July 8, 2011
It never fails. Every year we have the same problem with dumpster divers. No it's not the hipster artist looking for obscure objects for his next sculpture, and it isn't the local freegan looking for her next luncheon. It's actually Western Gulls, Larus occidentalis.
Here's an image I captured on my way back from lunch on my smartphone.
It follows the same routine every weekday. Soon after the field trippers have exited the building they descend to the lawns and eat their lunches. About this time the gulls appear in a massive flock, like a reenactment of Hitchcock's, The Birds. The gulls around here are not as aggressive as others I've seen on my high school campus in the Inland Empire, or those at Seaworld that literally snatch burgers out of patrons' hands! Instead the gulls of Exposition Park wait for our school children to "finish" their packed lunches and put them in the trash. Soon after the gulls go to work on the overflowing trash cans. Garbage is strewn left, right, and center as the gulls are looking for a tasty morsel. All those half eaten sandwiches, leftover lunchables, and wayward McDonald's French fries, are consumed and the packaging is left behind as an unsightly reminder of the carnage.
The Western gull’s willingness to consider our trash its treasure illustrates a common trait of urban animals. Creatures who are able to thrive once their native habitats have been altered by humans do so in large part because they are adaptable. While bears and mountain lions have been pushed to the fringes of the city, animals that make the most of what is around them become successful urbanites. If you’re willing to eat trash—a plentiful commodity in urban settings—you’ve got a lot more options for breakfast, lunch, and dinner!
Have you seen any wildlife dumpster divers in your neighborhood?
June 23, 2011
Last week Sam got an awesome package in the mail, our new camera trap! On Monday afternoon he set it up behind the Butterfly Pavilion to see if it worked. We were also curious to see if we'd capture any interesting images. Boy were we in for a surprise!Night 1: Monday pm-Tuesday am
Our first cat tail caught on camera! We've known for a long time about the feral cats, Felis catus, that live in Exposition Park, but we weren't expecting to capture one of them on camera so quickly.
Just over an hour later this Opossum, Didelphis virginiana, sidled into view. Again we knew they were around as we'd seen their tracks in the mud.Night 2: Wednesday pm-Thursday am
When Sam showed me this picture, I was blown away! I definitely wasn't expecting the trap to capture a juvenile Cooper's Hawk, Accipiter cooperii, in this space. I am very curious to know why it landed here, was it chasing a rat or a mouse, or did it just feel like posing?
I'm pretty sure this is the same cat as in the first image. If it is the same cat, it obviously goes on the prowl after dark. Maybe we'll have to move the camera trap to the bird feeders next time.
Here's another view of an Opossum. We can't be sure if it is the same one, or if there's a family that lives in the park. There's a possibility that there's a den under the shed. I think we'll have to investigate.
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!