43  Aging lizards and a mountain lion in Big Bend

My introduction to evolutionary genetics and the underlying relevance of demography (Chapter 42) led me to join forces (July 1989) with Art Dunhan and Karen Overall, who were doing a long-term demographic study of the lizard Sceloporus merriami in Big Bend, Texas. Over the years they and teams of helpers had marked thousands of lizards; Art and Karen knew each lizard’s age, sex, size, shape, etc. Our idea was to measure speed and stamina of these lizards. Then by following their survival (or eventual death), we could determine whether an individual’s speed and stamina influenced relative fitness (as indexed by survival or by female reproduction). Moreover, we could determine whether a lizard’s age affected performance, reproduction, and survival. At issue was an unresolved question in field biology: do animals in nature die before they senesce?

For several years I would join Art and Karen in Big Bend each July, catch, race, and release individuals. We had a great time, though regretfully we published only a fraction of the data (the remainder isstill buried if not lost in a sea of ancient databases).

I loved being there, despite the 3-day, 2000-mile drive each way. After we finished work late in the afternoon, we would all relax on the back porch of Quinta Barker, an adobe home above the Rio Grande. Quinta Barker was our research lab. Late afternoon was “Miller time,” and we would enjoy a cold beer and watch the glow of sunset on the escarpment of the spectacular Sierra del Carmen in Mexico to the SE. We would often play the “water game” with Maggie, Art and Karen’s lovable Australian Shepard. One of us would turn on the hose full blast, and Maggie would chase and attack the water, getting thoroughly soaked and thereby cool off despite the heat.

Art and Karen would stay nearby in an air-conditioned trailer. I rarely stayed at Quinta Barker, which was far too hot. It had 1-m thick adobe walls, which by July, were always too hot, even at night. A few of us would commute to a campground high in the Chisos Mountains (30+ miles and almost an hour away). It was a long drive, but worth it.

We would usually arrive between 11 and midnight. To unwind from the day and drive, we would look up at the the stars, which were spectacular because of the elevation and lack of light pollution from cities. Looking up, I expected to see scores of satellites but I was not seeing any! How could that be?

I quickly solved this ‘mystery.’ Satellites are visible only when they reflect sunlight, which happens only for about 90 min after sunset (or before sunrise). Thereafter, they are in the Earth’s shadow and hence not visible. In retrospect this was obvious, but surprisingly few people are aware of the time windows for viewing satellites.

One night, Aurora Castilla (a colleague from Spain) and I had our tents set up on the edge of the campground. We were awakened by the yelping of a dog and a woman screaming. We assumed the woman was being attacked, and we quickly jumped out of our tents. I was wearing only shorts and sandals.

Right in front of us at the edge of the campground was a mountain lion with its jaws affixed to the throat of a small dog. The dog had a long chain attached to its collar and secured to a steel post. The lion had dragged the dog until the chain was taut.

A woman was running frantically in a nightie. I’m guessing that she was in her mid-30s, and we later learned that this was the first camping trip of her life. She was hysterical, hopped in her car, and drove off.

Her small dog had been sleeping directly in front of the opening of her tent and thus directly in front of her face. The dog’s long leash was attached to a post, perhaps ten yards away. The mountain lion had come into the campground, attacked the sleeping dog, and tried to carry it away before being stopped by the chain.

What to do? Was the dog already ‘dead meat?’ I decided to try Plan A.

Plan A. I threw stones at the mountain lion, but I hadn’t thrown a baseball in decades, and throwing accurately via a headlamp is surprisingly hard (trust me). I finally hit the lion – it winced but held on to the dog.

At that point I decided not to throw more stones. What was the point? The dog was probably dead, and I did not see any gain from injuring the cat.

Plan B. Cats don’t like water, so I thought about filling a bucket with water and dousing the cat. However, I did not have a bucket in my kit nor did I know where a water faucet was.

Plan C. Light a car flare! I had a flare in the car (for potential emergencies), pulled it out, and lit it. Suddenly, fumes of smoke, purple and fuchsia colors – especially impressive in the darkness of the campground. The cat sat up and paid rapt attention to this novel sight.

I started walking towards the cat but then looked down own at my body. Shorts and sandals. I realized I would be completely helpless if the cat attacked, and I knew how fast big cats could move. When I was about 15 yards from the cat, I cided Plan 3 was unsafe. I dropped the flare on the bare ground and retreated.

Two teenage boys were camping nearby and joined us. One of them, who had obviously never seen how fast a big cat can move, picked up the flare and took a step or two towards the cat, which abruptly dropped dog and fled into the night.

To our surprise, the dog stood up quickly, shook himself, and came running over to us. He had a deep puncture wound on his skull, some cuts and copious cat saliva on his throat, but otherwise appeared unharmed.

The woman eventually came back, accompanied by a park ranger. She and her dog were reunited! I told the Ranger that he needed had to find a cabin for the woman and her dog. She would not have gone back into her tent, and I will bet that she never went camping again.

The cat had a radio-collar and a known history. It was a yearling and small for its size. Its mother had given birth to two cubs the year before but was unable to provide adequate food to both.

The rangers soon trapped the cat and moved it far from the campground. I never learned how long it survived. Not long, I suspect. If it was unable to kill a small dog restrained by a chain, it must be incompetent.