Natural History Journal

There are a lot of reasons to love California, particularly as a naturalist. The world's six major biomes, represented in California: Top row: Forest (Redwood State Park); Freshwater (Sword Lake); Desert (Joshua Tree National Park) Bottom row: Marine (Monterey Bay); Grassland (Stanislaus County prairie); Alpine tundra (Yosemite high country) California is a land of extremes, from submarine canyons to alpine peaks, from high heat and aridity to remarkable snow pack.  It boasts the tallest trees, the most massive trees, and the oldest [non-clonal] trees.  Within its borders, one can stand on the tallest point in the conterminous United States (Mount Whitney, 14,500 feet above sea level) as well as the lowest (Badwater Basin, 282 feet below sea level). In addition to the greatest difference in elevation, California also has the greatest range of latitude, the highest soil diversity, the largest range of average annual rainfall and the greatest range of average annua...

We're experiencing a beautiful spring here in California's Great Central Valley, with an abundance of water, wildflowers, and more butterflies than I've ever seen at one time!  One of my favorite places close to home to get out and explore a small piece of the Central Valley's grassland, wetland and riparian forests is the San Joaquin River National Wildlife Refuge.  A walk through its varied habitats is always an enjoyable experience, but there is something special about visiting during the spring. The San Joaquin River For those interested in botany, the looping, four-mile Pelican Nature Trail leads visitors through a mosaic of restored habitats, from upland vegetation to wetland and riparian plant communities where thousands of planted willows, oaks and cottonwoods are growing and thriving. View across restored riparian floodplain habitat toward the Coast Range. Native elderberry shrubs and wild roses are in bloom now, along with naturalized tree tob...

If you've been out and about much over the last week or two, especially in southern California, you may have noticed hundreds of fluttering gems filling the air.  Even in the Great Central Valley, the butterfly migration is underway.  The numbers of Painted Lady  butterflies are particularly high this year as the butterflies undergo their annual migration, traveling from the deserts of southern California and Mexico to the Pacific Northwest. This winter, high rainfall and suitable temperatures have created ideal conditions for annual wildflowers to germinate, bloom and flourish.  In fact, 2019 has already been labeled as another " super bloom " year in southern California!  If you can, don't miss the chance to get out to our deserts this spring and experience them in bloom!  I highly, highly recommend  Anza-Borrego Desert State Park ,  Joshua Tree National Park , and  Carrizo Plain National Monument .  (But places closer to home are...

Spring is a beautiful time in California's Great Central Valley - the grass is green, the wildflowers are in bloom, the wetlands and woodlands are teeming with new life.  But the season is all too short!  Soon, very soon, the heat will descend and the mercury will remain high until October or so.  In other words, get outside now, while the weather is pleasant!  May is an excellent time to catch the songbird migration through the Valley: flycatchers, vireos, warblers are particularly abundant during this season.   But even if you miss the small, flighty songbirds this spring, there is another type of winged wonder to capture the attention of the naturalist: butterflies!    Red Admiral on Brassica flowers, San Joaquin River NWR   The Red Admiral ( Vanessa atalanta ) is a familiar butterfly across North America.  It's colorful wings, which span nearly three inches, make it distinct enough to be accurately identified by begin...

Large, colorful and altogether conspicuous, the Western Tiger Swallowtail ( Papilio rutulus ) is among the most widespread butterflies of the western United States, as well as one of the easiest Californian butterflies to identify at a glance. Western Tiger Swallowtail feeding on thistle nectar at San Joaquin River NWR With a nearly four-inch wingspan and brilliant yellow wings patterned with distinctive black tiger striping, this swallowtail is hard to miss!  Tiger Swallowtails are equally likely to be found in woodlands, riparian areas and other wild lands as they are in backyards and suburban parks, provided nectar sources are present.  Adult Tiger Swallowtails feed on the nectar of a variety of plants, from wild thistles and our native California Buckeye, to backyard flowers like zinnias (I've even seen them on peach blossoms).  Likewise, females lay their eggs on several different host plants, including aspen and cottonwood (in th...

Earlier this week, I wrote about Sacramento's Gardens Gone Native garden tour and shared a few benefits of converting our exotic landscapes to natives.  Now, we continue the celebration of  California Native Plant Week (the third week in April) by highlighting a plant that is one of my favorites - and a favorite among birds as well - Blue Elderberry! Blue Elderberry ( Sambucus nigra ssp. caerulea , formerly S. mexicana ) is an excellent plant for a wildlife garden.  In the spring and early summer, it is covered in umbels of creamy white to buttery yellow flowers that are savored by butterflies.  By late summer, the flowers give way to clusters of dark blue berries which are relished by an array of bird species, including migratory species passing through and resident songbirds.  Blue Elderberry is also the only host plant of the Valley Elderberry Longhorn Beetle ( Desmocerus californicus dimorphus ), a Federally Threatened species. Along with ...

Last Saturday, I spent a very enjoyable day touring 13 of the 21 gardens featured in the 2018 Gardens Gone Native Tour, hosted by the Sacramento Valley chapter of the California Native Plant Society. The centerpiece of this front yard is a young Valley Oak (Quercus lobata).  It is surrounded by plantings of Silver Bush Lupine, Western Redbud, Deer Grass and more, all interlaced with inviting pathways and scattered with annual California Poppies. According to their website , "The purpose of the Gardens Gone Native Tour is to support the mission of the Sacramento Valley Chapter of the California Native Plant Society by raising awareness of the beauty and environmental functions of California's diverse native plants.  Our goal is to provide members of our community with the opportunity to view outstanding examples of native plant gardens, promote the benefits and use of California natives in home and public gardens, and provide information on how to ...

Ah, mistletoe, that oft-sought-after Yuletide greenery, that oft-maligned plague of landscape trees.  What is a naturalist to do with a plant that has been so misunderstood?  As always, a lesson in ecology is in order!  California is home to several native species of mistletoe ( Phoradendron spp . and Arceuthobium spp .), which are not to be confused with the few unfortunate occurrences of the non-native European mistletoe ( Viscum album ) found in Sonoma county.  European mistletoe was introduced to Sonoma county around 1900, ironically by the great horticulturist, Luther Burbank.  It is not terribly host-specific, meaning it will grow happily on a wide variety of plants, but it seems to be relatively contained to one small area north of the San Francisco Bay.  The vast majority of the mistletoe across California is exactly where it is supposed to be, contrary to what most of us have heard. Wi...

The Painted Lady ( Vanessa cardui ) is quite the cosmopolitan butterfly.  Found on every continent except Australia and Antarctica, it is considered by some to be the world's most widely distributed butterfly.  Additionally, it is one of the most common and familiar butterflies across all of North America.  Certainly the Painted Lady is a species that merits getting to know!  These pretty orange-and-black Lepidopterans are found in a variety of habitats, though they are perhaps most frequently encountered in open or disturbed areas, such as gardens and fields.  Females lay eggs on over a hundred different host plants, with thistles and mallows seemingly among their favorite.  Adults favor nectar from thistles and other members of the aster family, and will also partake of more standard butterfly fare, such as clover and milkweed.  Most of our Painted Ladies in California overwinter i...

When it comes to choosing topics to write on, I generally let the seasons dictate.  A walk outside reveals a host of ideas, and most often I like to write in keeping with current happenings in the natural cycle of seasons.  Hence, the autumn months ought to be filled with information on migrating Monarchs,  colorful leaves and the fall salmon run .  But at other times, an older photo jogs a memory or a book sparks an idea and I'll find myself reminiscing about the springtime desert in the fall, or summer in the Sierra during the depths of winter.  At still other times, a topic might not be as far-fetched as it may seem. Wildflowers, you might think, fall exclusively into the territory of spring and summer but that's not quite so, as California's mild Mediterranean climate tends to defy expectation.  With the start of what is supposed to be California's rainy season, autumn rather than spring marks the...