Pardon me, are you going to use those beans...?

"Hunger is a powerful incentive to introspection."
. Willa Cather, "The Burglar's Christmas," Home Monthly, Dec. 1896

Today was 'mark-recapture' theory day in my Ecology II course. First-year students, and a preparation for our trip to Waterberg where we'll be doing game counts and a mark-recapture exercise with small mammals. 'Mark-recapture' describes the process of capturing, marking, releasing, and recapturing animals to obtain data used to estimate population size. Animals can be marked with tags, paint, bands, etc.

The traditional way to explain the notion of sampling a population with mark-recapture is to use dried beans. Students take a handful of beans (unknown number) and count out 20 beans. The students use a marker to place a 'mark' on the beans. Then the 20 beans are thrown back in to the original handful, mixed up (like animals milling around) and another sample of 20 beans are selected. In this second sample, some proportion of beans will be marked (say, 30%). If 30% of that sample are marked, it infers that 30% of the entire population was marked the first time and you can estimate the population size. For those of you playing along at home, you should try it. The formula is: Total number of beans = (number marked first time*total number sampled second time)/number of second sample that are marked. It actually works best if you take bigger samples than 20--try 40 or 50 each time. Same reason biologists struggle to get large sample sizes--more precise estimates.

Today, the exercise started out a little differently. One of the students, Theofilus, asked me, "Sir, why are you wasting these beans?"

"I'm sacrificing them to teach you a lesson," I told him, winking. Did I mention I really like being called "Sir" by students?

"They taste like nuts," he said, as he munched on one of the dried, white kidney beans.

"I think you are supposed to cook them for a couple hours, Theofilus," I said. "And, be careful, you're causing mortality to your population before we even get started!"

The exercise went very well, as usual. But, when it was over, I didn't get any of the beans back.

Clean underwear and moving fast in the blogosphere

I had two wonderful grandmothers, both of which offered advice which can be used to help live a good life. One of Grandma Griffith's pieces of wisdom: "Always wear clean underwear, because you never know when you're going to be in an accident."

Grandma Powell offered: "If you keep moving fast, no one will notice if you've spilled something on your shirt."

I guess the take-home message from combining these is that being dirty is OK as long as you keep moving fast and stay out of accidents.

This whole blogging thing is new to our family, and it's been a lot of fun to share with people around the world. I tend to really enjoy finding gadgets to add to the blog--all the little things that tell you the temperature in Windhoek or show a map of where people come from to the blog. The latter has been especially fun to watch, and it helps us know who has been here. It is also a little scary.

One of the FEEDJIT gadgets shows what city people come from to the site, and also which web page they were on before they visited the site if they followed a link to get here. Did they follow a link from Facebook, the School of Natural Resources, another blog? If people found the blog via a Google or Yahoo (or other) search engine, it also shows that information, and it shows what they searched for.

It's most common for people to be searching for "Namibia sand dunes" or "Nebraska Sandhills" before they stumble onto our site. The photo we took of Windhoek on our first day in town regularly gets hits from Google Image searches--appearing high in the list of images of Windhoek. We're fairly certain that people mostly go away disappointed when they find us through these searches, as we don't really have information about the Sandhills or Namibia's sand dunes--except that they are both fun places to visit.

From time to time, there are other interesting searches that propel people to our site.

"Aluminum windows windhoek" got someone to the site. I'm sure they were disappointed.

"Apple" was a recent search for someone in Mexico who came to our page. I wonder how deep in the search results that person was before he found our link? Maybe it was the apple cake recipe we posted before we left Lincoln?

"Windhoek dentists" also got someone to our site. I'm really not sure that we've used the word 'dentists' before, but now we have....uh oh! I guess we will now have people find us when they are interested in how to 'clean underwear'. It's all about key words and the luck of the search engine.

I guess the message is that, if you also blog, your blog is out there on the internet for the world to see. And, according to my grandmothers, you have two options. One: you can keep it clean so that everyone in the world will find it acceptable. Or, two: you can just keep moving quickly in case you make a mistake. Those who know me know that I really try hard on the first tip, but most often have to rely on the second to save me.

According to these 'tips for blogging', I'm over my word limit for this post. Happy blogging to fellow bloggers!

Meat hunt

"No, I'm not a good shot, but I shoot often."
Teddy Roosevelt

Meat hunting in Namibia happens during June and July. Trophy hunting can occur virtually throughout the rest of the year, and each season is limited by quotas established for specific farms. But, the general population in Namibia can hunt animals for meat for two months during the winter.

We had a desire to stock the freezer with a bit of 'our own' meat, so I made arrangements with a local farmer to visit his farm and harvest a hartebeest. It was a fun hunt, and successful. Hartebeest are about the same size as white-tailed deer, and we ended up with about 65 pounds of meat. Meat hunting rates are significantly less than trophy hunting rates, and Kelly calculates that our hartebeest meat cost about US$3.50/pound. Still more than venison back home, where a hunting license costs about US$25 and public hunting areas do not charge for access. No such thing in Namibia, so paying a farmer for an animal is the only option.

The farmer went out with Tristan and I to help find the animal, and he led the stalking. When we came back with the hartebeest, the farm workers skinned and quartered it. I've decided this would be nice to have this service back in Nebraska after a tiring day of deer hunting!

Then, Kelly and Tristan and I spent the next morning boning and chopping up the meat into roasts and such. Family togetherness. It was a good experience to have, and it's nice to have a full freezer of local meat.

Because it was a meat hunt, and because we were successful at about dusk, we didn't take the traditional photo. Hartebeests are not a well-known animal and are a bit odd-looking. Tristan thinks they look like they were pieced together by Dr. Frankenstein. The photo here is one of Kelly's photos of hartebeest in Etosha.

Dune driving for daredevils: depicted by duplicating daguerrotype

We need to catch up on our video postings...these videos below are from our trip in June with the Pegg's and Hygnstrom's, our friends from Nebraska. We took a dune tour, south of Walvis Bay with the Mola Mola tour company. Namibia is home to a one-of-a-kind natural phenomenon, where a desert runs into the ocean. The red dunes are large and have been used as the backdrop for many Hollywood movies, including '10,000 BC' recently. Our driver, Francois, made the trip memorable with his adventurous driving abilities. Our friend, Mark, had been on this trip before, but kept mum about the thrill ride we were about to encounter.

First, a video of a 'roaring dune'. Francois stopped at the brink of the dune face, and turned off the engine. He then let the vehicle slide down the face, with the brakes on. In the video you can see sand being pushed in front of the vehicle. Turn up your speakers, and listen for a roar that sounds, as Kelly suggests in the video, like an airplane going overhead. That is the roar of the dune. Why do dunes 'roar'? Well, you can read all about the physics of roaring dunes here, but the basic answer is that the roar comes from the synchronized vibrations of the loose sand as the avalanche occurs. Cool.

The second video is of our thrill ride in our 4x4 'roller coaster' on Slingshot Hill. Hang on and come along for the adventure.

Photos of this trip in June are archived on our Picasa photo site.

Why did the elephant cross the road? To appear on our video...

During our trip with Mom and Dad Powell through the Caprivi and in Botswana, we often had to stop for elephants. Here is a video of a big group of bulls crossing the road in Botswana, south of Kasane.

In the video, Kelly mentions that the tusks are larger than the elephants we'd seen in Etosha. The reason is because Etosha elephants lack certain minerals that make their tusks softer. As the Etosha elephants use their tusks, the tusks wear down faster than the tusks of elephants in Botswana.

The video also shows the potential dangers of driving in Africa. Down the road a piece, we saw an elephant road-kill. See the Picasa album for that photo.

Vic Falls video

Video of Victoria Falls during our visit with Mom and Dad in July. Check out the cool wardrobe required to view the Falls.

Elephant charge video

Here is one of our favorite moments from a game drive in Mahango Game Park up in the Caprivi. Our driver, Chris, has learned to drive very well in reverse gear, which comes in handy when the elephant starts coming towards you. Click on the play button below.