Oh My, What Lovely Saddlebags You Have!

Quick Dragonfly Update!

I've documented another dragonfly visiting our pond. It was a Black Saddlebags, Tramea lacerata. My phone's camera couldn't capture a picture of this fast-flying critter, but I was able to send myself an e-mail documenting the find. Here's the e-mail:

"Saw a saddlebags by pond
August 22, 2012
3:00pm"

This brings our total number of dragonflies and damselflies to six species! Check out this recent post to see the the other five.

Black Saddlebags perching

Photo courtesy of JerryFriedman

Pond Babies: Dragonflies and Diving Beetles

Two weeks ago I told you I'd fill you in when I found dragonfly nymphs in our pond. I wasn't expecting to be able to give you this update so quickly, but SURPRISE, nature moves fast, people! In the last few weeks, I've found more than 50 dragonfly exuviae (the papery exoskeletons shed between molts) attached to the rocks of the pond. Of course, this prompted me to take out my dip net and look for nymphs in the water.

Here's a picture of one I found:

Variegated Meadowhawk, Sympetrum corruptum, nymph

Found May 5, 2012

While I was dipping for the dragonfly nymphs, I found a lot of other macro-invertebrates. The list isn't very long, yet, but includes immature mosquitoes, chironomid midges, mayflies, and predacious diving beetles!

Mayfly nymph found May 5, 2012

 Predacious diving beetle larva found in pond
May 4, 2012

I also found an adult predacious diving beetle

on

May 5, 2012



Who's Visiting the Pond?

On the tails (mammal and bird tails that is) of last week's post, I thought I'd continue to focus your attention on our wonderful new pond. Sam Easterson has set up some of his trusty camera traps next to the waterfall to see who might be visiting the pond. Check out the following images to see what he has found so far.

Nighttime is busy at the pond!

 Stray cat...sorry, there aren't any fish in the pond yet
and no you can't eat them when there are!

Opossum...no tin foil in the pond either.

Although these night time endeavors are interesting, I think the action during the light of day is even more so. Over the last few weeks, Sam's traps have captured over 50 images of birds hanging out by the pond.

American Crow, Corvus brachyrhynchos

That is one good bath!

Black-headed Grosbeak, Pheucticus melanocephalus,

 stops by for a moment.

 Western Gull, Larus occidentalis, going in for a drink.

Camera shy Swainson's Thrush, Catharus ustulatus.

Male Western Tanager, Piranga ludoviciana

For the grand finale, watch three bird species drinking from the pond at once! We've got a Mourning Dove, Zenaida macroura, on the far left, a Western Kingbird, Tyrannus verticalis, center frame, and a Warbling Vireo, Vireo gilvus, doing a fly-by.

 

Want to see more creatures caught on camera trap? No problem, check out lots more pictures and videos on our flickr pool.

InSEX: Mating's Risqué Business in the Insect World

Last night I hosted an InSEX dinner at an undisclosed and secret location. No, we weren't eating insects (in fact, we had a lovely vegetarian meal). Instead, we were discussing their weird, wonderful, and various reproductive strategies!

Vietnamese Walking Stick, Baculum extradentatum

A great example of asexual reproduction

I also took some impressive beetles to show off

Here's an excerpt:

Sperm Wars-Unlike honeybees, dragonflies don't have exploding penises. Instead, they have an equally impressive mode of sperm competition. When a male dragonfly grabs a mate—clasping her roughly behind the head—he carries her away for a nuptial flight. After some brief struggling, the male bends his abdomen around and inserts his aedeagus (that's insect for penis) into her reproductive tract. With his impressively spiked member he scoops out the sperm left over from a previous mating, thus ensuring it is his sperm and no other's that will fertilize the eggs she is about to lay...

But how does this all relate to the North Campus and L.A.'s urban nature? Simple—we found our first dragonfly at the pond! According to Museum Ornithologist, Kimball Garrett (yes, he does dragonfly identification too), this is a male Variegated Meadowhawk, Sympetrum corruptum. He was sunning himself on a rock, possibly waiting for a female dragonfly to make an appearance. Unfortunately for him, none showed up while I was there.

Over the next few months, the pond will attract more and more adult dragonflies and, soon enough, we'll have them mating. In tandem, the coupled dragonflies will approach the water's surface and the female will lay her eggs. Unbeknownst to many, the immature form of dragonflies actually live underwater! After the eggs hatch, the dragonfly nymphs will find a cozy spot to hide in the reeds. It's a dangerous and murky life down there, I mean who would want to get eaten by a fish? One way that dragonflies can evade predators is through jet propulsion. They pull water into their rectal chamber and eject it at high speed, thereby propelling themselves in a forward direction, and hopefully out of harm's way.

When they're not trying to evade their own predators, dragonfly nymphs are voracious predators themselves! They have extendable mouthparts that can be "shot" out of their heads in less than three one-hundredths of a second. This is very fast indeed, and allows the nymphs to sit and wait until something comes within mouth's reach. As you can tell, dragonflies are much more than just pretty insects good for putting on greeting cards and tattooing onto various bodyparts. I mean, what other creature can you think of that has jaws of death, rectal propulsion, and a highly modified penis for sperm removal?

Male Variegated Meadowhawk basking in the sun

Piranhas Found in L.A.!

Piranhas are the stuff of B-movies, sensationalized nature television, and the tropical rainforest. Most would think they have little bearing on life here in L.A., however as I learned last week, this is not the case.

Taxidermied Red Piranha, Pygocentrus nattereri 

"lips" removed to accentuate teeth

Piranhas are here in L.A.! They are sometimes confiscated from pet stores and, on occasion, they are even found in our waterways. The Museum's Ichthyology collection houses over 30 confiscated piranha, and at least one that was caught in the "wild." According to the collections record, this Red Piranha (see below) was netted from "Simi Valley Public Golf Course, Lake B." It was collected on April 28, 1988 and measured 275mm (almost 10 1/2 inches)! Most interestingly the capture method box of the record states that that the "fish was in distress." I wonder if the piranha would ever have been discovered had it not been in distress?

Before any of us decide to never go fishing for our wayward golf balls with our bare hands again, I have some happy news. Even in the Amazon basin, where Red Piranhas are native, humans are extremely unlikely to be injured by them, let alone die. The image of a school of piranha stripping all flesh from a whole cow or indeed a whole human, isn't much more than a sensationalized Hollywood gimmick (think James Bond's You Only Live Twice). This is because Red Piranha are actually scavengers preferring to eat dead, not living flesh. So next time you're fishing for your golf ball in the water trap, be safe in the knowledge that you're much more likely to get bitten by your neighbor's dog!

The Simi Valley Golf course piranha

Other piranha collected in L.A. come to the Museum directly from the California Department of Fish and Game (CDFG). CDFG staff often patrol pet stores and upon finding illegal creatures will confiscate them under California Law Title 14 Section 671. The fish are promptly brought to the Museum for identification and sometimes for permanent storage, though they may be taken briefly into a court of law as evidence! In May 2002, the Museum received 16 Red Piranha specimens confiscated from one pet store alone!

Red Piranha confiscated from pet store

I wonder if we'll ever find a piranha in the North Campus pond?

Today on the North Campus

I went out for a walk around the North Campus today and this is what I saw:

They are filling the pond to make sure there aren't any leaks and that the waterfall cascade is level.

Underneath the pedestrian footbridge is the best spot for mushrooms. I think this is a morel, Morchella esculenta. I am consulting with some mushroom experts to see if they can make a positive identification.

Apparently the Monarch caterpillar I found two weeks ago made its pupal case on a wall. I just love how green they are!

We're Building a Pond

This morning I got to work and did my usual cursory look out of the office window. This is what I saw:

 

Breaking ground on the pond

 

I know a hole in the ground doesn't get many people excited, but it definitely made my day. Working with the North Campus design team, we spent many months designing a pond that could increase the biodiversity of the North Campus and be a fun and engaging place for visitors. The pond will be teeming with wildlife such as fish, freshwater invertebrates, visiting birds, and hopefully a colony of Western Pond Turtles, Actinemys marmota. Here is a rendering created by Mia Lehrer + Associates, so you can get a sense of what the pond might look like.

 

View of pond facing the Age of Mammals exhibit

What is the North Campus?

We're taking the Museum outside! A new outdoor nature area is sprouting up around the Natural History Museum, bringing a fun and interactive park and habitat area right into the heart of the city. Think of it as the city's new backyard, filled with a range of garden environments and interactive opportunities for visitors of all ages to watch birds and search for bugs, stroll along a creek, ramble through a grove of trees, and gaze at butterflies and bees in a new Pollinator Garden.

For more details about the North Campus project check out our website.

To get you as excited as I am, here's a rendering of the pond by North Campus landscape designers Mia Lehrer + Associates