AgdaPkt 2004-09-13 - Laserfiche WebLink

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.q�2 The controversy at the Redwood Shores levee grew because the habitat was viewed in isolation from the rest of the Bair Island Complex. The controversy was focused solely on a small strip of a sloping levee wall. The assumed fragility of the Bird Island ecosystem was based in large part on the uncertain status of the Bair Island Complex. It drove many assumptions. Now, with the acquisition of the Bair Island Complex, these governments can use a broader palette to paint the future together. They can spread their plans out and distribute any impacts over a broader geography. New perspective means that we can, with better understanding, address the wider relationship of Bird Island with the greater refuge. In its proper perspective, Bird Island is additional habitat for California Clapper Rail on Outer Bair Island across Steinberger's Creek and adjacent to upland habitat and tidal refugia across Bay Slough. Clapper Rail survey data show a population on Bird Island of fewer than 10 birds. Since the rail data is gathered in the winter, we have no data to show if Bird Island is used as a rail nesting habitat. If rails are nesting at Bird Island, the results of that union (generally clutches range from 5 to 14 eggs) are not populating Bird Island. The Bird Island population, if a stable resident population at all, remains small. Bair Island has a much larger population and will always be the source population for the birds of Bird Island. On Bird Island, chicks and young adults are most likely either lost to predation (Redwood City Marsh, in FWS ownership, contains low elevation perch opportunities for raptors from abandoned pilings) or relocation to the larger habitat on Outer Bair Island. The levees at Redwood Shores were raised to a uniform 10 feet in order to protect public safety. Bird Island is marginal habit for the California Clapper rail. Rails build elevated nests out of grasses and sticks that are observable from above. In fact, the nests float with the ride. Clapper rail nests are perfectly adapted to protect eggs from rising water. Made of hollow, buoyant stems of cordgrass, they float up slightl�� with the tide. Rails build their nests far into the marsh where eggs and chicks are protected from predators. If surround.ing vegetation doesn't provide adequate cover, the ra.ils will cover the nest with loosely woven canopy of living or dead plant material. Bird Island is completely inundated during Bay high tide events. Although winter bird surveys show "pairing" behavior on the Island, there have been no known reports of completed rail nesting behavior on Bird Island. Outside of nesting behavior, the Bird Island habitat becomes completely inundated during high tide events. During inundation rails seek refuge in elevated areas such as the levee wall at Redwood Shores. It is the extent of danger ra.ils could be exposed to during these events that are crucial. Rails are uncommonly tolerant of 24