Happy Zebra clan and clues to social organization

Most of the end of October I was in Nairobi and that was long enough. By the time I returned to the Mara the migration activity had begun to subside and Happy Zebra clan was relocated in my absence. Uncovering the whereabouts of the Happy Zebra communal den seems blog worthy just given the amount of time and effort we have invested in pursuit of these animals. From call play backs, to checking old dens, to driving the most extreme edges of this clan’s suspected territory, and waiting nights after dark trying to pinpoint the location of distant whoops… we tried for the better part of September and October to find Happy Zebra. The unknown with this clan did not however begin when CSBY (the last adult female to occupy Alamo Den) was last seen with her two 4-week old cubs at the previous communal den. As earlier discussed on the blog, the death of KOI by lions removed the highest-ranking individual from the clan. This opened up Happy Zebra to uncertainty (at least for us observing) or possibly opportunity (for other females in the clan) as the social organization was determined to shift.

At the time of KOI’s death, Happy Zebra was composed of 11 adult females, 9 cubs, 6 subadults, and 4 adult males. KOI and her lineage comprised about 33% of the total Happy Zebra clan. All else equal and following the conventional inherited social rank descendent from KOI, COEL (KOI’s youngest female cub) should have been successive dominant female of Happy Zebra clan. However, given that COEL was less than a year old, this cub’s survival, far less its dominance, was not certain. The possible other successors to dominance could in theory have been any female in the clan, though most likely it would be some relation to KOI that arrived at the top. A breakdown of KOI’s lineage and prospective inheritance of dominance in Happy Zebra were organized in a list from a previous post, http://msuhyenas.blogspot.com/2011/07/kois-legacy.html. To discern the newest rank relations we would have to observe and record a series of dyadic interactions and tally aggressions and submissions between individuals in a matrix. The first steps…observe behavioral interactions.

 
On October 31^st, 2011 I saw Happy Zebra present at their communal den. Most notable in this session was the confirmation of PIKE (one of KOI’s older daughters and a likely candidate for the highest rank individual in Happy Zebra) having two 4 week old cubs. Also of interest were a number of interactions which occurred between the female members of KOI’s lineage. PIKE’s cubs were confirmed after they were seen nursing from PIKE. Also nearby was BOOM, a previous female offspring to PIKE. Like many female subadults interested in the business of babies, BOOM was being pesky and bothersome to the nursing PIKE. Not very note worthy in and of itself. However, a good context to achieve a brief, instantaneous glance at the social hierarchy is through a cascade of aggressions. For example if a high rank individual aggresses on a mid rank individual, and then the mid-rank individual takes out that aggression on low rank individual, we note the latter aggression as a scape goat context. It could be like, when my girlfriend reprimands me, and in my frustration I vent on my dog (that is assuming my dog doesn’t out rank me…data is still out on that); either way the aggression filters down through the ranks, clearly revealing who is dominant. Anyway my point, was that in being pesky to PIKE, BOOM was aggressed upon. It was also the case that COEL (KOI’s youngest cub and technically rightful heir to dominance) had recently arrived at the den.


 

COEL cautiously approaching one of PIKE’s newest cubs (the small black one on the right).

 

The good news is that the 9 month old orphan persisted through the migration season unaided by her mother. However, after being aggressed on by PIKE, BOOM redirected that aggression to COEL, who submitted and retreated. Shortly after words PIKE and BOOM, in a coalition aggression, again displaced COEL.

PIKE and BOOM in the background before they aggress on and displace COEL, who is already beginning to go ears back (a sign of submission).

Although far from conclusive, at the surface it seems that without the support of her mother to reinforce her social standing, COEL may not befall the highest rank spot in Happy Zebra. Other clues, like COEL arriving and flattening her ears as she approached to greet PIKE and BOOM also suggests her subordination to these two. More evidence is needed, including the observation of interactions between PIKE and some of the other adult females in this clan, but this was a good start to reorganizing the Happy Zebra social hierarchy.

High Season

At the end of low season the Mara was still a relatively quiet place when I went to bed…and then one morning I wake up and the wildebeest are here… and tourists are here, and the vultures are here, and more crocodiles are here, and all those hyenas I thought may have disappeared are in actuality, still here. And, it all seems to hinge on the fact that…well, the wildebeest are here. People plan and save and finally arrive in the Mara hoping to see a crossing; and I am right there with them as I shuffle camp’s land cruzer among that cross hatched mess of vehicles towards rivers edge. Just a little closer to line up a better view…hopefully the first wildebeest that enters the water is a bit slow or ill or young or old… I didn’t say it aloud, but I am likely not the only one thinking it. And in all the excitement you have to catch yourself as an observer from falling into reflective sentiments like, ‘Wow the circle of life’ as that that Elton John song drowns out a couple thousand bellowing widlebeest.

 

The migration starts with a crossing…the initialization of the circle of life… or at the very least, increased flight prices to and from the Mara.  Jambo high season.

The time surrounding the migration provides an opportunity to see a variety of animal behaviors. Underlying every decision and respective behavior in the animal world (even humans??? no I don’t have the gall to pursue that) there are tradeoffs that ultimately affect an individual’s somatic and reproductive fitness. Disney aside, you eat, are eaten, and/or reproduce. In two words you could argue that the process of living, from to sex, to eating, to death involves combinations of chasing and fleeing.

Sex seems an appropriate starting point.

To set the stage here is my 10-15 second pitch on how this works…I’ll use a pair of lions to illustrate my point.

Simple, right? In the time you read that, it is all over and both lions have once again sacked out. That is likely a hyena camp bias on some level, slighting the complexity and the social interactions involving a lion’s establishment within a pride. Not to mention what it takes to achieve reproductive success as a lion; that will require insight from someone more qualified.

Observing hyenas mating is not overly common, but since the wildebeest arrived I have seen two successful mating attempts and a few less successful pursuits. That being said I am obviously no expert so I’ll first provide a reference for a more technical source (http://scientistatwork.blogs.nytimes.com/2011/07/19/how-spotted-hyenas-mate/#more-12195).

The hyena mating events I have observed involve both a lot of chasing and fleeing of variable degrees of intensity. The first part of the chase is a slinky cautious approach by a male, towards a seemingly uninterested female in estrus who walks away (hardly an example of fleeing but it is movement away). As the female’s preoccupation and patience wanes she expresses her annoyance in an aggressive lunge or chase at the hovering male, who (because he is much smaller in stature than the female) flees, loping away to avoid injury. With persistence this exchange of ‘chasing’ and ‘fleeing’ continues and once in a while the result is that the female consents and success (such as that achieved by Trotsky with Sherman).

But success is relative, and as I suggested, all of this somatic and reproductive give-and-take involves the costs along with the benefits. I am not sure of the story behind each scar, but as highest-ranking male in the South territory clan, Dolittle, shows the wear of a life full of costs, from emigration to female courtship; all for ~15 minutes of intromission… maybe that’s worth more than “just” 15 seconds, as with those lions. On the other hand there is more to life than mating. 

I tune into the Discovery channel’s Shark Week each year not because it promises to unveil the latest footage of shark courtship. Rather, just as the tourists monitor the riverbanks for a potential crossing or scan the grass for a hidden predator, my intent is witnessing a kill. The energy flux that occurs between trophic levels involving predators and prey epitomizes chasing and fleeing in the wild and it captivates me…us… at least the reviews would suggest. This likely requires little explanation on my part, so I have captioned a series of photographs that demonstrate somatic maintenance among a variety of taxa.

Every chase begins with an approach. This young lion achieved little more than a few uncalculated test chases after a group of impala.

When pursuing prey that will inevitably flee, age is not the single determinant in success. I came across this young leopard suffocating a live and kicking impala that almost certainly weighed more than the leopard.

Even though age does not solely determine when a chase is more successful than the flight, size certainly achieves the endpoint with far less wear and tear. Shortly after the leopard had killed and drug the impala off the road leading into our camp, two lionesses ran out of the grass and darkness. Displaced, the smaller younger leopard was left to watch its catch consumed by the lions as nothing more than a faint pair of eye shines from the periphery of my headlights.

  If not just size and age, then numbers also put the odds in favor of both those chasing and those fleeing. Hunting both alone and in groups, hyenas are able to pursue a wide variety of prey. Although I did not see the progression of this kill (and a lone hyena is certainly more than capable of killing a wildebeest) these two adult hyenas and a cub shared the benefit of this wildebeest kill.

 

This was the fewest and least excited group of hyenas I have yet observed at a feeding session. Usually upon arriving at a fallen carcass,  one can rest assured that the chasing and fleeing has yet to really begin until after the prey is immobilized and the hyenas begin to sort the feeding privilege based on social rank.

The competition of chasing and fleeing is not merely a phenomenon of mammals in the Mara (as this blog seems to thus far suggest). So, as not to overlook birds and reptiles, I will include a few more photographs that highlight the endpoint of a chase. Both the eagle and the heron out matched their respective reptilian prey in these pictures.

That covers the majority of both sex and death, animal-pursuing-animal interactions I have encountered. Before wrapping this up, I have left out my most personal accounts of chasing and fleeing. Not for a meal or as successfully as birds, and not to achieve any sort of reproductive success (well at least not directly…although I used to think I could embellish a good snake story to my advantage while chatting some uninterested girl in a bar), but either way, I have always enjoyed catching reptiles…

That is all well and good when you know the reptile you are chasing, as with the skink above. It is less good when you hear that there is a big black snake under the guest tent in camp and the camp staff wants to kill it. Not wanting to see this snake meet its end, yet unable to get a controlled grip on the snake’s head through the tent floor, there was little else to do but chase it out from under the tent. Happy to escape my incessant prodding the snake left out from the tent into the bush when we realized there was another large black snake making its way towards the cool recline under the tent floor. This second snake made flight up a nearby tree, before making a second attempt to escape the heat of the day under the tent. Insert here the chasing and fleeing story. Warmed by the afternoon sun, this second black snake was much faster at fleeing than I was at chasing and catching, but we made our way through the forest on edge of camp. In all the excitement, I missed the memo when the snake no longer wanted to play this game. Fleeing stopped, and so halted my pursuit. The snake rose up off the ground, staring at me. Unfortunately I have no picture to demonstrate this; fortunately that spitting cobra had just poor enough aim that if I did have a picture of it, I would still be able to see it sitting here today.

Some pursuits are best slow, casual, and from a distance.

In a few weeks the high season will conclude. There won’t be as many wildebeest, or tourists, or vultures here, but with all that eating and mating I expect the Mara will still host some chasing and fleeing.

 

That was May in the Mara

I used to have a yellow lab when I was younger. Isaac (my brother) and I had this game we played where we would fish for our dog off the picnic table with a rawhide tied to a broom handle with some twine. To call this a bit odd seems fair, but I think the concept is accessible…drag the rawhide around and the dog chases it until he catches it, tug of war, and then embellish some heroic tall tale about catching a trophy; it is the kind of tale where the catch gets bigger and better each time the story is retold.

About 10:00 pm on June 2, 2011, the bait was secure and the line was cast. Following a Land Rover and the dead hyena in tow, 2-6ish hyenas (very much alive ones) revitalized my sense of excitement from my dog fishing days, as I hung on to the spare tire mounted on the back of the Land Rover. Although yellowish-tan, furry and pretty charismatic like my old lab, I hesitated in wanting this evening’s edition of carnivore fishing to end in a catch. Rather I was hoping that once the necropsied remains of the recently found dead Koi (alpha female hyena from the Happy Zebra clan studied by the Serena Hyena Camp within the Mara Conservancy Park) had been drug a safe distance from the camp drive way, I would be able unhook the tow cable from Koi’s body in a timely enough fashion that I would not be mistaken for the bait.

The fact that I am doing well and writing this now a few days later makes it clear that this tale has already lost the element of danger, and bravery, and tragedy that tend to weave a series of events into stories of epic proportion. Maybe a few beers in, sitting around with some friends a few months from now and a more exciting version will manifest, but because I have already unveiled the end of May and the beginning of June, I should fill in the story line up until this point in time.

Right, so Koi was found dead along the High road the evening of June 2^nd by a watering hole we call Egyptian Goose. That same evening Koi was brought back to camp and a handful of people (the water researchers, camp staff, a few visitors etc) all helped or watched the necropsy of Koi in the glow of mag lights and headlights. Koi appeared to have been dead for less than 24 hours. Her cause of death seemed most likely to be lion(s). This was determined by the puncture wounds found around the neck and amongst the writhing mass of ticks, flies, and non-descript ecto-parasites inhabiting Koi’s matted fur. I am not sure how many of Koi’s ecto-parasites decided to switch hosts and join my team that night. Still you are faced with a serious question when deciding whether to leave well enough alone or swat with a hand covered in hyena fluids ripened by the warmth of the Kenyan sun. To be fair not all of the excitement was at the focus of our scalpel blades and sample vials. Cast in the interface of shadow and trailing headlight or mag light beams that were focused away from the necropsy, a number of local North territory hyenas had gathered. I imagine, as much as I could smell Koi, these North hyenas must have been able to smell Koi from some distance. I have no idea what the North hyenas intent or interest was, but they paced and dodged in the artificial light with increasing energy and boldness as the necropsy continued. It was like if you have ever been at a small venue bar to see a show. Before the main act comes out the crowd kind of jostles in this uncoordinated but unified rhythm of impatient discontent directed at that first band; we were the lead singer for that unappreciated opening act the night of Koi’s necropsy. Soon enough though Koi had been preserved forever in the records and data logs, and was hooked in tow by a cable to the Land Rover. Out across the plane we go, with at least 6-12ish hyenas (very much alive and big ones) in pursuit…

Koi was not the only one to suffer lion troubles in May. On a morning earlier in the month, myself and a few other research assistant/grad students were at a den conducting a fairly standard obs session. The morning was nearing the time we might drive around and try to find other hyenas, but before leaving we saw two hyenas loping across the plane. In casual pursuit were three male lions. At first it did not appear as though the lions’ course would bring them much nearer than 100m from us and the den. That was an incorrect presumption. The lead lion quite intentionally shifted attention and gear, and came running at the adult and cub hyenas at the den. I will try not to sensationalize this part. However, a big male lion, when moved by some inspiration to do more than sun bathe and nap, becomes an impressive display of muscle contractions and potential killing force. This fact was also realized by the hyenas, and the adults all scattered while the cubs dove into the nearest den hole they could find, as the lead male lion leapt over a ditch next to the den. The male lion reached into the den with its paw but to no avail before it began urinating on the den. Mean while at a den hole about 50m away, one brave cub ventured a look out of the den. The hyena cub caught the lead male lion’s eye, and he again sprang into action running at the den and trying to reach in and grab the cub. Soon the other two adult male lions had arrived at the den. Again there was a series of macho displays in which the lions were urinating and pawing the ground with their rear legs on top of the den. Not long after marking the den, the lions moved on and retired for the day long nap that was sure to follow. We soon left as the morning was waning, as was the potential for a Mara headliner. It is not that we are impatient, but at that point in time it would be like trying to watch and episode of the Bachelor following an episode of Jersey Shore; relatively it had just become too tame.

Don’t get me wrong, it is not that tame is always bad, but I think everyone can better know where they stand day to day when the stakes go up. Take for example two other den sessions in which the only animal participants were hyenas…well at least live ones. Both of these session involved Clovis, the alpha female from our South territory clan. In two different cub provisioning events, Clovis provided her youngest cubs with almost exclusive feeding access on wart hog kills. If lions, as a context, tend to excite hyenas I think it is safe to say that food does as well. The question is then, if you are Clovis, why bring the wart hog remains back to the den and have to stand by vigilant to ensure that no other hyenas steal your cubs’ prize? It seemed most likely to be a lesson. Why bring the food back among all those other hungry hyenas? One reason might be, simply because you can… and that is the glory of being at the top of the social hierarchy. During the excitement of both of these apparent provisioning events, not only did Clovis provide a lesson to her cubs and the rest of the clan in regards to rank, but it also helped me rank my own status thus far in the Mara. Prior to the two wart hog den sessions, I figured myself close to adequate in terms of observing behavioral interactions among a group of hyenas. Well that day, even as a bystander, I was able to reflect and re-evaluate. Thank you Clovis for increasing the session energy and humbling me with nearly 160 tracks on my DVR to the tune of, ‘NOTE: …incomplete CIs.’

Well that was May and it has been fun and challenging and educational, but now it is already June. Just yesterday on the 5^th of June I saw the first of the migration (zebras) crossing the Mara River.

I am sure as the herds increase in number I will get many more opportunities to improve on my kill session data collection. Watching those first couple thousand zebras crossing the river I was struck by one peculiarity. Even after making a frantic effort to swim, run, or stumble past four large and waiting crocodiles, many of the zebras re-traversed the river back towards the bank they had just left behind. 

Maybe the grass is always greener, or maybe the adrenaline and sense of accomplishment is addicting? I think if I was I zebra I would at least look for another river to cross or maybe consider the lions still waiting just up the bank. Anyway I’ll save from some tacky analogy (I have likely exhausted those) involving my time in the Kenya, compared to a journey full of river crossings and crocodiles. Suffice it to say I am sure June will have at least one or two blog worthy events, but if not… Did I ever tell you about hyena fishing…