GorillasGorilla Numbers

Gorilla Numbers

  • Mountain gorilla in Rwanda (© Wolfgang Möller)

Before conservation measures for a gorilla population can be planned, their numbers and their exact distribution area have to be known. For this purpose, a Census is made. In general, survey teams walk along pre-determined straight lines (so-called transects) and note all gorilla traces they see. On this basis the distribution area is drawn and population numbers are calculated, and this allows experts to decide whether conservation measures are necessary and which ones are most urgent.

In mountain gorillas the situation is different: as their distribution is well known, Gorilla Groups are counted individually. If possible, such censuses are done every 5 years to track the development of the population.

Gorilla Numbers

Numbers of gorillas in various populations
The numbers of most populations are not known, and it is very difficult to give valid numbers. Recently, the number of gorillas has been cut severely by bushmeat hunting and Ebola. All gorilla species and subspecies are endangered or critically endangered according to the IUCN Red Data List.

Survey of the Cross River Gorilla at the Tofala Hill Wildlife Sanctuary in Cameroon

July 2017

In January 2014 I started to study the ecology of Cross River gorillas at the Tofala Hill Wildlife Sanctuary (THWS) in collaboration with the local...[details]

On the Road to Extinction? A Population Estimate of Great Apes in Itombwe

July 2017

Periodic censuses of threatened wildlife populations of high profile species help us to understand their population dynamics, assess the success of...[details]

First Twins Born to Habituated Western Lowland Gorillas

January 2017

At the end of January 2016 the Dzanga-Sangha Protected Areas complex in the Central African Republic recorded the first ever western lowland gorilla...[details]

Gorilla Habituation for Research and Tourism in Loango

January 2017

Two components of gorilla conservation are research and tourism. Research provides the baseline information concerning the natural ecological and...[details]

Grauer’s Gorilla Population Reduced Dramatically

April 2016

Grauer's gorillas are a subspecies of eastern gorillas and live in eastern Democratic Republic of the Congo - an area where fighting between various...[details]

The Sarambwe Reserve: Current Developments and Threats

January 2016

This article documents activities implemented in the Sarambwe Reserve and the almost continuous threats to the conservation of the reserve. It is...[details]

Rukina - Life Summary

July 2015

Rukina (© Martha M. Robbins/MPI-EVAN)

We estimate that Rukina was born around 1984. He was well identified as a group member of the Kyagurilo Group in the late 1990s when he was a young...[details]

Using Remote Video Camera Traps for Multi-Species Assessments in Gabon

July 2015

Camera trap (© Josephine Head)

Accurate population assessments of endangered species are of great importance for determining conservation priorities and measuring the success of...[details]

The Status of Grauer's Gorilla in the Usala Forest

July 2015

Nkomo mountain which supports gorillas, taken from Rama village (© Stuart Nixon)

The Usala forest sits at the heart of the 30,000 km² Maiko Tayna region of eastern Democratic Republic of the Congo, and is among the most...[details]

Maiko National Park Progress Report

January 2015

Taking notes at a gorilla nest in the Kahuzi-Biega National Park (© FZS)

Maiko National Park, Democratic Republic of the Congo, lies in one of the most remote forest areas in the world. It is an incredible wilderness area,...[details]

Gorilla Group Formation and Dynamics

December 2014

Gorillas spend the major part of their life in small social groups led by a mature silverback male. Only young blackback males and mature silverback...[details]

Two Silverbacks Die in Rwanda

December 2014

The 21-year-old silverback male Umushikirano (Rano), leader of Titus group in Volcanoes National Park, was found dead on July 28, 2014 by trackers....[details]

Two Leading Silverbacks Die

June 2014

Mishaya, the leader of the Mishaya group, died on 3 February, 2014 at the age of 28 years after a short illness. Preliminary results indicate that...[details]

History of Habituated Gorillas in Bwindi

June 2014

Habituation of wild gorillas has long been a useful tool for research and conservation programs. Decisions to habituate gorillas typically reflect a...[details]

Getting off the "in Danger" List: Kahuzi-Biega

June 2014

The Kahuzi-Biega National Park (KBNP) has been a UNESCO World Heritage Site since 1980. Since 1997, it has been on the list of World Heritage Sites...[details]

Gorillas in the Dimonika Biosphere Reserve

July 2013

Approaching the Dimonika Biosphere Reserve

Designated in 1988 under the UNESCO Man and the Biosphere Program, Dimonika Biosphere Reserve is located in the central Mayombe Mountain chain in the...[details]

Blood Samples from Tshiaberimu Gorillas

July 2013

On a small forested island in the western region of the Democratic Republic of the Congo's Virunga National Park, a tiny population of Grauer's...[details]

Gorilla Guardian Update

January 2013

Takpe chief receiving WCS in the community (© WCS/Takamanda-Mone Landscape Project)

The Cross River gorilla (Gorilla gorilla diehli) is Critically Endangered, with perhaps fewer than 250 individuals remaining within their range,...[details]

DFGF Grauer’s Gorilla Program

January 2013

Biruwe field technicians (© DFGFI)

The Dian Fossey Gorilla Fund In­ter­na­tio­nal (DFGFI) has expanded its efforts in the Democratic Republic of the Congo (DRC) to build a new Grauer’s...[details]

Bwindi Gorilla Number Increased to 400

November 2012

The census team working (© IGCP)

A census of the gorillas in Bwindi Impenetrable National Park conducted in 2011 confirms a minimum population of 400 gorillas, raising the world...[details]

The 2011 Kwita Izina

January 2012

Performance at the Kwita Izina (© Gabriele Müller-Jensen)

Rwanda demonstrates how much the country values its few remaining mountain gorillas. Every year, Kwita Izina is celebrated in June. All mountain...[details]

Key Species Monitoring Plan for Kahuzi-Biega

January 2012

Range areas of the gorilla groups (© Radar Birhashirwa Nishuli)

A monitoring plan for gorillas and elephants has just been launched in the highland sector of the Kahuzi-Biega National Park (KBNP). Its pur­pose is...[details]

Gorillas in Deng-Deng

July 2011

Location of the Deng Deng and Mbam et Djerem National Parks in Cameroon and Gorilla gorilla gorilla distribution (© Angela Meder (information: Fiona Maisels)

Deng Deng - Previous Surveys In 1998 an environmental impact survey of a proposed oil pipeline route from Chad to Cameroon was commissioned by the...[details]

Changing Ecological Conditions

December 2010

Cyril Grüter on top of a Virunga Volcano (© Cyril Grüter)

The mountain gorillas of the Virunga Volcano Massif have been the subject of intense research and conservation efforts by the Karisoke Research...[details]

Readaptation of an Injured Juvenile

December 2010

Petit Ngoû before the injury (15 August 2008) (© Chieko Ando)

Since 2003, we have been trying to habituate western gorillas (Gorilla gorilla gorilla) for the purpose of scientific research in Moukalaba-Doudou...[details]

Bai Hokou

June 2010

Shelly Masi with Makumba (© Ngombo Diedone)

The south-western region of the Central African Republic includes one of the most pristine tropical forests in the whole of Africa. Located in the...[details]

Gorilla Census in the Virungas 2010

June 2010

Augustin Basabose with an assistant during the census (© Augustin Basabose)

Recently, I spent 10 days in the field as part of a team counting mountain gorillas during a 2-month census which took place from 1st March to 25th...[details]

History of Mountain Gorilla Research

June 2009

Titus in 1974, 2 days old, in the arms of his mother Flossie (© Kelly Stewart)

Fifty years ago, in 1959, George Schaller left New York for Africa to begin a study of mountain gorillas that would have lasting impact. His year of...[details]

Survey in Itombwe 2006

December 2009

Itombwe Massif Conservation Landscape (© Angela Meder, Adapted from a map by WCS)

The Wildlife Conservation Society (WCS) has been undertaking biological inventories in the Itombwe Massif since 1995. This area holds the largest and...[details]

Mufanzala and Birindwa Groups

December 2009

The gorilla statue with the Vice-Governor of South Kivu, Jean Claude Kibala (the 4th person from the left) (© Radar Nishuli/Parc National de Kahuzi-Biega)

After the death of the two silverbacks of these gorilla groups on March 26th and May 30th 2009, respectively, several friends of the gorillas of the...[details]

Mufanzala

July 2009

Mufanzala's body as the rangers found it

On March 26th, 2009, the rangers and trackers of the Kahuzi-Biega National Park (KBNP) made the tragic discovery of the corpse of the silverback...[details]

Genetic Diversity: Cross River Gorillas

July 2009

Distribution of the Cross River Gorilla (© Angela Meder, mit Informationen von Rich Bergl)

Conservation research on gorillas has, to date, mainly focused on demographic factors, human impacts, and the influence of disease. Genetic data have...[details]

Bwindi: Genetic Population

July 2009

Map of the Bwindi Impenetrable National Park with the locations of gorilla groups found during the census. Stars denote lone silverbacks whereas circles represent groups. The size of the circle corresponds to group size. Each group and lone silverback is labeled with a unique identifier tag. Groups and silverbacks that were double-counted during the census are shown in bold and connected by a line. (© reprinted with permission from Elsevier)

Accurate population size estimates are an essential part of every effective management plan for conserving endangered species. Censusing rare and...[details]

Rapid Decline in the Largest Group of Mountain Gorillas

December 2008

Interaction between the Pablo group and Beetsme’s group (© Veronica Vecellio, DFGFI)

Pablo's group is the largest habituated group of mountain gorillas in the Volcanoes National Park, Rwanda, or anywhere in the world. The group was...[details]

New Gorilla Population Estimates in Northern Republic of Congo

December 2008

Petunia with her son Asta while visiting Mbeli Bai (© Thomas Breuer)

On 5 August, 2008, at the XXII International Primatological Society Congress in Edinburgh, the Wildlife Conservation Society (WCS) announced the...[details]

Conflict with the Nkuringo Group

June 2008

The silverback Safari (© Michele Goldsmith)

The Nkuringo group ranges at the edge of the southeastern part of Bwindi. Its habituation started in 1996 and it was not completed until 1998; the...[details]

The Gorillas of the Ebo Forest, Cameroon

June 2008

The mountains of the Ebo Forest near Locndeng (© Bethan Morgan)

Cameroon is an important country for both gorillas and chimpanzees. To the south of the Sanaga River, western lowland gorillas (Gorilla gorilla...[details]

Equipment for Gorilla Census

March 2008

Local porters carry the survey equipment through the forest (© Pius Nkumba, WCS TMLP)

For their patrols in the Sarambwe Reserve during one year the rangers were provided with food rations. Related News:Additional Support when the...[details]

News from Kahuzi-Biega 2007

June 2007

Available only within the Gorilla Journal PDF file[details]

Inventory of Kahuzi-Biega 2006

December 2007

Available only within the Gorilla Journal PDF file[details]

History of the Rugendo Family

December 2007

Available only within the Gorilla Journal PDF file[details]

The Silverback Mugaruka

June 2006

Available only within the Gorilla Journal PDF file[details]

Gorillas in Maiko South

December 2005

Available only within the Gorilla Journal PDF file.[details]

Update on Nigeria: WCS's Work

June 2005

Available only within the Gorilla Journal PDF file.[details]

Post-Conflict Inventory of Kahuzi-Biega

June 2005

Available only within the Gorilla Journal PDF file.[details]

Virunga Gorilla Census 2003

June 2004

Available only within the Gorilla Journal PDF file.[details]

The Gorillas of the Ebo Forest

June 2004

Available only within the Gorilla Journal PDF file.[details]

The Disappearance of Mishebere

December 2003

Available only within the Gorilla Journal PDF file.[details]

The Mikeno Gorillas 2002

December 2002

Available only within the Gorilla Journal PDF file.[details]

Number of Virunga Gorillas Increased

February 2001

Available only within the Gorilla Journal PDF file[details]

News from Kahuzi-Biega: Second Half of 2000

December 2000

Available only within the Gorilla Journal PDF file[details]

The Mikeno Gorillas 1998

December 1998

Available only within the Gorilla Journal PDF file[details]

Situation in the Babira Bakwame Area, Kahuzi-Biega Park

December 2010

Cassiterite bags ready to be shipped to Bukavu and Goma (© Isidore Kikukama Mupenda, WWF)

The Kasese region contains the Kahuzi-Biega National Park (KBNP), the Maïko National Park and various forests that are not gazetted as protected...[details]

New Gorilla Census in Bwindi 1997

December 1997

Available only within the Gorilla Journal PDF file[details]

The Status of Grauer's Gorilla

June 1998

Available only within the Gorilla Journal PDF file[details]

Situation in Kahuzi-Biega: First half of 2000

June 2000

Available only within the Gorilla Journal PDF file[details]

Good News for the Cross River Gorillas?

June 2002

Available only within the Gorilla Journal PDF file[details]

Census in the Tayna Gorilla Reserve

June 2002

Available only within the Gorilla Journal PDF file.[details]

Gorillas Frequenting the Mongambe Bais

December 2002

Available only within the Gorilla Journal PDF file.[details]

Presence of Great Apes in Bas-Congo

December 2006

Available only within the Gorilla Journal PDF file[details]

New Gorilla Census in Kahuzi-Biega 2010

June 2011

Chimanuka and one of his offspring (© Angela Meder)

A census team led by the Wildlife Conservation Society and the Institut Congolais pour la Conservation de la Nature (ICCN) in Kahuzi-Biega...[details]

Death on Mt. Tshiaberimu

December 2009

The silverback male Kanindo from the tiny gorilla population on Mt. Tshiaberimu died after falling down a ravine. He was thought to be in his late...[details]

A New Gorilla Group in Kahuzi-Biega

December 2008

The history of the "new gorilla group" in the Kahuzi-Biega National Park dates from 2004 when WCS conducted a survey of the area. During...[details]

Maheshe's Tragic End

December 1995

Available only within the Gorilla Journal PDF file[details]

The Mikeno Gorillas 1996

December 1996

Available only within the Gorilla Journal PDF file[details]

The Death of a Patriarch

June 1997

Available only within the Gorilla Journal PDF file[details]

Mushamuka's Story

December 1997

Available only within the Gorilla Journal PDF file[details]

Nindja is Dead

December 1997

Available only within the Gorilla Journal PDF file[details]

Gorillas in Mgahinga National Park

December 1998

Available only within the Gorilla Journal PDF file[details]

Gorilla Slaughter in Kahuzi-Biega

December 1999

Available only within the Gorilla Journal PDF file[details]

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