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.
December 28, 2011
A few weeks ago, Sam Easterson followed a trail of tin foil and discovered the den of a Virginia opossum, Didelphis virginiana, underneath one of the Museum's storage sheds. Since then he set up camera traps around the den to see what was going on. This is what we found...A night of tin foil escapades. What on Earth are they doing with all the tin foil? Tin foil hats to ward off alien thought control maybe?
All kidding aside, it seems that this opossum has extracted a tasty morsel from inside the shiny package and is taking it down into the den.
Afternoon stroll?The next day, one of the opossums emerges for a late afternoon jaunt in the park, and takes a peek at the camera trap!Running away from Museum security!Can you see the flash light?Doing the Chores Finally, we caught lots of images of the opossums collecting leaves with their tails! Their prehensile tails are a great tool for grasping small objects and are sometimes used for hanging upside down in trees. Though the notion that they sleep hanging upside down is a myth, their tails are not strong enough to hold them upside down for an entire night.
Wait, there's more tin foil!What is in store for 2012? Sam's got a few tricks up his sleeve, which I'm not willing to reveal just yet. Suffice it to say that we're all hoping there will be babies in the spring! Happy 2012!
May 26, 2011
I know you've seen a lot of still images from the Black Phoebe, Sayornis nigricans, nest, but I just had to share this footage. Honestly, it is too good not to post. At the beginning of the video you'll see one of the adults (hard to tell if it's the mom or dad, they both help to care for the nestlings) feeding a European Honey Bee, Apis mellifera, to one of the young. This in and of itself is pretty awesome to see, but it gets even better! Remember the Bushtit post? I told you all about how some species of birds produce fecal sacs, to make it easier to keep the nest clean and disease free. Well, Black Phoebes also produce fecal sacs, and this video gives you an insight to this behavior. I'll let you judge for yourself whether you think it's gross, cool, or just plain interesting.
May 17, 2011
Here is a quick nest update for the Black Phoebes, the babies have hatched! Sam was able to catch these images of the action.
Mom on the nest
Clamoring for food
Done with food, not clamoring anymore...
May 6, 2011
More Nest SurveillanceThis week we found another active bird nest! This nest belongs to a pair of Black Phoebes, Sayornis nigricans, and is built under the eaves of the Rose Garden maintenance shed. Once again this find is thanks to Kimball Garrett, who noticed the nest Monday morning on one of his regular Expo Park bird surveys. Footage of the phoebe landing on her nestNaughty NeighborsThis is the second nest Kimball has found in this location this year, but it is a site that has been used by phoebes in past years. Unfortunately, this year's first nest was disturbed by unknown causes, but it is possible that a squirrel is to blame. Eastern Fox Squirrels, Sciurus niger, are very common in Expo Park, and they are known nest predators. When they locate a nest they will eat any eggs or young birds they find. We'll never know for sure if a squirrel is to blame for the first nests' failure, but fortunately the phoebes persevered and built a second nest.
Eastern Fox Squirrel on top of the Butterfly PavilionBetter Luck This TimeUntil today we were not sure if the new nest contained any eggs. This morning Kimball and I went out with a mirror and now we can confirm there are four eggs!
Kimball checks out the nest
The mirror reveals four eggs in the clutchNow that we know there are eggs, we are going to regularly monitor the nest. I'll keep you posted as the eggs are incubated, they hatch and then the immature birds develop. If we are lucky, we'll be able to document the entire process.
April 29, 2011
A pair of Bushtits, Psaltriparus minimus, just built their nest in the live oak tree behind the Butterfly Pavilion. Kimball Garrett, our resident bird expert, found the nest this Monday and promptly sent me an e-mail detailing the nest's location. As soon as I got into work on Tuesday morning, I headed out to the Butterfly Pavilion to check it out.
Adult Bushtit, Psaltriparus minimus
Thankfully Kimball had given clear instructions to find the nest, as it was very well hidden in the oak foliage. The effort was well worth it, as it was one of the coolest nests I've ever seen in the wild. As the picture below shows their nests are woven from dry plant material and hang from branches of the tree. They are small and dainty, this one measures about seven inches from top to bottom. The small opening at the top of the nest, which is only about an inch in diameter, is just big enough for the adults to enter and exit.
Bushtit entering nest
After spending a good portion of my morning watching the nest, I realized I had to blog about it. But what is a blog without images, or even better some actual video footage. I ran up to my colleague, Sam Easterson's office to see if he could get some for me. Sam recorded the nest for about an hour, and we captured some interesting behaviors, including removal of fecal sacs! A fecal sac is clean, tough membrane that encloses the excrement of young birds. Not all birds produce fecal sacs, but for those that do sacs are usually produced directly after each feeding and promplty removed by the adult to maintain a clean nest interior.
Bushtit cleaning nest
Sam Easterson is a video naturalist and also our new Media Producer for the North Campus and Nature Lab exhibits. He's really into implanting cameras into natural environments, and is best known for his animal borne imaging work.
April 1, 2011
165 and Counting...Earlier this week, Kimball Garrett, NHMLA Ornithology Collections Manager, spotted a not-so-common sight, a pair of Rufous Hummingbirds, Selasphorus rufus, in the Rose Garden. This hummingbird species is now number 165 on Kimball's Exposition Park Checklist. Over the last 28 years, Kimball has been keeping track of all the birds he sees in Exposition Park, even those that are just doing a fly-over!
Male Rufous Hummingbird An Annual MigrationMost of the year Rufous Hummingbirds cannot be found in our region, but in March and April they are often seen passing through. Every year this bird makes an over 3,000 mile migration from its overwintering grounds in Mexico to the Pacific Northwest. It is easily confused with one of our local hummingbirds, the Allen's Hummingbird, and so is often missed in species counts (maybe that's why it has only just made it onto Kimball's checklist). Males of both species have red-brown markings on their sides and tails, but only the Rufous Hummingbird also has them on its back. If you have a hummingbird feeder in your yard, keep your eyes open for this hummingbird stopping by to fuel up!