Wings Over the Riparian Preserve
Notes from the Naturalist
August and September saw the return of hundreds of individual birds to the Riparian Preserve as they migrated between their nesting habitats and their winter feeding grounds. Some migratory birds will spend the coming winter in the Preserve’s riparian and wetland habitats, while other migratory species spent only days or weeks in the Preserve to rest and refuel before continuing their long journeys into central and South America. Wandering through the Preserve’s four and a half miles of trails in October, I continued to observe bird species arrive on migration.
At least eleven species of beautiful warblers visited the Riparian Preserve this August and September. Some Yellow Warblers and Black-throated Gray Warblers were still flitting through the riparian foliage in October in search of insects. Yellow-rumped Warblers arrived to the Preserve where they will stay the winter, just as most of the other warbler species migrated southward. The Orange-crowned Warblers will also overwinter in the Preserve.
The welcome song of the White-crowed Sparrow, another migratory species, can be heard throughout the Preserve. They have joined their resident cousin, the Song Sparrow for the winter in search of seed. Abundant numbers of juvenile White-crowns survived their first migration, accompanied by good numbers of adults. Green-tailed towhees foraged for seed along the trails with the smaller sparrows.
Some of the other songbirds on migration in October include the sprightly Ruby-crowned Kinglets and Blue-Gray Gnatcatchers, as well as the Bewick’s Wrens, a beautiful but elusive female Northern Cardinal, and the delicately patterned Hermit Thrush.
A gorgeous male Costa’s Hummingbird allowed myself and other birdwatchers to admire him on the day the Riparian Preserve celebrated its twentieth anniversary.
No less delightful are the year-round residents of the Riparian Preserve. Anna’s Hummingbirds hover and zoom along the Preserve trails. The Preserve is an excellent place to see the Abert’s Towhee, a riparian species which occurs almost exclusively in the southern half of Arizona. Another abundant riparian bird, the Verdin are a treat to watch as they gather fallen feathers and soft plant matter to line their winter nests. House Finch and Lesser Goldfinch brighten the foliage with their color and song. Northern Mockingbirds and Curve-billed Thrashers are common in the hackberry trees. The boisterous calls of Gila Woodpeckers can be heard throughout the Preserve, along with the Ladder-backed Woodpecker. Good numbers of Gambel’s Quail run along the trails, evidence of the health of the Preserve habitat and the treasured sanctuary it provides. Come visit the Preserve where you can see “quail on every trail.” A more elusive creature, the Greater Roadrunner appears when least expected.
Birds of prey, including American Kestrel, Cooper’s Hawk and Peregrine Falcon can also be seen at the Preserve at this time. The beautiful Osprey or “fish hawks” here on migration are amazing to watch as they skillfully catch fish from the ponds.
Since the summer, the Preserve has seen the arrival of hundreds of shorebirds. I have recorded well over four hundred Least Sandpiper and almost that number of Long-billed Dowitcher during my biological surveys this month. They have joined American Avocet and Black-necked Stilt whose numbers have also increased noticeably this month. They and other shorebirds fulfill the important ecological role of eating large numbers of aquatic insect larvae in the ponds. Greater Yellowlegs are a less numerous, but conspicuous shorebird that are currently in the wetland habitats. I spotted at least a dozen Wilson’s Snipe hiding among the dirt clods in the shallows in October, along with the much more numerous Killdeer that favor the mudflats.
This month, the wetlands and mudflats are the backdrop for a cosmopolitan scene of a diverse array of water-loving species. The elegant Great Egret and Snowy Egret wade in the wetlands and shallow ponds in search of fish. The Great Blue Heron, Black-crowned Night Heron, Green Heron and Least Bittern also hunt fish in the Preserve. Of all the water birds, the most conspicuous and magnificent visitors are the American White Pelican, three of which arrived in October. These birds have eight-foot wing spans. While the pelicans are not feeding, they rest in the shallows, joined by bands of much smaller birds such as shorebirds and ducks who know the pelicans are gentle giants. Swallows fly gracefully over the ponds and along the water’s edge, and lots of Black Phoebe catch insects on the wing.
One of my favorite waterbirds, a fluffy pair of Pied-billed Grebe, can be seen serenely floating and then suddenly diving in the deep zones of the ponds. Another species of waterbird, the Common Gallinule has been spotted on numerous occasions, its more sedate behavior contrasts with the amusing antics of its more common relative, the American Coot.
Migratory ducks and geese have continued arriving to the Riparian Preserve in October. Diving ducks, most notably, the Ring-necked Ducks have joined the Canada Geese, Mallard, Northern Shoveler, Green-winged Teal, Blue-winged Teal, Cinnamon Teal, American Wigeon and Northern Pintail. These and the other migratory birds are the survivors. Their return is a triumph of endurance and their arrival brings with them the gentler days of autumn and the promise of more temperate weather to come.
Jennie Rambo, Naturalist
The Riparian Preserve at Water Ranch