In this age of technology and information, we ponder the existence of bigfoot, sasquatch like creatures. To some of us it is no mystery, having validated for ourselves the existence of this creature. Even though, there are rudimentary questions that present themselves time and again. What is it, where did it come from? This question has left a lot of room for speculation concerning just what exactly this creature is. It is very hard to classify a creature who is as elusive as bigfoot. People have gone, will go, lifetimes without ever seeing this creature.
It has fallen upon the amateur researcher and
groups of researchers to prove the existence of this
creature, either to themselves or to others. This is
based on the perspective of the individual and uniform agreement among groups of researchers. In my own journey, I have come across interesting information that may help to explain what this creature may be. Included in this post is information about Gorillas and Orangutans, which may be useful in determining some characteristics of bigfoot. There are other interesting correlations which will be presented in the near future. The release of this post in no way insinuates that bigfoot is a true primate, yet at the same time does not say that bigfoot is of human origin either.
Night_Of_Wolves
" What have you done to benefit bigfoot research today?"
Information about Gorillas (Gorilla gorilla)
Social Behavior
The gorilla has a unimale social system and a polygynous mating system. The basic group is composed of one mature silver-back male (the leader of the group), one sub adult or black-back male (about 8 to 12 years old), three adult females, and two to three young (less than 8 years old) (Estes, 1991). Both males and females emigrate from their natal troop (Estes, 1991). When females leave they travel a long distance from their natal troop and either join a
lone silver-back male or a group with only a few females (Estes, 1991). Females may emigrate to avoid inbreeding because when she reaches sexual maturity the silver-back male is most likely her father (Stewart and Harcourt, 1987). There is a hierarchy amongst the females within the group, and a female’s rank is passed on to her offspring (Estes, 1991). The female’s rank is based upon when she became a member of the group, so the first female a lone silver-back makes part of his group would be the highest ranking female (Estes, 1991). High rank allows that female and her offspring to be closer to the silver-back male, and this could decrease the risk of predation (Estes, 1991). Grooming occurs between the silver-back and the adult females and the juveniles and the silver-back and between juveniles (Stewart and Harcourt, 1987). Males will only stay in their natal group if they are likely to be able to mate with females (Estes, 1991). This occurs if the silver-back male is old and is ready to die soon, the son will inherit the group
(Estes, 1991).
Males generally become solitary until about the age of 15 when they are strong enough and have a home range to start a group of their own (Estes, 1991). Lone
silver-back males will challenge a resident silver-back and try to get the females to come with him (Estes, 1991). The resident male does actively prevent the females from going with him, but rather performs
elaborate displays to keep the lone silver-back from
approaching (Estes, 1991). A lone silver-back will
generally approach a group that has a female undergoing estrus (Estes, 1991). Infanticide has been known to occur when a lone silver-back challenges the resident silver-back, he would do this because a female will start estrus sooner if her infant has died and is no longer nursing (Estes, 1991).
Immature gorillas at around the age of two will start to spend more time around the silver-back male (Stewart and Harcourt, 1987). The immatures will sit in close proximity to the silver-back and will sometimes groom the silver-back, and will sometimes groom them (Stewart and Harcourt, 1987). The silver-back will protect the immature gorillas from outside and within group threats (Stewart and Harcourt, 1987). Immature gorillas also spend much time playing with each other and grooming each other, and they tend to groom direct siblings than other immature gorillas (Stewart and Harcourt, 1987).
Ecology
The gorilla is a folivorous species, but will also eat fruit, seeds, flowers, roots, herbs, insects, and clay. The clay is eaten for the minerals that the gorilla can not obtain from its regular food sources (Estes, 1991).
The parts of the plants mostly eaten are the leaves,
stems, and pith. The favorite plants of the mountain
gorilla are the leaves of the hagenia and hypericum trees and wild celery. Western lowland gorillas in Gabon will eat insects, the most favorite being the weaver ant. Some populations consume such a large amount of succulent herbs that they do not need to drink much water (Estes, 1991). The lowland gorillas tend to consume more fruit than the mountain subspecies (Fleagle, 1988). This is a diurnal and a semi-terrestrial species, although the mountain gorilla is much less arboreal mainly the young
play in trees. Each night the gorilla will construct a nest of leaves on the ground which is generally a crude platform with a circular rim (Estes, 1991).
Locomotion
The gorilla moves quadrupedally, and has a special kind of quadrupedal gait called knuckle-walking (Fleagle, 1988). Unlike other quadrupedal primates which support their weight on the palms of the hands, gorillas support their weight on the dorsal surface of the third and fourth digits of the curled hands (Fleagle, 1988). When they travel through trees they climb, but are unable to move by suspensory behavior.
Vocal Communication
roar: This call is given by silver-back and large
black-back males (Estes, 1991). This call is low in pitch and is an outburst of sound through the open mouth (Estes, 1991). This call is given when the individual is under stress or threat, and the individual may give false charges and short lunges (Estes, 1991). The group hides behind the silver-back when hearing this (Estes, 1991).
wraagh: This call is also an outburst, but not deep as the roar, and is monosyllabic in nature (Estes, 1991). This call is mostly emitted by the silver-back male (Estes, 1991). This is emitted when the individual is experiencing sudden stress, and group members scatter when hearing this call (Estes, 1991).
hoot series: This call is low-pitched and consists of a series of "hoo-hoo-hoos" (Estes, 1991). This call is emitted by the silver-back male (Estes, 1991). This call is given in response to seeing members from another group, and it is used to maintain group spacing (Estes, 1991). This is given before chest-beating (Estes, 1991).
scream: This call is loud and is a shrill sound repeated many times (Estes, 1991). This call is emitted by all gorillas, and is given when the individual is upset or fighting with other gorillas (Estes, 1991).
question bark: This call consists of a short series of three notes, the first and third being lower in pitch
than the second (Estes, 1991). Mostly this is given by the silver-back male, and he emits this when he discovers someone that was concealed or another individual that is making noise but can not be seen (Estes, 1991).
cry: This is given by infants, and is a response to
extreme distress (Estes, 1991). This is a wail-like call that can build up to a shriek (Estes, 1991).
chuckle: This is a rasping sounding call, and is given by infants during play (Estes, 1991).
belch vocalizations: This call is given by all gorillas, generally when they are stationary, and generally communicates contentment (Estes, 1991). These noises consist of purring, humming, rumbling, crooning, moaning, and soft-grunting noises (Estes, 1991).
pig grunts: This call consists of a series of short
guttural noises (Estes, 1991). This call is given by
adult males and females, and communicates mild aggression (Estes, 1991). This call is emitted when the adult wants access to preferred foods or right of way (Estes, 1991).
whine: This call is given by infants and adult males when they are being left behind (Estes, 1991).
copulatory panting: This is a series of "o-o-o-o" sounds that are loud and low-pitched (Estes, 1991). This is given by the males during copulation (Estes, 1991)
Olfactory Communication
fear smell: This is produced by the silver-back male, and comes from glands under his armpits (Estes, 1991). This signals excitement or an aggressive threat (Estes, 1991).
Visual Communication
chest-beating: This behavior is done by all gorillas and the either one or two open-fist hands are clapped against the chest (Estes, 1991). Adult males produce a sound when doing this because of air sacs they have which are located on both sides of their throat (Estes, 1991). For the adult male this is a threat display (Estes, 1991).
strutting walk: This is a rigid walk with arms bowed and the hair bristled so that the individual looks bigger (Estes, 1991). The individual makes short steps and has the side facing the receiver and only looks at the receiver but for a few glances (Estes, 1991). This is a dominance display and is mainly performed by silver-back males especially when a lone silver-back is attempting to lure a female away from the group (Estes, 1991).
staring: This where the sender has its eyes fixed on the receiver, the eyebrows are lowered, the head is angled down, and the lips are parted and pursed (Estes, 1991). This communicates aggression or annoyance (Estes, 1991).
tense-mouth face: This is like staring but the gums and teeth are displayed having the lips curled back (Estes, 1991). This is a threat display for potential predators, mostly given by adult males, and is often accompanied by a mock charge and scream and roars (Estes, 1991).
pout face: This is where the lips are pursed, mouth is slightly parted or compressed, and the eyebrows are
raised (Estes, 1991). This is most often given by infants when their mothers leave them or they do not receive what they want, it is a display of light distress (Estes, 1991).
open-mouth grimace: This is where the mouth is wide open, the corners of the mouth are drawn back, the eyebrows are raised, the head is tilted back a little, and the eyes move back-and-forth (Estes, 1991). This is a fear display (Estes, 1991).
play face: This is where the mouth is open but not
showing the teeth or gums (Estes, 1991). This is seen
during play (Estes, 1991).
Tactile Communication
social grooming: This is where an individual will remove dead skin or parasites from the hair of another. This occurs between females and the silver-back, between immature gorillas, but not between adult females (Estes, 1991). This behavior is used to maintain the social bonds between individuals (Estes, 1991).
Reproduction
The gorilla gives birth to a single offspring every four years (Estes, 1991). The female is usually the one to solicit copulations from the male (Estes, 1991). Mating is usually dorso-ventral, but ventro-ventral (face-to-face) mating does occur (Estes, 1991).
Copulatory panting is emitted by the males during mating (Estes, 1991). Immature males might also try to mount preadolescent and adolescent females, the adolescent females have small sexual swellings (Estes, 1991).
Information about Orang-Utans (Pongo pygmaeus)
MORPHOLOGY:
The average body mass for an adult male orang-utan is
around 86 kilograms, and for the female it is around 38 kilograms. There is a high degree of sexual dimorphism in this species and it may be males are larger because of male-male competition for females, large males displace small males for access to females for mating (Rodman and Mitani, 1987). Pelage color ranges from reddish-orange to black. This species has a relatively short thumb. Males have flaps of fatty tissue on both sides of the face, and these develop in adulthood after the first mating. Males have throat sacs. The molars have thick enamel and low, flat cusps and have surfaces that are crenulated occlusally (Fleagle, 1988).
RANGE:
The orang-utan is found in the countries of Brunei,
Indonesia, and Malaysia on the islands of Sumatra and
Borneo. This species lives in tropical primary
rainforests, swamp forests, and montane forests up to
2000 meters.
ECOLOGY:
The orangutan is primarily a frugivorous species,
although it also eats insects, small vertebrates, leaves, bark, and pith are also consumed. Among the most consumed fruits are: mangoes, rambutan, jackfruit, figs, and durian, which is a thick-shelled fruit that requires much strength to open. To supplement the diet for minerals, the orangutan consumes soil. Water is obtained from tree holes by dipping the hand in and sucking up the water off
of the hand. This is an arboreal and diurnal species.
Each night this species constructs a nest made of
branches and leaves in the trees up to 24 meters.
LOCOMOTION:
The orangutan moves through the forest by slow
quadrumanous climbing (Fleagle, 1988). Older and heavier males will come to the ground and they move quadrupedally supporting themselves with the wrists on the forelimbs, unlike Gorilla gorilla which supports their weight on the knuckles (Fleagle, 1988). Because of their large size, orangutans must be careful when choosing supports when traveling (Rodman and Mitani, 1987), which may contribute to why they move slowly.
SOCIAL BEHAVIOR:
The basic group of the orangutan is composed of a mother and her offspring. Males have territories which overlap one or more females and they periodically check the females especially during breeding season. This species has a polygynous mating system. Adult males exclude all other adult males from their ranges. Males spend most of their time traveling solitarily. Subadult males which have not found a territory will travel and forage with adult females an will sometimes forcibly mate with them (Fleagle, 1988). Males disperse from their natal ranges and females disperse too, but will often settle in an area near her mother’s range (Rodman and Mitani, 1987).
VOCAL COMMUNICATION:
loud call: This call is given by the adult male and
consists of roars at first and then rises to bellows and is enhanced by the throat sac. This is used to demarcate territories and to attract a mate, and is important because the orangutan lives in such dense forests that it is difficult to see other individuals.
TACTILE COMMUNICATION:
social grooming: This is where one individual removes
dead skin and parasites from another. This serves to
maintain social bonds. In the orangutan this occurs
between the mother and her offspring.
REPRODUCTION:
The orangutan gives birth to a single offspring about
every five years.
presenting: This is where the female orangutan hangs
from a branch above the male and shows her perineum to
the male. She does this to solicit a mating from the male
(Hrdy and Whitten, 1987).
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