The black rhinoceros (diceros bicornis) is not merely an endangered species; it's a critically endangered species. As far as conservation status goes, this is as bad as it gets for an animal in the wild; the next stop is extinction.

In Samburu National Reserve, there are no black rhinos to see, because poachers killed them all years ago. Around Lake Nakuru National Park, the authorities put up a fence to keep the poachers out - yet there are only a few dozen black rhinos in the park. Even in Maasai Mara, as this web site notes, the black rhino's survival has been a touch-and-go affair:

“In 1971, the Maasai Mara Game Reserve had approximately 120 black rhinos, but by 1984 this number plummeted to just 18 individuals due to poaching. When the Mara Conservancy started in 2001, there was only one known rhino left in the Mara Triangle: an aggressive female, very wary of people and vehicles, and very difficult to spot. However, after only a few months of Mara Conservancy’s regular patrols and successful arrests of poachers, security in the area increased and in 2002, male rhino moved into the Triangle and mated with the female.

Three successful matings and the addition of other rhinos that migrated into the area has increased the Mara Triangle’s resident population upwards of ten individuals. Unfortunately this is not a reflection of the Maasai Mara population as a whole, which still hovers between 25 - 30 individuals. The Maasai Mara National Reserve has the country’s only indigenous black rhino population, unaffected by translocations. Due to the size of the Reserve, this population has the potential to become one of the largest in Africa, as long as it is protected.”

We were fortunate in the Mara: the day of our visit to the Maasai village was book-ended by rhino sightings.

On our morning excursion (we would typically rise before 06:00 for coffee, so that we could be out on the trails in the Mystery Machine by 06:30), I spotted a rhino in the wild for the first time in my life. It was not quite 07:00.

The black rhino - with its massive size, thick hide, prominent horns, and reputation for aggression - is said to be a fearsome creature. But it's also a herbivore that's known to be solitary and non-territorial. Here's what I recommend, based on my own limited experience: if you see a rhino, begin taking pictures immediately. Don't wait for the perfect shot. Before you know it, that rhino will turn tail and lumber off into the brush.

The day ended as it began. It was nearly 19:00, and we were returning to our glamp in the failing light. (Normally, we returned by 18:30.) But suddenly The Woman yelled, "Stop the car!"

In order that you understand how unexpected this was, I need to tell you about our customs in the Mystery Machine. As we zipped around the trails, The Doctor would stand at the front, so that she could have the best forward views. (This was not begrudged: as I've said, among the three of us, The Doctor was by far the best spotter.) I would stand behind The Doctor, looking left or right or ahead over her shoulder, depending on what was to be seen. As for The Woman, she preferred to sit in the back seat, reading on her iPad, rising only when George or The Doctor or I alerted her to a sight worth seeing.

That's why, as George stopped the car, The Doctor and I turned at once to The Woman. We feared she might have become carsick, or otherwise taken ill.

"What is it?" we asked.

She simply pointed and said, "Rhinos."

So much for the fourth of the Big Five.

And the last of the Big Five? We never did see an African leopard (panthera pardus pardus), or any kind of leopard (panthera pardus), on our safari. In the morning on this day, over the radio of the Mystery Machine, we got word of a sighting of three leopards - but by the time we reached the site, there were none to be seen. That was as close as we came - if indeed we were ever close at all.

We were mildly disappointed, but not at all surprised. The leopard's existence is not nearly as precarious as that of the rhino; its conservation status is near threatened. But the leopard is nocturnal, solitary and wary. And who could blame the creature for its wariness? Humans hunt it for sport; their agricultural and pastoral activities shrink and fragment its habitat.

I took the photo below about ten minutes before The Woman spotted the rhinos. I was simply trying to capture the sunset; it's an old hobby of mine. Later, I realized I'd also captured a group of animals silhouetted by the failing light.

If I had to pick just one photo to express how safari made me feel, this would be it. In six days in Kenya, I saw sights of great beauty, and these sights filled me amazement, or else a peaceful happiness. But I felt melancholy also, because the world is changing - we are changing it - and I saw creatures that I fear I will never see again. Already, their images grow hazy and indistinct in my memory. If they were to disappear from the world forever? The cost is perhaps best reckoned by Rebecca Solnit in A Field Guide to Getting Lost:

“‘They are all beasts of burden in a sense,’ Thoreau once remarked of animals, ‘made to carry some portion of our thoughts.’ Animals are the old language of the imagination; one of the ten thousand tragedies of their disappearance would be a silencing of this speech.”