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Archive for February, 2009

Bird Vocalization of the Month: Allen’s Hummingbird

by ocarmi on Feb. 26th, 2009 2 Comments

February species: Allen’s Hummingbird
Scientific name: Selasphorus sasin
Sounds: Anna’s song, Rufous’s buzz, Anna’s wing whirr
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Male Allen's Hummingbird
Male Allen’s Hummingbird, Selasphorus sasin

Photo credit: Sgrace

It is misleading to refer to this month’s blog entry as “Bird Vocalization of the Month.” The sounds I will focus on this month aren’t exclusively vocalizations. To add to that, it is probably unfair of me to refer to just one bird, because I will be discussing three!

I was walking across campus the other day, when I was stopped by a familiar sound I had not heard in a while—the buzz of a Selasphorus hummingbird.

Selasphorus (pronounced “sell-LASS-for-riss”) is a genus of hummingbirds, of which two species occur in the Bay Area. Birdwatchers use the term Selasphorus because the two species, Allen’s and Rufous Hummingbirds, are difficult to tell apart.

The reason I had not heard the buzz in a while is that Selasphorus Hummingbirds do not occur in the Bay Area year round. Allen’s Hummingbirds (Selasphorus sasin) breed in the Bay Area, and arrive by late January/early February. By late July they’ve all left for the “winter.” Rufous Hummingbirds (Selasphorus rufus) breed as far north as Alaska(!), and only migrate through the Bay Area. The first Rufous Hummingbirds to migrate north through the Bay Area do not appear until April or so, and on their move south, young birds (the last to migrate) do not start appearing here until the Allen’s Hummingbirds are all but gone. Thus, given the date, the Selasphorus hummingbird I encountered on campus was probably an Allen’s Hummingbird.

Male Rufous Hummingbird
Male Rufous Hummingbird, Selasphorus rufus

Photo credit: Rick Leche

A third species of hummingbird common in the Bay Area—the Anna’s Hummingbird (Calypte anna) —is found here in great abundance year-round.  Anna’s and Selasphorus hummingbirds look very different. Male Anna’s Hummingbirds, as shown below, are mostly green with an iridescent rose-red gorget and crown. Females are green, without the rose-red. Selasphorus hummingbirds, as shown above, are mostly green and rufous, and males have a brilliant orange-red gorget.

It was fun for me to learn to recognize the sounds produced by our local hummingbirds, because when I first heard them, I found them to be quite bizarre! For example, the song of the Anna’s Hummingbird sounds to me like a squeaky bike. The Cornell Laboratory of Ornithology’s All About Birds site links to a recording of an Anna’s Hummingbird song.

anna's hummer
Male Anna’s Hummingbird, Calypte anna

Photo credit: Len Blumin

The song of the Anna’s Hummingbird, and similar vocalizations of other hummingbirds, are produced in the syrinx—the vocal organ of birds. However, hummingbirds don’t produce sounds only by vocalizing. The buzz I heard while walking across campus was produced by the wings of the Allen’s hummingbird I encountered—males of Selasphorus hummingbirds have modified wing feathers that make this sound possible. Different species of hummingbirds have distinctive buzzes. For instance, check out a recording of the buzz of an Rufous Hummingbird, and compare it with the wing whirr of an Anna’s hummingbird (both recordings copyright NatureSongs 1997-2008).

The buzz or whirr caused by the wings of a hummingbird is a useful first cue that a hummingbird is present. If you hear a hummingbird buzzing, it is well-worth stopping and trying to spot it, because it is possible you may then be treated to a display dive! Display dives are used by males to attract females, or to ward off competing males from their fiercely protected feeding territories.

Each species of hummingbird has a distinctive dive pattern, which can be used to identify it. The display dive of an Allen’s Hummingbird consists of a series of swings, each one accompanied by an eerie, wheezy sound, followed by a high dive accompanied by a louder wheezy sound. The display dive of an Anna’s Hummingbird consists of a bout of singing in mid air, followed by a vertical rise and a fast J-shaped dive. There is a loud “pink” at the bottom of the dive. This entire display is then repeated multiple times. Researchers have long debated whether the beep (the “pink”) at the bottom of the dive is a vocalization or whether it is produced mechanically. Two researchers from the University of California, Berkeley, Dr. Christopher Clark and Teresa Feo, recently showed definitively through the use of a high-speed camera and some elegant experiments that this sound is produced by the tail of the hummingbird!

Your homework assignment: Listen to the recordings of these hummingbirds—especially to the wing buzzes and whirrs. See if you can notice these buzzes while spending time out of doors—you may be treated to an unsolicited hummingbird sighting!

Return of the Bay Area Ant Survey!

by megan on Feb. 19th, 2009 No Comments
Ant collection

Specimens received from citizen scientists! The collection grows…

Photo credit: Kelly Herbinson

Our beloved Citizen Science project is back in action!

The Bay Area Ant Survey is designed to give the public a chance to participate in Academy research by helping us obtain baseline data for ants living in local counties.

Major goals include:

• Documenting the ant diversity of the Bay Area

• Mapping the spread of invasive ants, including the problematic Argentine ant

• Creating a permanent collection of specimens for scientific research and teaching

• Allowing the community to experience scientific research firsthand

How does it work?
Citizens can participate by requesting an ant collecting kit from the Naturalist Center inside the California Academy of Sciences. Collecting kits include a data sheet, forceps, petri dish and a small vial filled with ethanol. All you have to do is collect ants, and send your ant-filled vial and corresponding data sheet back to the Naturalist Center. All specimens will be identified and databased by an Academy entomologist. Results are then uploaded to AntWeb where the location and identification of the ants are made public. Your contribution becomes a part of the scientific record!

What have we found?
So far the Bay Area Ant Survey has been a huge success! Over 800 citizen scientists have participated, finding a total of 34 different species. Better yet, twelve of these discoveries were new county records!

Can entire classrooms participate?
Of course! In fact, students have discovered ant species in their schoolyard that were never before documented as inhabiting our state. A more advanced version of the collecting kit is available especially for educators. Our Ant Collecting Classroom Kit includes all the resources you need to participate in the Bay Area Ant Survey as a class: a dissecting microscope, forceps, petri dishes, ethanol-filled vials, pooters, a hand lens, a dichotomous key to the ants of the Bay Area, and data sheets. To borrow this resource, a teacher must attend, or have attended in the past, the Ants in Your School Yard teacher workshop, which is next offered on April 9, 2009. Call 800.794.7576 (press 2, then 1) to register!
Argentine ant lateral view

The Argentine ant, though lovely in profile, has limited the distribution and abundance of native ant species. How might this affect the horned lizards of California?

Photo credit: AntWeb

What if I would rather use the basic kit for individuals?
Next time you visit the Academy, whether on a field trip, for a workshop, or with your family, stop by the Naturalist Center to pick up an ant collecting kit.

In Search of Scavenger Hunts

by megan on Feb. 18th, 2009 No Comments

We realize that many teachers using our database of exhibit-related activities in preparation for a field trip are particularly interested in scavenger hunts and museum worksheets. To make your search a bit simpler, here is a list of some resources that do not involve pre-teaching:

Tortoise from Madagascar!
This little one is featured in our newest scavenger hunt! Is it a turtle or a tortoise?
Photo credit: Michael Torres
Entire Museum
Tracking Turtles and Tortoises Scavenger Hunt, Grades 3-8

African Hall
Predator Prey Scavenger Hunt, Grades 3-8

Sketching in African Hall, Grades 9-12

Islands of Evolution
Lemurs and the Like Scavenger Hunt, Grades 3-8

Philippine Coral Reef
Is That a Fish?, Grades K-2

Rainforests of the World
Survive the Rainforest, Grades 6-8

Many scavenger hunts are associated with lessons that we call “Connected Experiences”. This category combines a pre-visit activity with an in-museum worksheet, so it involves about 20 minutes of pre-teaching before the field trip. Some of our most creative pieces are contained within this grouping, so don’t be intimidated by a short pre-visit activity:

And don’t think we haven’t noticed teachers bringing along their own masterpieces! There is no reason to let your hard work go to waste. If you feel comfortable sharing your personalized activity packets with other teachers, send them along to teachers@calacademy.org. I’ll gladly design them to match the look and feel of the official Academy scavenger hunts. I’ll be sure to attach a preferred credit line to recognize your creativity!

KQED QUEST Video: Chasing Beetles, Finding Darwin

by megan on Feb. 13th, 2009 No Comments

KQED QUEST recently televised a half-hour episode highlighting our own Senior Curator of Entomology, David Kavanaugh. Before presenting the video to your class, educators may be interested in reading the Producer’s Notes or downloading a Program Guide that includes further media-rich resources covering evolution.

How might Dave’s research on the Nebria genus in the Trinity Alps provide evidence for the adverse effects of climate change on beetle distribution? Learn more from an article in our Winter 2008 Member Publication, which complements this piece quite nicely.

Stream the episode below, or view the original video here.

Comprehension Questions:

1. In what type of environment does Dave often conduct his research on beetles of the genus Nebria?

2. When he discovered a new species in 1980 in the Trinity Alps, Dave named the beetle Nebria turmaduodecima. What provided the inspiration for this Latin name?

3. What did Dave notice about the two beetle species living in the Cascade Mountains of Washington? How did he apply this to his research in California?

4. What prediction did Darwin make that involved the co-evolution of two species?

5. Briefly state the main argument of natural selection, an idea proposed by Darwin in the mid-1800s. How does this idea conflict with some public perceptions of the origin and diversity of life, both then and now?

6. Who is Sean Schoville, where does he study, and how did he contribute to Dave’s research in the Trinity Alps?

7. What is the easiest way to determine if a insect specimen qualifies as a distinct species?

8. Why are islands often considered laboratories for studying evolution? How does this concept relate to the habitats supporting the beetles in question?

9. What analogy did Darwin provide his readers to illustrate how nature might selects for traits that influences an organism’s survival?

10. What aspect of natural selection was mysterious to Darwin? How can scientists today use our improved understanding of the process to demonstrate how species change over time?

Nebria riversi TYPE01619Nebria coloradensis TYPE05298Nebria lituyae TYPE13460

Did you know that you can view specimens in our Entomology collection via an online collections database?
I recommend the Types Collection, which features holotypes of over 50 Nebria beetle species. A holotype is a specimen used as the basis of the original published description of a taxonomic group, often serving as a representative of a newly discovered species.

A simple exercise: Interpreting labels in an insect collection
1. Surf to the Entomology Types Collection Database.
2. Conduct a search by typing “Nebria” in the Genus field and clicking “Get Types”.
3. Choose any beetle species whose record contains an image.
4. Search for key information about the specimen by reading those tiny pinned labels.

Some labels show data from the collection event. Those with the abbreviation “det” contain the identification information as determined by a researcher back at the museum. Because taxonomic systems change as new research is conducted, you’ll notice that some beetles were named decades after originally collected.

COLLECTION LABEL
Type number:
Location:
Date:
Collector:

IDENTIFICATION LABEL
Species:
As determined by:
Date:

Click on one of the beautiful beetles above to practice!