The Gelada
Created | Updated Oct 20, 2010
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<H1>
THE GELADA
</H1>
<H2>
1. Name, Classification and Relationships.
</H2>
<P>
<IMG SRC="http://www.fotango.com/p/eba00019870f00000035.jpg" align=left vspace=20 hspace=20 alt="A Gelada Male">
The Gelada, <i>Theropithecus gelada</i>, is a very unusual kind of baboon. All other baboons are classified in a single species, <i>Papio hamadryas</i>,
but the Gelada is given not only a species but also a genus of its own. The name of the genus, <i>Theropithecus</i>, means "Frightful monkey". "Gelada" is
its common name in Amharic, the dominant language of Ethiopia. In the
past baboons of the <i>Theropithecus</i> genus ranged more widely over Africa, and some reached the size of a Gorilla. Climate
fluctuations over recent millennia led to forests and grasslands shrinking and growing at the expense of each other in alternating cycles.
This factor, combined
with competition from the <i>Papio</i> baboons, and especially <b>humans</b>, led to <i>Theropithecus</i> being pushed back into forbidding mountainous regions, where finding a suitable
habititat is a matter of climbing or descending to slopes of the right attitude and aspect. They also minimised competition from other monkeys by developing
an ability to live on a diet almost entirely composed of grass. In these isolated regions, and with this unusual lifestyle, these baboons eventually
developed into the modern Gelada.
</P>
<H2>
2. Distribution and Habitat
</H2>
Geladas have a restricted range: they occur only in western regions of the highlands of Ethiopia,
at altitudes of 7 000 to 15 000 ft. above sea level. This is the highest part of these highlands and consists of jagged peaks, steep slopes, sheer
cliffs and grassy plateaus at various altitudes. The Gelada occurs in these mountain grasslands, and can reach high and isolated pastures through
its ability to climb cliffs.
It lives totally on the ground surface - it is probably the most terrestrial
of all primates. The reason why the Gelada doesn't climb trees is simple: there aren't any trees at the high altitudes and the habitat it chooses to
live in.
</P>
<h2>
3. Description
</h2>
<P>
The picture shows a large Gelada male. [People, be patient - I am going to put more pictures here, including females, side-on views, and the "lip-flip"
display - of all creatures in existence, this monkey is one of the weirdest and most interesting to look at.]
It has many features that set it apart from other baboons. Its face is somewhat different: typical baboons
have long, dog-like muzzles with their nostrils right at the tip; the Gelada has a shorter, more rounded face with its nostrils set much further
back, and turned upwards. It has a number of ridges stretching from its nose towards its eyes. Its facial expression seems somewhat strained, even
when it is totally relaxed. This is due to a very peculiar arrangement of facial muscles that are used for one of the strangest face displays to
be found in the entire mammalian class. It's called the "lip-flip": when a Gelada male wants to intimidate an intruder (whether of its own species
or not), it not only opens its mouth wide to show its impressive, long, sharp fangs, it also pulls its lips very far backwards until they
cover the nostrils. This exposes the teeth and gums of the entire jaw, which protrudes forward in a way reminiscent of the monsters in the "Alien/Aliens"
sci-fi movies.
</P>
<P>
Another facial display feature of the gelada is its light pinkish eyelids. When it turns its eyes down, these eyelids form prominent patches in its
dark face. This is also a sign of dominance, or a threat.
</P>
<P>
The male Gelada has a mane of very long hair, ranging from light cream to dark brown, that surrounds its face and hangs down over its shoulders like
a cape. The largest, strongest, most dominant males have the largest capes, and this of course makes them look even larger and more impressive. The
females also have long hair, though not developed into such a voluminous cape. This hair is waterproof and aside from its visual features it is also
very effective in keeping these monkeys warm and dry on the cold, rainy and windy mountain slopes.
</P>
<P>
Male and female geladas have large patches of bare, red skin on their chests, stretching upwards to the base of their necks.
In the females, this bare are is outlined by raised vesicles that
look like strings of blisters. This chest patch mimics the female's genital areas. In baboons, the buttocks and genitals are used as signs: submissive
animals display their buttocks to dominant ones as a sign to appease aggression, receptive females display their backside to indicate that they are
ready for intercourse, and animals of all kinds and ranks turn their bums towards each other as a sign of greeting. When females come into estrus, their
genitals swell up and become red from an infusion of blood. This is how it works in other baboons. But the Gelada spends most of its time sitting on its
butt, and therefore the backside cannot be easily and conveniently displayed. So the bare chest area takes over the function of the butt. In the female
Gelada, when she is in estrus and ready to mate, the same hormones that cause her genital vesicles to swell up also cause the vesicles on her chest to
become red and swollen. So males need only look at a female's chest to tell whether she's sexually receptive or not.
</P>
<P>
The male Gelada has a similar bare chest patch, but without the knobby vesicles. In the male it is merely a form of display used for greeting and for
the assertion of dominance. These red chests are very distinctive features of the Gelada, and has earned them the alternative name of 'Bleeding-heart
baboons".
</P>
<P>In size Geladas are within the typical baboon range. Males weigh 45 lbs on average, and females 25 lbs. Males are about four feet long, and females
three. The tufted tail makes up 16 to 22 inches of this length.
</P>
<h2>
4. Behavior and Diet
</h2>
<P>
As has been said already, Geladas live just about exclusively on the ground. They form large groups that can be properly called herds, having from 50
to 600 members. These herds are often made up by a number of different single-male many-female harems. To make up the balance, there are also groups
containing males only, sometimes associated with harem groups. These smaller groups within the herds are called bands, and contain from 5 to 30 animals
that feed and play together.
</P>
<P>
Geladas do not travel very far - they are lethargic, and spend most of their time sitting
down. They even drag themselves along on their bottoms to move small distances - they rarely stand up and/or walk.
This enables them to conserve energy, because their preferred food, grass,
is not very calorie-dense. To deal with the grass they have large cheek teeth, and also cheek pouches in which they can store food to chew later. An
adaptation to their backside-sitting and shuffling is that they have thick, horny callusses covering their butts. Other baboons have similar callosities,
in their case to help them sit comfortably in trees.
</P>
<P>
Large herds of gelada converge on suitable pastures, where they sit for long periods picking and uprooting grass leaves, stems and rhizomes. When they
have finished feeding the field is devastated, but the disturbed soil and open patches are quickly recolonized by fast-growing herbs and grasses. This
leads to a rapid rate of plant growth and a dynamic, diverse botanic community. These areas are called "Gelada fields".
</P>
<P>
The herds are not permanent formations. They come together, exchange members, and split up again according to local circumstances: abundances or shortages of food in
certain areas. Females are more loyal to groups, while males move around more.
Geladas are not territorial. In the large herds there will be several dominant males, each with his group of loyal female devotees. Ranges
of Gelada herds typically cover from half a square mile to 4 square miles. These ranges often overlap with those of other herds, and change over time
as the Geladas slowly move around from overutilized to fresh fields.
</P>
Within the herds Geladas interact frequently. The "lip flip" and eyelid signals have already been described, and are used to determine and assert
dominance among the males. They also communicate by body postures, in which the red chest area constitutes a significant cue. They also have a variety
of barks, grunts and calls, and these they use to stay in touch, warn of danger, and to indicate aggression and threat.
</P>
Despite their imposing appearance and threatening gestures, Geladas are very peaceful. They don't fight over food, because grass is easily available
everywhere. They don't clash over territory. The only competition is between males who want to gain access to females. Their conflicts are pure bluff
and showing off. They raise their manes, do the "lip flip" to show their fangs, scream, snarl and roar, and bounce all over the place. But they just about
never actually fight. The whole idea of the display is to give contenders an idea of who is REALLY the meanest, baddest dude among them, so that the
inferior ones can back out and avoid a battle that they clearly won't be able to win. This is in fact good for everybody, because the "runts" have
fangs long and sharp enough to inflict serious pain and suffering on the "hunks", even if in the full course of the battle they will be defeated. Nobody
wants a fight that is likely to turn out very costly for everybody.
</P>
<P>
Another important social activity is mutual grooming. This is usually done early in the day before feeding. They comb painstakingly through each other's fur,
making sure it is clean, dry and free from blood sucking invertebrate pests. This activity helps strengthen and maintain bonds between the different
band members, in addition to benefitting the animals by keeping their coats in good condition.
</P>
<P>
At night Gelada herds retreat to steep rock faces and cliffs, which they climb so as to sleep on ledges where they cannot easily be reached by
predators. They then set out for their feeding grounds again early the next morning.
</P>
5. Reproduction
</h2>
<P>
As noted, Gelada females who are in estrus develop red swellings on their bare chest areas as well as on their genitals. Estrus lasts about 35 days,
and occurs according to a seasonal pattern that hasn't yet been completely figured out. Females harass each other during the mating season and
establish a dominance hierarchy among themselves. Dominant females will mate more than their subordinates, and of course mostly with dominant males.
</P>
<P>
Gestation lasts almost six months, after which a single baby is born. Occasionally babies are killed by adults: this happens when one male takes over
the female of another, and she is pregnant or has children by the ousted male. Killing the offspring of his competitor gives the new male the advantage
in spreading his genes. This behavior has been noted in captivity, and it is not known how frequently it occurs in the wild.
</P>
<h2>
6. Enemies, Threats and Conservation
</h2>
<P>
There are still about half a million Geladas remaining. The inaccessibility of their native environment gives them a considerable degree of
protection. There aren't any large wild mammals that compete with them ecologically on a significant scale, and neither are there any large animals that
prey on them. Leopards do occur in the mountains, but not in large numbers, and they do not pose a significant threat to Geladas, whose habit of
forming large herds gives them sufficient protection. Occasionally, though, young Geladas are snatched away by eagles.
</P>
Geladas are largely tolerated by the humans
who live in the same regions, even though they occasionaly raid crops, because they mostly stay out of the way of people.
But Ethiopia's human population is expanding and the country experiences regular food shortages, and it is probable that people will increasingly graze
their livestock even in the remotest mountain regions where they can potentially come in conflict with Geladas. These will react by retreating into
ever-more inaccessible regions, but there isn't an infinity of those available. Gelada numbers are declining and they can be considered to be threatened with the possibility of extinction, even if
not in the foreseeable future.
</P>
<h2>
6. Links
</h2>
<P>
For additional information about the Gelada check out this web-page:
<BR/>
<a href="http://www.mindysmem.org/gelada.html">Mindy's Memory - Gelada Facts</a>
Please look at the entire Mindy's Memory Site: it is a great place with lots of information about and pictures of a great variety of primate species.
</P>
</BODY>
</HTML>
<BODY>
<BODY BGCOLOR="e8e8ff">
<H1>
THE GELADA
</H1>
<H2>
1. Name, Classification and Relationships.
</H2>
<P>
<IMG SRC="http://www.fotango.com/p/eba00019870f00000035.jpg" align=left vspace=20 hspace=20 alt="A Gelada Male">
The Gelada, <i>Theropithecus gelada</i>, is a very unusual kind of baboon. All other baboons are classified in a single species, <i>Papio hamadryas</i>,
but the Gelada is given not only a species but also a genus of its own. The name of the genus, <i>Theropithecus</i>, means "Frightful monkey". "Gelada" is
its common name in Amharic, the dominant language of Ethiopia. In the
past baboons of the <i>Theropithecus</i> genus ranged more widely over Africa, and some reached the size of a Gorilla. Climate
fluctuations over recent millennia led to forests and grasslands shrinking and growing at the expense of each other in alternating cycles.
This factor, combined
with competition from the <i>Papio</i> baboons, and especially <b>humans</b>, led to <i>Theropithecus</i> being pushed back into forbidding mountainous regions, where finding a suitable
habititat is a matter of climbing or descending to slopes of the right attitude and aspect. They also minimised competition from other monkeys by developing
an ability to live on a diet almost entirely composed of grass. In these isolated regions, and with this unusual lifestyle, these baboons eventually
developed into the modern Gelada.
</P>
<H2>
2. Distribution and Habitat
</H2>
Geladas have a restricted range: they occur only in western regions of the highlands of Ethiopia,
at altitudes of 7 000 to 15 000 ft. above sea level. This is the highest part of these highlands and consists of jagged peaks, steep slopes, sheer
cliffs and grassy plateaus at various altitudes. The Gelada occurs in these mountain grasslands, and can reach high and isolated pastures through
its ability to climb cliffs.
It lives totally on the ground surface - it is probably the most terrestrial
of all primates. The reason why the Gelada doesn't climb trees is simple: there aren't any trees at the high altitudes and the habitat it chooses to
live in.
</P>
<h2>
3. Description
</h2>
<P>
The picture shows a large Gelada male. [People, be patient - I am going to put more pictures here, including females, side-on views, and the "lip-flip"
display - of all creatures in existence, this monkey is one of the weirdest and most interesting to look at.]
It has many features that set it apart from other baboons. Its face is somewhat different: typical baboons
have long, dog-like muzzles with their nostrils right at the tip; the Gelada has a shorter, more rounded face with its nostrils set much further
back, and turned upwards. It has a number of ridges stretching from its nose towards its eyes. Its facial expression seems somewhat strained, even
when it is totally relaxed. This is due to a very peculiar arrangement of facial muscles that are used for one of the strangest face displays to
be found in the entire mammalian class. It's called the "lip-flip": when a Gelada male wants to intimidate an intruder (whether of its own species
or not), it not only opens its mouth wide to show its impressive, long, sharp fangs, it also pulls its lips very far backwards until they
cover the nostrils. This exposes the teeth and gums of the entire jaw, which protrudes forward in a way reminiscent of the monsters in the "Alien/Aliens"
sci-fi movies.
</P>
<P>
Another facial display feature of the gelada is its light pinkish eyelids. When it turns its eyes down, these eyelids form prominent patches in its
dark face. This is also a sign of dominance, or a threat.
</P>
<P>
The male Gelada has a mane of very long hair, ranging from light cream to dark brown, that surrounds its face and hangs down over its shoulders like
a cape. The largest, strongest, most dominant males have the largest capes, and this of course makes them look even larger and more impressive. The
females also have long hair, though not developed into such a voluminous cape. This hair is waterproof and aside from its visual features it is also
very effective in keeping these monkeys warm and dry on the cold, rainy and windy mountain slopes.
</P>
<P>
Male and female geladas have large patches of bare, red skin on their chests, stretching upwards to the base of their necks.
In the females, this bare are is outlined by raised vesicles that
look like strings of blisters. This chest patch mimics the female's genital areas. In baboons, the buttocks and genitals are used as signs: submissive
animals display their buttocks to dominant ones as a sign to appease aggression, receptive females display their backside to indicate that they are
ready for intercourse, and animals of all kinds and ranks turn their bums towards each other as a sign of greeting. When females come into estrus, their
genitals swell up and become red from an infusion of blood. This is how it works in other baboons. But the Gelada spends most of its time sitting on its
butt, and therefore the backside cannot be easily and conveniently displayed. So the bare chest area takes over the function of the butt. In the female
Gelada, when she is in estrus and ready to mate, the same hormones that cause her genital vesicles to swell up also cause the vesicles on her chest to
become red and swollen. So males need only look at a female's chest to tell whether she's sexually receptive or not.
</P>
<P>
The male Gelada has a similar bare chest patch, but without the knobby vesicles. In the male it is merely a form of display used for greeting and for
the assertion of dominance. These red chests are very distinctive features of the Gelada, and has earned them the alternative name of 'Bleeding-heart
baboons".
</P>
<P>In size Geladas are within the typical baboon range. Males weigh 45 lbs on average, and females 25 lbs. Males are about four feet long, and females
three. The tufted tail makes up 16 to 22 inches of this length.
</P>
<h2>
4. Behavior and Diet
</h2>
<P>
As has been said already, Geladas live just about exclusively on the ground. They form large groups that can be properly called herds, having from 50
to 600 members. These herds are often made up by a number of different single-male many-female harems. To make up the balance, there are also groups
containing males only, sometimes associated with harem groups. These smaller groups within the herds are called bands, and contain from 5 to 30 animals
that feed and play together.
</P>
<P>
Geladas do not travel very far - they are lethargic, and spend most of their time sitting
down. They even drag themselves along on their bottoms to move small distances - they rarely stand up and/or walk.
This enables them to conserve energy, because their preferred food, grass,
is not very calorie-dense. To deal with the grass they have large cheek teeth, and also cheek pouches in which they can store food to chew later. An
adaptation to their backside-sitting and shuffling is that they have thick, horny callusses covering their butts. Other baboons have similar callosities,
in their case to help them sit comfortably in trees.
</P>
<P>
Large herds of gelada converge on suitable pastures, where they sit for long periods picking and uprooting grass leaves, stems and rhizomes. When they
have finished feeding the field is devastated, but the disturbed soil and open patches are quickly recolonized by fast-growing herbs and grasses. This
leads to a rapid rate of plant growth and a dynamic, diverse botanic community. These areas are called "Gelada fields".
</P>
<P>
The herds are not permanent formations. They come together, exchange members, and split up again according to local circumstances: abundances or shortages of food in
certain areas. Females are more loyal to groups, while males move around more.
Geladas are not territorial. In the large herds there will be several dominant males, each with his group of loyal female devotees. Ranges
of Gelada herds typically cover from half a square mile to 4 square miles. These ranges often overlap with those of other herds, and change over time
as the Geladas slowly move around from overutilized to fresh fields.
</P>
Within the herds Geladas interact frequently. The "lip flip" and eyelid signals have already been described, and are used to determine and assert
dominance among the males. They also communicate by body postures, in which the red chest area constitutes a significant cue. They also have a variety
of barks, grunts and calls, and these they use to stay in touch, warn of danger, and to indicate aggression and threat.
</P>
Despite their imposing appearance and threatening gestures, Geladas are very peaceful. They don't fight over food, because grass is easily available
everywhere. They don't clash over territory. The only competition is between males who want to gain access to females. Their conflicts are pure bluff
and showing off. They raise their manes, do the "lip flip" to show their fangs, scream, snarl and roar, and bounce all over the place. But they just about
never actually fight. The whole idea of the display is to give contenders an idea of who is REALLY the meanest, baddest dude among them, so that the
inferior ones can back out and avoid a battle that they clearly won't be able to win. This is in fact good for everybody, because the "runts" have
fangs long and sharp enough to inflict serious pain and suffering on the "hunks", even if in the full course of the battle they will be defeated. Nobody
wants a fight that is likely to turn out very costly for everybody.
</P>
<P>
Another important social activity is mutual grooming. This is usually done early in the day before feeding. They comb painstakingly through each other's fur,
making sure it is clean, dry and free from blood sucking invertebrate pests. This activity helps strengthen and maintain bonds between the different
band members, in addition to benefitting the animals by keeping their coats in good condition.
</P>
<P>
At night Gelada herds retreat to steep rock faces and cliffs, which they climb so as to sleep on ledges where they cannot easily be reached by
predators. They then set out for their feeding grounds again early the next morning.
</P>
5. Reproduction
</h2>
<P>
As noted, Gelada females who are in estrus develop red swellings on their bare chest areas as well as on their genitals. Estrus lasts about 35 days,
and occurs according to a seasonal pattern that hasn't yet been completely figured out. Females harass each other during the mating season and
establish a dominance hierarchy among themselves. Dominant females will mate more than their subordinates, and of course mostly with dominant males.
</P>
<P>
Gestation lasts almost six months, after which a single baby is born. Occasionally babies are killed by adults: this happens when one male takes over
the female of another, and she is pregnant or has children by the ousted male. Killing the offspring of his competitor gives the new male the advantage
in spreading his genes. This behavior has been noted in captivity, and it is not known how frequently it occurs in the wild.
</P>
<h2>
6. Enemies, Threats and Conservation
</h2>
<P>
There are still about half a million Geladas remaining. The inaccessibility of their native environment gives them a considerable degree of
protection. There aren't any large wild mammals that compete with them ecologically on a significant scale, and neither are there any large animals that
prey on them. Leopards do occur in the mountains, but not in large numbers, and they do not pose a significant threat to Geladas, whose habit of
forming large herds gives them sufficient protection. Occasionally, though, young Geladas are snatched away by eagles.
</P>
Geladas are largely tolerated by the humans
who live in the same regions, even though they occasionaly raid crops, because they mostly stay out of the way of people.
But Ethiopia's human population is expanding and the country experiences regular food shortages, and it is probable that people will increasingly graze
their livestock even in the remotest mountain regions where they can potentially come in conflict with Geladas. These will react by retreating into
ever-more inaccessible regions, but there isn't an infinity of those available. Gelada numbers are declining and they can be considered to be threatened with the possibility of extinction, even if
not in the foreseeable future.
</P>
<h2>
6. Links
</h2>
<P>
For additional information about the Gelada check out this web-page:
<BR/>
<a href="http://www.mindysmem.org/gelada.html">Mindy's Memory - Gelada Facts</a>
Please look at the entire Mindy's Memory Site: it is a great place with lots of information about and pictures of a great variety of primate species.
</P>
</BODY>
</HTML>
