Foudouko’s Place in the Fongoli Community
We identified Foudouko as a sexually mature late adolescent or young adult male in 2003. We identified Foudouko as alpha male from early 2005, when adult males were habituated for nest-to-nest follows, until late 2007. He did not pant-grunt to any other adult males, and all other adult males pant-grunted to him. We estimated that Foudouko was likely in his late teens when he became an alpha male.
In 2006 and 2007, Foudouko was present in parties on 63.4% of observation days (N = 426 days) (Fig. 1). He lost alpha rank at the end of September 2007, at around the same time the beta male and Foudouko’s frequent coalitionary partner, MM, was severely injured (suffering a broken or dislocated hip or femur). We did not see MM with the other males in the community for ca. 6 weeks after this (October 19–December 3, 2007), and he was very frail when he returned, submitting to almost all adult males of the community, including a very aged male; females also ignored his displays.
The last day on which we collected focal observation data on Foudouko was March 27, 2008, and he disappeared at the end of March 2008. On one of the last days on which we saw Foudouko, observer D. Kante estimated that most or all of the community’s adult males chased him from one of the only permanent dry season water sources. We next saw Foudouko in December 2008, when K. Boyer Ontl and D. Kante found him with MM and two adult females (NI, NN) and their offspring (NE, TV), 263 days after he had disappeared. Foudouko was no longer tolerant of observers in that he repeatedly moved rapidly away from them and researchers abandoned their attempt to follow his party given the dry season heat stress.
Observers saw Foudouko once or twice per year with other chimpanzees in 2008, 2009, and 2010 but did not see him in 2011. In 2012 and 2013, Foudouko appeared to be slowly integrating back into the adult male social group. We saw him in small parties with several adult males and with the whole community on one occasion, but he was mainly associated with MM, who had regained beta male status (Table I). Although most males were aggressive toward Foudouko, alpha male DV and MM (maternal siblings, based on mtDNA analyses: Stewart 2011) affiliated with him and were not aggressive toward him as were other adult males; they did not participate when other males chased Foudouko. For example, on June 3, 2010, J. D. Pruetz witnessed Foudouko arriving at Sakoto ravine late in the day. Foudouko approached adult male DV and quietly pant-grunted to him. Afterwards, both males disappeared into the woodland. The next day, after the adult males had moved southeast, adolescent male LT alarm called, which resulted in the males returning rapidly and chasing something unseen >1.5 km south. We have not seen Fongoli chimpanzees chase predators (spotted hyenas [Crocuta crocuta], leopards [Panthera pardus]) or prey for such distances (Pruetz and Boyer-Ontl, in prep.), nor were the alarm calls of prey species, e.g., Papio papio, heard. We have never encountered extra-community males in the Fongoli home range. The alarm calls given by LT sounded different to observers from calls given in response to snakes and potential predators (Pruetz and Boyer-Ontl, in prep.). These factors led observers to speculate that the males were chasing Foudouko. In 2013, Foudouko quietly approached a party and directed his gaze at MM, who left to travel with Foudouko and disappeared for 1 week.
In late 2012 and in 2013, Foudouko spent more time in proximity to the social group of males, and continued to display nervousness around researchers, hiding or moving away. For instance, on February 26, 2013, K. Boyer Ontl followed a small party containing Foudouko, MM, NI, NN, TV (NI’s juvenile daughter), and VC (NI’s infant son) for most of the day (Table I). Foudouko stayed >75 m from the observer on an open grassland plateau when she first encountered the party at dawn, and although he tolerated her at closer distances, e.g., 20 m, later in the day, most of the time he positioned himself behind a tree or a tall tuft of grass. On several occasions, the behavior of Fongoli males suggested that Foudouko was in the vicinity, but observers did not see him. These encounters were almost always in the southwestern portion of the Fongoli chimpanzees’ range, near the core area used during the rainy season especially and in the vicinity of the Fongoli research camp. Once, J. D. Pruetz witnessed the adult males of the Fongoli group engage in what appeared to be an aggressive chase. Only alpha male DV and beta male MM refrained from taking chase. The observer then saw Foudouko as she was returning to camp at dusk, and she followed him for 15 min from a distance, undetected. He moved parallel to the other chimpanzees’ location at a nesting site at Maragoundi ravine (Fig. 2). He frequently climbed trees and gazed in the direction of the social group but disappeared on detecting the observer.
Circumstances Surrounding Foudouko’s Death in 2013
We last saw Foudouko alive on May 5, 2013 when we observed him in the company of adult males MM and KL. During the days before his death, observers suspected that Foudouko was in the vicinity on several occasions. For example, on June 12, 2013, J. D. Pruetz followed the entire Fongoli community, excluding Foudouko, to Maragoundi ravine. At 19:30 h, after a chimpanzee screamed west of the nesting party, the males left their nests and ran in that direction. The observer followed adult male KL who stopped short of what sounded like an aggressive encounter, and they met adult male BI returning from the area. She then found adult males BN, MI, and LT returning from the area, followed by adult male SI returning from an area nearby moments later. Beta male MM was nearby, although he did not appear to have been involved in the confrontation. MM then disappeared until 18:00 h the following day. On June 14, 2013, two researchers (DK and LB) reported a similar incident in which all the adult males raced in a certain direction as if giving chase to another chimpanzee.
Foudouko likely approached the chimpanzee group during the night of the June 14/15 after they had nested at Sakoto ravine. Fongoli village is ca. 1 km from Sakoto and during the early morning of June 15 observers heard vocalizations (pant-hoots, screams) between 02:00 and 03:00 h. They were atypical compared to the pant-hoots often heard from camp when chimpanzees nested at Sakoto in that they were very loud, extensive, and their placement indicated that some individuals had left their nesting area and had moved south. Calls indicated that individuals were rapidly moving on the ground and involved in extensive agonism. Alpha male DV’s pant-hoot, for example, indicated he was somewhere between the nesting site and the location where Foudouko was discovered dead the next morning. Beginning with the rank of alpha male, the adult male dominance hierarchy at the time of Foudouko’s death was 1) DV, 2) MM, 3) BO, 4) KL, 5) JM, 6) LP, 7) MI, 8) LT, 9) DF, 10) BI, 11) BN, 12) SI.
Treatment of Foudouko’s Body After Death
On the morning of June 15, 2013, a research assistant (M. Sadiakho) arrived before dawn at the chimpanzees’ nesting site. He returned to camp at ca. 08:00 h and reported that he had seen a dead chimpanzee, which he presumed to be Foudouko because all 12 other community males were present. He reported that most of the males had attacked Foudouko’s body (Table II). At this time, two additional researchers (J. D. Pruetz, E. G. Wessling) left to observe the body (Table II). On arrival at the scene, one observer identified the dead chimpanzee as Foudouko. When J. D. Pruetz and E. G. Wessling arrived in the vicinity of the body, they saw adult female FA (alpha male DV’s mother and presumably beta male MM’s mother) termite fishing <40 m from Foudouko and other chimpanzees in the area. For the next 2 h, observers recorded the chimpanzees’ reactions to Foudouko’s body, until the party departed (Table II). We observed fresh wounds on Foudouko’s hands, feet, back, and anus, with most of the wounds on the neck, torso, and appendages (Figs. 3 and 4) being inflicted postmortem (Tables II and III). Given their locations and severity, none of the bite wounds would have been lethal, save for possibly a severe bite to the right foot (Fig. 5) that could have considerably hindered his movement and escape and that could have resulted in significant blood loss. This foot wound was the most severe wound seen on Foudouko’s body when observers arrived at the scene. Chimpanzees may have inflicted this wound at or around the time of Foudouko’s death. We observed few wounds on any other individuals recorded in the vicinity of Foudouko’s body, i.e., potential attackers. Only older adult male BN exhibited fresh wounds, on his arm, and these appeared to be superficial. We approached Foudouko’s body after the party left the area. We found little sign of rigor mortis when we left his body at 11:20 h, suggesting he died within the previous 24 h. We judged livor mortis as minimal given the extent to which his neck wound still bled on rupture during the postmortem attacks. However, because multiple chimpanzees turned over and dragged Foudouko’s body, pooling patterns could have been interrupted. We found no extensive evidence of bleeding on the ground in the vicinity of Foudouko’s body.
During observations of Foudouko’s body, several young adult males beat his body and bit it repeatedly (Table III; Fig. 6), with young adult male BO most often attacking the body. Most group members, including several adult females, pulled on the body and smelled it intensely. Following BO, older adult female FA, mother of current alpha male DV and of adult male MM, attacked the body most frequently, and consumed more of it than any other chimpanzee. Neither of her sons attacked the body in similar fashion. These males had not behaved aggressively toward Foudouko earlier, and had engaged in affiliative behavior with him. MM displayed around the body several times, pulling Foudouko once and later stamping on him once. MM seemed to be attempting to rouse Foudouko, rather than trying to inflict injury, as his behavior was less aggressive than the other males’ displays, e.g., adult males BN, KL, BI, MI, BO, LT, and JM and adolescent males LX and DW. Alpha male DV approached and smelled the body several times but did not display toward Foudouko or attempt to move him. Numerous females and their offspring approached and smelled the body. FA and a young adult female (TM) fed on different parts of the body but ingested only small pieces of flesh.
No attackers were matrilineally related to Foudouko (Stewart 2011). Two of the frequent attackers, young adult males BO and LT, were matrilineally related to one another (Stewart 2011). LT is the son of adult female LU, brother to adolescent male LX, and likely nephew of BO, as BO’s mother WI (now deceased) was apparently LU’s mother. BO, LT, LU, and LX attacked Foudouko’s body. No other attackers were matrilineally related.
We buried Foudouko’s body near where we discovered his corpse, under the supervision of the local authorities. His bones will be exhumed for examination in the future.
Events in the Community Immediately after Foudouko’s Death
On June 16, 2013, an observer contacted the same chimpanzee party (N = 29 individuals) at dawn at their nesting site. At 06:05 h, almost all of the males and several females (TM, EV) traveled silently and rapidly toward the site where they had left Foudouko’s body. They began a pant-hoot chorus a few minutes after beginning travel, fell silent again, then reassured one another physically, e.g., touch fingers to mouth, hold genitals, embrace, as they traveled together, listening and looking toward the location where they left Foudouko’s body. All of the males were present except BI, BN, and alpha male DV. Alpha male DV then arrived in a silent, charging display. The party continued traveling to Foudouko’s burial site. Young adult male LT led the party, along with adolescent male DW and young adult males BO, MI, and JM. Young adult males JM and BO reassured one another by touching and embracing. DV and MM were further behind the party. All traveled silently and vigilantly. BN arrived at the rear of the party. At 06:35 h, the party neared the site where Foudouko’s body was last seen, and multiple males smelled the ground.
The party traveled quickly to the exact site where they last left Foudouko’s body and smelled the ground intensely. They then moved ca. 15 m to where we buried Foudouko. They smelled the rocks around the burial site, including where we laid the body to prepare to lower it into the grave. After smelling other areas where the body had been dragged, the party left the site at 06:50 h and traveled back to Sakoto ravine, backtracking along the same route taken from the night nests to the burial site. The group gave alarm calls nervously and frequently in the direction of Foudouko’s site, e.g., at 07:30, 08:41, 09:00, 09:20, and 12:40 h, despite having moved several hundred meters east. Third-ranked and young adult male BO hit beta male MM during a fight among the males at 09:25 h. MM and BI left the area, screaming. MM recruited his mother (based on behavioral indications and mtDNA analysis), adult female FA, who then helped recruit older adult males DF, LP, and BN to retaliate against BO. BO also attacked (hit) fourth ranked male KL at 13:35 h after the party returned to Sakoto. Such an attack by BO, on MM especially, was unusual. The party, including all adult males, nested at Sakoto on June 16, 2013. On June 17, the party left Sakoto ravine in the morning and traveled north ca. 2 km to Petit Oubadji ravine, in the direction opposite of Foudouko’s death site.
Alpha Males at Fongoli
Thus far at Fongoli, we have recorded four different alpha males in 11 yr of study following habituation for systematic data collection. The alpha male (YO) that rose from the third position in the hierarchy to take Foudouko’s place disappeared in 2010, <1 yr after LP usurped him from the dominant position. YO held the alpha position for ca. 15 mo, while LP was alpha for just over 3 yr. Following LP’s fall from alpha position in 2012, he was absent for a several weeks but then returned to range with community. LP dropped to the middle-lower end of the hierarchy, but he has since risen to middle ranking male. The ascendancy of young males into the dominance hierarchy (N = 12 adult males) created an unstable hierarchy for several years. Only the highest and lowest ranks remained stable over a period of >2 yr at Fongoli (2013–2014), with the hierarchy stabilizing in early 2015. The current alpha male DV is the longest reigning alpha thus far, having usurped LP in March 2012.