A scientific expedition will study the gorilla population affected by the 2003 Ebola outbreak in the Congo

Ebola outbreaks in 2003 and 2004 caused the disappearance of 95 % of wild gorillas in Lossi. Image: Germán Illera
Ebola outbreaks in 2003 and 2004 caused the disappearance of 95 % of wild gorillas in Lossi. Image: Germán Illera
Research
(19/07/2019)

Studying the impact of the Ebola outbreak in 2003 on the current gorilla populations in the Lossi Gorilla Sanctuary, in the Republic of the Congo, is the objective of a scientific expedition of the Faculty of Biology and the Biodiversity Research Institute of the University of Barcelona (IRBio), coordinated by researcher Magdalena Bermejo, in which the experts José Domingo Rodríguez-Teijeiro and Àlex Barroso also take part.

The campaign, to take place from August to September 2019, will study the mid-term effects of the Ebola outbreak- that is, fifteen years after the infectious outbreak- on the current population of this threatened ape. With a global perspective, the final objective is to analyse the way in which some fatal events -such as the Ebola outbreak- can influence on the long run the social dynamics and genetic and demographical viability of gorilla populations.

Ebola outbreaks in 2003 and 2004 caused the disappearance of 95 % of wild gorillas in Lossi. Image: Germán Illera
Ebola outbreaks in 2003 and 2004 caused the disappearance of 95 % of wild gorillas in Lossi. Image: Germán Illera
Research
19/07/2019

Studying the impact of the Ebola outbreak in 2003 on the current gorilla populations in the Lossi Gorilla Sanctuary, in the Republic of the Congo, is the objective of a scientific expedition of the Faculty of Biology and the Biodiversity Research Institute of the University of Barcelona (IRBio), coordinated by researcher Magdalena Bermejo, in which the experts José Domingo Rodríguez-Teijeiro and Àlex Barroso also take part.

The campaign, to take place from August to September 2019, will study the mid-term effects of the Ebola outbreak- that is, fifteen years after the infectious outbreak- on the current population of this threatened ape. With a global perspective, the final objective is to analyse the way in which some fatal events -such as the Ebola outbreak- can influence on the long run the social dynamics and genetic and demographical viability of gorilla populations.

 

The scientific expedition is an initiative from an international consortium launched by the entity Sabine Plattner African Charities (Congo Basin Conservation Research Network), with the participation of the government of the Republic of the Congo, the University Marien Ngouabi (Republic of the Congo), the University of Barcelona, the Institute of Evolutionary Biology (CSIC-UPF), the Doñana Biological Station (CSIC), Princeton University (United States) and the University of Rennes 1 (France).   

Gorilla gorilla
: an endangered species in the African continent

The western gorilla (Gorilla gorilla) is a critical endangered great ape -according to the IUCN Red List of endangered species. Hunting, trade, loss of natural habitat, outbreaks and effects of armed conflict in the African continent put at an extreme risk the survival of wild populations of primates that share more of the 98 % of genetic material with the human species.  

In the nature, catastrophic episodes are hard to predict and their effects are hard to precise due a lack of scientific monitoring in the long run. Also, the initial state of populations before the arrival of the extreme episode is usually unknown. Regarding the Lossi Gorilla Sanctuary, the initial state of the gorilla population was known due monitoring campaigns that had been carried out before the Ebola outbreaks in 203 and 2004. According to the experts, these severe outbreaks caused the disappearance of the 95 % of gorillas.

During the epidemic, Magdalena Bermejo, José Domingo Rodríguez-Teijeiro and Àlex Barroso conducted a field work in the original place which revealed the social behaviour of the gorilla as a determining factor in the transmission of the disease among the population. The severity of the outbreak crises stopped the research program in the Lossi Gorilla Sanctuary, a funded initiative by the European Union since 1994 -with a great involvement by the native population- and led by the researcher Magdalena Bermejo in collaboration with Germán Illera (Great Apes Conservation/Research Odzala-Lossi and SPAC gGmbH, Republic of the Congo).

In 2007, a new campaign (funded by the French governmentʼs program ECOFOR, and the Barcelona Zoo Foundation) stated that the gorilla population density had decreased by 95 % compared to the previous season to the Ebola outbreak (that is, from 5 to 0.5 gorillas/km2). The outbreaks also reduced the amount of individuals per family, while the proportion of lone individuals was higher compared to the unaffected areas by the virus. This demographical pattern was also found in 2007 in the gorilla population in Lokoué, in the Odzala-Kokoua National Park, affected by an Ebola outbreak in 2004.

Following the great apes in the Lossi Gorilla Sanctuary

As part of the new scientific expedition organized by the African Parks Network (APN) and subsidized by the entity Sabine Plattner African Charities and the Barcelona Zoo Foundation, the UB team and the experts Alberto Fernández and Jacinto Román, from the Doñana Biological Station (EBD-CSIC), will repeat the monitoring from 2007 to see the current state of the gorilla population compared to the data from 2007. With this scientific monitoring, involving the tracing of the gorillasʼ over-night-stay spots and gathering biological samples of hair and excrement, the aim is to discover the territorial distribution of the families as well as their numerical and proportional composites of sexes through genetic studies.

This international academic network in which the UB and IRBio experts take part, unfolds several projects on the protection of the biodiversity at the Odzala-Kokoua National Park in the Ngaga Research Center and the Lossi Gorilla Sanctuary.

The consortium focuses the efforts on studying three gorilla populations, with different behavioral and ecological traits regarding the Ebola outbreak -which could condition their social strategies depending on the uses of habitat and territory. In short, the aim is to analyze the variability of the social dynamics of the gorillas in different habitats, the long-term effects of extreme episodes and the influence of social dynamics on the genic flux at a temporary and territorial space.