Natural History Journal

Tree Swallows are, in my opinion, one of our most beautiful birds, with their pure white undersides and iridescent blue heads and backs.  As aerial insectivores that feed almost exclusively on flying insects, Tree Swallows are a great boon to have in the neighborhood.  Unfortunately, like many other aerial insectivores, their numbers are in decline .  As secondary cavity nesters, Tree Swallows' struggle for survival is exacerbated not only by a decline in the insects they feed on, but a lack of the natural cavities they require for nesting as well.  Secondary cavity nesters rely on nest cavities excavated by other species (usually woodpeckers), often in standing dead trees.  The widespread practice of removing such trees in recent decades has led to a sharp decline in available nesting sites.  And Tree Swallows aren't the only species that depend on these increasingly rare nesting sites.  Western Bluebirds, Ash-throated Flycatchers, House Wrens, White-...

The other day, while exploring one of the remaining patches of wetlands around my county, I came across a furry little critter that was a complete surprise for me: an American Mink!  Contentedly going about his (or her) business at the edge of the wetland, staying under the dense cover of an old clump of willows, the mink slipped out of sight before I was able to get a photograph.  But this mink sighting got me thinking about other mammals I've encountered here in California's Central Valley, and as it turns out... there have been quite a few!   California Ground Squirrel: A common sight in the Valley, and an important part of the ecosystem! Though the Central Valley is no longer the land of wild abundance it once was (at least not in terms of wildlife), more species of mammals than one might imagine still manage to make their living on the fringes of urban and agricultural land up and down the valley.  National Wildlife Refuges provide much-needed havens for a ...

In the world of birding, " Big Days " are competitions to see how many species of birds a birder can find in a specified area in just one 24-hour period.  They range from formal to informal, and the competition may be shared with others or simply with oneself.  This month, Eric and I were excited to set aside a whole day for our own, unofficial, just-for-fun "Big Day," setting ourselves the challenge of finding 100 species (or more) in our own county.   Here in North America, January is not the time of year when most Big Day birding events take place.  (In fact,  Global Big Day , a birding event in which birders from around the world participate, takes place annually in May - a much more reasonable season to be out birding!)  At this cold and often dreary time of year, many birds across much of the U.S. have migrated south for the winter, and most habitats are just too iced over to yield a great deal of bird diversity.   But here in the Cent...

During the first week of April, Eric and I spent six amazing days birding in South Texas, starting in the McAllen area and ending on South Padre Island.  Follow along with our journey here: Part I:  Lower Rio Grande Valley Thornscrub and Woodland Part II:  Coastal Prairie and Thornscrub Part III:  Gulf Coast Wading Birds Part IV:  South Padre Island Neotropical Migrants After moving down the Rio Grande River toward the Gulf of Mexico, we left the woodlands behind us and ventured out onto the coastal prairie of South Texas.  Here, we spent an incredibly windy April morning birding along Old Port Isabel Road, at Palo Alto National Battlefield, and, briefly, Laguna Atascosa National Wildlife Refuge.  The beautiful flowers of a prickly pear cactus In the open country of the coastal prairies, we spotted Scissor-tailed Flycatchers hanging out on barbed wire fences and powerlines.  This gorgeous flycatcher, with its long, elegant tail feathers and salmo...