Births and rainfall periods.

<p>Top: Frequency of births by month for those accurate to within two months (N = 84). Bottom: Average monthly rainfall. Error bars indicate inter-annual variation (SE).</p

Fecundity averaged over births observed from 2006–2012 for N = 280 females.

<p>The average ranges between 0.13–0.17 female offspring per individual per year. Data are provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0082788#pone.0082788.s007" target="_blank">Table S4</a>.</p

Estimated (a) ages at primiparity and (b) inter-birth intervals (IBI).

<p>Curves represent the cumulative probability that a female gives birth to her first calf at a particular age (a), or exhibits an IBI of a specified length (b). Histograms show counts of observed ages at primiparity and birth intervals respectively. Data are included as <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0082788#pone.0082788.s005" target="_blank">Tables S2</a> & <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0082788#pone.0082788.s006" target="_blank">S3</a>.</p

Female no. 33 (‘Tailless’), reference female for oldest age class.

<p>This unique female, who was distinctly identifiable even after death due to her tail which was broken at the base, was among the oldest individuals observed in this population. Top panels: Tailless in 2008 exhibits the sunken forehead and cheeks as well as reduction in breast mass characterizing the >60 yr age class. Bottom panels: both upper and lower molars exhibit severe wear with no signs of additional teeth to emerge.</p

Estimates of inter-birth-intervals with datasets ordered by decreasing accuracy.

<p>Estimates of inter-birth-intervals with datasets ordered by decreasing accuracy.</p

Injuries and mortalities by sex and cause.

<p>Anthropogenic causes - <i>Poison</i>: ingestion of toxic substance, usually hidden in food items such as pumpkins. <i>Snare/knife</i>: wounds that encircle or cut into an appendage from wire or rope. <i>Shot</i>: gunshots and swellings from gunshots. <i>Well</i>: abandoned water wells in which animals can fall. <i>Separation</i>: death of a calf due to death or disappearance of the mother after a human-caused injury. <i>Burn</i>: skin lesions caused by fire. Natural causes – <i>Old age/disease</i>: disappearance or confirmed death within the oldest age class, or known illness. <i>Premature</i>: calf born prematurely. <i>Emaciation</i>: extreme loss of body mass. <i>Jaw injury</i>: swelling or distortion of the lower jaw. <i>Separation</i>: separation of a calf from the mother without any sign of injury to the mother. <i>Other/unknown</i>: unknown circumstances, here grouped with ‘natural’ causes but human influence cannot be excluded. Includes the cases of isolated calves, where reasons for the absence of the mother were not known.</p

Sex of calves when births were observed within 2 months and sex was determined.

<p>Sex of calves when births were observed within 2 months and sex was determined.</p

Uda Walawe National Park.

<p>The study was conducted along the road network in the middle portion of the park, represented by the hashed lines (<100 Km²). Images sources: NASA Earth Observatory (<a href="http://earthobservatory.nasa.gov" target="_blank">http://earthobservatory.nasa.gov</a>), the Department of Wildlife Conservation, Sri Lanka, and the Center for Conservation Research, Sri Lanka.</p

Visual cues used for adult female age-class assignment.

*<p>The apparent age of an animal also varies with body condition, weight loss making it appear older. Ear folds and depigmentation are not reliable indicators of age class. If these visual attributes are used in other populations, corresponding ages should be assessed relative to individuals whose age can be confidently estimated, and after repeated observations of the same individuals to account for changes in condition.</p

Annual totals of recorded births and deaths.

<p>Although there are fewer mortalities than births observed, this should not be taken to indicate a growing population. Most carcasses go undetected due to the dense cover. Moreover chances of detection are likely to be even lower for individuals near the age of dispersal, because disappearance through death vs. dispersal are not distinguishable in this study.</p