The cotton-top tamarin (''Saguinus oedipus'') is a small
New World monkey
New World monkeys are the five families of primates that are found in the tropical regions of Mexico, Central and South America: Callitrichidae, Cebidae, Aotidae, Pitheciidae, and Atelidae. The five families are ranked together as the Ceboidea ( ...
weighing less than . This New World monkey can live up to 24 years, but most of them die by 13 years. One of the smallest
primate
Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians (monkeys and apes, the latter including huma ...
s, the cotton-top
tamarin
The tamarins are squirrel-sized New World monkeys from the family Callitrichidae in the genus ''Saguinus''. They are the first offshoot in the Callitrichidae tree, and therefore are the sister group of a clade formed by the lion tamarins, Goel ...
is easily recognized by the long, white
sagittal
The sagittal plane (; also known as the longitudinal plane) is an anatomical plane that divides the body into right and left sections. It is perpendicular to the transverse and coronal planes. The plane may be in the center of the body and divid ...
crest extending from its forehead to its shoulders. The species is found in
tropical forest
Tropical forests (a.k.a. jungle) are forested landscapes in tropical regions: ''i.e.'' land areas approximately bounded by the tropic of Cancer and Capricorn, but possibly affected by other factors such as prevailing winds.
Some tropical fores ...
edges and
secondary forest
A secondary forest (or second-growth forest) is a forest or woodland area which has re-grown after a timber harvest or clearing for agriculture, until a long enough period has passed so that the effects of the disturbance are no longer evident. ...
s in northwestern
Colombia
Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...
, where it is
arboreal
Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...
and
diurnal. Its diet includes
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
s and plant
exudate
An exudate is a fluid emitted by an organism through pores or a wound, a process known as exuding or exudation.
''Exudate'' is derived from ''exude'' 'to ooze' from Latin ''exsūdāre'' 'to (ooze out) sweat' (''ex-'' 'out' and ''sūdāre'' 'to ...
s, and it is an important
seed disperser
In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant.
Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...
in the tropical ecosystem.
The cotton-top tamarin displays a wide variety of social behaviors. In particular, groups form a clear
dominance hierarchy
In biology, a dominance hierarchy (formerly and colloquially called a pecking order) is a type of social hierarchy that arises when members of animal social animal , social groups interact, creating a ranking system. A dominant higher-ranking i ...
where only dominant pairs breed. The female normally gives birth to twins and uses
pheromone
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...
s to prevent other females in the group from breeding. These tamarins have been extensively studied for their high level of
cooperative care, as well as
altruistic
Altruism is the principle and moral practice of concern for the welfare and/or happiness of other human beings or animals, resulting in a quality of life both material and spiritual. It is a traditional virtue in many cultures and a core asp ...
and
spiteful behaviors. Communication between cotton-top tamarins is sophisticated and shows evidence of grammatical structure, a language feature that must be acquired.
Up to 40,000 cotton-top tamarins are thought to have been caught and exported for use in
biomedical research
Medical research (or biomedical research), also known as experimental medicine, encompasses a wide array of research, extending from "basic research" (also called ''bench science'' or ''bench research''), – involving fundamental scientif ...
before 1976, when
CITES
CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
gave them the highest level of protection and all international commercial trade was prohibited. Now, the species is at risk due to large-scale
habitat destruction
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
, as the lowland forest in northwestern Colombia where the cotton-top tamarin is found has been reduced to 5% of its previous area. It is currently classified as
critically endangered and is one of the rarest primates in the world, with only 6,000 individuals left in the wild.
Taxonomy and naming
''S. oedipus'' has the common names "cotton-top tamarin" and "cotton-headed tamarin" in English. Its name comes from the white hair that spans its head and flows down past the neck.
[ In Spanish, it is commonly called ''bichichi, tití pielroja, "tití blanco, tití cabeza blanca'', or ''tití leoncito''.][ In German-speaking areas, the cotton-top tamarin is commonly known as ''Lisztaffe'' (literally "Liszt monkey") due to the resemblance of its crest to the hairstyle of Hungarian composer and piano virtuoso ]Franz Liszt
Franz Liszt, in modern usage ''Liszt Ferenc'' . Liszt's Hungarian passport spelled his given name as "Ferencz". An orthographic reform of the Hungarian language in 1922 (which was 36 years after Liszt's death) changed the letter "cz" to simpl ...
.
The species was first described by Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
in his landmark 1758 10th edition of ''Systema Naturae''.[ as ''Simia oedipus''.][ Linnaeus chose the specific name ''oedipus'', which means ''swollen foot'', but as the species does not have particularly large feet, it is unknown why he chose this name. (Linnaeus often selected names from mythology without any particular rationale, and he may have used the name of ]Oedipus
Oedipus (, ; grc-gre, Οἰδίπους "swollen foot") was a mythical Greek king of Thebes. A tragic hero in Greek mythology, Oedipus accidentally fulfilled a prophecy that he would end up killing his father and marrying his mother, thereby ...
, the mythical Greek king of Thebes, more or less arbitrarily.)[ In 1977, ]Philip Hershkovitz
Philip Hershkovitz (12 October 1909 – 15 February 1997) was an American mammalogy, mammalogist. Born in Pittsburgh, he attended the Universities of Pittsburgh and Michigan and lived in South America collecting mammals. In 1947, he was appointed ...
performed a taxonomic
Taxonomy is the practice and science of categorization or classification.
A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...
analysis of the species based on fur coloration patterns, cranial and mandibular
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...
morphology, and ear size. He classified Geoffroy's tamarin
Geoffroy's tamarin (''Saguinus geoffroyi''), also known as the Panamanian, red-crested or rufous-naped tamarin, is a tamarin, a type of small monkey, found in Panama and Colombia. It is predominantly black and white, with a reddish nape. Diu ...
''S. geoffroyi'' as a subspecies of ''S. oedipus''.[ Subsequent analyses by Hernández-Camacho and Cooper (1976),][ ]Russell Mittermeier
Russell Alan Mittermeier (born November 8, 1949) is a primatologist and herpetologist. He has written several books for both popular and scientist audiences, and has authored more than 300 scientific papers.
Biography
Russell A. Mittermeier is ...
and Coimbra-Filho (1981),[ and later Grooves (2001)][ consider the ''S. oedipus'' and ''S. geoffroyi'' types to be separate species.
Some researchers, such as Thorington (1976),][ posit that ''S. oedipus'' is more closely related to the ]white-footed tamarin
The white-footed tamarin (''Saguinus leucopus'') is a tamarin species endemic to Colombia. It is a silvery brown colour with pale streaks and russet underparts, and is very similar in appearance to the cotton-top tamarin, from which it is separat ...
(''S. leucopus'') than to ''S. geoffroyi''. This view is supported by Hanihara and Natoria's analysis of toothcomb
A toothcomb (also tooth comb or dental comb) is a dental structure found in some mammals, comprising a group of front teeth arranged in a manner that facilitates grooming, similar to a hair comb. The toothcomb occurs in lemuriform primates ( ...
dental morphology (1987) and by Skinner (1991), who found similarities between ''S. oedipus'' and ''S. leucopus'' in 16 of 17 morphological traits considered.[
This species of white-headed tamarin is thought to have diverged from the other Amazonian forms such as ''S. leucopus''. This is supported by morphological considerations of the transition from juvenile to adulthood, during which the fur coloration patterns change. significantly and are similar between the two species.][ Hershkovitz proposed that the separation of the two species happened in the ]Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
at the height of the Atrato River
The Atrato River () is a river of northwestern Colombia. It rises in the slopes of the Western Cordillera and flows almost due north to the Gulf of Urabá (or Gulf of Darién), where it forms a large, swampy delta. Its course crosses the Cho ...
, where it intersected the Cauca-Magdalena. At that time, the area was covered by a sea, which created a geographic barrier that caused the species to diverge through the process of allopatric speciation
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...
. Today, the two species are principally separated by the Atrato River.[
]
Physical characteristics
The cotton-top tamarin is part of the most diminutive family of monkeys, Callitrichidae
The Callitrichidae (also called Arctopitheci or Hapalidae) are a family of New World monkeys, including marmosets, tamarins, and lion tamarins. At times, this group of animals has been regarded as a subfamily, called the Callitrichinae, of the fa ...
, the marmosets and tamarins; it weighs on average. Its head–body length is , while its tail—which is not prehensile
Prehensility is the quality of an appendage or organ (anatomy), organ that has Adaptation (biology), adapted for grasping or holding. The word is derived from the Latin term ''prehendere'', meaning "to grasp". The ability to grasp is likely der ...
—is slightly longer at around .[ The species is not ]sexually dimorphic
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
, the male and female are of a similar size and weight.[ Members of the Callitrichinae subfamily (including this species) have sharp nails ( tegulae) on all digits except the big toes, which have the flat nails ( ungulae) common to other ]primate
Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians (monkeys and apes, the latter including huma ...
s. Tegulae resemble a squirrel's claws and help with movement through trees.[
]
The cotton-top tamarin has a long sagittal crest
A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull (at the sagittal suture) of many mammalian and reptilian skulls, among others. The presence of this ridge of bone indicates that there are exceptiona ...
, consisting of white hairs, from forehead to nape
The nape is the back of the neck. In technical anatomical/medical terminology, the nape is also called the nucha (from the Medieval Latin rendering of the Arabic , "spinal marrow"). The corresponding adjective is ''nuchal'', as in the term ''nu ...
flowing over the shoulders. The skin of the face is black with gray or white bands located above the eyes. These bands continue along the edge of the face down to the jaw.[ Tamarins are generally divided into three groups by their facial characteristics: hairy-faced, mottled-faced, and bare-faced. The cotton-top tamarin has fine white hair covering its face, but they are so fine as to appear naked, thus it is considered a bare-faced tamarin. Its lower ]canine teeth
In mammalian oral anatomy, the canine teeth, also called cuspids, dog teeth, or (in the context of the upper jaw) fangs, eye teeth, vampire teeth, or vampire fangs, are the relatively long, pointed teeth. They can appear more flattened howeve ...
are longer than its incisor
Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whe ...
s, creating the appearance of tusk
Tusks are elongated, continuously growing front teeth that protrude well beyond the mouth of certain mammal species. They are most commonly canine teeth, as with pigs and walruses, or, in the case of elephants, elongated incisors. Tusks share c ...
s.[ Like other callitrichids, the cotton-top tamarin has two molar teeth on each side of its jaw, not three like other New World monkeys.][
The cotton-top tamarin has fur covering all of the body except the palms of the hands and feet, the eyelids, the borders of the nostrils, the nipples, the anus, and the penis. The back is brown, and the underparts, arms, and legs are whitish-yellow. The ]rump
Rump may refer to:
* Rump (animal)
** Buttocks
* Rump steak, slightly different cuts of meat in Britain and America
* Rump kernel, software run in userspace that offers kernel functionality in NetBSD
Politics
*Rump cabinet
* Rump legislature
* Ru ...
and inner thighs and upper tail are reddish-orange. The fur is distributed with varying densities throughout the body: the genital region (scrotum and pubic zone), axilla
The axilla (also, armpit, underarm or oxter) is the area on the human body directly under the shoulder joint. It includes the axillary space, an anatomical space within the shoulder girdle between the arm and the thoracic cage, bounded superior ...
, and the base of the tail have lower densities, while the forward region is much higher. Many individuals have stripes or whorls of fur of striking coloration on their throats. The cotton-top also has whiskers on its forehead and around its mouth.[
]
Habitat and distribution
The cotton-top tamarin is restricted to a small area of northwest Colombia
Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...
, between the Cauca and Magdalena River
The Magdalena River ( es, Río Magdalena, ; less commonly ) is the main river of Colombia, flowing northward about through the western half of the country. It takes its name from the biblical figure Mary Magdalene. It is navigable through much of ...
s to the south and east, the Atlantic coast to the north, and the Atrato River to the west. They are found exclusively in Colombia; 98% of their habitat has been destroyed. Historically, the entire area was suitable for the cotton-top tamarin, but due to habitat loss through deforestation, it survives in fragmented parks and reserves. One of the most important areas for the cotton-top is the Paramillo National Park, which consists of of primary and secondary forests.[
The cotton-top tamarin is found in both ]primary
Primary or primaries may refer to:
Arts, entertainment, and media Music Groups and labels
* Primary (band), from Australia
* Primary (musician), hip hop musician and record producer from South Korea
* Primary Music, Israeli record label
Works
* ...
and secondary forest
A secondary forest (or second-growth forest) is a forest or woodland area which has re-grown after a timber harvest or clearing for agriculture, until a long enough period has passed so that the effects of the disturbance are no longer evident. ...
s, from humid tropical forest
Tropical forests (a.k.a. jungle) are forested landscapes in tropical regions: ''i.e.'' land areas approximately bounded by the tropic of Cancer and Capricorn, but possibly affected by other factors such as prevailing winds.
Some tropical fores ...
s in the south of its range to tropical dry forest
The tropical and subtropical dry broadleaf forest is a habitat type defined by the World Wide Fund for Nature and is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive ...
s in the north. It is seldom found at altitudes above , but has been encountered up to .[ It prefers the lower levels of the tropical forests, but may also be found foraging on the ground and between the ]understory
In forestry and ecology, understory (American English), or understorey (Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the forest canopy without penetrating it to any great extent, but abov ...
and the canopy
Canopy may refer to:
Plants
* Canopy (biology), aboveground portion of plant community or crop (including forests)
* Canopy (grape), aboveground portion of grapes
Religion and ceremonies
* Baldachin or canopy of state, typically placed over an a ...
. It can adapt to forest fragments and can survive in relatively disturbed habitats. In the dry forests are pronounced seasons. Between December and April, it is dry, while heavy rainfall occurs between August and November which can flood the forest floor. Across its range, annual rainfall varies between .[
]
Ecology
The cotton-top tamarin has a diet of mainly fruit (40%) and animal material (40%).[ This includes insects, plant ]exudate
An exudate is a fluid emitted by an organism through pores or a wound, a process known as exuding or exudation.
''Exudate'' is derived from ''exude'' 'to ooze' from Latin ''exsūdāre'' 'to (ooze out) sweat' (''ex-'' 'out' and ''sūdāre'' 'to ...
s such as gum and sap
Sap is a fluid transported in xylem cells (vessel elements or tracheids) or phloem sieve tube elements of a plant. These cells transport water and nutrients throughout the plant.
Sap is distinct from latex, resin, or cell sap; it is a separa ...
, nectar
Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists ...
, and occasionally reptiles and amphibians. Due to its small body size and high food passage rate, its diet must be high-quality and high-energy. Insectivory
A robber fly eating a hoverfly
An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects.
The first vertebrate insectivores wer ...
is common in the cotton-top and the species hunts for insects using a variety of methods: stealth, pouncing, chasing, exploring holes, and turning over leaves.[
Tamarins act as seed dispersers in tropical ecosystems. While larger primates eat larger seeds, tamarins eat the smaller ones. The expelled seeds have a higher ]germination
Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, fer ...
rate than others and ingesting larger seeds may help to dislodge and expel intestinal parasites.[
The cotton-top tamarin is diurnal and sleeps with its social group in trees with foliage cover. The group leaves the sleeping tree together an hour after dawn and spends the day foraging, resting, travelling, and grooming.][ The species is thought to rise late and increases the speed of its foraging and travelling before dusk to avoid ]crepuscular
In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of daylig ...
and nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
predators. Its main predators include raptors, mustelid
The Mustelidae (; from Latin ''mustela'', weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, minks and wolverines, among others. Mustelids () are a diverse group and form the largest family in ...
s, felid
Felidae () is the family of mammals in the order Carnivora colloquially referred to as cats, and constitutes a clade. A member of this family is also called a felid (). The term "cat" refers both to felids in general and specifically to the dom ...
s, and snakes.[ The cotton-top tamarin is extremely vigilant, always looking for potential predators. When the group is resting, one individual moves apart and acts as a lookout to alert the group if it sees a threat.][
The cotton-top tamarin can live as long as 24 years in captivity, while its lifespan in the wild averages 13 years.][
]
Behavior
Social systems
The cotton-top tamarin is a highly social primate that typically lives in groups of two to nine individuals, but may reach up to 13 members.[ These small familial groups tend to fluctuate in size and in composition of individuals and a clear ]dominance hierarchy
In biology, a dominance hierarchy (formerly and colloquially called a pecking order) is a type of social hierarchy that arises when members of animal social animal , social groups interact, creating a ranking system. A dominant higher-ranking i ...
is always present within a party. At the head of the group is the breeding pair. The male and female in this pair are typically in a monogamous
Monogamy ( ) is a form of Dyad (sociology), dyadic Intimate relationship, relationship in which an individual has only one Significant other, partner during their lifetime. Alternately, only one partner at any one time (Monogamy#Serial monogamy, ...
reproductive relationship, and together serve as the group's dominant leaders.[
Dominant pairs are the only breeding pair within their groups, and the female generally has authority over the breeding male. While nonbreeding group members can be the leading pair's offspring, immigrant adults may also live with and cooperate in these groups. This social grouping in cotton-top tamarins is hypothesized to arise from ]predation
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...
pressure.[ Cotton-top tamarins exhibit ]prosocial behavior
Prosocial behavior, or intent to benefit others, is a social behavior that "benefit other people or society as a whole", "such as helping, sharing, donating, co-operating, and volunteering". Obeying the rules and conforming to socially accepted ...
that benefits other members of the group,[ and are well known for engaging in ]cooperative breeding
Cooperative breeding is a social system characterized by alloparental care: offspring receive care not only from their parents, but also from additional group members, often called helpers. Cooperative breeding encompasses a wide variety of group ...
whereby the group's subordinate adults help in rearing the offspring of the dominant pair. The dominant female is more likely to give birth to non-identical twins than a singleton, so it would be too energetically expensive for just one pair to raise the young.[
To prevent younger, subordinate females within the group from breeding, the dominant female uses ]pheromone
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...
s. This suppresses sexual behavior and delays puberty.[ Unrelated males that join the group can release the females from this reproductive suppression; this may result in more than one female of the group becoming pregnant, but only one of the pregnancies will be successful.][
]
Cooperation
In cooperative breeding, the effort put into caring for the dominant breeders' offspring is shared by the group members. Parents, siblings, and immigrant adults share young rearing duties for the breeding pair's young. These duties include carrying, protecting, feeding, comforting, and even engaging in play behavior with the group's young. Cotton-top tamarins display high levels of parental investment
Parental investment, in evolutionary biology and evolutionary psychology, is any parental expenditure (e.g. time, energy, resources) that benefits offspring.Clutton-Brock, T.H. 1991. ''The Evolution of Parental Care''. Princeton, NJ: Princeton ...
during infant care. Males, particularly those that are paternal, show greater involvement in caregiving than do females.[ Despite this, both male and female infants prefers contact and proximity to their mothers over their fathers.][ Males may invest additional support in rearing offspring as a form of ]courtship
Courtship is the period wherein some couples get to know each other prior to a possible marriage. Courtship traditionally may begin after a betrothal and may conclude with the celebration of marriage. A courtship may be an informal and private m ...
to win the favor of the group's dominant female. However, evidence indicates that time spent carrying infants does not correlate with a male's overall copulation
Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetrat ...
frequency.[
Since only one female in a group breeds, heavy investment in infant care ensures that all offspring survive until independence. Accordingly, cotton-top tamarins bear excessive costs to care for the group's young.][ Male carriers, especially paternal carriers, incur large energetic costs for the sake of the group's young. This burden may cause some male cotton-tops to lose up to 10–11% of their total body weight.][ The large weight loss may occur from reduced food intake as infant-carrying inhibits ]foraging
Foraging is searching for wild food resources. It affects an animal's Fitness (biology), fitness because it plays an important role in an animal's ability to survive and reproduce. Optimal foraging theory, Foraging theory is a branch of behaviora ...
ability for a carrier. The trend of male-carrier weight loss and decreased food intake is in contrast to the dominant female's periovulatory period, when she gains weight after increasing her own food intake and relinquishing much of her infant-carrying duties.[
]
Altruism
While caregiving by males appears to be altruistic
Altruism is the principle and moral practice of concern for the welfare and/or happiness of other human beings or animals, resulting in a quality of life both material and spiritual. It is a traditional virtue in many cultures and a core asp ...
, particularly in cotton-top sires, the costs of infant care may in fact be tolerated for selfish
Selfishness is being concerned excessively or exclusively, for oneself or one's own advantage, pleasure, or welfare, regardless of others.
Selfishness is the opposite of altruism or selflessness; and has also been contrasted (as by C. S. Lewis) w ...
reasons. Namely, the costs to male weight and foraging ability may, in turn, promote consecutive pregnancies in dominant females, thereby providing more offspring bearing the sire's genes
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.[ Additionally, the cooperative breeding structure of cotton-tops can change with group size and parental experience. First-time sires spend a greater amount of time carrying the infant than experienced ones, and in smaller groups, sires do a greater proportion of carrying and feeding the infant than in larger groups, where helpers take on more of the work. Total care for infants remains constant with varying group size, and infant outcome is not significantly different in groups that have differing levels of experience in raising offspring.][
]
The cooperative breeding
Cooperative breeding is a social system characterized by alloparental care: offspring receive care not only from their parents, but also from additional group members, often called helpers. Cooperative breeding encompasses a wide variety of group ...
hypothesis predicts that cotton-top tamarins engage with this young-rearing paradigm, and in turn, naturally embrace patterns of prosocial behavior.[ These monkeys engage in such behavior by acting altruistically within their groups in caring for infants, vocalizing ]alarm calls
In animal communication, an alarm signal is an antipredator adaptation in the form of Signalling theory, signals emitted by social animals in response to danger. Many primates and birds have elaborate alarm calls for warning Biological specific ...
, and in sharing food. Though some studies indicate that cotton-top tamarins have the psychological capacity to participate in reciprocally mediated altruism,[ it is unclear whether the cotton-top tamarin acts solely using judgments on ]reinforcement
In behavioral psychology, reinforcement is a consequence applied that will strengthen an organism's future behavior whenever that behavior is preceded by a specific antecedent stimulus. This strengthening effect may be measured as a higher freq ...
history.[
Other studies involving cotton-top tamarins have hinted that positive reciprocity and ]reciprocal altruism
In evolutionary biology, reciprocal altruism is a behaviour whereby an organism acts in a manner that temporarily reduces its fitness while increasing another organism's fitness, with the expectation that the other organism will act in a similar m ...
are irrelevant in the prosociality of these primates.[ Some researchers believe these primates tend to cooperate for selfish reasons and in situations where they incur some benefit for themselves. That is, cooperation in cotton-top tamarins can be better described by mutualism than by true altruism.][
Tamarins in captivity have shown the ability to distinguish other individuals based on cooperative tendencies and past behavior. Cotton-tops ultimately use this information to guide future cooperation. Brief periods of ]defection
In politics, a defector is a person who gives up allegiance to one state in exchange for allegiance to another, changing sides in a way which is considered illegitimate by the first state. More broadly, defection involves abandoning a person, ca ...
tend to cause swift, irreparable breakups between these primates and their cooperators. To avoid this, cotton-top tamarins may make economically-driven decisions based on the projected incentives of a potential cooperator.[
]
Spite and aggression
Despite an expansive array of altruistic behaviors, cotton-top tamarins engage in great bouts of spite through negative reciprocity and punishment. They have been observed to immediately start denying cooperation with monkeys that deny them benefits.[ Further, in captivity, these primates are not observed to increase altruistic behavior with fellow primates that are committed fully to cooperation. Based on this, researchers believe that repeated interactions in a cooperative society like that of the cotton-top tamarin can heighten the chances that an individual will designate behavioral punishments to others in its group.][ This reaction has also been observed in other species.][ However, these reciprocal punishments, or relative lack of altruistic actions, may alternatively happen as a result of response facilitation that increases the chances of a cotton-top punishing another primate after watching that individual perform a similar action.][
]
Another way to look at punishment in cotton-top tamarins is by observing their aggressive behavioral responses within and between groups, as well as between species. The cotton-top tamarin, like many marmosets, other tamarins, and specifically those in the genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''Saguinus'', stages aggressive displays almost exclusively towards fellow monkeys that belong to the same gender.[ These intrasexual displays of aggression are more frequent in females, and are vital when a breeding female is forcing both subadult and adult females to emigrate out of a familial group.][
Though aggression can occur within groups, the response towards intruders of another species is much more drastic and can involve a ]sexual dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
in displays. Females typically employ scent-marking
In ethology, territory is the sociographical area that an animal consistently defends against conspecific competition (or, occasionally, against animals of other species) using agonistic behaviors or (less commonly) real physical aggression. A ...
intruder response tactics, whereas males are more prone to vocalizing threats, physical aggression, and piloerection
Goose bumps, goosebumps or goose-pimples are the bumps on a person's skin at the base of body hairs which may involuntarily develop when a person is tickled, cold or experiencing strong emotions such as fear, euphoria or sexual arousal.
The f ...
.[ Scent-marking in cotton-top tamarins is done in two ways: either using ]anogenital
The perineum in humans is the space between the anus and scrotum in the male, or between the anus and the vulva in the female. The perineum is the region of the body between the pubic symphysis (pubic arch) and the coccyx (tail bone), includin ...
scent-marking, or suprapubic
The hypogastrium (also called the hypogastric region or suprapubic region) is a region of the abdomen located below the umbilical region.
Etymology
The roots of the word ''hypogastrium'' mean "below the stomach"; the roots of ''suprapubic'' mean ...
scent-marking. The ability to use both of these separate glandular
In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland).
Structure
De ...
fields for threat signals may indicate females have developed diverging evolutionary threats through differential use of these markings.[ These variable signals may be used to sign a territorial encounter, or serve as a reproductive signal. The intensity of female threats is generally comparable when directed at intruders of either gender. In contrast, male cotton-tops are considerably more threatening towards fellow males than towards females.][
]
Communication
The cotton-top tamarin vocalizes with bird-like whistles, soft chirping sounds, high-pitched trilling, and staccato
Staccato (; Italian for "detached") is a form of musical articulation. In modern notation, it signifies a note of shortened duration, separated from the note that may follow by silence. It has been described by theorists and has appeared in music ...
calls. Researchers describe its repertoire of 38 distinct sounds as unusually sophisticated, conforming to grammatical
In linguistics, grammaticality is determined by the conformity to language usage as derived by the grammar of a particular variety (linguistics), speech variety. The notion of grammaticality rose alongside the theory of generative grammar, the go ...
rules. Jayne Cleveland and Charles Snowdon performed an in-depth feature analysis to classify the cotton-top's repertoire of vocalizations in 1982. They concluded that it uses a simple grammar consisting of eight phonetic variations of short, frequency-modulated
Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. The technology is used in telecommunications, radio broadcasting, signal processing, and computing.
In analog freque ...
"chirp
A chirp is a signal in which the frequency increases (''up-chirp'') or decreases (''down-chirp'') with time. In some sources, the term ''chirp'' is used interchangeably with sweep signal. It is commonly applied to sonar, radar, and laser system ...
s"—each representing varying messages—and five longer constant frequency "whistles". They hypothesize that some of these calls demonstrate that the cotton-top tamarin uses phonetic syntax, while other calls may be exemplars of lexical syntax
In computer science, lexical analysis, lexing or tokenization is the process of converting a sequence of Character (computing), characters (such as in a computer program or web page) into a sequence of ''lexical tokens'' (String (computer science ...
usage.[ Each type of call is given a letter signifier; for example, C-calls are associated with finding food and D-calls are associated with eating.][ Further, these calls can be modified to better deliver information relevant to auditory localization in call-recipients.][ Using this range of vocalizations, the adults may be able to communicate with one another about intention, thought processes, and emotion, including curiosity, fear, dismay, playfulness, warnings, joy, and calls to young.][
]
Language acquisition
Over the first 20 weeks, after a cotton-top tamarin is born, it is not fully capable of producing the range of vocalizations that an adult monkey can. Despite this limitation on speech producibility, researchers believe that language acquisition
Language acquisition is the process by which humans acquire the capacity to perceive and comprehend language (in other words, gain the ability to be aware of language and to understand it), as well as to produce and use words and sentences to ...
occurs early on with speech comprehension abilities arising first.[ Infants can at times produce adult-like chirps, but this is rarely done in the correct context and remains inconsistent across the first 20 weeks of life. Regardless, infant cotton-tops are able to respond in behaviorally appropriate ways to varying contexts when presented with adult chirps. This indicates that verbal perception is a quickly acquired skill for offspring, followed closely by auditory comprehension, and later by proper vocal producibility.][
]
Castro and Snowdon (2000) observed that aside from inconsistent adult-like chirping, cotton-top infants most often produce a prototype chirp that differs in vocalization structure from anything seen in the full adult range of vocalizations. Infants are thought to imitate adult speakers, which use differing calls in various contexts, but by using solely the infant prototypical chirp. For instance, adult cotton-tops are known to significantly reduce the amount of general alarm calling in the presence of infants.[ This is likely adapted so that adults in close proximity to the groups young do not attract the attention of predators to infant-dense areas. Additionally, infants reduce their prototype chirping in the presence of predators. Whether infants are shadowing the calling behavior of adults or they are comprehending danger remains unclear. However, researchers argue that young cotton-top tamarins are able to represent ]semantic
Semantics (from grc, σημαντικός ''sēmantikós'', "significant") is the study of reference, meaning, or truth. The term can be used to refer to subfields of several distinct disciplines, including philosophy, linguistics and comput ...
information regardless of immature speech production.[
To confirm the notion that language acquisition occurs as a progression of comprehension before production, Castro and Snowdon (2000) showed that infants respond behaviorally to vocalizing adults in a fashion that indicates they can comprehend auditory inputs. When an adult produces a C-call chirp, used to indicate food preference and when navigating to a food source, an infant approaches the adult caller to be fed, but do not use the prototype calling as a proxy for C-calls.][ This finding argues for the idea that infants are able to understand vocalizations first, and later acquire the ability to communicate with adult vocalizations.
]
General calling
Among the typical cotton-top tamarin communicative vocalizations, the combination long call (CLC) and the alarm call (AC) are the most heavily represented in the literature. CLCs encompass a range of contact call Contact calls are seemingly haphazard sounds made by many social animals (such as a chicken's cluck). Contact calls are unlike other calls (such as alarm calls) in that they are not usually widely used, conspicuous calls, but rather short exclamatio ...
s that are produced by isolated individuals using chirps and whistles.[ This type of call is also used for seemingly altruistic alarm calls, thus adding to its range of cooperative behaviors. It is issued in the presence of kin when a threatening llamas predator is seen. Predators of the cotton-top tamarin include ]snakes
Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more joi ...
, ocelots
The ocelot (''Leopardus pardalis'') is a medium-sized spotted wild cat that reaches at the shoulders and weighs between on average. It was first described by Carl Linnaeus in 1758. Two subspecies are recognized. It is native to the southwe ...
, tayras
The tayra (''Eira barbara'') is an omnivorous animal from the weasel family, native to the Americas. It is the only species in the genus ''Eira''.
Tayras are also known as the ''tolomuco'' or ''perico ligero'' in Central America, ''motete'' in ...
, and most notably, hawks
Hawks are birds of prey of the family Accipitridae. They are widely distributed and are found on all continents except Antarctica.
* The subfamily Accipitrinae includes goshawks, sparrowhawks, sharp-shinned hawks and others. This subfamily a ...
.[ Early observations by Patricia Neyman even showed that cotton-tops produce diverse sets of alarm calls that can discriminate the presence of birds of prey versus ground-based predators.][
]
CLCs involve the production of complex sequence multisyllabic vocalizations. Researchers have argued that long calls exhibit individual differences, thus can carry information sufficient for recipients to determine caller identity. Using habituation-discrimination paradigms in language experiments, this theory has been confirmed multiple times in literature.[ However, the individual syllables within a complete CLC vocalization in isolation of each other do not transfer sufficient information to communicate messages between monkeys. Scientists thus consider the whole, intact string of vocalizations to be the unit of perception for CLCs in the cotton-top tamarin.][ These examinations may confirm that cotton-tops incorporate a lexical syntax in areas of their communication.
Since tamarins can discriminate between predatory threats using varying vocalizations, recipients of an AC are thought to extract various complex signals from this form of communication. Primarily, cotton-tops are able to glean the identity of the cooperating tamarin through differences in individuals' alarm calls.][ Further, adults are able to discriminate the gender of callers from their ACs and determine the range of calls within a related tamarin's alarm calling repertoire.][ Alarm call-based identification is postulated to play a number of functional roles in the cotton-top tamarin. Firstly, an AC recipient is able to identify a cooperating tamarin, and by recognizing which in their group it is, be able to judge the reliability of the AC from past experience. This may arise from a selective pressure for being able to statistically determine the amount of risk present, and how endangered an individual and its group are.][
Additionally, being able to localize auditory signals may help determine predator location, especially in the presence of a second AC from a different tamarin in the group. This can help confirm predator presence, type (e.g. flying versus ground-based), and support the recipient in triangulating a predator's location. In the context of the cotton-top's cooperative breeding groups, this is postulated as being adaptive for determining the variable risk to one's group members.][ For example, a call recipient is able to determine which of its kin are and are not at risk (e.g. young offspring, mates, subordinates, relatives, carriers, etc.) and plan subsequent actions accordingly.
]
Food calls
The cotton-top tamarin makes selective, specialized vocalizations in the presence of food.[ These include the C-call, produced when a cotton-top approaches and sorts through food, and the D-call, which is associated with food retrieval and is exhibited while eating.][
C-call chirping is believed to be an honest signal for communicating food preference, and a cotton-top tamarin more often and more rapidly vocalizes with these chirps when approaching a highly favored food source. Functionally, this behavior may inform other tamarins of the actions the caller will take in a feeding context and whether a preferable food source is available.][ Despite this research indicating that food calls may be informative to fellow group mates, other observations of cotton-tops show that quantity and distribution of food and audience do not significantly alter a caller's food-centered vocalizations.][
The cotton-top tamarin is seen to produce food calls both in the presence and absence of group members.][ Additionally, response to food calls are directed back to an original caller independent of visual confirmation of a food source. While this may appear to be a result of a very primitive form of communication, Roush and Snowdon (2005) maintain that the food-calling behavior confers some mentally representable information about food to recipient tamarins.
]
Conservation status
The wild population is estimated at 6,000 individuals, with 2,000 adults.[ This species is critically endangered, and was listed in "]The World's 25 Most Endangered Primates
The World's 25 Most Endangered Primates is a list of highly endangered primate species selected and published by the International Union for Conservation of Nature (IUCN) Species Survival Commission (SSC) Primate Specialist Group (PSG), the In ...
between 2008 and 2012."[ The publication lists highly endangered primate species and is released every two years by the International Union for Conservation of Nature Species Survival Commission Primate Specialist Group. The cotton-top tamarin was not selected for the 2012–2014 publication.][
]
Habitat destruction through forest clearing is the main cause of this collapse, and the cotton-top has lost more than three-quarters of its original habitat to deforestation
Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated d ...
,[ while the lowland forest in which it lives has been reduced to 5% of its historical range. This land is then used for large-scale agricultural production (i.e. cattle) and farming, logging, ]oil palm
''Elaeis'' () is a genus of palms containing two species, called oil palms. They are used in commercial agriculture in the production of palm oil. The African oil palm ''Elaeis guineensis'' (the species name ''guineensis'' referring to its co ...
plantations, and hydroelectric
Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...
projects that fragment the cotton-top tamarin's natural range.[
The illegal pet trade and scientific research have also been cited as factors by the IUCN. While biomedical studies have recently limited their use of this species, illegal capture for the pet trade still plays a major role in endangering the cotton-top. Before 1976, when ]CITES
CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
listed the species under Appendix I banning all international trade, the cotton-top tamarin was exported for use in biomedical research
Medical research (or biomedical research), also known as experimental medicine, encompasses a wide array of research, extending from "basic research" (also called ''bench science'' or ''bench research''), – involving fundamental scientif ...
.
In captivity, the cotton-top is highly prone to colitis
Colitis is swelling or inflammation of the large intestine ( colon). Colitis may be acute and self-limited or long-term. It broadly fits into the category of digestive diseases.
In a medical context, the label ''colitis'' (without qualification) ...
, which is linked to an increased risk of a certain type of colon cancer
Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel mo ...
. Up to 40,000 individuals were caught and exported for research into those diseases, as well as Epstein-Barr virus, for the benefit of humans. The species is now protected by international law. Although enough individuals are in captivity to sustain the species, it is still critically endangered in the wild.[
The Proyecto Tití ("Project Tamarin")][ was started in 1985 to provide information and support in conservation of the cotton-top tamarin and its habitat in northern Colombia. Proyecto Tití's programs combine field research, education, and community programs to spread awareness about this endangered species and encourage the public to participate in its protection. It now has partner status with the ]Wildlife Conservation Network
The Wildlife Conservation Network (WCN) is a United States-based 501(c)(3) non-profit organization that protects endangered wildlife by supporting conservationists in the field who promote coexistence between wildlife and people. WCN does this by ...
.[
In January 2015, two captive cotton-top tamarins at the Alexandria Zoological Park in ]Alexandria, Louisiana
Alexandria is the ninth-largest city in the state of Louisiana and is the parish seat of Rapides Parish, Louisiana, United States. It lies on the south bank of the Red River in almost the exact geographic center of the state. It is the prin ...
, died when a caretaker left them outside overnight in temperatures as low as 30 °F. One other individual survived.
References
{{Taxonbar , from=Q137528
cotton-top tamarin
The cotton-top tamarin (''Saguinus oedipus'') is a small New World monkey weighing less than . This New World monkey can live up to 24 years, but most of them die by 13 years. One of the smallest primates, the cotton-top tamarin is easily recogn ...
Mammals of Colombia
Endemic fauna of Colombia
Mammals of the Caribbean
Critically endangered animals
Critically endangered biota of South America
cotton-top tamarin
The cotton-top tamarin (''Saguinus oedipus'') is a small New World monkey weighing less than . This New World monkey can live up to 24 years, but most of them die by 13 years. One of the smallest primates, the cotton-top tamarin is easily recogn ...
cotton-top tamarin
The cotton-top tamarin (''Saguinus oedipus'') is a small New World monkey weighing less than . This New World monkey can live up to 24 years, but most of them die by 13 years. One of the smallest primates, the cotton-top tamarin is easily recogn ...
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