December 30, 2019

Update on the Cape Peninsula Baboons

Update on the Cape Peninsula Baboons
By Karin Saks

In 1990, following the culling of an entire troop of baboons in Kommetjie, the Kommetjie Environmental Awareness Group (KEAG) was formed. Through the efforts of KEAG, the Baboon Management Team was started, which essentially involved all the relevant authorities to find management options for resolving conflicts between humans and baboons on the southern peninsula of Cape Town (Mail and Guardian, January, 2005).
Based on population censuses from 1998 and 1999 (Kansky and Gaynor 2000) which showed an apparent high birth and mortality rate coupled with a highly skewed adult male to female ratio, it was suggested that  the baboon population was under severe human predation pressure and therefore in need of management intervention (Beamish, E.K. 2009). In her booklet, Baboons on the Cape Peninsula, 2002, Kansky described the Cape Peninsula population as critically endangered (according to Red Data list criteria) as there were less than 250 mature individuals left.
Age/sex ratios of the Cape Peninsula were recorded between 2005 and 2008 showing that 66% of the troops had one or no adult males due to high mortality in the late 1990’s leading to a skew in the male to female ratio at 1:8. Humans were seen to be responsible for the skewed adult sex ratio which resulted in a higher alpha male turnover and increased rate of infanticide (Kansky and Gaynor 1999; Peterson pers.comm. 2008).
This resulted in concerns that extinction of the population was likely if high mortality rates of males continued and various measures were introduced: Field rangers were used to chase two of the raiding troops away from urban areas. Government authorities, consultants, members of the public and NGOs formed the Baboon Management Team (BMT). The BMT devised management plans and a strategy document which included an option as a last resort to euthanise baboons that posed risks to humans. Although it was understood that euthanasia could be used a last resort, this was not one of the BMT’s strategies. Various sources draw comparisons between the BMT and BTT in terms of successful management of the baboon population in spite of the fact there is no accurate comparison due to the fact that the BMT managed two troops and was limited by financial restraints at times.

Baboon Social Structure Improves:
Ruth Kansky noted in 2002 that when baboon monitors were present, they succeeded in keeping baboons out of residential areas most of the time.

Illustration above: Baboons on the Cape Peninsula, Ruth Kansky, 2002
By 2003, the adult sex ratios had improved to 1:5 (Beamish, 2009) and by 2005 the situation had further improved as the adult male to female ratio was 1: 3,5 (Beamish, 2009). By 2011, adult sex ratios showed further improvement  at 1 male to 2.5 females (O Riain, Apr. 2011) and improved further in 2015 at 1:3+ (Beamish, E.K.).

 Lethal Methods as a Management Strategy:
In 2010, Nature Conservation Corporation took over the tender for managing baboons on the Peninsula with Human Wildlife Solutions taking over in August, 2012.Although euthanasia had been a management strategy for “raiding” baboons as a last resort while the BMT was managing two baboon troops, this was lethal method was avoided. Various sources  today attempt to defend the use of lethal methods by comparing the health of baboons during the time the BMT managed two troops (restrained by various financial difficulties) with the period whereby euthanasia has become standard practice (2010 – 2019) yet these two periods are incomparable. 

Under the Lethal Protocol, adult and subadult males appear to be the most targeted group. Because targeting male baboons contributes to a skewed adult male to female ratio, and a healthy adult male to female ratio is crucial to a healthy baboon population, killing “raiding” baboons under the current protocol needs to be removed from the management program while stronger measures are put in place that encourage residents not to harm or kill baboons.

The 2019 population census shows that the adult male to female ratio is 1 male to 8+ females indicating that the baboon social system has been damaged.
By June, 2019, the adult sex ratio has returned to the same state it was in during the late nineties when stakeholders realized that protective measures were desperately needed.

The Baboon Social System – Crucial to a Healthy Population:
The Cape Peninsula baboon population has challenging characteristics that are specific to the area that contribute to unhealthy populations. However within this framework, for the conservation, health and welfare of the Cape Peninsula baboons, it would be beneficial to strive for baboon troops that are as healthy as possible. Without this, the baboon social system will continue to break down, become more and more dysfunctional and then lead to extinction.  
The social system of baboon troops is more important for determining the health of a population than the amount of individuals.
The chacma baboon has a multi-male multi-female social system. A troop is not made up of autonomous, unrelated individuals and therefore evaluating a baboon population solely in terms of numbers gives an inaccurate picture. On the contrary, a healthy baboon troop is reliant on a cohesive social system of bonded allies and families Healthy baboon troops have healthy behavior that is not only necessary for conservation but is crucial when baboons live close to human areas.

The health of a baboon troop is measured by the sex/age ratio of individuals with an acceptable adult sex ratio being 1 male to 3 (or 4) females. An absence of adult and/or subadult males is a strong indication that the fragile, cohesive social system required for a healthy functional baboon troop has been broken down.

Human Intervention:
Predation generally accounts for 5-10% of the deaths of certain primate populations (Kansky, 2002). Although there are no natural predators, the Cape Peninsula baboons face death and injury when electrocuted on pylons, hit by vehicles, attacked by dogs, shot with pellets or bullets, poisoned or drowned. The Cape Peninsula baboon population is therefore most threatened by human intervention.

Targeting Age-Sex Classes:
Although the Lethal Protocol claims not to target age/sex classes (see excerpt taken from the Lethal Protocol below), the population censuses of 2018/2019 suggest this is not the case. 

The Role of Adult Males:
 Males contribute to the group for various reasons, one being that they deter the threat of infanticide. Troops that have a skewed adult sex ratio that is biased towards females show slow growth (Beamish, 2009).  Female and male baboons form cooperative friendships, another natural process that has been obstructed by the absence of males.

Targeting Single/Dispersing Males:
Males in a baboon troop first leave the troop to move into another troop when they become sexually mature. Males will do this a few times in their lives while the females stay in their birth group for life forming the stable core. The reason for this is genetic mixing.
These males are particularly vulnerable at this stage as they do not have the protection or guidance of the troop. As a result we often find that single males are drawn towards human properties where they may opportunistically forage. These single dispersing males appear to be the most targeted group under the Lethal Protocol. They are not given the chance to get through the vulnerable dispersal process of moving towards a new troop. Typically single dispersing males will follow the lead of the troop once they have joined a new group, hence “raiding” behavior tends to cease when this happens.
The natural process required for genetic mixing which is seen when dispersing males leave their troops to look for new ones is an important natural process that is obstructed when male baboons are killed.

 As a result of damaged social structures, in spite of the number of individuals that is incorrectly used as a barometer to measure the health of populations, the Cape Peninsula baboon population is currently (again) heading towards extinction and new solutions are required to protect them.

Adult Sex Ratio of Managed Baboon Troops – June, 2019:

The June, 2019, the adult sex ratio shows that 1 troop has no adult male (if we include the Misty Cliff group, 2 troops do not have adult males), 3 troops have no subadult females and 3 troops have no subadult males.
There are 200 adult/subadult individuals to 249 immature individuals: fifty more immatures than adults.

How the Health and Welfare of Baboons is Compromised:
On their website, the South African Baboon Forum (, states that their methods not only ensure “the safety of residents but also the conservation, health and welfare of the baboons”.
If the goal is to truly work for the conservation, health and welfare of the Cape Peninsula’s baboons, acknowledging that human bias affects scientific research (whether it be conscious or not) and the agenda underlying important decisions may need to be revisited at times while exploring new solutions.
The baboon social system is made of close groups of allies and families, relationships that are negatively altered on various levels (from both a psychological and conservation perspective) when individuals are removed from a group by human predators.

Charles Darwin was one of the first scientists to write about the existence and nature of animal emotions. He believed that humans share universal emotive expressions and suggested that animals share these. His observational approach has since developed into a more robust, hypothesis-driven, scientific approach. The existence and nature of emotions in animals are believed to be correlated with those of humans and to have evolved from the same mechanisms (Panksepp, J. (1982). ,"Emotions help animals to make choices". University of Bristol. 2010.,Turner, J.,D'Silva, D.(2006), Wong, K. (2013).)

 In her book Almost Human, Shirley Strum pointed out that science in the past, paid little attention to the emotional and mental lives of animals as these aspects were fraught with difficulty and projection. As a result, animals were largely denied these qualities. In doing so we were left with a misconception about other species. This applies to our understanding of baboons, especially because of their reputation as “problem causing animals”.

Recently, the study of nonhuman animal emotions has become more legitimate.
Today, science recognises that primates have complex social lives and are highly
intelligent creatures. Because of the specialized organ that is unique to primates,
our brain, we can reasonably infer that there will be some behavioral correlation
between ourselves and other primates. Primates are studied in the field of biology,
psychology, and the bourgeoning science of evolutionary psychology in order to
gain some understanding about human behavior. To give the baboons the best chance we can, I suggest that the field of psychology is included in our attempt to understand them. This will not only help with their health and welfare but will impact positively on the environment (whether it be urban or natural habitat) they survive in as well.

The premise that “we share an emotional language” (Shirley Strum in Almost Human) is illustrated in the photos below. These photos also clearly show the stress involved when a member of the troop is lost.   

Given that a baboon troop is made up of close allies and families, it is reasonable to conclude that the manner in which humans are damaging their social system by using lethal methods for “raiding” baboons  is causing emotional and mental stress which further impacts on the ability of baboons to operate in a healthy way.

If we accept that damage caused to troop structures is likely to lead to the extinction of baboon populations on the Cape Peninsula, new solutions are urgently required to protect the remaining baboons.

References:1.     Beamish, E.K. 2009.Causes and Consequences of Mortality and Mutilation in the Cape Peninsula Baboon Population, South Africa.
  1. Enviro News, Understanding the Baboon Troops in the South Peninsula, April 2011. Michele King.
  1. Mail and Guardian, Whose mountain is it, anyway? ( Jan, 2005.
  1. Kansky, R, 2002, Baboons on the Cape Peninsula. A guide for Residents and Visitors.
  1.  Panksepp, J. (1982). "Toward a general psychobiological theory of emotions". Behavioral and Brain Sciences. 
  1.  "Emotions help animals to make choices (press release)". University of Bristol. 2010.
  1. 7. Jacky Turner; Joyce D'Silva, eds. (2006). Animals, Ethics and Trade: The Challenge of Animal Sentience.
  1. Wong, K. (2013). "How to identify grief in animals". Scientific American.

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