Janet D. Stemwedel (whose nom de blog is Dr. Free-Ride) is an associate professor of philosophy at San Jose State University. Before becoming a philosopher, she earned a Ph.D. in physical chemistry. Email her at dr.freeride@gmail.com.
Yes, there will still be Friday Sprog Blogging this Friday. No, Wednesday Sprog Blogging is not going to become a regular feature.
On the walk to school this morning:
Younger offspring: I wonder if we'll see that pair of crows or ravens on the field again today. I like how they can jump.
Dr. Free-Ride: Hey, you know how you asked me yesterday morning what the difference was between crows and ravens?
Younger offspring: Yeah?
Dr. Free-Ride: I did a little research to find out.
Elder offspring: So what's the difference?
Dr. Free-Ride: It turns out to be a little complicated. Ravens are actually part of the same grouping of birds as crows, the genus Corvus. And, if I'm remembering correctly, "corvus" means crow.
Elder offspring: So ravens are crows?
Dr. Free-Ride: Well, there are a few different species in the genus Corvus that are called ravens. For example, the common raven is Corvus corax -- its genus is Corvus and its species is corax. But there are lots and lots of species within the genus Corvus that are called crows. I'm guessing around here we'd be most likely to see the American crow, Corvus brachyrhynchos.
Elder offspring: Is the American crow's genus Corvus and is its species brachyrhynchos?
Dr. Free-Ride: You've got it!
Younger offspring: So what did we see yesterday?
Dr. Free-Ride: Hmm. What I read said that ravens are bigger than crows -- the crows we'd see would probably be about the same size as pigeons --
Younger offspring: The birds we saw were about the same size as pigeons.
Dr. Free-Ride: And ravens are more of a glossy black color that's almost bluish or purplish in the sunlight --
Elder offspring: The birds we saw yesterday were not bluish or purplish in the sunlight.
Dr. Free-Ride: Also, the tails of crows are shaped more like fans while the tails of ravens are shaped more like wedges.
Elder offspring: I wasn't really paying attention to the shape of the tail, but I'm pretty sure we saw crows.
Younger offspring: But ravens are crows?
Dr. Free-Ride: Well, ravens belong to the genus that's mostly crows. Corvus is a superset of ravens, and ravens are a subset of Corvus.
Younger offspring: Huh?
Dr. Free-Ride: Cheerios is a subset of breakfast cereals, so the set of all the breakfast cereals would be a superset of Cheerios.
Elder offspring: You could have done that example with fish and guppies instead.
Dr. Free-Ride: Yeah, but it's still close to breakfast time. Hey, I bet there's information on genus and species in a bunch of your nature guidebooks. That dinosaur one, certainly.
Elder offspring: I also have a rocks and minerals guidebook.
Dr. Free-Ride: But you won't find genus and species information for rocks and minerals, because they're non-living.
Elder offspring: OK, but there's still information about how rocks and minerals are categorized.
Dr. Free-Ride: Sure. One more thing I should tell you about the genus-species classification system for living things.
Elder offspring: What?
Dr. Free-Ride: The guy who came up with it, Carl Linnaeus, was born in Sweden 300 years ago today.
Younger offspring: Really?
Elder offspring: Cool!
Younger offspring: We should have cupcakes to celebrate!
Comments
I aspire to be a mom like you some day. Seriously. I always say that every moment is a teachable moment . . . and you make some damn fine teachable moments.
How old are your kids? I'm impressed that they know about genus, spp, subsets, etc.
Posted by: Leah | May 23, 2007 1:35 PM
and to think I just quoted something from Linnaeus in my thesis no more than 5 minutes ago. Happy birthday, Linnaeus!
remind me to brush up on my science before hanging out with the sprogs again. sheesh!
Posted by: JM | May 23, 2007 1:47 PM
Yay! A bonus Sprog Blog!
Posted by: Elf Eye | May 23, 2007 1:51 PM
Celebratory cupcakes are a great idea.
They're also a subset of cakes. Which reminds me I need to finish my donut.
Posted by: Warren | May 23, 2007 1:52 PM
You may want to read this post of Chris Clarke's from back in February on Ravens.
Down in the comments he gives some more Ravens/Crow distinguishing characteristics.
Posted by: JP Stormcrow | May 23, 2007 3:01 PM
Ravens tend to avoid heavily populated areas, whereas crows don't seem to care.
http://www.flickr.com/photos/cephyn/31087543/
note the curved bill. I also have a good pic of a HUGE raven I saw in Alaska - they were all very big there, nearly hawk sized. I may post it later.
Posted by: cephyn | May 23, 2007 5:40 PM
How old are your kids? I'm impressed that they know about genus, spp, subsets, etc.
They're now finishing up kindergarten and second grade. My impression is that they know a lot more than I did at their ages, but possibly I've just forgotten what I knew and when I knew it.
They are both voracious bookworms, which means they learn all sorts of stuff without our having to make any special effort to teach 'em. When we see sparks of interest, we try to be ready to fan them into flames.
Posted by: Janet D. Stemwedel | May 23, 2007 5:53 PM
We have urban ravens locally. They won't go into heavily built up areas, but I suspect that's due more to our urban peregrines and the relative lack of chow.
Raven territory is also shared by red-tailed hawks. Great Horned Owls and egrets have been seen in Balboa Park* BTW.
*Our city park. The San Diego Zoo is located there.
Posted by: Alan Kellogg | May 23, 2007 8:23 PM
If I remember correctly, young ravens will live in small packs (making a nuisance of themselves), and when older will leave the pack and pair up into couples to rear young. They are opportunistic and adaptible, so the most likely reason is that young, inexperienced birds would have a hard time making it and benefits from both the protection of, and the learning experiences gotten from a group.
Posted by: Janne | May 23, 2007 10:12 PM
Crows here in Oregon are e-nor-mous. Stark, the only raven I've ever had the pleasure of knowing, was a little guy. About the size of a local crow. (He died this last year at about 20 years of age.) So, at least in these parts, size can be deceptive.
A few months ago I bought the book "In the Company of Crows and Ravens" after attending an author talk. It's the "next" one on my list to read -- after I finish the books I keep checking out of the library. (Finishing up "Monkey Girl.")
Posted by: Gerry L | May 24, 2007 12:00 AM
but possibly I've just forgotten what I knew and when I knew it.
So will your NEXT CAREER be in politics? Looks like you won't need any more advanced study; your statement indicates you are ready now!
Posted by: Super Sally | May 24, 2007 11:12 AM