Recent Posts ~ April 2018
Recent weeks have seen three new additions to our roster of local park profiles:
- Mount Burdell: a wonderland for spring songbirds, lush wildflowers, and magnificent, verdant oaks.
- Olompali State Historical Park: the other side of Mount Burdell, with shadier woods and a rich human history.
- Stafford Lake: rich in both winter ducks and a hotspot for arriving tropical songbirds like Bullock’s orioles and western kingbirds.
In other news, we assembled a fairly exhaustive appreciation of one of our chief avian stars of summer: orioles. And on the practical side of things, we presented a nice, handy lesson on how to use binoculars while avoiding common mistakes and frustrations.
Slightly farther back in the rear-view mirror were a few February posts of continued relevance, including an introduction to Backyard Birdsong and a two part entry covering first our local Neighborhood Hawks and then venturing beyond the residential neighborhoods to survey our Wildland Hawks.
This Month in Nature: April
We’ve now officially passed the equinox, with even the laggard calendars now admitting what many birds have been saying for months: it’s spring! The hills are speckled with a thousand wildflowers, trees have unfurled their billowing green photosynthesis factories along every branch, and dawn birdsong eases us further into the season with each morning that arrives.
- Orioles are here! These brilliant golden birds winter in Mexico, then move north for nesting. They are attracted to nectar feeders, jelly feeders, and palm trees for nesting. Read more on orioles.
- There’s still time to put up bird houses, but not much! Bluebirds, swallows, and ash-throated flycatchers will begin construction soon. See the store website for more on attracting birds with nest boxes.
- Sparrows and other winter birds are leaving. In most yards, this tends to result in an overall decrease in bird activity as ubiquitous white-crowned and golden-crowned sparrows head north and many other species break up their winter flocks in favor of more distributed nesting pairs.
The Beginning of the Thick of the Nesting Season
Birds, like many animals, time their breeding season to coincide with longer days, kinder weather, and greater food abundance. Many birds are now establishing nest sites and starting construction, with the first batch of birdhouse-using birds like titmice and chickadees already on eggs. You still have a little time to put up nesting boxes for later-nesting individuals and for bluebirds, as well as for the migratory house-users like tree swallows, violet-green swallows and ash-throated flycatchers who will be searching for nest sites over the course of the month. On average, the house-using birds nest relatively early in the year (an enclosed cavity will help protect from late winter storms), while many more birds that build more exposed nests will lay eggs in April and May.
April’s flurry of nesting activity also sees the peak of the “dawn chorus,” the morning torrent of birdsong that rises with the sun on each spring day as birds vie to impress both would-be territorial rivals and potential mates with their heath and vigor. Song will continue over the next few months, but will gradually decrease in volume as birds move from the early “impress the ladies” phase to the later “shh! don’t tell anyone we have a nest” period. In your backyard, some of the prominent members of this ensemble might include oak titmice, juncos, Bewick’s wrens, spotted towhees, robins, or mockingbirds. If you go out to a diverse native woodland early in the morning, you’ll hear an even more varied rendition of the dawn chorus, with purple finches, Hutton’s and warbling vireos, and newly arrived orange-crowned warblers adding to the music. If you’d like to get started learning the songs of our most common local birds, take a look at our Backyard Birdsong article.
New Birds for Summer
In backyards, bird activity decreases overall in summer, as many seed-eating birds head north for nesting and are replaced by a more limited palette of tropical insect-eaters. The most notable of these are the hooded orioles. The first orioles have already appeared, with more of these migrants from Mexico appearing during the first weeks of April. Orioles can be attracted to feeders offering jelly or sugar water, but you have to have the right habitat around to keep them in your yard throughout the summer. Hooded orioles nest essentially exclusively in California fan-palms, a tree native to southern California, but which has been planted extensively enough to expand the oriole’s range into our latitudes. The Bullock’s oriole is less common in yards, but can be seen using oaks and other native trees at places like Stafford Lake or Mount Burdell.
Early spring (Jan-March) saw the arrival of Allen’s hummingbirds, tree swallows, and violet-green swallows. But the migrants continue to trickle in during March and April, with a number of largely insect-eating birds moving into the canopies of our woodlands and forests. These birds include warblers (orange-crowned and Wilson’s), flycatchers (Pacific-slope and ash-throated), western kingbirds, and warbling vireos. There are a few seed-eating summer birds, notably lazuli buntings, lark sparrows, and grasshopper sparrows, but all of these birds tend to avoid yards in favor of wild habitats that provide appropriate nesting sites.
The Long Goodbye
Meanwhile, golden-crowned and white-crowned sparrows—among our most abundant winter birds—become pretty scarce by mid-April, as do Townsend’s warblers, yellow-rumped warblers, and ruby-crowned kinglets. The slow exodus starts in March and will limp into May, but April is typically the month when you suddenly lift your head up, look at your feeding area, and notice the sparrows are gone. So say farewell until October!
In the wider world of bird diversity beyond the yard, April also sees a marked decline in our local duck and shorebird populations. Many of these birds are here only in winter, with ducks like pintail, bufflehead, canvasbacks, shovelers, wigeon, teal, and ruddy ducks already on their way north. Shorebirds like willets, godwits, curlews, sandpipers, and dunlins are close behind, with numbers decreasing over the course of this month and May. Some of these shorebirds can be seen in their more colorful breeding plumage before they make their big trip, so take another look at them before they go!