First Baby Oaks Sprout Up in the North Campus

The North Campus is the proud parent of some baby oak trees!

Baby coast live oak sheltered by wall

Carol Bornstein, our new Director of the North Campus Gardens, discovered a couple of oak saplings on one of her recent outdoor forays. The babies are coast live oaks, Quercus agrifolia, of which we recently planted several trees. We've also planted another species of oak, the Engelmann oak, Quercus engelmanni (we planted only three of this species). Both species reside in the section of the garden called the urban wilderness which is composed of several kinds of California native trees and shrubs.

This might be the mother oak!

Oak trees provide amazing habitat value, and this is the main reason we planted them. By putting in such a  sizable stand of oaks we're hoping our created wilderness will provide habitat for a whole slough of organisms rarely, if ever, seen before in Exposition Park. In just one oak tree it would be easy to find hundreds of species of associated plants and animals and thousands of individuals (think how many birds, ants, or squirrels you find in an oak tree). One species that has already shown up with our oaks, is a tiny insect called a whitefly.

Crown whitefly nymphs on oak leaf

(each nymph is only 1 millimeter long)

It was once again thanks to Carol, who was out inspecting our lovely oaks, that we discovered these small insects. At first we thought they might be a scale insect, but Brian Brown, the Museum's Curator of Entomology, identified them as crown whiteflies, Aleuroplatus coronata. As adults these small white homopterous insects (group of insects consisting of aphids, cicadas, scales, etc) fly around to find a suitable location to lay their eggs. For the crown whiteflies their plant of choice is oak. What you see in the image above are the nymphs (immature forms) of the whitefly, they have no wings but are covered with white waxy secretions that make them look like little crowns. The nymphs feed on the leaf's juices by piercing and inserting their mouthparts into the leaf. They can cause damage to the plant's health if their numbers are high enough, and they can also transmit disease organisms from one tree to another (not unlike mosquitos transmit malaria).

Go check out your local oaks and see what animals live on them!

Feral Parrots

Have you ever seen a wild parrot in L.A.? Like many other North American cities, Los Angeles has a healthy population of many species of parrots, the most commonly seen of these species in Exposition Park is the Yellow-chevroned Parakeet, Brotogeris chirri.

Yellow-chevroned Parakeets feeding on coral tree nectar

Jail Break!
People like to keep parrots as pets. To satisfy this demand, literally hundreds of thousands of parrots have been imported legally (and untold numbers illegally) into the United States over the past 50 plus years. In some cases this demand has lead to demonstrable drains on natural populations and even endangerment of some species. Inevitably, imported birds escape or are released, and over the decades enough free-flying parrots have survived to establish breeding populations in the U.S.A., particularly in metropolitan areas of south Florida and Southern California.

Time to Get Liquored Up

If you’ve never seen a feral parrot around L.A. you might start looking for them in trees. At this time of year the parrots can be seen feeding on blossoms and nectar in flowering coral trees in the genus Erythrina (see picture above). This behavior is not unique to feral parrots as coral trees also appear in their native range. However other food sources they exploit in this region, such as Eucalyptus, are not found in their native range which is another example of adaptation to our altered L.A. landscape.

Yellow-chevroned Parakeets are native to Brazil and adjacent areas, and were introduced to L.A. earlier this century. No one knows exactly how the introduction happened, but we do know it was from parrots that were imported here for the pet trade.

Bushtits Move In

New Neighbors

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

Nest Hunt

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

Bushtit Behavior

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.

New Trees for Transition Garden

This week we have been planting trees in the Transition Garden.

Before I launch into an animated discussion on the individual plants we've chosen for the space, let me give you a basic primer on what the Transition Garden is all about. Firstly, this is the space that ramps you up from the lower level of our new Car Park to the Entrance Plaza where you'll get your tickets. It is a nice gentle slope, so it will be easy for people of all abilities to make their way into the North Campus. It is also a stepped garden on a fairly severe slope. With these points in mind Mia Lehrer + Associates (ML+A) had to design a garden that would function physically, biologically, and thematically (we wanted more than just a random selection of plants). Thanks to ML+A this garden tells a great story.

The Story of Plant  Introductions in Los Angeles 

The plants that exist in L.A. today are a mixed and varied bunch, a real representation of our altered nature. They have been brought here purposefully and sometimes accidentally. As one enters the ramp from the lower deck of  the Car Park you'll encounter plants introduced to L.A. over the last 200 years. So far we have California Pepper Trees, Schinus molle, from Peru; iconic Los Angeles palms, Washingtonia robusta, from northwestern Mexico; Olive trees, Olea europaea, from the Mediterranean basin; Citrus species from Asia including Eureka lemon and oranges; and finally Red Ironbark Eucalyptus, Eucalyptus sideroxylon, from Down Under. Check out this picture to see the progress!

     Photo by Cordell Corporation