Editing Pygmy marmoset (section)

=== Communication ===

[[File:Pygmy marmoset (Cebuella pygmaea) climbing tree.jpg|thumb|upright|Groups use [[contact calls]] to stay together when foraging, feeding, and travelling.]]

Pygmy marmosets are well known for their communication abilities, including an intricate system of calls. The trill is used during feeding, foraging, and when travelling and the group is close together. The J-call is a series of fast notes repeated by the caller and is used at medium distances. Both calls are used as [[contact calls]]. The long call is used when the group is spread out over distances greater than 10 m or in response to a neighboring group.<ref name="de la TorreSnowdon2002" /> The pygmy marmoset uses the trill for short-distance communication, J-calls for intermediate distances, and long calls for long distances; these have respectively decreasing frequencies. They interpret these calls not only by type, but also through subtle sonic variance, by individual calling. Research based on audio playback tests shows that calls recorded from different individuals in captivity varied significantly in all seven auditory parameters analyzed for each type of call. Behavioral responses to trills were greatest when the caller was the dominant male of the group. Responses to J-calls were greatest when the caller was the monkey's mate or a same-sex monkey from outside the group. Varying responses to individual callers were only observed when the call was given spontaneously from another animal rather than being played back from a recording, with one exception. That exception was that male monkeys responded to playbacks of their own calls differently from those of other monkeys, when the call was played back from a familiar location. The pygmy marmoset is thought to react at first to the type of call that is being made and then adjusts its behavior slightly to react to the specific individual that is making the call. This allows the marmoset to react appropriately to all calls, but show some variation when the call gives extra information.<ref name="SnowdonCleveland1980" />

Environmental factors play a role in communication by affecting the [[frequency]] of the signal and how far the signal can travel and still be audible to communicate the desired message. Since pygmy marmosets are often found in the rain forest, plant life and the humid atmosphere add to the normal absorption and scattering of sound. Because low-frequency calls are affected less by the disturbances than high-frequency ones, they are used for communication across longer distances.<ref name="de la TorreSnowdon2002" /> The pygmy marmoset changes the characteristics of its calls when its social environment is changed. Adult marmosets show modifications in the structure of their calls, which mimic those of their group members. In addition to changes of existing calls, novel calls may be heard from marmosets after pairing.<ref name="SnowdonElowson1999">{{Cite journal | last1 = Snowdon | first1 = C. T. | last2 = Elowson | first2 = A. M. | doi = 10.1046/j.1439-0310.1999.00483.x | title = Pygmy marmosets modify call structure when paired | journal = Ethology | volume = 105 | issue = 10 | pages = 893–908 | year = 1999 }}</ref>

Pygmy marmosets have other ways to communicate information about matters such as a female's ovulatory state. New World monkeys do not show [[genital swelling]] during [[ovulation]] as female Old World monkeys do. Instead, a lack of female aggression towards males can serve as a signal of ovulation. Scent glands on her chest, anus, and genitals are also rubbed on surfaces, which leave [[Olfactory communication|chemical signals]] about the reproductive state of the female.<ref name="Converse_etal1995">{{Cite journal | last1 = Converse | first1 = L. J. | last2 = Carlson | first2 = A. A. | last3 = Ziegler | first3 = T. E. | last4 = Snowdon | first4 = C. T. | title = Communication of ovulatory state to mates by female pygmy marmosets, ''Cebuella pygmaea''| doi = 10.1016/0003-3472(95)80194-4 | journal = Animal Behaviour | volume = 49 | issue = 3 | pages = 615–621 | year = 1995 | s2cid = 54321327 }}</ref> Pygmy marmosets also perform visual displays such as strutting, back-arching, and [[piloerection]] when they feel threatened or to show dominance.<ref name="Soini1988b">{{Cite book | last = Soini | first = P. | year = 1988 | chapter = The pygmy marmoset, genus ''Cebuella'' | editor1-last = Mittermeier | editor1-first = R. A. | editor2-last = Coimbra-Filho | editor2-first = A. F. | editor3-last = da Fonseca | editor3-first = G. A. B. | title = Ecology and Behavior of Neotropical Primates | volume = 2 | location = Washington DC | publisher = World Wildlife Fund | pages = 79–129 | oclc = 180684863}}</ref>