Natural History Journal

In a state known for its incredible biodiversity , one county stands above the rest in terms of sheer number of species: San Diego County.  Tucked in the southwestern corner of California and bordered by two extremes - the Pacific Ocean to the west and the Colorado Desert to the east - San Diego county encompasses a wide range of habitats.  And within those diverse habitats live more species of wildlife than any other single county in the country.   On an early spring visit to San Diego county, we tallied up nearly 150 species of birds over the course of a couple of days as we made our way from quintessentially Californian chaparral-covered hills and sandy beaches, to arid desert scrubland and even out onto the open ocean. Yellow-crowned Night Heron As we wandered through salt marsh habitat at the Tijuana Slough National Wildlife Refuge, we were surprised by the abundance and prominence of Yellow-crowned Night Herons at this location.  These close relatives of o...

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 ...

Not all blackbirds are black birds. And not all black birds are blackbirds. Confused yet?  You're not alone. Distinguishing a blackbird from a mere black-colored bird involves more than just grammatical pedanticism: it's a matter of taxonomy.  Red-winged Blackbird (California bi-colored subspecies) Taxonomy may be defined as the systematic classification of living organisms into groups based on shared characteristics.  But taxonomy is not just for ornithologists; understanding how certain species are similar to each other can add a lot to the casual bird watcher's understanding of and appreciation for our avian friends. Tricolored Blackbird: Similar to Red-winged Blackbird in appearance, but endemic to California and entirely different in sound and breeding habits. When an ordinary casual observer of birds describes a bird as a "black bird," they're often referring to the bird's color: maybe the bird really is a blackbird, but it could just as likely be a ...

American Robins are one of the most common and recognizable birds across the North American continent.  They may also be one of our most beloved.  Their largeish size, distinctive coloration, beautiful song and tendency to favor the open grassy habitat of lawns and parks all contribute to the American Robin's happy status as a bird that even non-birders know and appreciate. Robins are at home in every state of the Lower 48 for at least part of the year, as well as nearly all of Alaska and Canada, and much of Mexico as well!  They are either residents in their range, meaning they stick around all year, or short-distance migrants that move south out of Canada and expand down into the southwestern U.S. and Mexico for the winter months.   Male American Robin, carrying food back to his nest.  CO American Robins are members of the thrush family, Turdidae, along with bluebirds, solitaires and, naturally, the thrushes.  Confusingly, the Eurasian Blackbird (fo...