Editing Indri (section)

== Behavior ==

The indri practices long-term [[Monogamy in animals|monogamy]], seeking a new partner only after the death of a mate. It lives in small groups consisting of the mated male and female and their maturing offspring. In the more fragmented forests of their range, the indri may live in larger groups with several generations. [[Habitat fragmentation]] limits the mobility and capacity of these large groups to break into smaller units.<ref name=PowzykThalmann2003 />

Like many other species of lemur, indri live in a female dominant society. The dominant female often will displace males to lower branches and poorer feeding grounds, and is typically the one to lead the group during travel.<ref>{{Cite journal|last=Pollock|first=J.I.|date=1979|title=Female Dominance in ''Indri indri''|journal=Folia Primatologica |volume=31|issue=1–2|pages=143–164|doi=10.1159/000155877|pmid=114465 |url=http://eprints.uwe.ac.uk/3035/}}</ref>

It is common for groups to move 300–700 m daily, with most distance travelled midsummer in search of fruit. Indris sleep in trees about 10–30 m above ground and typically sleep alone or in pairs. It is common for young female indris, occasionally adult females, to silently play wrestle anywhere from a few seconds up to 15 minutes. Members of a single group will urinate and defecate jointly at one of their many selected areas of defecation in their territory.<ref name= "Quinn">{{cite journal |last1=Quinn |first1=Aleta |last2=Wilson |first2=Don E. |title=Indri indri |journal=Mammalian Species |date=2002 |volume=694 |issue=1 |pages=1–5 |doi=10.1644/1545-1410(2002)694<0001:ii>2.0.co;2 }}</ref>

=== Reproduction ===
Indris reach sexual maturity between the ages of 7 and 9.<ref name=Quinn /> Females bear offspring every two to three years, with a gestation period around 120–150 days. The single infant is usually born in May or June.<ref name=Mittermeier/> The mother is the primary caregiver, though the father assists, remaining with his mate and offspring.<ref name=PowzykThalmann2003 /> Infants are born mostly or completely black and begin to show white coloration (if any) between four and six months of age.<ref name=Quinn /> The infant clings to its mother's belly until it is four or five months old, at which time it is ready to move onto her back. The indri begins to demonstrate independence at eight months, but it will not be fully independent from its mother until it is at least two years old.{{fact|date=February 2025}}

=== Communication ===
{{listen
| type     = sound
| filename = Roep Indri Indri.ogg
| title    = Indri duet
| description = The wailing "song" of the Indri
}}
[[Image:Iiv AGrandidier 1204.jpg|right|thumb|229px|Drawing by [[Alfred Grandidier]]]]
The indri makes loud, distinctive songs, which can last from 45 seconds to more than 3 minutes. Song duration and structure varies among and even within groups, but most songs have the following three-phase pattern.<ref name=Pollock>{{Cite journal|last=Pollock|first=Jon I.|date=June 1986|title=The song of the Indris (Indri indri; Primates: Lemuroidea): Natural history, form, and function|journal=[[International Journal of Primatology]] |volume=7|issue=3|pages=225–264|doi=10.1007/BF02736391 }}</ref>

Usually, a roaring sequence lasting for several seconds will precede the more characteristic vocalizations. All members of the group except the very young participate in this roar, but the song proper is dominated by the adult pair. They follow the roar with a long note sequence, characterized by notes of up to five seconds in duration. After this is a descending phrase sequence. The wails begin on a high note and become progressively lower-pitched. It is common for two or more indri to coordinate the timing of their descending notes to form a duet.<ref name=Pollock/>

Different indri groups typically sing sequentially, responding to one another. As well as solidifying contacts between groups, the songs may communicate territorial defense and boundaries, environmental conditions, reproductive potential of the group members, and warning signals.<ref name=Pollock/> The indri may sing after disturbances such as thunder, airplanes, bird calls, and other lemur calls.<ref name=Quinn /> A group will sing almost every day, up to seven times daily. The peak singing hours are between 7 and 11 am. Daily frequency of song is highest during the indri's breeding season from December to March.<ref name= "Glessner">{{cite journal |last1=Glessner |first1=Kellie D. G. |last2=Britt |first2=Adam |title=Population Density and Home Range Size of Indri indri in a Protected Low Altitude Rain Forest |journal=International Journal of Primatology |date=August 2005 |volume=26 |issue=4 |pages=855–872 |doi=10.1007/s10764-005-5326-2 }}</ref>

Several other indri vocalizations have been identified. The "roar" is also used as a warning signal for aerial predators such as hawks.<ref name=Quinn /> The indri emit a "hoot" or "honk" to warn of terrestrial predators such as the [[Fossa (animal)|fossa]]. Other vocal categories include the "grunt", "kiss", "wheeze", and "hum". The purpose of these is not well understood.<ref name=PowzykThalmann2003 />

Before singing, the indri move to the tree tops, which allows them to be heard up to 4&nbsp;km away.<ref name= "Giacoma">{{cite journal |last1=Giacoma |first1=Cristina |last2=Sorrentino |first2=Viviana |last3=Rabarivola |first3=Clement |last4=Gamba |first4=Marco |title=Sex Differences in the Song of Indri indri |journal=International Journal of Primatology |date=August 2010 |volume=31 |issue=4 |pages=539–551 |doi=10.1007/s10764-010-9412-8 }}</ref>

===Diet and feeding===

The indri is [[herbivore|herbivorous]] and primarily [[Folivore|folivorous]]. It prefers young, tender leaves, but will also eat seeds, fruits, and flowers. Female indri seem to have greater preference for immature leaves than males do and spend more time foraging among them. A wide variety of plant species are consumed, with members of the [[Lauraceae|laurel family]] featuring prominently in the diet. The indri consumes little nontree vegetation.<ref name=Quinn />

To feed, the indri plucks off a leaf or other plant part with its teeth. It uses its hands to pull tree branches closer to its mouth.<ref name=PowzykThalmann2003 />

Reproductively mature females have priority access to food sources, therefore they forage higher in the trees than males.<ref name="Giacoma" />