July 27, 2015
Outline of a gorilla group interaction
Fossey Fund trackers and researchers monitor gorilla groups every day, and this includes collecting information on the gorillas’ behavior. Sometimes this is not a simple task, such as when a group interacts with another group. When we witness this, we try to record all the behaviors seen. Here is an excerpt from our detailed notes regarding one interaction, which took place in June between Titus’ group and Isabukuru’s group.
From Isabukuru group: silverbacks Isabukuru and Kubaha; adult females Nyandwi and Isaro; juvenile Sakara; and subadult male Mushya.
From Titus’ group: silverbacks Pato and Urwibutso; blackback Segasira; infant male Ndizeye (approximately 3-1/2 years old).
The interaction started at 11:15, when Kubaha displayed at Segasira who replied by screaming. Immediately, Pato, Urwibutso and Kurudi approached Segasira. Pato went close to him while Urwibutso stayed 5 meters away with Kurudi. Pato didn’t react, but watched.
At 11:17 a.m., Mushya joined Kubaha and displayed at Pato at 11:18.
At 11:19, Kubaha stood in strut stance posture at Pato, followed by a display at 11:20.
At 11:21, Mushya displayed at Pato.
At 11:23, Segasira displayed at Mushya followed by a hit at 11:24, and Mushya replied by dragging him.
At 11:26, Segasira displayed at Mushya who replied at 11:27 by a display too.
At 11:28, Mushya played with Segasira and at that time, Mushya transported Ndizeye.
At 11:29, Ndizeye invited Mushya to play but Mushya ignored.
At 11:30, Mushya played with Segasira and Ndizeye invited Mushya to play but he ignored.
At 11:31, Ndizeye played with Mushya and from 11:31 to 11:33, Mushya played with Segasira (3 times).
At 11:32, Mushya transported Ndizeye.
At 11:33, Mushya played with Ndizeye.
At 11:35, Kubaha displayed at Urwibutso who was still with Kurudi, 5 meters from Kubaha and he replied by taking the strut stance posture.
At 11:38, Kubaha charged Urwibutso; he moved away and Kubaha didn’t follow him.
At 11:40, Isabukuru approached the interaction site, Nyandwi and Isaro followed him and the group was still in 8 meters.
At 11:44, Isabukuru did a pig grunting vocalization at Isaro but the females ignored and kept following him and at 11:46, Isabukuru hit both Nyandwi and Isaro; they returned to their group.
At 11:47, Kubaha displayed at Segasira and at this same time, Sakara was playing with Ndizeye.
At 11:48, Segasira played with Mushya and at 11:49; Mushya played with Segasira too.
At 11:50, Segasira displayed at Mushya and one minute later, Segasira screamed at him.
At 11:52, Segasira displayed at both Mushya and Sakara.
At 11:53, Segasira played with Mushya and Sakara charged Segasira.
At 11:55, Segasira played with Mushya.
At 12:00 p.m., Isabukuru approached Titus’s group and he displayed at the group but Titus’group ignored.
At 12:03, Segasira displayed at Mushya.
At 12:05, Segasira played with Mushya.
At 12:06, Isabukuru stood in strut stance position at Titus’group and Titus’group individuals only watched him. They were separated by 7 meters.
At 12:07, Urwibutso wanted to approach Isabukuru and Isabukuru displayed at him then Urwibutso withdrew.
At 12:09, Segasira played with Mushya. At 12:10, Mushya played with Segasira and after, Sakara played with Segasira.
At 12:11, Sakara displayed at Ndizeye. From 12:13 to 12:17, Mushya played with Segasira twice and Sakara played once with Segasira.
At 12:18, Segasira, Mushya and Sakara were playing and Urwibutso approached them and started feeding.
At 12:19, Segasira hit Mushya.
At 12:20, Segasira kicked Sakara.
At 12:21, Sakara played with Segasira.
At 12:22, Segasira kicked Mushya and at 12:23 p.m., Sakara displayed at Segasira supporting Mushya; one minute later, Sakara played with Mushya.
At 12:25, Mushya displayed at Segasira.
At 12:26, Urwibutso bit Sakara who screamed, and Mushya charged Urwibutso supporting Sakara.
At 12:28, Sakara ran away and went to join the group in 50 meters.
At 12:30, Mushya played with Segasira.
At 12:36, Segasira displayed at Mushya.
At 12:38, Mushya stood in strut stance position at Segasira.
At 12:39, Segasira followed Urwibutso and moved with the group in Muntu direction while Mushya went joining the group at 12:40 p.m. and they all moved feeding in Rutaka direction.
At 12:41, both groups were still moving Titus’ group in Muntu direction while Isabukuru’s group was moving in Rutaka direction and were separated by 150 meters. Trackers left them at 2:02 p.m., separated by 700 meters from each other. No transfers or wounds occurred during this interaction.
In total, Kubaha did 4 displays, Mushya did 4 displays, Segasira did 6 displays, Sakara did 2 displays and Isabukuru did 2 displays.
Observers: Jean Bosco Ntirenganya, Prosper Kaberabose, Francois Nizeyimana, Edward Wright, Venuste Nkunduwenda, Honore Rudahinyuka, Theobard Uwamahoro, Joseph Mutabazi, Eric Tuyihimbaze and Melanie Mirville.