Friday, December 23, 2011

hedge-row birding

hedgerow at edge of harvested sugar-cane field
16 December 2011, Lafayette parish, LA

Ecotones are places where two or more different habitat types meet. Ecotones are known for high rates of plant and animal diversity, since they most often contain plants and animals from both/all of the involved habitat types. Woodland edges – where forests meet with other habitat types such as prairies, meadows, marshes, etc. – are fine local examples of ecotones.

Similarly, agricultural hedgerows are artificially-generated systems that mimic woodland edges in both structure and species composition. Structurally, hedgerows are linear thickets, usually about 25' in height and width, and densely-packed with trees, shrubs, and vines.

hedgerow flanking a small water course
20 December 2011, Acadia parish, LA

From a bird perspective, hedgerows represent super-safe areas where songbirds can rest and eat in near total concealment. A concealed songbird is a happy bird; and a concealed songbird surrounded by ample food resources is a super-happy bird. Ultimately, a concealed songbird surrounded by ample food and water resources is a blissfully-happy bird!

Hedgerows snake through agricultural lands of all makes and models. Here along the southern Gulf Coastal Plain of the U.S., hedgerows are most often comprised of trees such as water oak, rough-leaf dogwood, hollies, hawthorns, prickly-ash, and cedar; shrubs, like elderberry, viburnums, beautyberry, palmetto, and Chinese privet; and vines, including blackberry, catbrier, moonseed, honeysuckle, poison ivy, and wild grape. Tons of cover and tons of juicy berries.

Rusty-blackhaw Viburnum fruits

Rough-leaf Dogwood fruits

parsley hawthorn fruits
(photo by Annette Parker)

poison ivy fruits

Here in watery Louisiana, agricultural hedgerows flank small bayous, coulees, and artificial irrigation canals and ditches, nicely completing the ultimate food/cover/water formula sought by all wildlife.

Birding along hedgerows is usually very very good, especially during the fall/winter months, when berry production is at its peak, and most of the foliage has fallen, allowing for easier viewing. Following the law of the ecotone – or “edge effect” as it is more commonly known, hedgerow bird communities are very diverse, and include numerous species of hawks, doves, woodpeckers, flycatchers, vireos, wrens, thrushes, mimic thrushes, warblers, sparrows, and others. Let's take a closer look at a few:
the tiny Blue-gray Gnatcatcher is a very common
hedgerow inhabitant, especially near water, where
it subsists on gnats, mosquitoes, and tiny fruits such
as poison ivy berries

White-eyed Vireos occupy hedgerows on a year-round basis
photo by Russ Norwood

like gnatcatchers, kinglets are very tiny birds...
this Ruby-crowned Kinglet is a common winter resident
in southern hedgerows
photo by Russ Norwood

less common winter resident is the Palm Warbler
(note white "eyebrow" and yellow undertail) a bird
which tends to favor Baccharis shrub colonies
(photo by Matt Conn)

tiny lil' bandit! this Common Yellowthroat is a shrub-loving warbler species
which also seems extraordinarily fond of Baccharis shrub colonies
(photo by John Spohrer)

Swamp Sparrow placidly munching on ironweed seed
(photo by Russ Norwood

King o' da Hedge: White-crowned Sparrow
(photo by Russ Norwood

and....(drumroll).....Cooper's Hawk (immature): the bane of all
hedgerow-dwelling songbirds!
(photo by Eric Adcock)


case of da red-hot screamin' meemees

mr. mocker...mad? glad? sad?

On the afternoon of December 06 I was rudely awoken from a nice afternoon nap by furious rapping on our bedroom window, accompanied by shrill hollering. Our bedroom gives onto the back porch, and there near the window sat a mockingbird on an overturned bucket. From there, he'd launch himself up against the window, pecking and shrieking, time and again. During spring breeding season, this sort of behavior is not uncommon in hormone-crazed male mockingbirds and cardinals. But in the dead of winter? What gives?

Stomping out onto the back porch, I went to remove the overturned bucket. I guess in my sleepy mind I figured if I removed his perch, he'd give up and leave. 

da bucket in question

 Staring down at the bucket, I noticed strange reddish mocker-droppings. Whoa. Was this blood? Was he sick? Dying?

Checking around the nearby porch railing, I found more piles of mocker-droppings -- ten(!) more, to be exact.

ouch! cayenne pepper droppings!

Aha. Those droppings were filled with seeds. Pepper seeds. Cayenne pepper seeds (I could tell by their size and shape). A grand total of thirteen piles of cayenne pepper droppings. Oh man. You crazy beast; what have you done?

Most of you are probably aware that birds like peppers. Dried peppers are included in commerical parrot feed. I've personally seen at least a half-dozen species of songbirds eating small native peppers called "bird pepper" or chile pequin (Capsicum annuum glaberisculum). Why do birds like hot peppers? Is it for the shot of vitamin C that they contain? Or for the systemic stimulation/rush of capsacin in the old blood stream? Or are peppers actually nutrient-rich from a food standpoint? Maybe all of the above? I don't know the answer(s), and I'm not sure whether anyone's studied on it.

One thing's for sure: this particular mocker hadn't just nibbled on a cayenne pepper and leave it at that. He had in fact eaten LOTS of cayenne pepper (we had lots of leftover cayennes in our garden, only about 15' away from the back porch), and he was acting crazy.

An hour or so later as I went out to my truck, there he was, perched on a rear-view mirror, hollering and defecating all over the top of the mirror and all over the pick-up bed -- another good dozen piles of pepper-poo in all. 

What the...? I mean, did he eat until his entire GI tract was crammed with pepper??

Ah, Nature. You just never know what you'll encounter next . . .