Mikkel Stelvig

Knowledge about distribution of primate species and their densities is crucial for conservation and management. However, such information is often lacking or anecdotal, even for seemingly abundant species. Long-tailed macaques (Macaca fascicularis) are distributed across Southeast Asia and recognized by the IUCN SSC PSG as both widespread and rapidly declining. Precise local density and abundance data are scarce across their range. To provide density and abundance estimates for a long-tailed macaque population we conducted line transect distance sampling throughout Baluran National Park (250km2), East Java, Indonesia covering all habitats. Long-tailed macaque density was 41.4ind/km2 (95%CI 23.04 – 74.39), with an estimated abundance of 10350 individuals (95%CI 5760 – 18598). A density of 41.4ind/km2 is lower than previous estimates for other sites in Java. Species distribution and habitat suitability analysis revealed a macaque preference for areas close to or on roads and trails, invasive acacia and/or native savannah. Long-tailed macaques were provisioned with human food by commuters and tourists along roads and trails, probably structuring their distribution/habitat use. To evaluate if long-tailed-macaques have been overestimated for years, we also conducted a non-random point distance sampling survey according to macaque presence restricted to roads and trails. This survey provided density and abundance results much higher than the line transect distance sampling survey. Our study provides much needed baseline data for this species. Baluran National Park management and management in other areas can use these results to create informed management decisions regarding long-tailed macaques. We recommend conducting systematic surveys of long-tailed macaques throughout their range, and possibly reassessing conservation status, and conservation and management measures for long-tailed macaques

Captive polar bears (Ursus maritimus) are well-documented as being prone to behavioural disorders and, as a result, their welfare is the cause of increasing concern. There is therefore a need for an evidence-based approach to the assessment of the welfare of this species and identification of valid welfare indicators is the first step towards achieving this. To this end, a critical evaluation of peer-reviewed literature was undertaken. Searches of Web of Science and Scopus took place in May 2020 for publications relevant to the welfare of captive polar bears which met inclusion criteria. Further, validity of extracted indicators was assessed via investigation of evidence of content, construct and criterion validity along with strength of evidence at publication-level. Database searches and snow-balling unearthed 46 publications included for review. Identified indicators were sorted into nine behavioural, four physiological (based on physiological or biological sampling) and five phy...

Background In highly seasonal environments, animals face critical decisions regarding time allocation, diet optimisation, and habitat use. In the Arctic, the short summers are crucial for replenishing body reserves, while low food availability and increased energetic demands characterise the long winters (9–10 months). Under such extreme seasonal variability, even small deviations from optimal time allocation can markedly impact individuals’ condition, reproductive success and survival. We investigated which environmental conditions influenced daily, seasonal, and interannual variation in time allocation in high-arctic muskoxen (Ovibos moschatus) and evaluated whether results support qualitative predictions derived from upscaled optimal foraging theory. Methods Using hidden Markov models (HMMs), we inferred behavioural states (foraging, resting, relocating) from hourly positions of GPS-collared females tracked in northeast Greenland (28 muskox-years). To relate behavioural variation...

The effect of food provisioning on ranging patterns of long-tailed macaques (Macaca fascicularis) in non-anthropogenic areas is largely unknown, as most published studies have focused on urban macaques. In this study, we quantified habitat selection, daily path length and home range size in long-tailed macaques in Baluran National Park, East Java, Indonesia, comparing a non-provisioned to a provisioned group. To track the groups, we deployed six GPS-collars on females in both groups, of which only two collected data. Home range size (90% Auto-correlated Kernel Density Estimate) was 23 times smaller for the provisioned group (10.62 ha) than the non-provisioned group (249.90 ha). Home range size and area changed from dry to wet season for the non-provisioned group. Provisioned group home range size correlated negatively with number of visitors in the national park. Daily path length was significantly higher for the non-provisioned group. The provisioned group preferred settlements, wh...

Background Research of many mammal species tends to focus on single habitats, reducing knowledge of ecological flexibility. The Javan lutung (Trachypithecus auratus) is considered a strict forest primate, and little is known about populations living in savannah. In 2017–2018, we investigated the density and distribution of Javan lutung in Baluran National Park, Indonesia. We conducted ad libitum follows and line transect distance sampling with habitat suitability analysis of Javan lutung. Results Estimated density was 14.91 individuals km− 2 (95% CI 7.91–28.08), and estimated population size was 3727 individuals (95% CI 1979 – 7019). Long-tailed macaque (Macaca fascicularis) habitat suitability was the main driver of lutung habitat suitability as the probability of lutung occurrence increased greatly with macaque habitat suitability. Distance to roads, and distance to secondary forest had a negative relationship with lutung occurrence. Lutung habitat suitability decreased with incre...

For free-ranging animals living in seasonal environments, hypometabolism (lowered metabolic rate) and hypothermia (lowered body temperature) can be effective physiological strategies to conserve energy when forage resources are low. To what extent such strategies are adopted by large mammals living under extreme conditions, as those encountered in the high Arctic, is largely unknown, especially for species where the gestation period overlaps with the period of lowest resource availability (i.e. winter). Here we investigated for the first time the level to which high arctic muskoxen (Ovibos moschatus) adopt hypothermia and tested the hypothesis that individual plasticity in the use of hypothermia depends on reproductive status. We measured core body temperature over most of the gestation period in both free-ranging muskox females in Greenland and captive female muskoxen in Alaska. We found divergent overwintering strategies according to reproductive status, where pregnant females mai...

Abstract Immobilizing and handling large, free-ranging animals without proper facilities in harsh environmental conditions poses significant challenges. During two field expeditions, a total of 29 female muskoxen (Ovibos moschatus) were immobilized in Northeast Greenland (74°N, 20°E). Fixed doses of immobilizing drugs were used regardless of animal size: 2 mg etorphine, 30 mg xylazine, 0.3 mg medetomidine, and 40 mg ketamine. Physiologic and behavioral monitoring was performed during the second expedition on 15 female muskoxen. The observed heart rates were 35–58 beats/min and respiratory rates were 25–30 breaths/min. Mean arterial pressures measured using oscillometry ranged between 117–142 mmHg. Pulse oximeter readings ranged from 91–98% with oxygen supplementation, nasal end-tidal carbon dioxide values were 24–42 mmHg, and rectal temperature ranged from 38.9–39.6°C. Induction time was 6–8 min, recovery time 2–6 min after reversal, and duration of anesthesia was 50–100 min. This anesthetic regime thus provided reliable immobilization with minimal pathophysiologic alterations.

Mate choice studies suggest that choosy females benefit from increased fecundity, litter size, and offspring survival. Thus, providing females with the opportunity to choose among potential mates, deemed genetically suitable based on studbook data, might improve breeding management in production and zoo animals and thereby the sustainability of captive populations. Investigating mate preference via odor from potential mates before animal transfer is a proposed strategy for incorporating mate choice into breeding management. In this study, we test whether olfactory cues and signals from males can be used to assess and measure female mate preference in American mink. Eighteen females were subjected to a 4-day stimulus test in which females showed a preference for one of two males' urine and feces. Subsequently, each female was subjected to a 10-day mate preference test involving the same two males of the first test. Paternity tests revealed that 13 females had offspring, which cou...