-Headed owls ever, the regal Great Gray Owl, is an uncommon resident of Yosemite Valley, see photo below: the color and texture even match).

In owls, the “Half-Dome Head” effect arises from the front of the Owl’s head (in other words its face, to use the technical term) being shaped like a radar dish, to be efficient at gathering sensory input — in other words, light and sound.  But take away the feathers and an owl’s cranium is shaped pretty much like a hawk’s, or even a chicken’s skull (check out these images).  An owl is after all a bird, albeit a fairly specialized one, so it’s built like a bird.  The forward-oriented flat face that we humans find so fascinating (probably for anthropocentric reasons) is due more to posture and feather-arrangement than underlying skeletal structure: the owl generally holds its bill slightly downward rather than forward like other birds.  This gives prominence to the distinctive “facial disc” — the specialized array of radar-dish-like plumage around an owl’s eyes and ears — and positions it so it functions optimally.

The owl’s Facial Disc is a precise specialization for nocturnal hunters who require every available bit of light and sound directed into their sensory apparatus to ensure the highest possible success rate while hunting.  Several features of the facial disc are noticeable: short flat-lying feathers sweep away from the eyes and “cheeks” so as not to impede forward vision; stiff vertically-arranged feathers edging the facial disc help funnel sound into the ear openings, which are asymetrically arranged on either side of the face behind the eye to create aural parallax (and are nowhere near the cranial tufts we commonly call “ears”); and rictal bristles (“whiskers”), which are specialized sensitive filamental feathers on either side of the gape (the flexible corners of the mouth which allow the beak to open and close), that enable the owl to perform preening and feeding activities — including the feeding of owlets — by feel, since their large eyes are immovable in the skull and so can’t focus efficiently at very close ranges.

But that’s just the flat front of the “Half-Dome”: the round back, the helmet-shaped fullness of feathers on the back of an owl’s head also transmits owliness to our perception.  This is also due to the owl’s skeletal configuration: the bird’s upright posture is possible because its skull is joined to a nearly vertical spine.  Most birds’ backs go off at a more or less right angle to their necks (think of a dove), somewhat shortening the curve at the back of the head.  But the feathers on the back of an owl’s head arc smoothly down to the back, which continues downward steeply.  The photo above shows Half-Dome head creating Owliness in an MLO (Moderately Large Owl) I’m currently working on for a client.

Photos: from top to bottom: IBO barred owl, A.Shock; Half Dome Yosemite, Carroll Ann Hodges, USGS; Great Gray owl, Canada (Sorry; don’t know who to credit this photo to); Three Star Owl “eared” owl effigy in progress, A.Shock.  And finally, a Gratuitous Cranky Owlet chillin’ with the Big Boys…

And?  Then Sunday evening, a warm, calm, acacia-fragrant evening while it was still light, I looked down on the Nid from the upstairs window, and saw Fascinating Behavior.  The first was a definite look at a dark, fuzzy head with a now orange-yellow bill restlessly moving in and out of sight from the depths of the Nid.  This was very exciting.  Then nothing for several minutes — the Hen was away for quite a while on this outing.  It gave me a chance to study the inner edge of the far side of the Nid, and think how clean it was: no poop.  I realized I’d never seen a hummer carrying a white fecal sac away from a nest, like many songbirds do to keep their nests clean: food in, fecal sacs out.  I wondered if a nestling hummer produced a fecal sac that was just so small I’d never noticed.  Just then a gray fuzzy lumpish shape appeared over the rim: a second nestling!… but, no — it has no face?  What…? Then: SPLORTCH!  Like a jet of ‘baccy juice from the lips of a cartoon hillbilly, a tiny projectile squirt came shooting over the rim of the nest and arced towards the ground.  So that’s how it’s done!  No fecal sacs here for mom to cart away, just a butt-skywards and a quick squeeze, and business has been taken care of.

The second event was the Hen returning.  And, to my relief and fulfilled expectation, she perched on the edge of the nest and pointed her beak downward.  Just like in the nature films, two little heads rose up to meet her, and she poked her bill down one gullet and then the other, dispensing yummy liquid Gnat-in-Nectar stew to each Nidling in turn, the bigger one going first.

To the right is a close-up of an Anna’s hummingbird stamp on a Three Star Owl “Hummingbirds of Arizona” cylindrical vessel.  (Both photos: A.Shock)

No pictures of any of this excitement.  I’ll try, but I’ve decided to paper over the window until fledging.  It would be awful if our voyeurism, or the cats, who love to sit and “read the backyard newspaper” from this window, caused her to abandon the nest.  I’ll leave a flap to peek through, like an impromptu blind, and maybe before long I’ll manage to get a photo.  The best I can do is leave you with this link to someone else’s photo of exactly what I saw.

Cactus wrens are a large (for a wren), lively, and common presence all over the low-elevation deserts in the American Southwest.  The photo to left left shows one sitting on a cholla branch.  They do that a lot, often while making all sorts of  mechanical-sounding vocalizations like drbrdrbrdrbrdrr or krakrakrakrakrakra.  Cactus wrens are expert at landing on, perching on, and building in fiercely prickly vegetation, usually constructing their unruly globular “kitchen sink” nests weaving fiber, litter, twigs and plastic safely into the protective arms of seriously spiny cactus species like cholla.

Last week we found a Cactus wren dead in our yard, stuck in the leaves of a yucca.  Here’s a photo I took of it (take my word for it, the spotty plumage is diagnostic):

This was certainly sad, but it also seemed very odd.  We couldn’t tell how the bird died, but there it was, a sorry speckled-feathery carcass wedged in the leaves of a Soaptree yucca.  Was it stashed there by a predator?  Not likely; there are predators that do that, but they don’t frequent our yard.  Did it die in the foliage above and fall there?  That doesn’t seem likely, either — it was wedged in tight, and somewhat horizontally.  Did it get stuck there, somehow, maybe a foot caught in the narrow leaves?  Possibly.

Here’s another wren story, not sad and perhaps enlightening.

Just a few days after the macabre yard find, E and I visited Boyce Thompson Arboretum, and paused on our walk for a few moments to watch a pair of Cactus wrens (Campylorhyncus brunneicapillus) busily working on a nest in the upper branches of a tree Prickly pear, a really tall variety of Opuntia. You can see the main support pad in the photo on the left, with the fibrous nesting material sticking out to the right, and the streaky bird’s head poking out to the left.  The wren was about to launch itself into the next plant over, a Soaptree yucca, to continue rummaging between the rigid leaves to gather tough hair-like fibers (visible especially clearly in the carcass photo above) that grow along the yucca stem at the bases of the leaves.  It did this over and over again, each time going deep into the spiky growth to tug and pull at the free building material to use in its nest.  Below is the best photo we managed of the wren reappearing with its beak full of yucca fibers.  Considering the tough and pointy nature of the vegetation as well as the close quarters, it looked like hazardous work, although poking around in nooks and crannies, probing with their narrow, strong beak, is what cactus wrens are built to do.  (I’ve tried to extract unwanted volunteers like fan palm sproutlings and African sumac seedlings from inside yucca clumps, and let me say that gloves, eye protection and long sleeves are often not up to the task.)

So did our hapless yard wren get caught somehow while carrying out this dangerous domestic mission?  We can never know for sure, but it seems in the realm of possibility.  It’s hard out there for a bird.

(Top photo, from Wikimedia Commons, by Mark Wagner.  Other photos by A&E Shock)

Another dire tale of cactus wren-related nesting mishap casts the spectre of botanical revenge on this story: a couple of years ago, the continuous plucking of fiber off of a hairy “Old Man” cactus in the yard by a diligently nesting Cactus wren denuded the plant’s crown so much it experienced horrible sun-burn, and died.

It’s confirmed — the Hen’s egg(s) has/ve hatched!

This afternoon (Thursday April 2) just after one pm, I was finally able to catch the Hen away from the Nid — she’d been sitting tighter than usual this morning — and could look down on the nest from the upper window.  The first discovery was that the black thing on the rim of the nest is not a tiny beak; it’s just crud.  Having established that, I was about to put the binoculars down because the nest looked entirely empty. Just a second before lowering my arms, though, there was movement: a little yellow-gaped head briefly poked up, wavered around a little, and then dropped back in.  I kept watching, and saw the movement repeated a couple of times.  Once there may have been a glimpse of a second yellow gape (two would be the usual number of nestlings for Anna’s hummers), but I can’t be certain.  In between sightings the nest looked perfectly empty.  I determined to watch until the Hen came home.  After a couple of minutes she did, and just settled right in on top of her hatchling(s), no feeding, just sitting.  It/they disappeared entirely under her.  The nestling(s) must be very very newly hatched, because the little bill was still so very short and entirely yellow.  The head supporting the beak was pink and unfinished-looking.

I have no pictures yet of the ‘ling(s), but here’s yet another of the Hen from earlier in the day.  For now, you’ll have to imagine there are brand new pink-scalped dino-nestlings under her.  (Digiscoped photo A. Shock)

…a little pointy beak?

Here is this morning’s photo of the Anna’s hummingbird Hen on her Nid.  I began looking very carefully for evidence of nestlings yesterday, April 1, since that was my estimate of the earliest her eggs might hatch.  This morning, I checked first thing, and still didn’t see any sign of young birds.  But on examination of this digiscoped photo, there’s a tiny dash of a black line visible at the rim of the nest, showing against her gray fluffy undertail coverts.  Is it or isn’t it a little beak?  I can’t tell.

I’ll check back on the Nid when the Hen is away; more might be visible.  Stay tuned.

(Photo A.Shock)

…a true kindred spirit:

Adult Burrowing owl giving the entire world StinkEye at the Adobe Mountain Wildlife Center display at Boyce Thompson Arboretum‘s “Welcome Back Buzzards Day”. (Photo A.Shock)

One of my favorite places to go in the Phoenix area at any time of year (except perhaps in the heat of summer) is the Boyce Thompson Arboretum.  It’s a botanical garden of native and non-native desert plants up in the desert mountains around Superior Arizona about an hour’s drive east of Phoenix.  It’s spectacularly sited along craggy Queen Creek gorge at the foot of Picketpost Mountain.  And it’s great for plants, birds, walking, picnicking — even shopping, like now when their twice-annual plant sale is going on.  If this sounds like an ad, that’s okay, I’m happy to enthuse about the place.

We made a visit earlier this week: the place is rocking with wildflower color, the penstemons are at their peak, and the aloes are still going; the spring migrant birds are coming in and the residents are singing and nesting like mad.  For some reason, male Costa’s hummingbirds — sturdy little desert hummers with bright purple mustaches (in the right light*) — are particularly in evidence; the hens are probably on their nests now. Here are three images E captured of male Costa’s intently working over various penstemon blooms.

Three upper photos by E. Shock.  Remember to click on each for a slightly larger image.

Hen update: The Stalwart Hen (who you will recall is an Anna’s Hummingbird) is sitting tighter than ever on her tidy nest atop pine cones in the big Aleppo pine.  The breezy air has rearranged the branches around her, and although it’s still easy to see her on the nest, it’s tougher than ever to get photos.  But, she’s there.

Speaking of Costa’s hummingbirds and hummingbirds in the yard, I regret to report that we are currently not seeing Miss Thang, the female Costa’s who’s been so regular in our front garden.  There is one male Costa’s very actively performing display flights on the edge of the property, but he’s currently the one Costa’s individual who we know has stayed the entire season here.  We’re hoping Miss Thang (or a suitable replacement!) will be back sometime around the beginning of June, which is when there seems to be an increase in Costa’s in the yard.

*Here’s a bonus shot of just how purple a Costa’s gorget can look in the right light: it’s a head-on view of a Costa’s at one of our yard feeders (photo A. Shock):