Ebird Checklist: https://ebird.org/checklist/S119151503
Date: September 21, 2022
Location: Rodeo Lagoon
Latitude, Longitude: 37.8307697, -122.5314747
Elevation: 10 ft (3 m)
Site Description: The whole of Rodeo Valley winds through the Marin Headlands and has grassy, wind-swept hillsides. The valley and the lagoon contain miles of coastal trails and backcountry and offer a habitat for many creatures, including birds, butterflies, and bobcats.¹ These coastal lagoons also support a variety of wildlife and vegetation, such as small plants and egrets, herons, ducks, and even migratory birds as well.² The lagoon environment also can provide a home to some less common creatures such as the brown pelican, an endangered species, and even rare fish such as the tidewater goby. The vegetation around provides habitats for many warblers and smaller finches as well. Similarly, the cliffs and offshore rocks that flank the area are havens for seabirds, and the lagoon also has loons, scoters, numerous species of ducks, and sandpipers.³ Below is a map of the topography of the area.⁴
Species Account: White-Faced Ibis – Plegadis chihi (Species name), Pelecaniformes (Order) > Threskiornithidae (Family). These birds are medium-sized with long legs, a thick, oval-shaped body, and a strongly curved bill with broad and fairly rounded wings. They have purple, green, and bronze plumage with a ruby-red eye and a sharp white mask with pink legs. Both sexes are between 18.1-22.1 in (46-56 cm) in length and weigh about 15.9-18.5 oz (450-525 g) with a wingspan of 35.4-36.6 in (90-93 cm). Although they may look dark and almost blackish at a distance, their color really pops out in the light and when they get close enough. White-faced Ibises are seen in flocks while foraging and nesting, and they feed by lowering their long, strong bill into the mud, soil, or water to sweep around and feel for prey. They stay in wetland environments with shallow water and exposed mud and also feed in farm fields or open areas. Salt, brackish, and freshwater marshes all provide foraging habitats. These birds eat mostly invertebrates, such as earthworms and insects. They are visual and tactile feeders and pick prey in both vegetation and on the water’s surface. Although the bulk of their diet consists of invertebrates, they can also eat vertebrate prey such as fish, frogs, and even small rodents, although they do stay away from seeds or plant material. The female usually selects the nest site from the ones that the male offers and is usually a flat platform made of vegetation. Although pair formation and mating systems have not been well studied, male and female preen each other and present material at nest sites. Both sexes play a role in nest building, and both also defend the area surrounding the nest and share incubation and chick-feeding duties. Resting birds also sometimes sunbathe to warm and dry themselves by raising their wings in an open position. White-faced Ibis population size has increased by almost 3% since 1968, and the species is a 7/20 on the Continental Concern Score, indicating a species of low conservation concern, although human interruption has caused many problems with nesting and egg viability.⁵
Picture from e-bird.
Picture from e-bird of flying Ibis.
Narrative: We left at around 8:15 or 8:20 am and arrived at the site at 8:42 am. The area was a brackish and semi-salt water lagoon. We stayed at the corner of the road that looked over the water and saw several species there. Then we circled back and went to the other side of the lagoon through a small trail where we saw two deer – a buck and a doe. There was a lot of excitement over that, and I even got a picture of them both. From the other side of the lagoon, where we had a high point, we could see both the water and the trees and short scrubs behind us, so we got several other bird species as well. Several of us were interested in going down to the beach, but sadly that did not happen this time around. We then spent a couple minutes searching for the rare White-faced Ibis, which we saw at a distance, before turning back around and heading back to the cars. We left at around 11:40 ish and got back at around noon. I managed to get several pictures of some very cool birds, so overall, this trip was absolutely amazing.
Additional photos or media:
Sources:
¹ Rodeo Lagoon/Valley. Golden Gate National Parks Conservancy. (2019, May 15). Retrieved September 27, 2022, from https://www.parksconservancy.org/parks/rodeo-lagoon-valley
² U.S. Department of the Interior. (n.d.). Wildlife of rodeo lagoon interpretive wayside (U.S. National Park Service). National Parks Service. Retrieved September 27, 2022, from https://www.nps.gov/places/wildlife-of-rodeo-lagoon-interpretive-wayside.htm
³ U.S. Department of the Interior. (n.d.). Rodeo lagoon birdwatching (U.S. National Park Service). National Parks Service. Retrieved September 27, 2022, from https://www.nps.gov/thingstodo/rodeo-lagoon-birdwatching.htm
⁴ Rodeo Lagoon Topo map in Marin. TopoZone. (n.d.). Retrieved September 27, 2022, from https://www.topozone.com/california/marin-ca/lake/rodeo-lagoon/
⁵ White-faced ibis life history, all about birds, Cornell Lab of Ornithology. , All About Birds, Cornell Lab of Ornithology. (n.d.). Retrieved September 27, 2022, from https://www.allaboutbirds.org/guide/White-faced_Ibis/lifehistory