Natural History Journal

While I was supposed to be looking for Sandhill Cranes and early-season Greater White-fronted Geese at Merced National Wildlife Refuge  yesterday, a much smaller winged creature caught my eye.  Flying low near the ground around a patch of heliotrope flowers were several tiny fluttering gems.  Since I strive to be an equal-opportunity naturalist, I crouched down on the ground to devote some time to studying these little butterflies, Western Pygmy-Blues ( Brephidium exile ). According to Kaufman's Field Guide to Butterflies of North America, this species is abundant in salt flats, salt marshes, deserts and other alkaline areas collectively thought of as wastelands.  The plants they were visiting, Heliotropium curassavicum , are also generally associated with similar conditions: common names include Salt heliotrope, Alkali heliotrope and Seaside heliotrope.  Salt-bush ( Atriplex spp. ), Lambsquarters ( Chenopodium album ), other members of...

Reports of Sandhill Cranes ( Antigone canadensis ) in the Great Central Valley have been trickling in for the last couple of weeks.  The migrants usually start turning up in our fields and wetlands around mid-September, after the journey from their summer breeding grounds in the far north.  I've been looking forward to the arrival of the cranes, and was able to take a quick trip out to see them yesterday. Sandhill Cranes at Merced NWR As of this week (the week of September 25th) nearly 1,000 Sandhill Cranes have returned to one of my favorite wetlands in the valley, Merced National Wildlife Refuge.  By Thanksgiving, somewhere around 20,000 cranes will have settled in for the winter at this one location alone!  The air is already filled with their unique croaking call, and their elegant dancing forms bring the wetlands back to life once again. Greater White-fronted Geese at Merced NWR In addition to the cranes...

Every year during the last week of September, citizens have the chance to join marine institutions and researchers in celebrating one of our cutest keystone species: the sea otter ( Enhydra lutris ).  But there is much more to these large members of the weasel family than their winsome demeanor and dog-like appearance.  Sea otters are a keystone species, a species upon which the health of their entire ecosystem is largely dependent.  During the 18th and 19th centuries, sea otters were hunted to near-extinction for their valuable pelts.  Before the 1700's, the range of the sea otter extended in a continuous belt around the Pacific, from Japan to Baja California.  Today, sea otter numbers are slowly recovering, but their distribution remains fragmented and patchy throughout their former range.  Source: http://www.seaotters.org/otterspot/World-Range.gif By the early 1900's, excessive ...

Every year after the long, hot summer, I eagerly await the arrival of fall.  The transition between seasons may be gradual or abrupt, but each year there is one moment when you sense it: change is coming.  There is a hint of autumn in the smell of the air, a certain color to the morning light, a crispness in the breeze that has long been absent.  As dusty browns mellow into pleasant gold and the cool wind blows, creatures begin to stir. The wild world is waking up after a drowsy summer. Yosemite Valley (mid-November of last year) In central California, the changing of the seasons is not as vividly dramatic as New England postcards, but it can be just as markedly beautiful if you know where to look.  Fall is an excellent season to see wildlife, as many species are on the move.  Shorebirds and songbirds migrate, Sandhill Cranes and other northern breeding birds return to the valley from the Arcti...

I have lamented before my lack of entomological knowledge.  Yet, armed with field guides, binoculars, a hand lens and the trusty internet, I slog on in my attempt to learn more about the fascinating world of insects.  Perhaps most interesting to me (and every other nature-loving child or adult, I imagine) are butterflies, if for no other reason than that they are often the most conspicuous!  (I also love finding other lepidopterans - namely moths - as well as dragonflies and damselflies.) An abundance of butterflies seem to be out and about in our local wild lands this time of year.  I'm working on honing my butterfly identification skills (though personally, I find them even more difficult and flighty than warblers!)  An easy butterfly to start with is the California Sister ( Adelpha bredowii californica ).  They are frequently seen in California's foothills and at mid-elevations in the mountains, most frequently ...

Summer in the high Sierra is rapidly coming to an end.  Nighttime temperatures are already dipping below freezing, and daytime highs remain in the sixties (Fahrenheit) or lower.  The seasons are changing, grading gently from summer into autumn, and Sierra Nevadan wildlife are busily preparing for the long winter ahead.  On a recent visit to Yosemite's Tuolumne Meadows, the Belding's ground squirrels ( Urocitellus beldingi , syn. of  Spermophilus beldingi ) were particularly busy.   Belding's ground squirrels live in high meadows between 6,500 and nearly 12,000 feet in elevation.  Other open areas favored by Belding's ground squirrels include sagebrush flats and areas of mixed shrubs and grasses.  In addition to the Sierra Nevada, Belding's ground squirrels can be found in eastern Oregon, southwestern Idaho, and parts of Nevada.  They typically remain fairly close to a source of water. Belding's ground squirrels eat a var...

Late summer is a quiet time at our local Central Valley wildlife refuges, but anticipation hangs in the air.  The wetlands have been dry since the early part of summer, as they are drained after the departure of our migratory birds.  But in September, the dry marshes slowly return to life.  Soon, very soon, the birds will return! Last week, we took a quick trip out to Merced NWR to see how the wetlands are looking.  The marshes closest to the parking area and main observation deck are still dry, but three separate marsh areas along the back leg of the auto loop are filling with water.  Right now, Black-necked Stilts, Killdeer, White-faced Ibis and Great Egrets abound!  I was surprised by the number of shorebirds we saw!  There are yellowlegs, dowitchers and a few Least Sandpipers as well.  The first of the Northern Shovelers have also arrived. Sandhill Cranes  will start showing up a...

The North American Beaver ( Castor canadensis ) is unapologetically one of my favorite mammals.  Considered pests by some, this large rodent is a master ecosystem engineer and keystone species in its environment. During the 19th century, the humble beaver was nearly eradicated from the western United States, including California, through habitat loss, hunting and trapping for fur, and deliberate extermination.  The beaver is sometimes considered a nuisance species, since their enthusiastic lumberjack work may cause trees to fall across roadways, and their dams, ponds and levee burrows can cause flooding.  But it turns out that the beaver provides a suite of unexpected ecosystem services, including increasing wildlife habitat and water storage potential in the arid, drought-prone west.  Beaver lodge at San Luis National Wildlife Refuge, April 2017 Beavers are hydro-engineers and excel at altering the flow of water though the...

Birds' nests are some of the most intricate, strong and beautiful structures found in nature.  They range in design from little more than a divot in the earth to elaborate mud condos and woven wonders, from enormous stick platforms to diminutive, delicate cups.  Nests of North and South America's hummingbirds are among the smallest nests found in the world. While out for our daily walk a few weeks ago, I happened to look down at just the right moment and was delighted to find a hummingbird nest on the ground.  The nest was below a eucalyptus tree that is frequented by Anna's Hummingbirds ( Calypte anna ), and this nest almost certainly was built by a member of that species.  Presumably, the nest fell out of the tree before it served its purpose of housing young, as a used nest would be flattened (and soiled) from the rapid growth of the little birds inside.  Nonetheless, I was excited by this discovery, since I have long wanted to ...

For those of us living in the Great Central Valley, autumn is the time to head to the coast.  Of course, there is no bad time to visit California's magnificent coastline.  But as the heat and haze of summer drag on in the Valley, the sea becomes increasingly tantalizing: September and the onset of autumn bring sunny weather and an abundance of migratory seabirds and shorebirds to our coast. A new birder visiting California's Central Coast will undoubtedly be met with a splendid array of very confusing birds.  Among these are small shorebirds like  "peeps" (sandpipers), Sanderlings and various  plovers .  But the larger birds can be just as confusing, until you learn a few distinguishing features.  Four large shorebirds that are commonly seen (and commonly confused) along California's Central Coast are Godwits, Curlews, Willets and Whimbrels. Marbled Godwit (upper left), Whimbrel (upper right), Long-billed Cu...

Gulls are a fascinating group of birds, a group that seems to draw polarizing opinions from even the most inexperienced naturalist or quasi-outdoorsman.  To some, the "seagull" is a loud and brazen theft of picnickers' food, boisterous scavenger and fouler of pristine boat decks.  But to others, the group of birds known as the gulls is an intriguing bunch of intelligent, opportunistic, charismatic and slightly rougish birds; without their presence, our sea sides would be very dull indeed. Heermann's Gull in Monterey, California, expressing his opinion and dispelling rumors! There is no such thing as a "seagull."  Let us dispense with that falsity immediately!  (Likewise, "starfish" also do no exist; the correct generic term is sea star.)  The group that belongs to the family Lairdae, along with terns and skimmers, may be referred to generally as gulls, or specifically by each species' common name, such as ...