Population Survey of Bornean White-Bearded Gibbon, Hylobates albibarbis,in Two Selective Logging Concessions in Central Kalimantan and West Kalimantan.

We surveyed Bornean white-bearded gibbon, Hylobates albibarbis, population densities in lowland and hill dipterocarp forests within the Sari Bumi Kusama and Suka Jaya Makmur logging concessions. These surveys were conducted from 20 to 30 March 2018 in Sari Bumi Kusuma areas and 14 to 24 April 2018 in Suka Jaya Makmur. We used a fixed-point count method to detect and plot morning song bouts of gibbon groups at systematically placed listening posts. At each location in Sari Bumi Kusuma and Suka Jaya Makmur, 18 listening posts were established, and 2 observers noted and plotted gibbon morning great calls. Gibbon group density was higher at Suka Jaya Makmur than at Sari Bumi Kusuma; we estimated that there were 2.29 groups per square kilometre in the former area and 1.86 groups/km2 in the latter. Since Bornean white-bearded gibbons are strictly protected by the Government of Indonesia and listed as an Endangered species by the International Union for Conservation of Nature (IUCN), we need better management practices to protect the populations of this species within production forests (outside protected areas).

Seed Dispersal of Threatened Tree Species by a Critically Endangered Primate in a Brazilian Hotspot.

In the northern Atlantic Forest, hunting and habitat loss have eliminated most large mammals that disperse zoochoric fruits. Due to the decrease in populations of large seed dispersers, yellow-breasted capuchins (Sapajusxanthosternos) are currently one of the largest arboreal fruit-eating mammals in the region. During 26 months, we followed 14-25 capuchins aiming to (1) present data on their dietary ecology, (2) verify the conservation status of plants in the diet, and (3) determine distance and habitat of seed deposition based on gut retention time. Capuchins showed a preference for feeding in old secondary forests in spite of the greater availability of primary forests. They fed on 109 species of fruits (42.7% of feeding frequency) and swallowed 85 species of seeds (mean width: 0.73 ± 0.57 cm; mean length: 1.17 ± 0.83 cm). Capuchins consumed mostly oil palm and manilkara fruits. We observed long distances of seed deposition (median 300-360 m); 36.8-41.7% of these events occurred in a distinct habitat, and seeds of 12 late-stage trees swallowed in the primary forest were deposited in old secondary forests. S. xanthosternos has an important role in the first phase of seed dispersal (seed removal from the parent tree and seed deposition), particularly for 23 endemic and 3 endangered plants.

Meat-eating by a wild Bornean orang-utan (Pongo pygmaeus).

We present the first evidence for consumption of meat by a wild Bornean orang-utan (Pongo pygmaeus). Meat-eating has been reported in Sumatran orang-utans, specifically the hunting and consumption of slow lorises (Nycticebus coucang), but loris-hunting behaviour has not been observed in the Bornean species and meat of any species is essentially absent from their diet, with only two anecdotal reports of vertebrate meat consumption prior to this current finding in over 40 years of study. In August 2012 an unhabituated adult flanged male orang-utan was observed eating an adult horse-tailed squirrel (Sundasciurus hippurus) carcass in the Sabangau peat-swamp forest, Central Kalimantan. We suspect this to be a case of scavenging, never reported previously in a Bornean orang-utan.

Outcomes After Ulnar Nerve In Situ Release During Total Elbow Arthroplasty.

PURPOSE: Ulnar nerve (UN) lesions are a significant complication after total elbow arthroplasty (TEA), with potentially debilitating consequences. Outcomes from a center, which routinely performs an in situ release of the nerve without transposition, were investigated. METHODS: Eighty-three primary TEAs were retrospectively reviewed for the intraoperative management of the UN and presence of postoperative UN symptoms. RESULTS: Three patients had documented preoperative UN symptoms. One patient had a prior UN transposition. The nerve was transposed at the time of TEA in 4 of the remaining 82 elbows (5%). The indication for transposition in all cases was abnormal tracking or increased tension on the nerve after insertion of the prosthesis. Of the 4 patients who underwent UN transposition, 2 had postoperative UN symptoms. Both were neuropraxias, which resolved in the early postoperative period. The remaining 78 TEAs received an in situ release of the nerve. The incidence of postoperative UN symptoms in the in situ release group was 5% (4 of 78). Two patients had resolution of symptoms, whereas 2 continued to experience significant UN symptoms requiring subsequent transposition. Seven patients had preoperative flexion of less than 100°. Of these, 2 had a UN transposition at the time of TEA. Of the remaining 5 elbows with preoperative flexion less than 100°, 2 had postoperative UN symptoms after in situ release, with 1 requiring subsequent UN transposition. CONCLUSIONS: A 3% incidence of significant UN complications after TEA compares favorably with systematic reviews. We do not believe that transposition, which adds to the handling of the nerve and increases surgical time, is routinely indicated and should rather be reserved for cases with marked limitation of preoperative elbow flexion or when intraoperative assessment by the surgeon deems it necessary. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Total elbow arthroplasty: outcomes after triceps-detaching and triceps-sparing approaches.

BACKGROUND: Total elbow arthroplasty (TEA) is associated with high complication rates compared with other large-joint arthroplasties. The frequency and type of complication may differ, depending on the surgical approach. A comparison of outcomes with triceps-off and triceps-on approaches was investigated. METHODS: Seventy-three patients underwent 83 primary TEAs between 2003 and 2012. Forty-six elbows had a triceps-off approach, and 37 had a triceps-on approach. Results were reviewed at a mean of 4.2 years. Cementing technique was graded according to Morrey's criteria, and clinical outcomes were assessed by means of the Mayo Elbow Performance Score. RESULTS: There was no statistically significant difference between the triceps-off and triceps-on groups with regard to the patient's age, gender, preoperative Mayo Elbow Performance Score or range of motion, or previous surgery on the affected elbow. Among patients who underwent a TEA for an inflammatory arthropathy, there was a significant difference in outcome between groups with regard to final flexion, extension, arc of motion, and pronation. Cementing technique in the triceps-off group was adequate in 70%. In the triceps-on group, cementing technique was adequate in 92%. The complication rate in the triceps-off group was 32.6% and included 7 triceps ruptures. Three patients who had attempted repairs of the triceps rupture developed deep infections requiring multiple further surgeries. The complication rate in the triceps-on group was 8.1%. CONCLUSION: A triceps-on approach in TEA results in consistently good clinical outcomes with no risk of triceps rupture, and the approach does not compromise the cement mantle. We believe that this approach will reduce complication rates in TEA.

Fine-scale habitat use by orang-utans in a disturbed peat swamp forest, central Kalimantan, and implications for conservation management.

This study was conducted to see how orang-utans (Pongo pygmaeus wurmbii) were coping with fine-scale habitat disturbance in a selectively logged peat swamp forest in Central Kalimantan, Borneo. Seven habitat classes were defined, and orang-utans were found to use all of these, but were selective in their preference for certain classes over others. Overall, the tall forest classes (≥20 m) were preferred. They were preferred for feeding, irrespective of canopy connectivity, whereas classes with a connected canopy (canopy cover ≥75%), irrespective of canopy height, were preferred for resting and nesting, suggesting that tall trees are preferred for feeding and connected canopy for security and protection. The smaller forest classes (≤10 m high) were least preferred and were used mainly for travelling from patch to patch. Thus, selective logging is demonstrated here to be compatible with orang-utan survival as long as large food trees and patches of primary forest remain. Logged forest, therefore, should not automatically be designated as 'degraded'. These findings have important implications for forest management, forest classification and the designation of protected areas for orang-utan conservation.

Extrapair paternity in golden-cheeked gibbons (Nomascus gabriellae) in the secondary lowland forest of Cat Tien National Park, Vietnam.

We observed 18 groups of golden-cheeked gibbons (Nomascus gabriellae) in the secondary lowland forest in Cat Tien National Park from January 2004 to December 2005 to obtain information about the social organization of this little-studied species, in an area where the population is recovering through increased protection and forest regeneration. DNA from faecal samples of 10 infants and juveniles identified 1 case of extrapair paternity. DNA from faecal samples of 18 adults from three communities revealed the majority of adults sampled of both sexes to be related to adults in neighbouring territories. Overall, the indications are that in this empty habitat, gibbons appear to be able to establish territories adjacent to those of their kin.

The orang-utan mating system and the unflanged male: A product of increased food stress during the late Miocene and Pliocene?

The orang-utan is unique among apes in having an unusually long male developmental period and two distinct adult male morphs (flanged and unflanged), which generally, but not exclusively, employ different reproductive strategies (call-and-wait vs. sneak-and-rape). Both morphs have recently been shown to have roughly similar levels of reproductive success in the one site where such a study has been conducted. This is in stark contrast to the unimale polygynous gorilla, in which dominant males sire almost all infants. Despite this, evidence on sexual dimorphism, life history, diet, and socioecology of extant and extinct apes, as well as the ontogeny, reproductive morphology, and physiology of extant apes, all indicate that the orang-utan's present-day mating system most likely evolved from a gorilla-like base, with one dominant male guarding a harem of females. The available evidence indicates that, due chiefly to the likely onset of the El Niño Southern Oscillation (generally regarded as the trigger for mast fruiting in dipterocarps) approximately 3-5Ma, southeast Asian forests would have begun to experience longer and more severe periods of low food availability. This change in food availability would have meant that full-time gregariousness was no longer energetically tolerable and, as a result, females dispersed more widely in search of food and adult/flanged males were no longer able to effectively guard a harem of females. A niche for a quiet, quick, opportunistic "sexual predator" (i.e., the unflanged male) then became available. This finding implies that, despite being anatomically quite chimpanzee-like, the ancestral hominoid probably had a social and mating system more similar to the gorilla than any other living ape.

Sexual swellings of female gibbons.

Female gibbons were observed for labial swellings from March 2002 to August 2003. Data were collected on length of time each female was swollen, changes in swelling period as females matured, and cycle length (number of days between onsets of consecutive swellings). Data were also collected on the behaviour of the males when the females were swollen. There was a significant relationship between age of the female gibbon and number of days she had labial swelling. There was no significant relationship between the age of the gibbon and the cycle length, nor between species (Hylobates agilis albibarbis and Hylobates muelleri) and number of days swollen. Copulation was more common when females were swollen. Swelling in female gibbons may be related to copulatory behaviour and serve to provide the male with some certainty of paternity through fertilisation insurance.