June 23, 2015
Cliff swallows have moved onto, rather than into the Museum! Last week, Kimball Garrett, Museum bird expert, reported finding a nest under the eaves of the building directly facing the historic LA Memorial Coliseum. As he got close enough to snap this photograph, Kimball observed a pair of young swallows peering out of their finely crafted mud dwelling.
Check out that architecture! The adult breeding pair work together to collect mud pellets from the immediate area and use their bills to transport and mold them into a viable nest. Cliff swallows, Petrochelidon pyrrhonota, have historically nested on our building–back in the 80s and 90s Kimball would see them every year–but recently they have been noticeably absent. We are not sure what has caused them to return, but we're definitely tracking their progress and hope they return next year. As their name implies, before humans came along these birds would build their mud nests on vertical cliff faces. Today, they are just as easily found nesting under freeway bridges, and in the eaves of buildings. Locally, cliff swallows are remembered fondly as the, "famous Mission San Juan Capistrano birds." For two centuries a celebration has been held for the annual appearance of these birds at the mission. The story goes that like clockwork the birds would show up on March 19th, Saint Joseph's Day, to nest on the old church buildings. But recently, due to urbanization, the birds have been bypassing the mission and nesting elsewhere. Although we don't have hundreds of swallows nesting at the Museum, we are an attractive enough site to host a nest–we have everything they need. A building where they can find good attachment points with physical protection from above, a decent supply of flying insects to eat, and mud for constructing their nest. However, as Kimball points out life in the city isn't easy for a cliff swallow, there are aggressive animals to deal with. The two creatures of concern are house sparrows, Passer domesticus, and unfortunately, us humans. In the bird world, house sparrows are notorious aggressors. They steal nests, destroy eggs, throw baby birds out of nests, and generally wreak havoc on all manner of other birds. Because house sparrows are not native to North America (they were purposefully introduced to the US in the 1850s) and are such a threat to native bird species, some bird enthusiasts choose to actively deter them and/or remove them from their property. It is important to note that, because house sparrows are an introduced species and therefore not protected by the Migratory Bird Treaty Act of 1918, people are allowed to remove house sparrows and their nests. Not true for the native cliff swallows. However, many home and business owners chose to illegally knock down swallows nests constructed on their buildings. We here at the Museum choose to celebrate our cliff swallows and all of the nature that calls our Nature Gardens home.