Giacomini Wetland Restoration Project: Restoration: Giacomini Wetlands: A Haven for Ducks: Introduction

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Ducks near Dairy Mesa.

Perhaps, the most visible evidence of the early success of restoration efforts at Giacomini can be seen during the fall and winter, when thousands of birds are scattered across the shimmering expanse of blue. On a still day, the air reverberates with the sounds of flapping wings, splashing water, and the low hum/drone of chattering birds. The water that blankets the newly restored Giacomini Wetlands during the migratory season results in an explosion in waterbird numbers each fall and winter, and the numbers of these migratory converts continue to grow substantially each year. Numbers of waterbirds, particularly waterfowl, in Year Three greatly exceed that of Years Two and One, although shorebird numbers have varied dramatically since the levees were breached.

Tidal wetlands in the greater San Francisco Bay area region provide especially valuable habitat for migrating and wintering waterbirds (Shuford et al. 1989; Goals Project 2000 in ARA 2010), and Tomales Bay is part of a network of Bay Area coastal estuaries that support waterbird populations of hemispheric importance (Kelly 2001). Fall is a period of avian movement and migration, the transition of species between nesting territories and wintering grounds (ARA 2009). Overall waterbird use tends to be low in the fall, but migratory flocks "stop-over" to forage for brief periods before moving on (ARA 2009). As one of the key coastal wetland stepping stones for migrating shorebirds along the Pacific coast, Tomales Bay provides a crucial stopover feeding habitat (Kelly and Condeso 2009). Individuals may stay only a few days to refuel before moving on, or they may stay longer (ibid). During fall migration, first year birds select wintering areas they will to return to in subsequent years (ibid). Little is known about this selection process, but most of them will probably make this choice by mid-November (ibid).

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Great Blue Herons and Great Egrets in wetlands.

Before restoration, bird use of Giacomini was seasonally sporadic and rather limited. Pastures were used for roosting by Canada geese, Great blue herons, Great egrets, and mallards and nesting by grassland species such as Song and Savannah sparrows (ARA et al. 2002). The limited number of water features left in the dairy such as ditches and managed creeks also supported low numbers of Mallards, Gadwall, Lesser scaup, and Eared grebes (ARA et al. 2002). Occasionally, diving ducks such as Buffleheads used some of the old Duck Ponds created by the Giacominis for hunting (ARA et al. 2002). During the winter and spring, bird use would climb dramatically, with sustained flooding of lower elevation areas in the northeastern corner of the East Pasture, known as the Shallow Shorebird area. Dabbling ducks such as Gadwall, American wigeon, and Green-winged Teal stopped here, but the highest use probably came from shorebirds that would roost and forage here when tides were high in Tomales Bay (ARA et al. 2002). The most common shorebird visitors were Dunlin, Dowitcher, Greater yellowlegs, Common snipe, Willet and Killdeer (J. Kelly, ACR, pers. comm.).

With restoration, waterfowl use of the Project Area was projected to remain similar to historic levels or increase slightly, while shorebird use was predicted to increase more dramatically (NPS 2007). As the marsh had subsided--or dropped in elevation very little since first being leveed in the 1940s--the former dairy ranch was expected to convert relatively quickly to a marsh very similar to the one directly north of Giacomini, near Inverness. This tidal marsh is predominantly marshplain with an intricate network of intertidal tidal creeks. This type of habitat would have great value for foraging shorebirds, but, without large ponds or open water areas, ducks would not find the restored marsh that attractive. Also, with conversion of pastures to marsh, numbers of grassland-associated species were expected to suffer the largest decline (NPS 2007). What actually happened astonished all.

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<-- Page 1. What's Going on at Giacomini--in a Nutshell

Page 3. Year One -->

 

Giacomini Wetlands: A Haven for Ducks
Page 1. What's Going on at Giacomini--in a Nutshell
Page 2. Introduction
Page 3. Year One
Page 4. Year Two
Page 5. Year Three
Page 6. Conclusions
Page 7. Citations

 

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restoration includes:

Restoration Water, Water, and More Water How Long Will It Take For Tidal Wetlands To Develop? Two Years Later: Already Dramatic Improvements in Water Quality Giacomini Wetlands: A Haven for Ducks

Spring is in the Air--and in the Water Untangling the Food Web: Changes in Prey Base Following Restoration What's the Long-Term Future of the Restored Wetlands? How Can We Learn About the Restoration? How Can We Be A Part of the Restoration Process? Kids in Wetlands - Learning Through Experience Where Can We View the Restored Wetlands?

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