Musings of a roaming nature nerd

Archive for June, 2011

Lesser Nighthawks

Certain mammals naturally captivate our interest- Grizzly Bears, Wolves, Moose, Bison. Our admiration, curiosity, sometimes even hatred or fear of these animals is as considerable as their silhouettes. So it is with certain birds. We find charisma, beauty and intrigue in many species- Great Blue Heron, Northern Cardinal, Wood Duck, Bald Eagle. Yet our continent is alive with thousands, millions of more creatures than the ones so immediate and bright in our gaze. And occasionally the subtle and elusive lives are those which intrigue us the most.

Out here on the western edge of the Sonoran Desert the inconspicuous bird, which has captured my interest and affection is the Lesser Nighthawk. Whether watching them forage for insects over the rooftops of Yuma or enjoying their acrobatic maneuvers over the Colorado River at dawn, I can’t help but be fascinated by these little mottled brown birds, which all but disappear by sunrise. They circle and trill and eventually settle down to roost in the shade of the cool sandy ground, and are typically only seen again as the sun begins to set. Unless of course one goes traipsing through their habitat as I do everyone morning during my surveys!

Startling a Nighthawk from its roost is one thing, but this is nesting season and carefully trying to navigate through their territories without spooking them from their nests is quite another. Nests are mere scraped indentations on the ground, usually at the base of shady vegetation, and typically containing two little gray speckled eggs. Chicks are born partially precocial and are able to walk and run within 2 days of hatching. They are very rarely seen due to their camoflagued coloring and their ability to sit absolutely still and look like dirt until danger passes by. A month ago I found my first nest after flushing the mother when I inadvertently walked too close. She landed nearby fluttering her wings in a half-hearted broken wing distraction attempt, while puffing her throat and calling softly. Females spend all day sitting on their eggs, without moving, so I felt guilty for disturbing her, but was thrilled at my first look at her pebble like eggs.

A well camouflaged female Lesser Nighthawk sits on her nest

 

Little speckled pebble-like eggs amongst the fallen arrowweed leaves

 

Since then I have diligently watched for chicks and found evidence of their presence in the form of recently hatched eggs. Yet only by accident did I finally get a look at them this past week. As I blazed through yet another plot covered in arrowweed and tamarisk I happened to glance down and notice two slightly discolored patches of dirt on the salty surface of the soil. With a second look at this oddity, I realized I was standing over two tiny chicks about the size of my palm. Completely still in the middle of my transect, tiny slits for eyes watching my movement, I would have stepped right over (or on!) them had I not glanced down at that moment. I snapped a few photos and watched them for another moment and then moved on. When I walked back 10 minutes later there was no sign except two little droppings left where they had sat. My gigantic shape stomping through their home had obviously startled them quite a bit!

Evidence of hatchlings!

 

Chicks!!! Still as can be and carefully watching my every move.

 

Notice that their tails haven't yet grown in. Also notice how ridiculously cute they are!

 

Once grown and fledged and independent (a process that only takes a few weeks) these juvenile Nighthawks will join their parents and dozens of others in aerobatic feeding, opening their wide mouths and swallowing up insects by the hundreds in the waxing and waning light of the sun. It was while watching and hearing their cousin, the Common Nighthawk diving at dusk in the Tetons years ago that first opened my eyes to a world after dark I thought had only belonged to stealthy predators such as fox and owls. At that time I also recalled Whip-poor-wills singing their fairytale like songs in still, cool New Hampshire nights. This world of low light, hidden nests, and subtly enchanting little birds is one I am delighted to have been privy to over the years and recent months. As we now head to Nevada I look forward to discovering what hidden life may emerge to capture my interest and my heart in the weeks ahead.

A photo Jason took of a male feeding on insects at daybreak over the water

 


The Intensives… C

The marsh. I always feel a sense of guilty pleasure as I slip the kayak into the river and let the morning chorus envelop me; gliding by, enchanted and focused on deciphering each voice in the cacophony. Am I really working?! The marsh changes constantly. The birds, muskrats, beaver, fish, insects and I all share borrowed water. Unnatural releases and holds on water slated for downstream irrigation mean tiny channels for paddling one day and wide open water the next. When the water is low and there appears to be more territory to go around, the birds somehow seem to tolerate each other less. They sing and defend their territories aggressively. With high water and less space, rather than creating competition, everything quiets. Birds seem to abandon the marsh completely rather than fighting for what is left. But the ones that remain loudly keep up the chattering, warbling chorus, perhaps in some way sensing how fortunate they are to still have nests in tact and food to be found.

A recent high water day exposed three American Coot nests, which are otherwise buried deep within the bull rush. With everything flooded, I could paddle into areas formerly inaccessible and discovered the nests. Two contained carefully guarded eggs (the parents splashing around and calling nearby to distract me away from the nests) and the third housed two fuzzy chicks. Still too hidden to photograph, I watched through binoculars as mama nuzzled and preened her babies and they climbed all over her and the grassy nest!

Secretive marsh birds, such as the Least Bittern, Sora and Yuma Clapper Rail creep about amongst the vegetation and occasionally reveal themselves in awkward moments teetering between bravery and foolishness. As I pulled my kayak out of the water the other day to survey the fields which make up part of my plot, a Clapper Rail watched me for several minutes before ducking into the grass never to be seen again!

The recent wildfire scorched the land to within 200 meters of the edge of the marsh, but fortunately didn’t make the jump across the fields to impact the marsh itself. While I surveyed, three coyotes watched me very warily as they trotted along through the burned trees. Through much of the west, coyotes are considered vermin due to their portrayal as livestock killers. If unlucky enough to cross property boundaries they are often shot on sight. Despite being one of the only large predators left, (most of their prey being mice, rabbits, quail and the occasional small deer) their key role in the ecosystem is overlooked due to this reputation. These coyotes had every reason to watch me cautiously as they skirted the now open territory between cultivated fields and charred cottonwood groves. They have learned over time what the presence of humans can mean.

Every survey site I visit offers something unique and special, but getting to know this particular plot has been a real joy. Next week I will glide through the channels, walk the fields, and get algae and wet bull rush slopped across my clothes for the last time. And when I paddle the somewhat grueling 364 strokes up the Colorado to my take out point I will undoubtedly feel melancholy, but also so fortunate to have been part of this amazing habitat and witness to its changes over the weeks and months.

The marsh during high water

 

Water level changes of almost a meter are common

 

Least Bittern making a quick flight between patches of bull rush

 

American Coot nest and eggs

 

Not the best photo of a Yuma Clapper Rail

 

Agricultural fields

 

Fire damage across the ag. fields

 

As this map of Marsh Wren territories shows, boundaries can be confusing week to week!