Leopard, Contained

Today I watched a leopard pace in its tiny cage.  Male leopards are used to 30 square miles of home range, and this one was lucky to have 30 square yards.  This subspecies of leopard, the Amur leopard, is critically endangered in the wild, and the zoo is participating in a conservation program that likely helps to maintain biodiversity so the species doesn't go extinct.  Nevertheless, this leopard was pacing.  There was a clear path worn in the grass, and he was bored.

Amur Leopard, Panthera pardus orientalis.

Leopards are often confused with jaguars and cheetahs, but once you look carefully at their spots, you won't confuse them again.  Leopards have hollow spots, called rosettes.  Jaguars' rosettes have little black spots inside each one.  Cheetahs have solid spots.  Leopards are the largest and stockiest of the three, with large males tipping the scales at 200 pounds, though most are smaller.

Notice the empty rosettes that indicate this is a leopard, not a jaguar.

Leopards' biggest difference from other big cats is a behavioral characteristic.  They are generalist carnivores.  They will eat anything from the size of a dung beetle to a 2000 pound male eland, as long as it is in the Animal Kingdom.  They prefer prey in the 44 pound - 175 pound range, which is a bit disconcerting for a species with most of its members in the preferred prey size range.  Leopards could take humans for prey easily - their range overlaps with humans, they are well camouflaged, and they can hide around human settlements.  For some reason, leopards don't choose to take humans - they hunt all other animals preferentially.  A few leopards that were injured or sick have taken humans as prey in the past, and once they started, they kept doing it until they were killed.

As explained in a previous post, generalist predators tend to have more intellectual capacity than predators that don't have to make as many decisions or learn about as many different types of prey.  Leopards hunt alone, which means they are unlikely to evolve complex social interactions, which is likely cold comfort to their prey.  Leopards are definitely stronger than other big cats of similar size, and they have been observed hauling prey up to three times their weight high up into trees to save for a later meal.  This combination of strength and intelligence makes the leopard particularly awe-inducing to me. 

The highlight of our leopard-watching for the day was a dangerous game between the leopard and a squirrel, two smart-cookie generalist consumers.  The squirrel had found a prized piece of hot dog bun near the leopard cage and was trying to decide whether to eat it in place or carry it away to another location, a vegetarian version of the leopard's prey-stashing.  The leopard heard the leaves rustling around the squirrel, crouched, sighted the squirrel and pounced.  The leopard was denied its afternoon snack by only a thin wire fence.  The squirrel continued to appear to frolic in the leaves, rustling them unnecessarily along the edge of the cage for another minute or two before it left to gorge on simple carbs.  The leopard was as agitated as a house cat being teased with crinkly paper.  It struck me that the squirrel had learned the fence would hold and ignored the deadly but contained predator.  The leopard had not completely habituated to the fence and continued to respond to temptations on the other side.  It either hadn't learned the fence was immutable or its brain was so exquisitely tuned to the rustling prey sounds that there was no other possible behavioral response the leopard could offer at the moment.  If you have ever played with  house cat, it certainly seems that they are compelled to pounce on rustling things - perhaps it is the same with big cats.

Leopard focused on a squirrel just two feet away.

Turnips

Turnips are ridiculously under-appreciated.  They are the easiest vegetable to grow.  They are marvelously delicious.  They produce anti-cancer compounds and their nutritional profile is similar to broccoli even though they look more like potatoes.  Their greens are the richest-tasting greens of all cooking greens.  To top it all off, they are in my favorite vegetable genus, Brassica.

The picture below is of an enormous purple turnip at the Chicago Botanic Garden, a fabulous botanic garden with an extensive fall vegetable section.  This turnip is pure white on the inside (I assume - I didn't cut it open), and it should also be white below the soil.  Sunlight causes the root epidermal cells to become pigmented in this variety of turnip.  The pigment seen here is an anthocyanin, but some turnips have a green suntan from chlorophyll production. 

A gigantic turnip!

The turnip in the portrait above, since it's very large and pigmented, is likely to have some zip to its flavor, much like a radish.  The greens will be piquant as well, like mustard greens.  The root would be delicious cooked in a stew with other vegetables, and the greens could be tamed by throwing out the first round of steaming or boiling water if necessary. 

My favorite turnips are Hakurei turnips, which are pure white regardless of sun exposure, smaller, and not hot.  They are sweet and fruity and even the greens can be eaten raw.  You can find them at farmers' markets in the fall and spring.  Their texture is divine when cooked - smooth and silky, and I like them sauteed or cooked into soups.  It's absurd to think of eating turnips without the greens in my book, so I always get the roots cooking while I prep the greens.  Then I cook the greens with the roots for the last few minutes for a great combination of flavors and textures.  YUM.

Turnip and greens, Brassica rapa.

 To grow turnips, just sow a thick line of seeds and cover them with a little soil.  As the turnips grow, you can thin the young plants by collecting some greens before the roots start to fill out.  In just a few weeks the turnip roots will grow and you can harvest them as you need them for several weeks.

Turnips and butterhead lettuce.

Turnips are members of the genus Brassica, which is a group of unassuming weedy-looking plants with fast growth rates and fantastic variation in growth forms.  Each brassica species modifies a different plant part to store energy, usually in response to humans breeding the plants to make agricultural varieties.  Turnips store energy in their roots (as do rutabagas), and the rest of the plant looks pretty normal.  Other brassicas put lots of energy into leaves (cabbage and kale), leaf stems (bok choi, seen below), flower buds and stems (broccoli and cauliflower), leaf buds (Brussels sprouts, seen below), stems (kohlrabi), and seeds (canola, mustard).  It's fascinating to me that these plants are so closely related with such striking similarities in leaf and flower structures but with such vast differences in other plant parts.

Brussels sprouts, Brassica oleracea var. gemmifera.

Bok choi, Brassica chinensis.

Brassicas generally are quite nutritious and low in calories.  Consuming these vegetables regularly appears to have a protective effect against many cancers, though the mechanism is not well understood.  For optimal amounts of the cancer-fighting compounds, eat these vegetables raw or lightly steamed, not cooked into oblivion.  Some brassicas contain bitter compounds detectable by a subset of the human population.  These people can't enjoy the wonderful flavors of brassicas because they find them to be too bitter.  Also, children are better at tasting bitter compounds than adults, which explains why they more commonly dislike vegetables. 

Consciousness

I just finished a completely fascinating book about what scientists think about the human brain.  It's called Incognito: The Secret Lives of the Brain, written by David Eagleman, a neuroscientist at Baylor College of Medicine.  The book summarizes the latest ways of conceiving of and explaining the functions of the human brain.  It's a completely captivating science book and manages to also be a quick, easy read - I recommend it to everyone who has a brain.

Among neuroscientists, there is considerable debate about what consciousness is and whether other animals have it.  Dr. Eagleman wrote a compelling explanation about why humans have consciousness and who else might have it.  To explain, I'll need to start with a little background.

Animals have nervous tissue, the tissue for communicating information from one area of the body to another.  For animals like this scud, the nervous system is composed of a few neurons (cells) that can sense and carry information, as best we can tell.  The information carried in these neurons appears to be simple, like "there is more salt in the water ahead".

Scud captured in pond water (40x magnification)

It's impossible for humans to know what it feels like to be a scud, but people who study scuds are almost certain they are not conscious.  Scuds show evidence of a what Eagleman describes as modules or programs for conducting specific behaviors.  In the scud, such modules would be genetically programmed behaviors such as "swim away from the light" and "chew on rotten organic matter".  The scuds don't have choices, and they can't modify their behavior - each behavior is either done or it isn't, and there is a clear way of prioritizing behaviors so the scud doesn't have to think about it (because it can't think).

Organisms with a wider variety of behaviors have many modules for solving problems.  For example, a squirrel can eat many types of foods, and they can search for foods in many ways.  Consciousness starts to become necessary as a way of deciding which program to run in which circumstance.  Squirrels may have rudimentary consciousness, since they can choose to hunt acorns or raid the bird feeder.  Nevertheless, squirrels don't seem to be able to recognize themselves in mirrors or solve math problems.

A fat squirrel peeking out from behind a tree in Lincoln Park.

The more redundancy and plasticity in behavior types a species has, the greater the need for consciousness.  Humans have enormous behavioral variety, so we need consciousness to figure out which behaviors we're going to do when (should I hunt for food at Trader Joe's or Dominicks?).

Eagleman also points out that just because we have consciousness, doesn't mean we need to use it very often.  For activities we have learned, we have committed those skills to the comparably vaster unconscious part of our brain.  Have you ever driven across town then wondered how you managed to get there since you don't remember any stop lights or roads?  That wouldn't happen if you were driving a new route.  The apparent amnesia is a sign that you have learned the route so well your unconscious brain can handle it and let your conscious brain do other things, like learn a new song on the radio or talk to your mom on the phone.  If the routine deviates from normal, for example if a car swerves in front of you or there is a blocked road, your conscious brain takes over and figures out what to do - and you don't forget to tell your friends about the road block or near accident. 

Conscious activities are usually new activities.  When you are learning something new and doing something new, you notice so much more about the world, and time seems to go more slowly, since there is a lot more 'happening' in a conscious period of time.  Unconscious activities, like being zoned out while jogging or working or chopping onions, etc., kill a lot of time quickly without you noticing it has passed.  So the trick to getting through boring activities like waiting in line is either to zone out somehow or to turn it into a new experience.  If you want to slow down time and live a longer life (at least a seemingly longer one), have a wider variety of experiences.

Eagleman claims there are degrees of consciousness, which makes me wonder what consciousness would be like if I had an even more complex brain.

Of Birds and Meat

I saw two birds yesterday.  One was standing on the pavement next to Lake Michigan, and the other was chopped into bits in a pan in my kitchen (also next to Lake Michigan).

Inland gull hanging out in my town.

Chicken hanging out in my kitchen.

The first bird is a type I see nearly every day as I'm walking around town.  I know it's a type of seagull, though I don't know which type (never was a birder).  Seagulls are found anywhere there's water, not just at the ocean.  When they are found away from the ocean, they're often called inland gulls.  Seagulls are regarded as pest birds by some, but I love them.  They are great scavengers, and this gull no doubt is helping to keep our lake shore clean of all kinds of technically edible trash.  Seagulls are incredible fliers.  I watched one fly during the giant storm last week with gusts of wind up to 60mph, and it was doing just fine.  Since gulls are strong fliers, it means their wing muscles are strong, tough and dark in color (more on this in a minute).

All we have of the second bird to compare it to the first is its wing muscles.  Chicken's wing muscles (not the actual wings, but the breast meat - the part that actually pulls on the wings) are giant by comparison to the gull's, but despite their size, they are weak, flaccid and white.  Chickens don't use their wings, really.  Commercial chickens have been bred to have giant breast muscles, since that's the most commercially profitable part to sell in the US.   Chickens don't fly a lot when they have access to the sky, but when kept in confinement as they grow in a factory, they can't fly at all.  

The white color of commercial chicken breast meat arises from a combination of factors.  First, the genetic characteristic of chickens being more walking birds than flying birds means that their wings aren't adapted to being strong.  Secondly, these birds'  enforced lifestyle is one of all standing or sitting and no flying.  Muscles adapted to working hard, and muscles that are exercised are usually darker in color, most apparent in poultry meat.  Dark meat's color comes from its large quantities of a reddish-brown-pigmented molecule called myoglobin.  Myoglobin does the same thing as hemoglobin (the dark red protein found in the blood), but it is found in the muscles.  Hemoglobin and myoglobin both hold oxygen from the air we have breathed in.  For muscles that work harder and at fast speeds, the need for oxygen is intense.  Having myoglobin present to store extra oxygen means that muscles can work harder and faster.  Muscles can genetically have more myoglobin in them, and the quantity of myoglobin increases with increased muscle usage.

Though I have never eaten or dissected an inland gull, it would probably have dark breast meat, since it uses its wing muscles so much.  If you have ever eaten duck breast, you may have noticed that it was very dark - because ducks are good fliers.  Duck leg meat is usually lighter than the breast meat.

Time for lunch?