February 2012 home page

Two Years of Birding the San Dieguito Lagoon
Ed Mirsky | Hoska Drive


Ferruginous Hawk. Photo Tom Grey


The San Dieguito Lagoon Area Monthly Bird Survey completed two years of monthly counts in December 2011. The 200th bird species, a Common Murre, was recorded in November and the 201st species, a Ferruginous Hawk, was recorded in December. There was a good turnout of excellent birders in December, and 123 bird species were seen. To put these numbers in perspective, the Penasquitos bird count, which extended from the Penasquitos Lagoon through Los Penasquitos Canyon, lasted for 26 years and recorded a little over 250 species.

The Common Murre observed in November was a great sighting. The Common Murre is a penguin-like bird of cooler northern oceans. It is abundant farther north in coastal California. Although it is regularly seen on pelagic trips in southern California, it is rarely seen from shore. The Ferruginous Hawk seen in December is a regular but infrequent visitor to San Diego County outside the breeding season. (During the breeding season it is found in the Northern Plains.)

The count is affiliated with the San Dieguito River Park, whose rangers oversee the area and give us entry to areas closed to the public. The survey area begins at the Pacific Ocean at the mouth of the San Dieguito River in Del Mar, and then it follows the San Dieguito river east to El Apajo road in Fairbanks Ranch. Along the way, it includes the salt marsh and ponds of the lagoon, the riparian habitat along the river, the grassy fields of the polo fields, and the ponds and grassy fields of the horse ranches in Fairbanks Ranch. The survey even includes Crest Canyon, where Torrey Pines and chaparral add to the species diversity. This diversity of habitats, all of which support the lagoon with nutrients, is the reason the survey produces such a large number of bird species.

Species abundance and numbers vary from month to month according to the migration patterns of the species. There is a core of some 36 species we see every month: Osprey, Snowy Egret, Horned Larks.... Add to that number various species that come to visit each month and the tally goes up to about 100 species per month. Then, in the spring and fall, migratory ducks, shorebirds, warblers and an assortment of other migratory species join the party.

The results of the bird survey may be seen on the Friends of the San Dieguito River Valley’s website at:





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