Bird Ecology of the San Lorenzo Lagoon Gary

Bird Ecology of the San Lorenzo Lagoon Gary Kittleson Environmental Consulting

Lower San Lorenzo River Study Area • Document all bird species • Assess relative abundances • Characterize patterns of occurrence and distribution through the fall migration period

San Lorenzo River Watershed 137 mi. sq. (87, 680 acres) Lower River Study Area 0. 14 mi. sq. (91 acres)

Summary Townsend warbler • A total of 202 bird species (and 26 other taxa) have been recorded in the project area. California towhee • The 2015 study team observed 103 bird species in the project area during September, October and November. • During 17 field surveys, a total of 9, 036 birds were identified and counted. European starling

Bird use in the San Lorenzo Lagoon is a reflection of the time of year and available habitat Habitat types ➢ ruderal grassland ➢ mixed riparian forest ➢ willow thickets ➢ freshwater marsh ➢brackish-water tule marsh Native riparian tree species present ➢ arroyo willow (Salix lasiolaepis) ➢ white alder (Alnus rhombifolia) ➢ yellow willow (Salix lucida ssp. lasiandra) ➢ black cottonwood (Populus tricocarpa) ➢ redwood (Sequoia sempervirens) ➢ box elder (Acer negundo)

1931 1940 Historic Habitat Conditions

2015

Flood Control Maintenance and Vegetation Removal Activities ➢Annual vegetation thinning and periodic sandbar “ripping” to minimize channel roughness and to encourage scour. ➢Annual maintenance program limits the size of riparian trees to <4” dbh, and creates 4’-10’ wide strands of immature willow, alder, cottonwood, and sycamore. ➢Annual maintenance activity limits bird nesting.

Marsh species ➢cattail (Typha latifolia) ➢ matted water primrose (Ludwegia peploides ssp. peploides) ➢ water smartweed (Polygonum amphibium ➢ bulrush (Scirpus californicus) The levee crests are paved and the levee-top ruderal community is regularly mowed and weed-whipped.

The tidally influenced areas downstream of Soquel Avenue Bridge have limited riparian habitat due to brackish conditions and vegetation management. The landside slopes of the levees were re-vegetated with native tree, shrub and groundcover species as part of the USACE/San Lorenzo River Flood Control and Environmental Restoration Project (1999 -2003).

Most Commonly Observed Bird Species San Lorenzo River in Fall 2015

Scrub jay Resident vs. migratory species Tropical kingbird

Nesting species Pie-billed grebe floating nest Cliff swallow Wood duck female with young Common merganser female with young Wood duck male

Breeding Species and Locations Cliff swallows, N. rough-winged swallows, pigeons, black phoebes, mourning doves on bridges. Pie-billed grebes and marsh wrens along the tule edge. Song sparrows, hummingbirds, and orioles in riparian thickets and mature trees. Red-shouldered hawk in eucs. at Hwy 1 bridge. Cavity nesters like wood-ducks, common mergansers and belted kingfishers upstream of Hwy 1 bridge in mature and decadent riparian trees.

Eared grebe Cedar waxwing

Raptor Species Merlin Osprey Red-shouldered hawk

Waterfowl, wading birds and shorebirds Great egret Spotted sandpiper Great blue heron

Species Residency Status Guild Canada Goose (Branta canadensis) Mallard (Anas platyrhynchos) Bufflehead (Bucephala albeola) Common Goldeneye (Bucephala clangula) Common Merganser (Mergus merganser) Ruddy Duck (Oxyura jamaicensis) Pied-billed Grebe (Podilymbus podiceps) Horned Grebe (Podiceps auritus) Eared Grebe (Podiceps nigricollis) Double-crested Cormorant (Phalacrocorax auritus) Pelagic Cormorant (Phalacrocorax pelagicus) Brown Pelican (Pelecanus occidentalis) Year-round Winter Grazer Dabbler Diver Winter Diver Year-round Winter Fisheater Diver Year-round Fisheater Year-round Pelagic Fisheater

Species Great Blue Heron (Ardea herodias) Great Egret (Ardea alba) Snowy Egret (Egretta thula) Green Heron (Butorides virescens) Black-crowned Night Heron (Nycticorax nycticorax) Virginia Rail (Rallus limicola) Sora (Porzana carolina) Common Gallinule (Gallinula galeata) American Coot (Fulica americana) Killdeer (Charadrius vociferus) Spotted Sandpiper (Actitis macularius) Wilson's Snipe (Gallinago delicate) Red-necked Phalarope (Phalaropus lobatus) Residency Status Guild Year-round Heron Year-round Year-round Winter Heron Rail Dabbler Shorebird Winter Phalarope

Kittleson Environmental Consulting 3284 Malibu Drive Santa Cruz, CA 95062 kittlesonenvironmental@gmail. com