More on the Melanistic Serval
As Meredith posted the other day, one of our camera traps caught a melanistic serval. Melanism is known across a broad variety of animals, but is particularly prevalent in the cat family. Of 37 known species of cat, at least 13 species have melanistic individuals: the domestic cat, the jungle cat, the leopard, the jaguar, the bobcat, Geoffroy’s cat, the kodkod, the oncilla, the colocolo, the jaguarundi, the Asian golden cat, the marbled cat, and the serval.
Why some individuals are melanistic and why cats are particularly prone to melanism is still a bit of a mystery. It is generally thought that melanism is maladaptive – that is, that individuals with melanism are at a disadvantage because they stand out more than normally colored individuals and so are more likely to be targets of predators and competitors. The consequence is that in populations with a lot of melanism, there ought to be some sort of advantage to offset the disadvantage.
Melanistic serval
One possible explanation for melanism is that cats’ black fur helped keep them warm at higher elevations by absorbing more sunlight. This idea came from the fact that many cat populations with high rates of melanism are found at higher elevations. More recently, there have been studies suggesting that melanistic individuals are more resistant to disease.
There’s not a lot of literature on melanistic servals. But I did find an article in the Journal of East African Natural History that listed the known locations of melanistic serval populations in East Africa. Interestingly, the four main populations with melanism are all highland locations: Mt. Kenya and the nearby Aberdare highlands in Kenya and Mt. Kilimanjaro and North Pare Mountains in Tanzania. All of these are in the general geographic region of Serengeti National Park, so it’s perhaps not too surprising that melanistic servals are there too. What is unusual is that the Serengeti is not a highland.
Our long-term Serengeti experts, with their decades of experience in the Serengeti, are surprised by the melanistic serval snapped by our cameras. David Bygott says that he’s never heard of a melanistic serval in the Serengeti, and Craig Packer says that while he’s seen melanistic individuals of other animals up on the rim of Ngorongoro Crater (a highland), he’s never seen a melanistic serval anywhere. So this Snapshot Serengeti image is likely the only documented evidence of melanistic serval in the Serengeti.
Happy Mother’s Day!
Yesterday was Mother’s day here in the US and Canada. So in honor of moms of all shapes, sizes, and fur color, here’s a collection of Snapshot Serengeti “family photos.”
Here mom, let me get that for you…
Teenagers. Er, um, pretty much all lions.
Going for a meal…
Wobbly baby eland!
Too cute for words…
Owch.
Oh the cuteness… the cuteness is unbearable.
Giraffe battle
I thought I would share these video clips from my camera trap with you. During my research using camera traps in South Africa I mostly used the picture mode but in the early days when I was trying to figure out what the camera trap was capable of and what was most valuable from my research point of view I messed around with the video option.
From my research perspective it wasn’t that great, I found that the camera was slower to trigger in video mode and so particularly at night I was left with lots of footage of nothing. But from pure interest value it sometimes proved very interesting.
On this occasion I had set up the camera on a sand road hoping to capture the leopard who frequently passed that way leaving its pug marks for all to see. I was pretty sure of capturing the leopard. What I didn’t bank on was getting a full 17 minutes of footage of two giraffe battling it out. Nor was I expecting the unique perspective from which the camera shot the footage. Oh and the leopard never showed. Typical!
I hope you enjoy the following three short clips.
Lions and cheetahs and dogs, oh my! (final installment)
I’ve written a handful of posts (here and here and here) about how lions are big and mean and nasty…and about how even though they are nasty enough to keep wild dog populations in check, they don’t seem to be suppressing cheetah numbers.
Well, now that research is officially out! It’s just been accepted by the Journal of Animal Ecology and is available here. Virginia Morrell over at ScienceNews did a nice summary of the story and it’s conservation implications here.
One dissertation chapter down, just two more to go!
The History of Lions
Barbary Lion, BBC
Here’s a great post by the BBC about some genetic work that has just been done to shed light on the evolutionary history of lions. Apparently, it’s a bit tricky reconstructing lion history due to the fact that they don’t fossilize particularly well (generally not conducive conditions in lion habitat) and that humans create giant holes in the record by wiping out entire sub-population.
However, from genetic analyses of living lions and museum specimens, these authors have determined that there are two evolutionary groups of lions – those in India and Central/West Africa and those in Eastern/Southern Africa. This happens to have some interesting implications for lion conservation and reintroduction — check out the article!
The legend of wolves and wapiti
The story of how reintroduced wolves transformed Yellowstone is now well known. According to the story, wolves scared elk away from the riversides, which allowed the willows and aspen to recover, allowing beavers to come back because they had home-building material big enough to use, and the beaver dams restored the health of the watershed.
I remember reading this story in college. I was sitting at a computer in UVA’s Alderman Library, digging up articles for a class presentation, when I stumbled on the now highly controversial article, “Wolves and the Ecology of Fear.” It blew my mind: right then and there, at the beginning of my last year of college, I knew I wanted to study how predators drove ecosystem dynamics.
It’s a beautiful story, and one that changed the trajectory of my career. And it’s one that’s been very hard to let go of, despite mounting evidence over the last decade that this story might not be more than a myth.
Dr. Arthur Middleton a post-doc at Yale and former graduate student at UWyoming, recently penned a fantastic op-ed about this in the NYtimes.
I had the good fortune of meeting Arthur at the Ecological Society of America talk last summer. I was a big fan of the work that he’d done, and that of his Ph.D. advisor, Dr. Matt Kaufman. But I didn’t envy either of them as they stepped into the fire of trying to take down what has become a beloved, monumental, epic tale. There’s no doubt that behaviorally-mediated trophic cascades do exist, and that predators can have profound influences on ecosystems, but the long-standing poster child for this simply isn’t real.
If you do one thing on your coffee break today, read his piece. While I could summarize the debate here, I couldn’t begin to do justice to Arthur’s eloquent argument.
Scratch that. If there’s one thing you do today, read Arthur’s piece. Not only will it make you think about wolves and ecology, but it will make you think about what nature we save, why we save it, and why that matters.
Interesting finds from Season 7!
Season 7 is up and running, and we’re already running into some interesting critters!
melanistic serval
No, that’s not a house cat wandering through the middle of the savanna. If you check out the gigantic ears, it appears that we’ve caught sight of a melanistic serval! Melanism involves a genetic mutation that causes the development of dark pigments in the skin, like a reverse albinism. For comparison, these guys normally look like this:
regular ol’ serval
According to our field assistant, Daniel, the serval population is booming in the Serengeti at the moment. Perhaps with so many animals, it’s not entirely unexpected to find one or two odd cases like this.
Let’s see what other interesting finds pop up in the latest season of Snapshot Serengeti!
Just for fun
Watching animals in the wild, I’m always amazed at their power, agility, stealth, grace…I could go on. Even our household pets seem way more adept at maneuvering in this world than I feel on a daily basis.
And so this site
http://animalssuckingatjumping.tumblr.com/
makes me giggle because it reminds me that I am not the only one who sometimes has trouble making her feet land where they are supposed to. Although I have to admit that if I ever tried to leap upwards ~10x my height, it would end far less gracefully than for these four-legged acrobats, who always seem to walk away completely unscathed.
Happy Monday!
Male lion takeovers
This series of photographs documents a stand-off between two male lions — a younger male attacking? defending against? an older male. Interestingly enough, at the last minute, a pair of lionesses jump in and join the young male in evicting his older competitor.
In lion societies, males leave their birth prides at a young age and join together with other males, forming coalitions. These groups, which vary in size from 2-9 individuals, range across territories and attempt hostile takeover of established female prides from other males. While it may seem that the only obstacle to taking over a pride is the coalition of males who have already set up shop, it isn’t always in the females’ best interest to stand by passively and the males duke it out.
A group of male lions’ first order of business upon gaining tenure of a new pride is to off all the females’ dependent offspring. Loss of cubs brings females back into heat sooner, giving the new males a reproductive incentive to commit infanticide. The female, on the other hand, suffers an immediate loss in fitness — all the reproductive effort invested in her cubs is gone! Females have evolved a number of ways to reduce the risk of infanticide by males, including behavioral strategies such as banding together with their current coalition to stave off intruders. Is that what’s going on here? Perhaps, perhaps not. The female-defended male looks fairly young the be in this type of a situation. Cub loss, however, is an important factor to keep in mind when considering sport-hunting of mature male lions. The effect of removing a resident male is removed may cascade through his social group, leading to additional deaths within his pride when new males move in to his vacated niche.
Grinnell, J. and K. McComb. 1996. Maternal grouping as a defense against infanticide by males: Evidence from field playback experiments on African lions. Behavioral Ecology, 7(1): 55-59.
Packer, C., Scheel, D., and A. Pusey. 1990. Why lions form groups: food is not enough. American Naturalist, 136(1): 1- 19.
If you’ve got the time to sit down for 15 minutes and subject yourself to some truly awe-inspiring photography, check out this TED talk from the documentary film-making couple, Beverly and Dereck Joubert as they recount their adventures in Africa interacting with big cats and their big personalities.
Beverly and Dereck Joubert. (Photo Credit: © Wildlife Films Botswana / Mike Meyers)
https://www.ted.com/talks/beverly_dereck_joubert_life_lessons_from_big_cats
Snapshot Serengeti 