Skip to main content

Whose the daddy Gorilla?


With television shows  emotionally uniting children with their long-lost 'real fathers', paternity clearly matters to us humans. Many species show discrimination in rearing their own offspring.  But, it appears not to matter so much to mountain gorillas.


Gorilla Fathers from Dian Fossey Gorilla Fund on Vimeo.

Recent research published in the journal Animal Behaviour shows that being the biological daddy isn’t so important for male gorillas when it comes to their relationships with the youngsters in the group. What matters is their rank.

Mountain gorillas (Gorilla beringei beringei) live in groups in the forests of central Africa.  They are unusual among primates because one group, or troop, of gorillas can have more than one male, as well as several females.  So, do the males behave differently to the youngsters in the group? Or do they treat them all the same?  Is there any sign they are distinguishing their 'own' young?

The Thin End

Rank more important than genetic parentage  

The researchers tracked the way male mountain gorillas interact with infants to see if their behaviour is similar to other primates that live in troops with more than one male. The results show that being the biological father does not influence the way male gorillas interact with infants.

Primates like chimpanzees that live in troops with more than one male have a way of recognising which infants belong to which males. For animals that live in groups with only one male this is not necessary, as the male is most likely to be the father of all the infants in the group. The researchers wanted to determine whether gorillas have evolved a way of recognising their own offspring or father.

The researchers followed gorillas in Volcanoes National Park, Rwanda, and monitored the way the males and infants interacted. They looked at the amount of time the gorillas spent grooming each other and playing, and noted every ten minutes which gorillas were physically close to one another. They also looked at which males were dominant in the group.

The researchers analysed more than 1500 hours of data and found that there is no evidence to suggest that gorillas recognise their own offspring or father. Or at least if they do it doesn't affect the way they interact. 

Dominant males are gentle and nurturing 

Instead, they found that a male gorilla’s dominance or social rank had a stronger influence on its relationships with infants; alpha males tend to be more nurturing and have stronger relationships with infants in the troop. While statistically they are most likely to be the father, many infants are also sired by other males, but this doesn't affect they way they are treated.

“When we think of a human alpha male, we have a very specific set of cultural norms that go along with that, like aggression and not being very paternal,” says lead researcher Dr. Rosenbaum.

In gorillas, dominant males are often the biggest in the group, but they are gentle and nurturing with the infants.
Mountain gorillas are not only capable of living in multi-male groups, they may actually benefit from doing so. Advantages to living in multi-male groups include better female retention, since females seem to prefer multi male groups, and lower risk of infanticide.     

There are also clear benefits to the offspring. Infants in multi male groups are still generally safe even if the dominant male dies, since other males in the group can deter infanticidal outsiders.




Comments

Popular posts from this blog

Ian Duncan-Smith says he wants to make those on benefits 'better people'!

By any account, the government's austerity strategy is utilitarian. It justifies its approach by the presumed potential ends. It's objective is to cut the deficit, but it has also adopted another objective which is specifically targeted. It seeks to drive people off benefits and 'back to work'.  The two together are toxic to the poorest in society. Those least able to cope are the most affected by the cuts in benefits and the loss of services. It is the coupling of these two strategic aims that make their policies ethically questionable. For, by combining the two, slashing the value of benefits to make budget savings while also changing the benefits system, the highest burden falls on a specific group, those dependent on benefits. For the greater good of the majority, a minority group, those on benefits, are being sacrificed; sacrificed on the altar of austerity. And they are being sacrificed in part so that others may be spared. Utilitarian ethics considers the ba

The secret life of Giant Pandas

Giant pandas, Ailuropoda melanoleuca , have usually been regarded as solitary creatures, coming together only to mate; but recent studies have begun to reveal a secret social life for these enigmatic bears.  GPS tracking shows they cross each others path more often than previously thought, and spend time together.  What we don't know is what they are doing when together.  Photo by  Sid Balachandran  on  Unsplash For such large mammals, pandas have relatively small home ranges. Perhaps this is no surprise. Pandas feed almost exclusively on bamboo. The only real threat to pandas has come from humans. No wonder then that the panda is the symbol of the WWF.  Pandas communicate with one another through vocalization and scent marking. They spray urine, claw tree trunks and rub against objects to mark their paths, yet they do not appear to be territorial as individuals.  Pandas are 99% vegetarian, but, oddly, their digestive system is more typical of a carnivore. For the 1% of their diet

A time for every purpose

All life moves. Or, more precisely, all life moves purposefully.  This is true even for trees and plants.  Movement is essential for maintaining life.  Animals migrate; plants disperse.  Some form of migration is an ingredient of all life.  For many organisms, it is a key function of reproduction.  We don't reproduce merely to create a new organism, but also to disperse the population - finding new fertile ground, or resources. Reproduction is a form of migration. Reproduction isn't merely to replicate. Reproduction produces change and diversity.  While we may have strong resemblences in families, we also have differences.  Creating a difference is how evolution works.  In this sense, nature is a continuous exploratory process, finding what works best.  Nature senses change and responds.  Some of this is immediate and physiological or behavioural; some of it is over generations.  If we look at a forest over long periods of time, we would see that it shifts. There is a movement