One of the new Big Five…

The gorilla has recently been named among the ‘New Big Five’ along with the lion, tiger, elephant and polar bear.

It’s certainly an intriguing creature, and its similarity to humans lends itself to anthropomorphism in photography.

It was always thought that gorillas were just one species, but it’s now generally agreed that there are two species, the eastern and western gorilla, each of which has two subspecies.

I’ve seen gorillas at London Zoo and Cabárceno Natural Park in Spain, and I’ve seen wild mountain gorillas in Rwanda, where I managed to get within a few metres of a couple of ‘troops’ without feeling unsafe.

Gorillas are not generally aggressive, but I did have to learn a kind of ‘clearing-of-the-throat’ sound to use in order to persuade them of my friendly intentions!

The most important thing to remember from a photographic perspective is to use negative exposure compensation.

Gorillas are very dark grey or black, so you need to make sure your camera doesn’t overexpose them.

They’re also quite peaceful and spend a LOT of time just eating, which means getting ‘action shots’ of gorillas is very tricky!

Basic facts

Order: Primates

Family: Hominidae

Species: Western gorilla, eastern gorilla

Scientific name: Gorilla gorilla, Gorilla beringei

Subspecies: Western lowland gorilla (G. g. gorilla), Cross River gorilla (G. g. diehli), Mountain gorilla (G. b. beringei), Eastern lowland gorilla (G. b. graueri)

Mass: males 136 to 227 kg (300 to 500 lb), females 68–113 kg (150–250 lb)

Height: males 1.4 to 1.8 m (4 ft 7 in to 5 ft 11 in), females 1.25 to 1.5 m (4 ft 1 in to 4 ft 11 in)

Arm span: males 2.3 to 2.6 m (7 ft 7 in to 8 ft 6 in), females smaller

Appearance: Great ape with black fur all over except for male ‘silverbacks’, which have grey fur on their backs. The eastern gorilla is darker than the western gorilla, with the mountain gorilla being the darkest of all.

Top speed: 40 km/h (25 mph)

Gestation period: 8.5 months

Lifespan: 35-40 years (up to a maximum of 60 years in captivity)

IUCN Red List Status: Critically Endangered

Population: 2,600 mature individuals, decreasing (eastern gorilla), 316,300 mature individuals, decreasing (western gorilla)

Habitat: All subspecies of gorillas live in tropical and subtropical forests, but that may be in moist lowland or swamp or moist montane areas. Western gorillas live from 0-1,900 metres above sea level whereas eastern gorillas live from 600-3,800 metres.

Distribution: Africa. Western gorillas are found in Angola (Cabinda enclave), Cameroon, Central African Republic (CAR), mainland Equatorial Guinea (Rio Muni), Gabon, Nigeria and Republic of Congo. Eastern gorillas are found in eastern Democratic Republic of Congo (DRC), north-west Rwanda and southwest Uganda.

Territory

Gorillas live in ‘troops’, which generally consist of a dominant male over 12 years of age (called a ‘silverback’), various females and perhaps a few adolescent males (from 8-12 years old) known as ‘blackbacks’.

Some troops consist entirely of male gorillas.

When different troops meet, there is a chance that the two silverbacks will fight to the death, using their long canines to bite each other.

Males usually leave their troops to start their own by attracting females, but some stay to take over their natal troop when the reigning silverback dies. Otherwise, the troop will simply disband.

Their daily routine is divided into periods of travel, feeding and rest, as determined by the silverback:

• Gorillas’ home ranges vary from 3 to 15 km² (1.16 to 5.79 square miles), and their movements range around 500 m (0.31 miles) or less on an average day.

• Their diet largely consists of plant material, including foliage and a small amount of fruit, but they also eat termites and ants. They rarely have to drink water as there is so much liquid in the food they eat.

• Gorillas sleep in nests that they build from branches, either in trees or on the ground.

Breeding

Gorillas mate all year round.

Females reach sexual maturity at 10–12 years (although earlier in captivity), and males at 11–13 years. A female's first ovulation occurs at six years of age and lasts for 30-33 days, but she won’t be fertile until a few years later.

Males can also be fertile before reaching adulthood.

Mating can be initiated by the male or female:

• A female will approach a male while pursing her lips and maintaining eye contact. If that doesn’t work, she may reach out to him or slap the ground to attract his attention.

• A male will approach the female, touch her and give out a ‘train grunt’.

After that, the male will usually mount the female from behind, but there have been cases of face-to-face sex observed.

The gestation period lasts 8.5 months.

When they’re born, baby gorillas are dependent on their mothers for the first five months, suckling at least once an hour and sleeping together in the same nest.

The distance between mother and baby and the frequency of separation gradually increase.

• At 12 months, they can move up to five metres (16 feet) from their mothers, and the frequency of nursing falls to once every two hours.

• At 30 months, infants spend half their time away from their mothers.

• At 36 months, they enter their juvenile period, when they are weaned and start to sleep in separate nests.

The father does not have much of a parenting role, but he’ll stay close, looking after the troop and protecting his offspring from any aggression from other gorillas.

Territory

Although males will interact with their partners and cubs at times, leopards are solitary creatures. In Kruger National Park, for example, they tend to keep around 1 km (1⁄2 mi) apart.

A leopard will defend its territory (or a kill) if threatened, but fights are rare.

The territories of males tend to be larger than those of females, and they often overlap with them. This is also the case with the territories of females and their cubs.

The exact size depends on habitat and the availability of prey:

• In the Serengeti, they are as small as 33–38 km² (12.5–14.5 sq mi) for males and 14–16 km² (5.5–6 sq mi) for females

• in northeastern Namibia, they are as large as 451 km² (174 sq mi) for males and 188 km² (72.5 sq mi) for females

• In Nepal's Bardia National Park, sizes of 48 km² (18.5 sq mi) for males and 5–7 km² (2–2.5 sq mi) for females are smaller than those generally observed in Africa.

Leopards have been seen walking 1–25 km (1⁄2–151⁄2 mi) across their range at night. They may even wander up to 75 km (47 mi) if disturbed.

Communication

Gorillas are known to be very intelligent and can produce 25 different types of call, including the following:

• grunts

• barks

• screams

• roars

• belches

Scientists even managed to teach one gorilla called Koko a primitive form of sign language.

Their intelligence is also shown by gorillas’ ability to laugh, feel sad, develop deep family bonds, pass on different methods of food preparation and perhaps even have quasi-religious or spiritual experiences.

Like all the great apes, they have also been observed using tools.

• A gorilla in the Nouabalé-Ndoki National Park in the Democratic Republic of Congo was seen using a stick to check the depth of water while crossing a swampy area.

• Another gorilla in the Republic of Congo was found using rocks to break open palm nuts.

Other forms of non-verbal communication include mating displays and the ritualised charge, which is unique to gorillas and consists of nine separate phases:

1. progressively quickening hooting

2. symbolic feeding

3. rising bipedally

4. throwing vegetation

5. chest-beating with cupped hands

6. one leg kick

7. sideways running, two-legged to four-legged

8. slapping and tearing vegetation

9. thumping the ground with palms to end display.

Threats

The most endangered of the gorilla subspecies is the mountain gorilla, and only 880 are believed to be left in the wild.

The IUCN deems the gorilla to be in its ‘critically endangered’ category, and it faces many threats to its existence:

• poaching

• disease

• predation (from leopards)

• habitat degradation and destruction

• climate change.

Sources: Wikipedia, IUCN (western and eastern gorilla)

If you’d like to order a framed print of one of my wildlife photographs, please visit the Prints page.

If you’d like to book a lesson or order an online photography course, please visit my Lessons and Courses pages.