Changes

= Ape status = <!--An overview of ape population status (population sizes, trends, etc.), followed by a table of specific surveys and results -->

= Ape status = <!--An overview of ape population status (population sizes, trends, etc.), followed by a table of specific surveys and results -->

{{#ev:youtube|https://www.youtube.com/watch?v=1VNYuUaWnPo|330x220|}}

{{#ev:youtube|https://www.youtube.com/watch?v=1VNYuUaWnPo|alignment=right|330x220|}}

Ornithologists discovered the population of Cross River gorillas at the site in 2004. At the time, it was estimated that between 20 and 30 individuals were living in the sanctuary. Among the 14 Cross River gorilla subpopulations, the Tofala population is the only one about which no scientific data have been available, and the anthropogenic pressure exerted upon the gorillas living in the examined area is very high because there are ten villages adjacent to the area. Based on surveys conducted in 2014, 2015 and 2016, gorillas avoid the southern part of the reserve, since there is not much forest left; also the northern area of the sanctuary showed no signs of gorillas. All signs of gorillas were found in the central part of the sanctuary, in an area of 6.5 km² (Linnarz 2017).

Ornithologists discovered the population of Cross River gorillas at the site in 2004. At the time, it was estimated that between 20 and 30 individuals were living in the sanctuary. Among the 14 Cross River gorilla subpopulations, the Tofala population is the only one about which no scientific data have been available, and the anthropogenic pressure exerted upon the gorillas living in the examined area is very high because there are ten villages adjacent to the area. Based on surveys conducted in 2014, 2015 and 2016, gorillas avoid the southern part of the reserve, since there is not much forest left; also the northern area of the sanctuary showed no signs of gorillas. All signs of gorillas were found in the central part of the sanctuary, in an area of 6.5 km² (Linnarz 2017).

A three-month camera trap survey was conducted from January to April 2016 to calculate the population size and density of gorillas at the site. No gorilla was recorded while the cameras were in the field for 76 days. Using the program "Presence", a population size of only two to four gorillas  was estimated, and a density of 0.03 gorillas per km². The estimates seem to be realistic because the maximum nest group size was three nests and because no camera trap was able to picture a gorilla during the survey period. There have been three very short direct observations of gorillas by the guides and volunteers in 2014 and 2015; they saw one or two gorillas at these sightings (Linnarz 2017).

A three-month camera trap survey was conducted from January to April 2016 to calculate the population size and density of gorillas at the site. No gorilla was recorded while the cameras were in the field for 76 days. Using the program "Presence", a population size of only two to four gorillas  was estimated, and a density of 0.03 gorillas per km². The estimates seem to be realistic because the maximum nest group size was three nests and because no camera trap was able to picture a gorilla during the survey period. There have been three very short direct observations of gorillas by the guides and volunteers in 2014 and 2015; they saw one or two gorillas at these sightings (Linnarz 2017).