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Friday, August 31, 2012

What's that Bird of Prey Eating?

We've had another visitor at the pond. Since it's a bird, Kimball was kind enough to write this week's post!


"Cooper’s Hawks, Accipiter cooperii, such as this adult, have frequently been recorded by Sam Easterson’s “camera traps” as they drink and bathe at the Natural History Museum’s North Campus pond.  These hawks are among the most conspicuous vertebrate predators in urban Los Angeles – a significant turn of events given that this species was on the National Audubon Society’s “Blue List” as recently as the 1970s.  The “Blue List” – a sort of early warning list of potential endangerment – included species “suffering population declines or range diminution in all or parts of their range.”  Cooper’s Hawk populations have rebounded spectacularly in part because of reductions in the use of certain pesticides, but also because they are now rarely persecuted as the pest their nickname “chicken hawk” alludes to.  

But the increasing population of Cooper’s Hawks in our region is not without ecological consequences.  These hawks, and other species in the genus Accipiter, are bird-eaters – they catch songbirds, doves, and many other kinds of birds by ambushing them with short flights over and through vegetation.  We don’t know the extent to which declines in populations of some urban bird species (such as the introduced Spotted Dove, which is now virtually gone from southern California, or the Inca Dove, whose population in the Tucson, Arizona region has plummeted) can be attributed by increased predation pressures by Cooper’s Hawks.  Careful observations by scientists and citizens – and Sam’s technological wizardry – may help us better understand the role of predators such as the Cooper’s Hawk in regulating populations of their prey species."

Thanks Kimball! Finally, here's some footage Sam's trap captured of the hawk taking a bath in the pond!


video

Friday, August 24, 2012

More L.A. Mushrooms

As I proclaimed in last week's blog, it's been hot! Not the sort of weather you would expect to be finding mushrooms in the arid Southwest. However, Carol Bornstein, Director of North Campus and  gardens found mushrooms on her way into work on Monday morning. As she parked her car, she noticed some yellow patches under a citrus tree. Upon closer investigation, Carol discovered they were clumps of emerging yellow mushrooms!

Needless to say, I was out there quick as a flash to snap some photos. This is what I found:


When I parked the next morning the mushrooms had completely changed!

 Picture taken by Patrick Tanaka, Museum outreach instructor

According to Florence Nishida, Museum research associate and L.A. Mycological Society member, this mushroom is likely Leucocoprinus birnbaumii. Although it doesn't have a common name, it is often encountered in potted houseplants and sometimes in mulch outside! Through my research, I have discovered that people can get quite frantic upon finding these mushrooms in their homes. In particular, MushroomExpert.com has an entire article about frantic questions received from homeowners worried about the dangers of this mushroom.

The good news is, they are practically harmless. The plant is in no way affected by this cohabitant and as long as no person or pet eats it, everyone will be safe and sound. So next time you find yourself wondering if you should pick and eat that little yellow mushroom, stop yourself and remember safety first!


Friday, August 17, 2012

We've Got Flying Neon Toothpicks in Our Pond

I admit it! I totally stole the title of this week's blog from my Facebook friend John Acorn, aka The Nature Nut. To be specific, I gleaned this gem of a title from one of his books, Damselflies of Alberta: Flying Neon Toothpicks in the Grass.

Today, instead of taking lunch like a normal person, I went out to the pond with Kimball Garrett to survey for adult Odonates. Odo-what? I mean dragonflies and damselflies (the flying neon toothpicks), the jeweled predators of the sky.

Among other things, Kimball and I found damselflies for the first time. Yay! Here are some pictures of what we found:

The first ever damselfly to be found in the pond!
Pacific Forktail, Ischnura cervula

Flame Skimmer, Libellula saturata, in Kimball's hand

Kimball also thought he saw a Wandering Glider, Pantala flavascens. Thankfully, Sam Easterson had snapped this picture earlier in the morning, confirming the presence of this impressive dragonfly.

Sam's shot of a Wandering Glider

So the list of Odonates in the pond has grown to 5 species:
Green Darner, Anax junius
Flame Skimmer, Libellula saturata
Wandering Glider, Pantala flavascens
Variegated Meadowhawk, Sympetrum corruptum
Pacific Forktail, Ischnura cervula

In other Odonate news, Black Phoebes love them! Here's the proof, from one of Sam's camera traps:

Tasty dragonfly lunch for a hungry Black Phoebe


Friday, August 10, 2012

Who are Those Ants in Our Homes and Gardens?

Lots of people in the L.A. area have been complaining about the heat. Over the last week, cities in our region have been experiencing temperatures well into the 90s. On Monday, Woodland Hills reached 108 degrees!

Whenever the temperature rises like this, I start to notice ants indoors. Only this morning during our Nature Lab meeting, I found a trail of ants leading to the sink, and another leading to the snack shelf.

The ants I found are Argentine Ants, Linepithema humile. They are an introduced species from South America (Argentina and Brazil) and are now considered the most common ant in our area. According to the Insects of the Los Angeles Basin book, these ants were "introduced to New Orleans before 1891 in coffee shipments from Brazil, and it has since spread rapidly over much of the United States."

This is what the same book has to say about their pest status:

"The species is one of the most persistent and troublesome of all our house-infesting ants. Argentine Ant workers seek out and feed on almost every type of food, although they are especially fond of sweets. Making themselves most objectionable, the ants invade the house through minute crevices and cracksfiling along baseboards, across sinks, and over walls and tables in endless trails."

How do you feel about ants in your home? While writing this blog, I've found it interesting to ponder this question. As you may have noticed I am a nature lover, however I am definitely not a fan of ants in my house and will go to great lengths to remove them. Many times this feels like a losing battle, especially because I'm not one for spraying pesticides all over the place I live.

Argentine Ant about to take drink of water in our Nature Lab trailer
(It is one eighth of an inch long)


The Argies, as we "fondly" refer to them, have also been found throughout the North Campus. This isn't surprising as it is well documented that this ant species has displaced many of our native ants. According to Alex Wild, author of the Myrmecos ant blog, Argentine Ants, "can drive native arthropods to extinction, instigating changes that ripple through ecosystems. In California, horned lizard populations plummet. In South Africa, plant reproduction is disrupted. Worldwide, the Argentine Ant is a persistent house and crop pest. This is not a good ant." Here are some pictures of their activities on the North Campus:

Argentine Ants killed all the paper wasps in this nest

Argentine Ants tending citrus scales in our orange trees

When I found the ants had killed all the paper wasps in the nest pictured above, I have to admit I was disappointed. I know many would be cheering for the ants, as paper wasps are viewed as a pest themselves. However, I had already become invested in the livelihood of that particular wasp nest and would check up on it every time I was out in the gardens. I find it infinitely interesting to ponder our notion of pest. What is acceptable in some circumstances is unacceptable in others. However, I still haven't come across anyone who is a fan of Argentine Ants!

Need tips of managing ants in your home? Check out the UC Davis Integrated Pest Management website.

Friday, August 3, 2012

Bugging Out in Arizona

Hey folks, I'm out of town this week at the Invertebrates in Education and Conservation Conference in Tucson, Arizona. Forgive me for not providing you with your weekly dose of L.A. urban nature, hopefully the images I'll share of the insects we're finding here in Tucson will suffice!

The conference I'm attending with Shawna Joplin, our Coordinator of Animal Care and Education, is put on by the Sonoran Arthropod Studies Institute (SASI). SASI is a non-profit organization devoted to fostering awareness, knowledge and appreciation of all nature through the study and interpretation of the vital roles arthropods play in the Sonoran Desert ecosystem.

I go to this conference every year to meet up with other entomologists, invertebrate educators, and of course the USDA staff who give us permits to operate our Butterfly Pavilion, and Insect Zoo. The most fun part of the conference are the field trips. Last night Shawna and I both went on one of the night lighting trips. Here are some images from our trip.

Mercury vapor night light set-up, look at all those insects! 

Male ox beetle, Strategus aloeus 

 Your author with poplar sphinx moth,
Pachysphinx occidentalis

Yes I admit it, I Instagrammed this glorious scarab beetle!
Chrysina gloriosa