Sometimes Nature is Cool!

As an apology for the traumatizingness of the last post, I offer you these highlights from my latest camera trap collection:

Reticulated giraffe

Black rhino

Tommy calf mid-frolic

Sometimes Nature is Gross

Ah the rains. They have arrived, quelled the dust, and put a little moisture back in the air and a little green back in the landscape. They have also brought lots of mud, which makes driving a (mostly fun) challenge.

Less exciting than the mud are the bugs. I've started to notice more bugs in the dining area and in my banda. I'm sure this trend will continue. What I hope stops immediately and I never have to experience again is the massive insect orgy that occurred in, on and around (but mostly in and on) my car this morning.

The culprits

I braved the mud from last night's rain to get out to Scott's plain for some observations. I made it and parked near a promising group of female tommies. Not minutes after my car had stopped did I start noticing small black insects flying around outside my window. Within minutes of that, hundreds of them had landed on the windows on one side of my car and the hood, windshield and roof. It sounded like it was raining, so many of them were knocking into the car. As soon as they touched down they began a random search until they encountered another insect or clump of insects, at which point they began fornicating furiously.

Get a room!

I had the window on the other side of the vehicle rolled down so that I could watch out of it and use my rangefinder and camera. As the horde of insects accumulated, I decided it would be prudent to seal the car as best I could (which is not very well since there is a two-inch gap between the window and frame in my back windows. Soon they overtook the other side of the car. In the meantime, my tommy moms had begun some interesting behaviors. I couldn't stop observations on account of the bugs, but I also couldn't continue observations with the windows rolled up. So I rolled one down, only far enough to peer out of. That was far enough though, and in no time the party had moved inside and I had horny insects crawling and doing the deed on my equipment, clothing, legs, and hair. I protested ineffectively by flicking as many as I could.

Eventually my tommy moved far enough away that I had to move the car to keep her in sight. Eager for the possibility of escaping the swarm, I started the car and moved several hundred meters. I hoped that if I could escape the cloud, the insects would stop coming in and I would only have to deal with those that were already inside. No such luck. The bugs seemed attracted to the car and the cloud followed. Worse, the movement of the car seemed to excite them, like a vibrating bed in a cheap motel. They began doing it even more enthusiastically, with more buzzing.

Gross.

After about an hour and a half of this, they all began dying, an endeavor that I encouraged with many well-placed stomps of my shoe (for some reason they congregated in the footwell). By lunchtime, all I had to show for the ordeal was a sprinkling of dead bodies spread throughout my car, an incomplete tommy observation (the bugs had distracted me to the point that I lost sight of her in a herd), and a much less charitable attitude towards small winged invertebrates.

Camera Trap Results

I retrieved the photos from the camera traps after the first three days of trapping, and I have to say the results are encouraging.

First, only one camera of the eight was too crooked to capture what it needed to. It was tilted such that it was aimed too high, which I discovered when I downloaded a lot of photos of animals' backs and this photo:


Very entertaining, but I really need to be able to photograph animals without them having to stand on their tippy toes. I returned to this camera and lowered it, so hopefully that helps.

Second, I got a wide variety of species: 11 in only three days at 8 cameras. I of course got tommies as well as loads of zebra,

impala,
and warthog.
Rarer captures included giraffe,
Grant's gazelles,
and spotted hyenas (which thankfully did not try to snack on the cameras - a concern even despite the steel casing).
I also got one shot each of cheetah,
white-tailed mongoose,
and a super cool striped hyena, which tends to be a very elusive creature.

In addition to all the wild species, I got more than my share of photos of cattle and sheep. Even some curious cattle herders made an appearance:

Despite all the attention, no cameras were knocked over, mauled, stolen, or otherwise tampered with, which is very encouraging. Tomorrow I will put the remaining two traps out, move a couple around, and hopefully collect some more cool photos to share with you!

Smile for the Camera!

Yesterday I put eight of my ten camera traps up. The camera traps are intended to give me an idea of the relative activity levels of different predator species in the habitats used by my tommies. As I said in an earlier post, mother tommies’ behavior should vary according to the predator assembly they are dealing with: if there are lots of large predators mothers should prioritize their own safety, but if there are many small predators mothers might spend more time and energy protecting their offspring.


The camera traps are Scoutguard SG550s ($200.00 retail if you want to put one up in your back yard). They are triggered by heat and movement. I have them set so that when they are triggered they take two photos in rapid succession. Then they reset and cannot be triggered for 30 seconds. Hopefully these settings will strike the right balance so that I am getting good photos of my predators without filling up the memory cards when a herd of zebras or cows decides to camp out around it. We’ll see.

Putting the traps up was hard work. I had the steel casings equipped with hardware so that I could mount them on steel poles that I would hammer into the ground. Problem: the ground is hard and I have the arm strength of an infant. The hammering was probably pretty comical. The poles also tended to go slanted if I stopped steadying them with my left hand, which was inevitable because my right arm was spent after about three and a half swings so I always ended up switching to a two-handed pounding approach. I imagine I looked a lot like some primitive and mentally-impaired primate, only less adept:

Blairopithecus hard at work

Most of the poles ended up pretty cock-eyed, but still vaguely oriented to an area where animals might walk.

I think the angle will give the photos an artsy feel

The four that I saw today were still upright also, so that’s a good sign.

Before I left I tested the cameras in the office and in my back yard. I leave you with a couple photos from the tests. Hopefully by my next post I’ll have some more exotic photos to show off. Come on, aardvark!

There, I Fixed It!

Last Tuesday I went under the hood of my car to check the oil and water levels and generally check that everything was in order. This is something that one should do very regularly when so much of one’s productivity depends on an operable vehicle. When I filled the overflow bottle for the radiator, it leaked profusely onto the ground until it was a quarter full, right where it had started. This wasn’t ideal, but since it was just the overflow and it was holding at least some water, I didn’t feel it needed to be addressed urgently. I had not yet been cleared to get fuel and repairs done at Ol Pejeta’s workshop, Kamok, so I decided I would keep and eye on it and get it done as soon as I was cleared.

On Thursday after an overnight trip to Mpala, I checked on it again in preparation for driving the 30 minutes to town. No bottle. None. It must have jiggled loose and fallen out somewhere between Ol Pej and Mpala. Not being comfortable with the possibility of overheating on my way to town and just having been cleared to get repairs done at Kamok, I postponed the trip to town and got a work order to get the problem fixed. Kamok is about a 20 minute drive away, so I attempted a temporary fix by tying a water bottle in place with a piece of nylon rope. I wasn’t sure the knot was going to hold, but it looked like it would get me to the workshop anyway.

My bottle fell out on the way to Kamok, but I had made it and was eager for a more permanent, professional fix. I spent about two hours in the workshop (they also had to rewire the electrics for the windshield sprayer), at the end of which I had…a plastic bottle tied in place of the real bottle. They didn’t have the actual part on hand, so they had to order it and in the meantime, they jerry-rigged the same solution I had come up with. Granted, they did it a bit more securely than I did, fashioning a pouch out of canvas and tying the whole thing together with strips of old tire tubing. But still! I was pretty impressed with my bush mechanic creativity! Photo of the “solution” below.

Science Lesson

An explanation of my project is in order for those of you who aren’t familiar with the science behind why I am halfway around the world.

I am studying maternal investment decisions in Thomson’s gazelle, or “tommies”. That is, I am interested in how mother gazelle decide how much to care for their offspring. Some of you likely expect that mothers are naturally caring and pre-programmed to sacrifice anything and everything for the well-being of their progeny. A warm fuzzy thought, but not so in the animal kingdom (or in humans, for that matter! For more on this, see Sarah Blaffer Hrdy’s extremely interesting and accessible book, Mother Nature).

A mother’s evolutionary “goal” is to make the largest possible contribution to the gene pool. This is best accomplished by producing a large number of offspring who are highly reproductively successful themselves. Mothers are limited in their ability do to this in two ways. First, time is limiting: mothers only have from the time they reach sexual maturity until the time they die (or reach menopause, in the case of humans and some few other species) to produce offspring. Each offspring produced is also time-consuming: the female must first become pregnant (a quick step in the tommy’s case thanks to ever-vigilant and eager males), then the fetus must gestate (about five and a half months), and finally the female’s body must become receptive to pregnancy again (a relatively short two weeks or so in tommies, much longer in other species that experience lactational amenorrhea). Thus, a female tommy, who will reach maturity sometime between 9 and 12 months of age and, if she is lucky, will live to a maximum of 12 years in the wild, can produce at the very most twenty-two young (tommies give birth only to singletons, so we do not find super-productive Octo-moms).

So we might expect every tommy mother to produce a fawn every six months and invest identically in each fawn such that at the end of her 12 years she has produced the maximum twenty-two offspring. However, a mother is limited in her capacity to invest. According to parental investment theory, investing in one offspring decreases the mother’s (or father’s) ability to invest in other offspring. This decrease in investment ability can come to pass in two main ways: the mother can either suffer a survival cost (i.e. she dies before she can reproduce again) or a fecundity cost (she is alive, but not fertile). For example, a mother investing heavily in her young may attempt to defend it against an attacking predator. This benefits the offspring by increasing its chances of survival, but inflicts a survival cost on the mother by increasing her chances of being killed by the predator. A mother may also invest in her offspring by keeping it in an area of low predator density, as humpback whales, some caribou populations, and many seals do. These areas are often also lacking or completely devoid of food for the mother. Again the investment increases the offspring’s chance of survival, but this time the mother’s fecundity may suffer as a result of her reduced forage intake; she may have to fatten up before reproducing again.

Given that raising young is costly, mothers should be choosy about which young they invest in and how much they invest. So how do they decide? There are many variables that can influence a mother’s level of investment. She may invest more in stronger or older offspring as those are the most likely to make it to adulthood. Or she may invest in weaker or younger offspring because those stand to benefit more from higher levels of investment. She may invest more in one sex that is likely to have higher reproductive success. She may invest more when environmental conditions are favorable such that the cost of investment is lower. There are many predicted patterns of investment, few of which have been demonstrated conclusively or seem to hold true across all species. In my project, I will be examining four possible drivers of maternal investment decisions: predation risk, maternal forage intake, offspring age, and maternal condition.

Ungulate species employ one of two primary maternal care strategies. Horses, camels, rhinos, wildebeest, and caribou (among others) exhibit the “following” strategy wherein the offspring stays with its mother continuously from the time it can walk until it is independent. Tommies, along with all other gazelle, most other antelope and many cervids (deer) exhibit the “hiding” strategy. Hiding is a bit more complex than following. After the young is born and gains its feet, it selects a hiding spot in nearby vegetation. It remains crouched and motionless in this hiding spot for hours until its mother retrieves it, feeds and grooms it, and leads it to another hiding area where it hides again. This process repeats for the duration of the hiding phase, which can last anywhere from one day (in impala) to four months (in bushbuck). For tommies, hiding is intensive for the first two weeks of life and then tapers off until, by two months of age, the fawn no longer hides at all.

While field scientists have often marveled at the infant’s ability to stay more or less motionless for hours on end, waiting patiently for its mother to return, I am more interested in the mother’s side of the equation. It appears that hider mothers have the opportunity to greatly limit the amount of investment required of them and thus raise relatively cheap offspring. Compared to follower mothers, who must constantly monitor their young, be highly vigilant for predators that may target their vulnerable offspring, and endure their infant’s disruptive play, begging and general harassment, hider mothers seem to get off easy. They park their young for hours at a time during which they are free to tend to their own needs (i.e. maintain themselves in order to enable future reproduction). However, rather than leave to seek the safety of groups or lush feeding habitats, mother tommies often hang around near their hiding young, seemingly incurring costs that may reduce their ability to reproduce in the future. The point of this “hovering” as I have come to call it seems to be to enable the mother to intervene in the event of a predator attack. Tommy moms are known to vigorously attack jackals and birds of prey that disturb their young and even try to distract cheetahs and hyenas that come across them.

My primary goals are to determine just how costly hovering is to mothers and to identify drivers of hovering behavior. Do mothers hover only when it is cheap for them in terms of predation risk and feeding costs? Only when the environment is particularly dangerous for their offspring? Some combination of both? To this end I will be spending many hours watching tommy mothers and recording their behavior. I will also record the behavior of non-lactating females. These non-mothers will serve as a baseline against which to compare maternal behavior: they have no offspring to worry about, so their behavior represents the optimal behavior pattern for a female investing completely in self-maintenance. Deviations from this pattern on the part of mothers represent potential costs of maternal investment. In addition to collecting behavioral data, I will be setting up camera traps on the plains on which I am watching the tommies. These camera traps will hopefully capture images of predators that use the plains. Relative densities of predator species will help to contextualize mothers’ behavior: if there are many small predators that threaten tommy young but not adults, one might expect mothers to be more willing to hover (since the predation risk to themselves will be low, but the benefit to their young will be high). However, if the plain is commonly used by cheetahs, which are highly dangerous to adult gazelle, I would expect mothers to behave so as to reduce their own predation risk, perhaps by reducing their investment in their young. The last main component of the project is habitat analysis. I will return to the locations where I observe mothers and young and measure grass height, greenness and leafiness. I will also take vegetation samples from which I will measure various nutritional components. This will help me to determine if mothers are incurring a foraging cost while hovering by confining themselves to suboptimal foraging habitats.

So that’s roughly the project. I will try to go into more detail on particular components as my field season progresses!