Living Along an Urban River: Birds of the San Lorenzo River

White-crowned x golden-crowned sparrow hybrid. Photo taken at the San Lorenzo River mouth, Santa Cruz, California. Photo courtesy of and © John Garrett. — White-crowned x golden-crowned sparrow hybrid. Photo taken at the San Lorenzo River mouth. Photo courtesy of and © John Garrett.

The San Lorenzo is the largest (and possibly the most beautiful) watershed in Santa Cruz County, spanning 135 square miles. The last stretch of the river with predominantly fresh water (little to no seawater influence) runs from the Highway 1 bridge to the Water Street bridge. This section of the urban river is home to a host of unique plant species including California sycamore, creek dogwood, and thimble berry.The generous populations of trees and shrubs in this section of the San Lorenzo River provide for a variety of beautiful bird species.

Song Sparrow. Photo courtesy of — Song sparrow. Photo by Factumquintus.

Sparrows and finches are among the most numerous birds. Song sparrows and house finches nest in the shrubs and trees along the banks all year round. Other year-round residents include black phoebes and swallows which often build nests on the nearby bridges.

House finch. Photo courtesy of — House finch. Photo by John Benson.

The violet green swallow, cliff swallow and the rough-winged swallow are cavity nesters meaning they build mud nests on bridges or buildings. They also dig holes along the muddy riverbank to nest in. Swallows are most commonly seen during their breeding season which spans late March to July.

Violet Green Swallow. Photo courtesy of — Violet green swallow. Photo by Alan Vernon.

Seasonal winter visitors include the white crowned sparrow and lincoln’s sparrow as well as the american and lesser goldfinches.

White Crowned Sparrow. Photo courtesy of Wolfgang Wander. — White crowned sparrow. Photo by Wolfgang Wander.

Listen to some of these bird songs here:

song sparrow
house finch
violet green swallow
cliff swallow
rough-winged swallow
If you happen to go out along the San Lorenzo and snap some pictures of the local birds we would love to share them. E-mail them to julia@mobileranger.com. We credit all photographers!

Learn more about the work of the Coastal Watershed Council and the San Lorenzo River Alliance here.

Take the Self-Guided Mobile Tour

This piece is part of the San Lorenzo River Tour by the Coastal Watershed Council. Download the free app with many tours of the Santa Cruz area and beyond.
1. Sources Used
  Lower San Lorenzo River and Adjacent Areas. scbirdingguide.org
  
  San Lorenzo Urban River Plan. City of Santa Cruz. June 24, 2003.
  
  Flood Control Failure: San Lorenzo River. Gary B. Griggs, Lance Paris. Environmental Management. 1982. Volume 6, Issue 5,pp 407-419.
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