Staff Profiles

 

Research interests

• Conservation
• Primate ecology
• Nocturnal primates
• Wildlife trade

 

Research group membership

 

• Nocturnal Primate Research Group
• Oxford Wildlife Trade Research Group

 

Journal articles

• Molyneaux A, Hankinson E, Kaban M, Svensson MS, Cheyne SM, Nijman V, 'Primate Selfies and Anthropozoonotic Diseases: Lack of Rule Compliance and Poor Risk Perception Threatens Orangutans'
  Folia Primatologica 92 (2021) pp.296-305
  ISSN: 0015-5713 eISSN: 1421-9980
  Abstract

  Our understanding of the transmission of anthropozoonotic diseases between humans and non-human primates, particularly great apes due to their close genetic relationship with humans, highlights a serious potential threat to the survival of these species. This is particularly the case at tourism sites where risk of disease transmission is increased. We focus on the interaction between tourists and the Critically Endangered Sumatran orangutan (Pongo abelii) at Bukit Lawang in the Gunung Leuser National Park, Indonesia, before and after the park was closed due to the threat of COVID-19 in April 2020. Through analysis of posts on Instagram we determine the extent of compliance by visitors with the rule to keep a minimum distance of 10 m from orangutans and assess the positional behaviours of the orangutans. Of the 2,229 photographs we assessed between November 2019 and July 2020, 279 depicted one or more orangutans. Forty-two of these contained both a human and an orangutan, and of these all showed inappropriate behaviours (direct contact, feeding orangutans, close proximity <5 m) providing direct evidence of non-compliance with the 10-m distance rule. Most of these photographs additionally showed orangutans performing abnormal positional behaviours such as being low to or on the ground rather than their natural high position in the canopy; being near the ground and in close proximity to humans increases the risk of anthropozoonotic disease transmission. As expected, we found a significant decrease in number of photographs that were posted following the closure, and a decrease in the proportion of photographs that showed orangutans, or tourists feeding orangutans. Tourists do not seem to perceive that they pose risks to the orangutans and therefore increased awareness, education and enforcement of rules by all stakeholders, tourism bodies and government officials need to be actioned in order to safeguard this important population, which is crucial to the future survival of the Sumatran orangutan.

  Website 
• Daniels C, Cheyne SM, Waters S, Svensson MS, 'Professional primate keepers and online primate imagery: an assessment of knowledge and attitudes'
  Journal of Zoo and Aquarium Research 9 (4) (2021) pp.259-265
  ISSN: 2214-7594 eISSN: 2214-7594
  Abstract

  In January 2021, the International Union for the Conservation of Nature’s Primate Specialist Group Section for Human Primate Interactions (IUCN PSG SHPI) published best practice guidelines on the use of non-human primate imagery online. This paper explores the contribution of professional primate keepers to the detrimental online sharing of images involving humans and primates, and their knowledge and opinions towards this subject. A total of 421 primate keepers responded to an online questionnaire shared in March 2021, providing information about their use of primate imagery on social media platforms and sharing their understanding of scientific studies on this topic. Over half (56%) of primate keepers admitted to sharing images online of themselves and primates, that could be considered irresponsible. A complementary review of posts shared on Instagram™ under the hashtag #primatekeeper revealed that 64% of 128 images surveyed depicted primates in situations which prior research has shown to have negative consequences for primate conservation, in addition to affecting the way the public perceives the conservation status of species in such imagery. Of the respondents, 53% had not heard of the IUCN PSG SHPI, and 67% of primate keepers were unaware of the new guidelines published by the group. It is recommended that the best practice guidelines are disseminated to zookeepers directly through appropriate forums to ensure primate keepers are acting in line with the recommendations in the best practice guidelines, and that further research is conducted regarding human-primate two-shot images to better guide decisions made by primatologists and others working both in and ex situ with primates.

  Website 
• Muir J, Barnett AA, Svensson MS, 'Preliminary investigation into the differences in vocalisations between wild saki monkeys (Pithecia spp.)'
  Neotropical Primates 27 (1) (2021) pp.32-36
  ISSN: 1413-4705
  Website 
• Parsons J, Svensson MS, 'Attack of an infant by a female in a troop of howler monkeys (Alouatta pigra)'
  Neotropical Primates 27 (1) (2021) pp.27-29
  ISSN: 1413-4705
  Website 
• Schowe D, Svensson MS, Siriwat P, Jose-Domínguez JM, Fourage A, Malaivijitnond S, Nijman V, 'Assessing the welfare of coconut-harvesting macaques in Thailand'
  Applied Animal Behaviour Science 242 (2021)
  ISSN: 0168-1591
  Abstract

  Pig-tailed macaques are used by coconut farmers in Southeast Asia to harvest coconuts. We assessed the welfare of northern pig-tailed macaques Macaca leonina involved in coconut harvesting in southern Thailand. We interviewed 89 coconut farmers in three provinces focusing on quantifying basic demographics of this trade, i.e., species, where the macaques were sourced, diet, sex, and age. Independent from the interviews, we assessed the welfare of 158 working macaques through direct observations using the ‘five domains’ criteria. Based on our scoring system, the mean welfare score of 4.8 out of the maximum 12 points indicates a need for improvement. Overall, we found good agreement between the interviews data and the welfare assessments. The most important individual welfare modifications required for working macaques to obtain a good level of welfare that benefits both the farmers and macaques include: providing access to conspecifics, adding opportunities to hide from stressors, and increasing the freedom of movement. This study highlights the individual welfare concerns and necessity of legislative changes regarding working macaques and other working animals of wild origins.  
  

  Website 
• Svensson MS, Morcatty TQ, Nijman V, Shepherd CR, 'Shedding light on the trade in nocturnal galagos'
  Primate Conservation 35 (2021)
  ISSN: 0898-6207 eISSN: 2162-4232
  Abstract

  Primates are traded yearly in the tens of thousands for reasons such as biomedical research, as trophies and pets, for consumption and to be used in traditional medicine. In many cases, this trade is illegal, unsustainable and considered a major impediment to primate conservation. Diurnal primates make up the vast majority of this trade, but recent studies have found that the trade in nocturnal primates is more common than previously thought, and among them are the galagos. There are currently 19 galagos recognized but there is still a dearth of research on these species and subspecies. The purpose of our study was to provide a more comprehensive picture of the trade in galagos within and across their African range countries, to help determine whether it is illegal or its sustainability needs to be assessed, and to provide baseline data and management recommendations to better regulate this trade, including strengthening policy, enforcement and conservation interventions. We gathered information on trade and use of galagos using an online questionnaire (May–August 2020), and on country-specific legislation relating to wildlife trade, hunting and legal protection of galagos, and looked at each range country’s Corruption Perception Index score to gain an understanding of the obstacles in the way of effective law enforcement. We received 140 responses to our online questionnaire, from 31 of the 39 galago range countries. Respondents from 16 of these countries reported on first-hand observations of galagos being traded or used. Out of these, 36% reported seeing galagos sold or used for consumption, 33% as pets and 25% had observed them sold or used for traditional practices (including medical and magical purposes and for witchcraft). Most reports came from West Africa followed by Central Africa, East Africa and Southern Africa. We found that the number of reports on galagos being traded was higher in countries with higher numbers of galago species. Countries with more restrictive legislation experienced a higher number of reports of trade. Galagos observed in the pet trade was more common in East Africa, whilst reports of them in the bushmeat trade were more common in Central and West Africa. Galagos observed in the trade for traditional practices was by far most common from West Africa. We found that all galago range countries have some level of legal protection for some or all of their native galago species. It is evident that use and trade of galagos occurs throughout their range, albeit localized to certain areas. We urge galago range countries to adequately protect all species and to ensure legal trade is effectively regulated. Range countries that prohibit the use and trade in galagos must ensure legislation is adequately enforced. Further research into the drivers behind the use and trade of galagos should be initiated in countries with high levels of use and trade to further inform conservation and policy actions and to catalyze enforcement actions against poaching and illegal trade.
  

  Website 
• Van Hamme G, Svensson MS, Morcatty TQ, Nekaris KAI, Nijman V, 'Keep your distance: Using Instagram posts to evaluate the risk of anthroponotic disease transmission in gorilla ecotourism'
  People and Nature 3 (2) (2021) pp.325-334-334
  ISSN: 2575-8314 eISSN: 2575-8314
  Abstract

  1. Mountain gorilla Gorilla beringei beringei trekking is a substantial source of revenue for the conservation of this threatened primate and its habitat. Trekking, however, may pose a threat of human-to-gorilla disease transmission that could have disastrous effects on wild gorillas.
  

  2. We used 858 photographs posted on Instagram in 2013–2019 to analyse the proximity of tourists visiting mountain gorillas in the wild. We classified photographs of the encounters according to the distance between the closest gorilla and human, the age class of the gorilla, the trekking location and presence of a surgical face mask on the tourist. We ran a generalised linear mixed model to test whether these variables influenced the distance between the human and the wild gorillas in the photographs, and to test whether these distances have changed over time.
  

  3. Most sampled photographs (86%) showed tourists within a critical 4 m of the gorillas, with 25 incidents of physical contact between a tourist and a gorilla, and only 3% at the recommended distance of 7 m or more. We only were able to record face mask use in the Democratic Republic of Congo, where these were present in 65% of uploaded photos.
  

  4. Tourists and immature gorillas tended to get closer to each other than tourists and adult gorillas, and this is more pronounced in female tourists than male tourists. The mean distance between human and wild gorillas decreased by ~1 m between 2013 and 2019.
  

  5. The results indicate that existing rules are not enforced and raise attention to this unsustainable aspect of mountain gorilla trekking as it is practiced today. These ever-growing tourist attractions in the range countries pose risks of disease transmission in both directions between tourists and wildlife. The popularity of photograph-based social media may stimulate closer contacts and influence people into risky behaviours.
  

  6. We advocate the establishment and reinforcement of regulations relating to the distance between animals and tourists in any in situ wildlife ecotourism context,as well as campaigns to raise awareness regarding the risks of anthroponosis, and fines applied in case of non-compliance.
  

  Website 
• Tavares AS, Mayor P, Loureiro LF, Gilmore MP, Perez-Peña P, Bowler M, Lemos LP, Svensson MS, Nekaris KAI, Nijman V, Valsecchi J, Queiroz Morcatty T., 'Widespread use of traditional techniques by local people for hunting the yellow-footed tortoise (Chelonoidis denticulatus) across the Amazon'
  Journal of Ethnobiology 40 (2) (2020) pp.268-280
  ISSN: 2162-4496 eISSN: 0278-0771
  Abstract

  Understanding the repertoire of hunting techniques used by traditional peoples in tropical forests is crucial for recognizing the role of traditional knowledge in hunting activities, as well as assessing the impact of harvests on game species. We describe the hunting techniques used across Amazonia by Indigenous and non-Indigenous peoples for hunting yellow-footed tortoises (Chelonoidis denticulatus), one of the most consumed species in the biome. We interviewed 178 local people in 25 communities living in seven study areas in the Peruvian and Brazilian Amazon. We used a Principal Coordinate Analysis (PCoA) and Analysis of Similarity (ANOSIM) to compare the hunting techniques between ethnic groups and the ages of the interviewees. Four different techniques were reported: (1) trapping with bait (46%; n = 122); (2) hunting with dogs (35%; n = 92); (3) active searching (14 %; n = 37); and (4) visiting fruiting trees (5%; n = 14). Trapping with bait was alleged to be the most cost-effective technique by 67% of the interviewees. Among the baits used, 93% involved the use of wild species as rotten meat. Hunting with dogs was also frequently cited and involved eight different methods of training. The hunting techniques recorded were not significantly different among ethnic groups or generations. The consonance among the technique repertoire likely reflects a shared knowledge still in use across different cultural groups. There is a potential for applying the hunting techniques to large scale community-based monitoring and management programs, but the impact on additional species affected, such as species intentionally captured to be used as bait, should be considered. Local assessments and community-based management plans that incorporate traditional ecological knowledge are recommended to guarantee the maintenance of livelihoods and ensure the species' conservation in Amazonia.
  

  Website 
• Morcatty T, Bausch Macedo JC, Nekaris KAI, Ni Q, Durigan C, Svensson MS, Nijman V, 'Illegal trade in wild cats and its link to Chinese‐led development in Central and South America'
  Conservation Biology 34 (6) (2020) pp.1525-1535
  ISSN: 0888-8892 eISSN: 1523-1739
  Abstract

  Seizures of hundreds of jaguar heads and canines in Central and South America from 2014 to 2018 resulted in worldwide media coverage suggesting that wildlife traffickers are trading jaguar body parts as substitutes for tiger parts to satisfy the demand for traditional Asian medicine. We compiled a data set of >1000 seized wild cats (jaguar [Panthera onca], puma [Puma concolor], and ocelot [Leopardus pardalis]) from 19 Central and South American countries and China. We ran generalized additive mixed models to detect trends in wild-cat seizures from 2012 to 2018 and assess the effects of socioeconomic factors of source countries and between those countries and China on the number of wild cats seized. Jaguar seizures increased over time, and most of the seized jaguar pieces were canines (1991 of 2117). Around 34% (32 of 93) of the jaguar-part seizure reports were linked with China, and these seizures contained 14-fold more individuals than those intended for domestic markets. Source countries with relatively high levels of corruption and Chinese private investment and low income per capita had 10-50 times more jaguar seizures than the remaining sampled countries. The number of Chinese residents in Central and South America was not significantly related to the number of jaguars seized. No socioeconomic factors influenced the seizures of puma and ocelots. Legal market chains may provide structure for the illegal chain; thus, the influx of illegal jaguar products is potentially a side effect of the economic partnership between Central and South American countries and China. Poverty and high levels of corruption in the source countries may motivate local people to engage in illegal activities and contribute to the growth of this trade. Supply-side interventions to curb this threat to Neotropical wild cats may include improved training for officials and promotion of governance and the value of protecting these animals to local people.
  

  Website 
• Muir J, Barnett A, Svensson MS, 'The vocal repertoire of golden-faced sakis, Pithecia chrysocephala, and the relationship between context and call structure'
  International Journal of Primatology 40 (2019) pp.721-743
  ISSN: 0164-0291 eISSN: 1573-8604
  Abstract

  Vocalizations are a vital form of communication. Call structure and use may change depending on emotional arousal, behavioral context, sex, or social complexity. Pithecia chrysocephala (golden-faced sakis) are a little-studied Neotropical species. We aimed to determine the vocal repertoire of P. chrysocephala and the influence of context on call structure. We collected data June–August 2018 in an urban secondary forest fragment in Manaus, Amazonian Brazil. We took continuous vocal recordings in 10-min blocks with 5-min breaks during daily follows of two groups. We recorded scan samples of group behavior at the start and end of blocks and used ad libitum behavioral recording during blocks. We collected 70 h of data and analyzed 1500 calls. Lowest frequencies ranged 690.1–5879 Hz in adults/subadults and 5393.6–9497.8Hz in the only juvenile sampled. We identified eight calls, three of which were juvenile specific. We found that, while repertoire size was similar to that of other New World monkeys of similar group size and structure, it also resembled those with larger group sizes and different social structures. The durations of Chuck calls were shorter for feeding contexts compared to hostile, but frequencies were higher than predicted if call structure reflects motivation. This finding may be due to the higher arousal involved in hostile situations, or because P. chrysocephala use Chuck calls in appeasement, similar to behavior seen in other primates. Call structures did not differ between sexes, potentially linked to the limited size dimorphism in this species. Our findings provide a foundation for further investigation of Pithecia vocal behavior and phylogeny, as well as applications for both captive welfare (stress relief) and field research (playbacks for surveys).
  

  Website 
• Luncz LV, Gill M, Proffitt T, Svensson MS, Kulik L, Malaivijitnond S, 'Group-specific archaeological signatures of stone tool use in wild macaques'
  eLife 8 (2019)
  ISSN: 2050-084X
  Abstract

  Stone tools in the prehistoric record are the most abundant source of evidence for understanding early hominin technological and cultural variation. The field of primate archaeology is well placed to improve our scientific knowledge by using the tool behaviours of living primates as models to test hypotheses related to the adoption of tools by early stone-age hominins. Previously we have shown that diversity in stone tool behaviour between neighbouring groups of long-tailed macaques (Macaca-fascicularis) could be explained by ecological and environmental circumstances (Luncz et al., 2017b). Here however, we report archaeological evidence, which shows that the selection and reuse of tools cannot entirely be explained by ecological diversity. These results suggest that tool-use may develop differently within species of old-world monkeys, and that the evidence of material culture can differ within the same timeframe at local geographic scales and in spite of shared environmental and ecological settings.
  

  Website 
• Svensson MS, Butynski TM, de Jong YA, Bearder SK, Schneiderová I, Nijman V, 'Low Geographic and Subspecific Variation in the Loud Call of the Widespread and Phenotypically Cryptic Northern Lesser Galago (Galago senegalensis) Suggests Taxonomic Uniformity'
  Folia Primatologica 90 (5) (2019) pp.300-318
  ISSN: 0015-5713 eISSN: 1421-9980
  Abstract

  Like other nocturnal primates, many species of galago (Galagidae) are phenotypically cryptic, making their taxonomic status difficult to resolve. Recent taxonomic work has disentangled some of the confusion. This has resulted in an increase in the number of recognised galago species. The most widespread galago species, and indeed the most widespread nocturnal primate, is the northern lesser galago (Galago senegalensis) whose geographic range stretches >7,000 km across Africa. Based on morphology, 4 subspecies are currently recognised: G. s. senegalensis, G. s. braccatus, G. s. sotikae and G. s. dunni. We explore geographic and subspecific acoustic variation in G. senegalensis, testing three hypotheses: isolation by distance, genetic basis, and isolation by barrier. There is statistical support for isolation by distance for 2 of 4 call parameters (fundamental frequency and unit length). Geographic distance explains a moderate amount of the acoustic variation. Discriminant function analysis provides some degree of separation of geographic regions and subspecies, but the percentage of misdesignation is high. Despite having (putative) parapatric geographic ranges, the most pronounced acoustic differences are between G. s. senegalensis and G. s. dunni. The findings suggest that the Eastern Rift Valley and Niger River are significant barriers for G. senegalensis. The acoustic structures of the loud calls of 121 individuals from 28 widespread sites are not significantly different. Although this makes it unlikely that additional unrecognised species occur within G. senegalensis at the sites sampled, vast areas of the geographic range remain unsampled. We show that wide-ranging species do not necessarily exhibit large amounts of variation in their vocal repertoire. This pattern may also be present in nocturnal primates with smaller geographic ranges.
  

  Website 
• Luhrs AM, Svensson MS, Nekaris KAI, 'Comparative ecology and behaviour of eastern potto Perodicticus ibeanus and central potto P. edwardsi in Angola, Cameroon, Kenya, Nigeria, Rwanda and Uganda'
  Journal of East African Natural History 107 (1) (2018) pp.17-30
  ISSN: 1026-1613 eISSN: 2224-8862
  Abstract

  Comparative behavioural research reveals both intra- and inter-species diversity among primates. Few long-term behavioural studies have been conducted on African nocturnal primates. Here we describe and compare behavioural and ecological observations on two species of pottos (Perodicticus ibeanus and P. edwardsi) across ten sites. We observed a total of 51 P. edwardsi and 28 P. ibeanus. We recorded all 21 postures within an established lorisid ethogram, as well as 42 of 50 behaviours. Eating, locomotion, freezing, resting and sniffing were the most common behaviours. We recorded behaviours not previously described for perodicticines, including bark chewing and unique vocalisations. Three species of pottos are now recognised, with potentially more species to be revealed within this cryptic and nocturnal genus. Although there are similarities among potto species, we show that unique ecological adaptations and behaviours may further elucidate their diversity.
  

  Website 
• Svensson MS, Nekaris KAI, Bearder SK, Bettridge C, Butynski T, Cheyne SM, Das N, de Jong Y, Luhrs AM, Luncz L, Maddock ST, Perkin A, Pimley E, Poindexter SA, Reinhardt KD, Spaan D, Stark DJ, Starr CR, Nijman V, 'Sleep patterns, daytime predation and the evolution of diurnal sleep site selection in lorisiforms'
  American Journal of Physical Anthropology 166 (3) (2018) pp.563-577
  ISSN: 0002-9483 eISSN: 1096-8644
  Abstract Objectives: Synthesize information on sleep patterns, sleep site use, and daytime predation at sleep sites in lorisiforms of Asia and Africa (ten genera, 36 species), and infer patterns of evolution of sleep site selection. Materials and methods: We conducted fieldwork in twelve African and six Asian countries, collecting data on sleep sites, timing of sleep and predation during daytime. We obtained additional information from literature and through correspondence. Using a phylogenetic approach, we establish ancestral states of sleep site selection in lorisiforms and trace their evolution. Results: The ancestral lorisiform was a fur-clinger and used dense tangles and branches/forks as sleep sites. Use of tree holes and nests as sleep sites emerged ~22 Mya (range 17-26 Mya) in Africa, and use of bamboo emerged ~11 (7-14) Mya in Asia and later in Africa. Nests are commonly used by Galagoides, Paragalago, Galago and Otolemur, tree holes by Galago, Paragalago, Sciurocheirus and Perodicticus, tangles by Nycticebus, Loris, Galagoides, Galago, Euoticus, Otolemur, Perodicticus and Arctocebus, and all but Sciurocheirus and Otolemur additionally sleep on branches/forks. Daytime predation may affect sleep site selection and sleep patterns in some species of Nycticebus, Galago, Galagoides, Otolemur and Perodicticus. Most lorisiforms enter their sleep sites around sunrise and leave around sunset; several are active during twilight or, briefly, during daytime. Conclusion: Variations in sleep behavior, sleep patterns and vulnerability to daytime predation provide a window into the variation that was present in sleep in early primates. Overall, lorisiforms use the daytime for sleeping and no species can be classified as cathemeral or polycyclic.Website 
• Proffitt T, Luncz LV, Malaivijitnond S, Gumert M, Svensson MS, Haslam M, 'Analysis of wild macaque stone tools used to crack oil palm nuts'
  Royal Society Open Science 5 (2018)
  ISSN: 2054-5703
  Abstract The discovery of oil palm (Elaeis guineensis) nut-cracking by wild long-tailed macaques (Macaca fascicularis) is significant for the study of non-human primate and hominin percussive behaviour. Up until now, only West African chimpanzees (Pan troglodytes verus) and modern human populations were known to use stone hammers to crack open this particular hard-shelled palm nut. The addition of non-habituated, wild macaques increases our comparative dataset of primate lithic percussive behaviour focused on this one plant species. Here, we present an initial description of hammerstones used by macaques to crack oil palm nuts, recovered from active nut-cracking locations on Yao Noi Island, Ao Phang Nga National Park, Thailand. We combine a techno-typological approach with microscopic and macroscopic use-wear analysis of percussive damage to characterize the percussive signature of macaque palm oil nut-cracking tools. These artefacts are characterized by a high degree of battering and crushing on most surfaces, which is visible at both macro and microscopic levels. The degree and extent of this damage is a consequence of a dynamic interplay between a number of factors, including anvil morphology and macaque percussive techniques. Beyond the behavioural importance of these artefacts, macaque nut-cracking represents a new target for primate archaeological investigations, and opens new opportunities for comparisons between tool using primate species and with early hominin percussive behaviour, for which nutcracking has been frequently inferred.Website 
• Luncz LV, Svensson MS, Haslam M, Malaivijitnond S, Proffitt T, Gumert M, 'Technological Response of Wild Macaques (Macaca fascicularis) to Anthropogenic Change'
  International Journal of Primatology 38 (5) (2017) pp.872-880
  ISSN: 0164-0291 eISSN: 1573-8604
  Abstract Anthropogenic disturbances have a detrimental impact on the natural world; the vast expansion of palm oil monocultures is one of the most significant agricultural influences. Primates worldwide consequently have been affected by the loss of their natural ecosystems. Long-tailed macaques (Macaca fascilularis) in Southern Thailand have, however, learned to exploit oil palm nuts using stone tools. Using camera traps, we captured the stone tool behavior of one macaque group in Ao Phang-Nga National Park. Line transects placed throughout an abandoned oil palm plantation confirmed a high abundance of nut cracking sites. Long-tailed macaques previously have been observed using stone tools to harvest shellfish along the coasts of Thailand and Myanmar. The novel nut processing behavior indicates the successful transfer of existing lithic technology to a new food source. Such behavioral plasticity has been suggested to underlie cultural behavior in animals, suggesting that long-tailed macaques have potential to exhibit cultural tendencies. The use of tools to process oil palm nuts across multiple primate species allows direct comparisons between stone tool using nonhuman primates living in anthropogenic environments.Website 
• Falótico T, Luncz LV, Svensson MS, Haslam M, 'Cashew nut positioning during stone tool use by wild bearded capuchin monkeys (Sapajus libidinosus)'
  Folia Primatologica 87 (6) (2017) pp.392-397
  ISSN: 0015-5713 eISSN: 1421-9980
  Abstract Wild capuchin monkeys (Sapajus libidinosus) at Serra da Capivara National Park, Brazil, regularly use stone tools to break open cashew nuts (Anacardium spp.). Here we examine 2 approaches used by the capuchins to position the kidney-shaped cashew nuts on an anvil before striking with a stone tool. Lateral positioning involves placing the nut on its flatter, more stable side, therefore requiring less attention from the monkey during placement. However, the less stable and never previously described arched position, in which the nut is balanced with its curved side uppermost, requires less force to crack the outer shell. We observed cashew nut cracking in a field experimental setting. Only 6 of 20 adults, of both sexes, were observed to deliberately place cashew nuts in an arched position, which may indicate that the technique requires time and experience to learn. We also found that use of the arched position with dry nuts, but not fresh, required, in 63% of the time, an initial processing to remove one of the cashew nut lobes, creating a more stable base for the arch. This relatively rare behaviour appears to have a complex ontogeny, but further studies are required to establish the extent to which social learning is involved.Website 
• Svensson MS, Bersacola E, Mills MSL, Munds RA, Nijman V, Perkin A, Masters JC, Couette S, Nekaris KAI, Bearder SK, 'A giant among dwarfs: a new species of galago (Primates: Galagidae) from Angola'
  American Journal of Physical Anthropology 163 (1) (2017) pp.30-43
  ISSN: 0002-9483 eISSN: 1096-8644
  Abstract Objectives. Based on vocalization recordings of an unknown galago species, our main objectives were to compare morphology and call structure with known closely-related taxa and describe a new species of galago.
  Materials and methods. We conducted field surveys in three forest habitats along the escarpment region in western Angola (Kumbira Forest, Bimbe Area, and Northern Scarp Forest), and examined galago specimens from museums worldwide. We digitized and analyzed calls using Avisoft SASLab Pro software. We also compared museum specimens from Angola with other Galago and Galagoides specimens, and conducted comparative analyses (ANOVA and between group principle component analysis) based on a set of twelve linear measurements of skulls and teeth.
  Results. We describe the new species to which we give the name Angolan dwarf galago, Galagoides kumbirensis sp. nov. The new species has a loud and characteristic crescendo call, used by other Galagoides spp. (sensu stricto) in West Africa to attract companions and repel rivals. However, this call shows species-typical differences from its closest relatives. Galagoides kumbirensis sp. nov. is also distinguished by differences in the skull morphology, pelage color and facial markings, as well as a larger body size, similar to that of Galago moholi, which is not known to be sympatric.
  Conclusion. This discovery points to the importance of Angolan forests as refuges for endemic biodiversity. These forests are under severe threat from overexploitation, and there is an urgent need to establish conservation measures and designate protected areas.Website 
• Svensson M S, Shanee S, Shanee N, Bannister FB, Cervera L, Donati G, Huck M, Jerusalinsky L, Juarez CP, Maldonado AM, Martinez Molinedo J, Méndez-Carvajal PG, Molina Argandoña MA, Mollo Vino A D, Nekaris KAI, Peck M, Rey-Goyeneche J, Spaan D, Nijman V, 'Disappearing in the night: an overview on trade and legislation of night monkeys in South and Central America'
  Folia Primatologica 87 (5) (2017) pp.332-348
  ISSN: 0015-5713 eISSN: 1421-9980
  Abstract The international trade in night monkeys (Aotus spp.), found throughout Central and South America, has been regulated by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) since 1975. We present a quantitative analysis of this trade from all 9 range countries, over 4 decades, and compare domestic legislation to CITES regulations. Night monkeys were exported from 8 of the 9 habitat countries, totalling 5,968 live individuals and 7,098 specimens, with trade of live individuals declining over time. In terms of species, the most commonly traded was Aotus nancymaae (present in Brazil, Colombia, Peru) followed by A. vociferans (Brazil, Colombia, Ecuador, Peru) and A. zonalis (Colombia, Panama). There was no significant correlation between levels of trade and species' geographic range size or the number of countries in which a species occurs. Five countries have legislation that meets CITES requirements for implementation, whereas the other 4 countries' legislation showed deficiencies. Research conducted in Colombia, Peru, and Brazil suggests significant cross-border trade not captured in official international trade registers. Although international trade has diminished, current trends suggest that populations of rarer species may be under unsustainable pressure. Further research is needed to quantify real trade numbers occurring between habitat countries.Website 
• Svensson MS, Ingram DJ, Nekaris KAI, Nijman V, 'Trade and ethnozoological use of African lorisiforms in the last 20 years'
  Hystrix, the Italian Journal of Mammalogy 26 (2) (2015) pp.153-161
  ISSN: 0394-1914 eISSN: 1825-5272
  Abstract Trade in primates is considered a major impediment to primate conservation globally. The bushmeat trade in West and Central Africa is considered largely unsustainable and represents one of the main threats to biodiversity. Furthermore, the use of primates in traditional practices and medicine includes a third of the African primate species. Little is known about the trade in the African mainland lorisiforms; pottos, angwantibos and galagos. Aiming to fill this knowledge gap we created an online survey, conducted a literature review, and analyzed CITES trade records, focusing on the last two decades. We obtained 188 questionnaire responses from researchers and people working in 31 different countries in sub-Saharan Africa. We found a total of 33 publications reporting on trade in African lorisiforms, and CITES records indicate that almost 2000 lorisiforms were traded internationally from African range countries. Fifty-three percent of respondents provided meaningful details about aspects of the trade in African lorisiforms from 50% of the range countries. Galagos were reported by respondents in larger numbers than pottos and angwantibos, and mainly occurred in the pet trade. Pottos were the most frequently mentioned taxon in the literature, when all trade types were combined. Across all of the sources (online survey, literature and CITES database), trade in pottos and angwantibos was reported from 12 countries, and galagos from 23 countries. Trade was reported to occur mainly within rural settings (64%), potentially indicating that demand is not high enough to fuel long distance trading. However, as seen in the Asian lorisiforms, once quantitative studies were conducted, the threat that trade posed became alarmingly apparent and is now considered a major impediment to their conservation. Our insight into the trade of African lorisiforms should be followed up with concerted studies, with an emphasis on quantifying trade to  the species level.Website 
• Bersacola E, Svensson MS, Bearder SK, 'Niche partitioning and environmental factors affecting abundance of strepsirrhines in Angola'
  American Journal of Primatology 77 (11) (2015) pp.1179-1192
  ISSN: 0275-2565 eISSN: 1098-2345
  Abstract The African nocturnal primates (galagos, pottos and angwantibos: suborder Strepsirrhini) are the result of the first major primate radiation event in Africa, and are found in different primate communities spread across the entire sub-Saharan Africa. Thus, they represent an interesting group of taxa to investigate community strategies to avoid interspecific competition. Here we present the result of the first study on nocturnal primate communities in western Angola. We aimed to identify habitat factors influencing strepsirrhine abundance, collect evidence of spatial niche segregation and discuss possible indications of competitive exclusion in this region. We conducted nocturnal surveys at four study sites: Kumbira, Bimbe, Northern Scarp and Calandula. At each encounter we recorded species, group size, height of animals above ground and GPS
  location. We sampled vegetation using the point-centered quarter method and collected data on canopy cover, disturbance and undergrowth density. We observed a total of five strepsirrhine species with varying community structures. We did not encounter Gala goides thomasi but we recorded a new species Galagoides sp. nov. 4. Levels of disturbance, canopy cover and undergrowth density were the habitat factors that most influenced variation in abundance of Galagoides demidovii and Perodicticus edwardsi, the latter also preferring the habitat with higher tree density. Vertical separation between sympatric strepsirrhines was strongest in Northern Scarp, where overall relative abundance was also highest. Competitive exclusion between G. thomasi and G. sp. nova 4 may explain why the former was not present within the Angolan Escarpment sites. We observed coexistence between mainly allopatric Otolemur crassicaudatus and P. edwardsi in Kumbira, and of Galago moholi and G. demidovii in Calandula. Both unusual
  combinations showed some levels of spatial segregation. Habitat characteristics of the Escarpment region are likely to allow for unique nocturnal primate species assemblages. We urge immediate conservation interventions in the Angolan Escarpment.
  Website 
• Nekaris KAI, Arnell AP, Svensson MS, 'Selecting a conservation surrogate species for small fragmented habitats using ecological niche modelling'
  Animals 5 (1) (2015) pp.27-40
  ISSN: 2076-2615 eISSN: 2076-2615
  Abstract Flagship species are traditionally large, charismatic animals used to rally conservation efforts. Accepted flagship definitions suggest they need only fulfil a strategic role, unlike umbrella species that are used to shelter cohabitant taxa. The criteria used to select both flagship and umbrella species may not stand up in the face of dramatic forest loss, where remaining fragments may only contain species that do not suit either set of criteria. The Cinderella species concept covers aesthetically pleasing and overlooked species that fulfil the criteria of flagships or umbrellas. Such species are also more likely to occur in fragmented habitats. We tested Cinderella criteria on mammals in the fragmented forests of the Sri Lankan Wet Zone. We selected taxa that fulfilled both strategic and ecological roles. We created a shortlist of ten species, and from a survey of local perceptions highlighted two finalists. We tested these for umbrella characteristics against the original shortlist, utilizing Maximum Entropy (MaxEnt) modelling, and analysed distribution overlap using ArcGIS. The criteria highlighted Loris tardigradus tardigradus and Prionailurus viverrinus as finalists, with the former having highest flagship potential. We suggest Cinderella species can be effective conservation surrogates especially in habitats where traditional flagship species have been extirpated.Website 
• Svensson MS, Friant SC, 'Threats from trading and hunting of pottos and angwantibos in Africa resemble those faced by slow lorises in Asia'
  Endangered Species Research 23 (2) (2014)
  ISSN: 1863-5407 eISSN: 1613-4796
  Abstract Hunting and trading of wildlife, including primates, has been occurring for thousands of years. However, the rapid escalation of the bushmeat trade and the trade in live animals and body parts in recent years have come to present a serious threat to biodiversity. Asian slow lorises Nycticebus spp. are at a high risk of extinction due to their trade in wildlife markets. The African lorisiformes (pottos Perodicticus spp. and angwantibos Arctocebus spp.) are closely related to Asian slow lorises, and show similar behaviour and ecology. Here, we present an exploratory study comparing the threats faced by African and Asian lorises. Furthermore, we examine the overall trend of the African lorisid trade. We conducted a comprehensive literature review covering all African lorisid range countries, analysed export and import data from the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) database, distributed questionnaires to researchers in the field and carried out an in-depth questionnaire in Nigeria. Pottos were the most commonly hunted primate in the Nigerian focal villages studied herein, and 72% of respondents reported eating their meat at least once a month. The questionnaire responses from researchers reported on all types of trade, varying across different areas. The literature reported hunting of Perodicticinae, but it did not mirror our findings from the 2 questionnaires. Increased research into Asian slow lorises has revealed trade to be a real impediment to their conservation, and our data strongly suggest that the threat is of equal importance to the conservation of their African counterparts.Website 
• Bersacola E, Svensson MS, Bearder SK, Mills M, Nijman V, 'Hunted in Angola: Surveying the Bushmeat Trade'
  SWARA 2014 (Jan/March) (2014) pp.31-36
  
• Svensson MS, Bersacola E, Bearder SK, Nijman V, Mills M, 'Open sale of elephant ivory in Luanda, Angola'
  Oryx: The International Journal of Conservation 48 (1) (2014) pp.13-14
  ISSN: 0030-6053 eISSN: 1365-3008
  Website 
• Svensson MS, Bearder SK, 'Sightings and Habitat Use of the Northern Lesser Galago (Galago senegalensis senegalensis) in Niumi National Park, The Gambia'
  African Primates 8 (2013) pp.51-58
  ISSN: 1093-8966 eISSN: 2325-6109
  Abstract Galago senegalensis have the widest distribution of any nocturnal primate in Africa, extending from Senegal through to East Africa, a distance of over 7000 km. Yet few field studies of this species are published. Here we present the first field study from The Gambia, in the westernmost part of their geographical range. The study was conducted in Niumi National Park from 28 April to 12 May 2012. We aimed to determine whether there are any differences in the habitat use and characteristics of G. senegalensis in The Gambia compared to elsewhere, and to assess possible
  conservation threats. We took systematic measures of heights used by galagos during their activity, their grouping tendencies, sleeping site use and ad libitum observations of behaviour and pelage colour. We collected 703 data points related to habitat use and inter-individual distances. Galagos used all vegetation strata from the ground to 15 m with a modal height of 4-6 m. Animals slept alone on 30% of the observations and in groups on 70%. Twenty-four calls were recorded. Calls were similar to those recorded for other populations of G. senegalensis but pelage coloration differed from other populations. In The Gambia, G. s. senegalensis was more social during their active period compared to G. s. braccatus. Individuals of G. s. senegalensis were observed solitary in 40% of the encounters and in groups of ≥3 individuals in 23%. The galagos in Niumi NP were observed near human settlements, and were not reported to be hunted. However, there is concern that the natural vegetation is being undermined by high levels of anthropogenic disturbance, specifically trampling of the undergrowth by cattle, thus decreasing the preferred habitat for galagos. Niumi NP provides an ideal location for long term studies of G. s. senegalensis. Website 
• Svensson MS, Bersacola E, 'Sightings of thick-tailed greater galago Otolemur crassicaudatus monteiri (Bartlett in Gray, 1863) near Lake Mburo National Park, south Uganda'
  African Primates 8 (2013) pp.63-66
  ISSN: 1093-8966 eISSN: 2325-6109
  Website 
• Svensson MS, Samudio R, Bearder SK, Nekaris KAI, 'Density estimates of Panamanian owl monkeys (Aotus zonalis) in three habitat types'
  American Journal of Primatology 72 (2) (2010) pp.187-192
  ISSN: 0275-2565 eISSN: 1098-2345
  Abstract The resolution of the ambiguity surrounding the taxonomy of Aotus means data on newly classified species are urgently needed for conservation efforts. We conducted a study on the Panamanian owl monkey (Aotus zonalis) between May and July 2008 at three localities in Chagres National Park, located east of the Panama Canal, using the line transect method to quantify abundance and distribution. Vegetation surveys were also conducted to provide a baseline quantification of the three habitat types. We observed 33 individuals within 16 groups in two out of the three sites. Population density was highest in Campo Chagres with 19.7 individuals/km2 and intermediate densities of 14.3 individuals/km2 were observed at Cerro Azul. In la Llana A. zonalis was not found to be present. The presence of A. zonalis in Chagres National Park, albeit at seemingly low abundance, is encouraging. A longer‐term study will be necessary to validate the further abundance estimates gained in this pilot study in order to make conservation policy decisions.Website 

Book chapters

• Svensson MS, Luhrs AM, 'Behaviour of pottos and angwantibos' in Nekaris KAI, Burrows AM (ed.), Evolution, ecology and conservation of lorises and pottos, (2020)
  ISBN: 9781108429023 eISBN: 9781108676526
  Abstract

  Studies on the behaviour of the African lorisiforms are scarce, but there are clear morphological, ecological and behavioural differences between the robust pottos (Perodicticus spp.) and the smaller, gracile angwantibos (Arctocebus spp.). Pottos have a wide distribution across the African rainforest zone, while angwantibos are restricted to the forests of western equatorial Africa. African lorisiforms are not as obviously gregarious as some of their diurnal primate relatives and have thus often been described as solitary animals. This description does not mean these animals do not exhibit any social behaviour – as Charles-Dominique (1977a) wrote, solitary is not the opposite of social, but of gregarious. Indeed, increased research attention and improved methods have slowly revealed an extensive repertoire of nocturnal primate social behaviour. In this chapter, we review existing research on social behaviour, mating and parental care, feeding and food acquisition, as well as positional and defensive behaviour in pottos and angwantibos. We also highlight their major differences and recommend areas for future research.
  

  
  

  Website 
• Hofner AN, Svensson MS, 'Pottos and angwantibos traded for bushmeat' in Nekaris KAI, Burrows AM (ed.), Evolution, ecology and conservation of lorises and pottos, (2020)
  ISBN: 9781108429023 eISBN: 9781108676526
  Website 
• Beja P, Vaz Pinto P, Veríssimo L, Bersacola E, Fabiano E, Palmeirim JM, Monadjem A, Monterroso P, Svensson MS, Taylor PJ, 'The mammals of Angola' in Huntley BJ, Russo V, Lages F, Ferrand N (ed.), Biodiversity of Angola Science & Conservation: A Modern Synthesis, Springer (2019)
  ISBN: 9783030030827 eISBN: 9783030030834
  Abstract

  Scientific investigations on the mammals of Angola started over 150 years ago, but information remains scarce and scattered, with only one recent published account. Here we provide a synthesis of the mammals of Angola based on a thorough survey of primary and grey literature, as well as recent unpublished records. We present a short history of mammal research, and provide brief information on each species known to occur in the country. Particular attention is given to endemic and near endemic species. We also provide a zoogeographic outline and information on the conservation of Angolan mammals. We found confirmed records for 291 native species, most of which from the orders Rodentia (85), Chiroptera (73), Carnivora (39), and Cetartiodactyla (33). There is a large number of endemic and near endemic species, most of which are rodents or bats. The large diversity of species is favoured by the wide range of habitats with contrasting environmental conditions, while endemism tends to be associated with unique physiographic settings such as the Angolan Escarpment. The mammal fauna of Angola includes 2 Critically Endangered, 2 Endangered, 11 Vulnerable, and 14 Near-Threatened species at the global scale. There are also 12 data deficient species, most of which are endemics or near endemics to the country.
  

  Website 

Other publications

• Wenborn M, Collinson R, Nijman V, Svensson MS, 'Highland elephants keeping a low profile in Namibia'
  (2022)
• Svensson MS, Pimley E, 'Milne-Edwards's Potto (Perodicticus edwardsi). The IUCN Red List of Threatened Species 2019'
  (2020) eISSN: 2307-8235
  Website 
• de Jong YA, Butynski TM, Perkin A, Svensson MS, Pimley E, 'East african potto (Perodicticus ibeanus). The IUCN Red List of Threatened Species 2019.'
  (2020) eISSN: 2307-8235
  Website 
• Svensson M, Nekaris KAI, 'Golden angwantibo (Arctocebus aureus). The IUCN Red List of Threatened Species 2019'
  (2020) eISSN: 2307-8235
  Website 
• Oates JF, Svensson M, 'Calabar angwantibo (Arctocebus calabarensis). The IUCN Red List of Threatened Species 2019'
  (2020) eISSN: 2307-8235
  Website 
• Bearder SK, Svensson MS, Butynski TM, 'Southern lesser galago (Galago moholi). The IUCN Red List of Threatened Species 2019'
  (2020) eISSN: 2307-8235
  Website 
• de Jong YA, Butynski TM, Svensson MS, Perkin A, 'Northern lesser galago (Galago senegalensis). The IUCN Red List of Threatened Species 2019'
  (2020) eISSN: 2307-8235
  Website 
• de Jong YA, Butynski TM, Svensson MS, 'Senegal lesser galago (Galago senegalensis ssp. senegalensis). The IUCN Red List of Threatened Species 2019'
  (2020) eISSN: 2307-8235
  Website 
• de Jong YA, Butynski TM, Perkin A, Svensson MS, 'Garnett's greater galago (Otolemur garnettii). The IUCN Red List of Threatened Species 2019'
  (2020) eISSN: 2307-8235
  Website 
• Maisels F, Hart J, Ron T, Svensson MS, Thompson J, 'Southern talapoin monkey (Miopithecus talapoin). The IUCN Red List of Threatened Species 2019'
  (2020) eISSN: 2307-8235
  Website 
• Svensson MS & Bearder SK, 'Thomas's dwarf galago (Galagoides thomasi). The IUCN Red List of Threatened Species 2019'
  (2020) eISSN: 2307-8235
  Website 
• Svensson MS, Bersacola E, Bearder SK, 'Demidoff's dwarf galago (Galagoides demidoff). The IUCN Red List of Threatened Species 2019'
  (2020) eISSN: 2307-8235
  Website 
• Svensson MS, Bersacola E & Bearder SK, 'Demidoff's dwarf galago (Galagoides demidoff ssp. demidoff). The IUCN Red List of Threatened Species 2019'
  (2020) eISSN: 2307-8235
  Website 
• Svensson MS, Pimley E, Oates JF, Wiafe E, 'Bosman's Potto (Perodicticus potto ssp. potto). The IUCN Red List of Threatened Species 2020'
  (2020) eISBN: 2307-8235
  Website 
• Svensson MS, Oates JF, Pimley E, Gonedelé Bi S, 'West African Potto (Perodicticus potto). The IUCN Red List of Threatened Species 2020'
  (2020) eISBN: 2307-8235
  Website 
• Svensson MS, Ambrose L, Bearder SK, 'Makandé Squirrel Galago (Sciurocheirus makandensis). The IUCN Red List of Threatened Species 2020'
  (2020) eISBN: 2307-8235
  Website 
• Oates JF, Ikemeh R, Nobimè G, Svensson MS, 'Benin Potto (Perodicticus potto ssp. juju). The IUCN Red List of Threatened Species 2020'
  (2020) eISBN: 2307-823
  Website 
• Svensson MS, Bersacola E, 'Pluto monkey (Cercopithecus mitis ssp. mitis). The IUCN Red List of Threatened Species 2020'
  (2020) eISBN: 2307-8235
  Website 
• Svensson MS, Bersacola E, Nijman V, Mills M, Munds R, Perkin A, Bearder SK, 'Angola Dwarf Galago (Galagoides kumbirensis). The IUCN Red List of Threatened Species 2020'
  (2020) eISBN: 2307-823
  Website 
• Svensson MS, Nijman V, Nekaris KAI, 'In Situ and Ex Situ Conservation of African Pottos and Angwantibos: Where Are We and Where Do We Need to Go?'
  Folia Primatologica 82 (2012) pp.390-390ISSN: 0015-5713 eISSN: 1421-9980
  Abstract

  Despite a large geographic distribution, the African nocturnal perodicticines, pottos (Perodicticus) and angwantibos (Arctocebus ) remain amongst the least studied primate taxa. Only two one-year field studies have been conducted on pottos, with only circumstantial data onangwantibos, coming from field data on shot animals. Through a meta-analysis, based on published literature and unpublished reports, we here review recent skeletal and genetic evidence that point to five species, and indicate far more diversity: Perodicticus potto, P. Ibeanus, P. edwardsi, Arctocebus aureus, A. calabarensis. Pelage colour, dorsal markings and tail characteristics (for pottos) supplement the genetic data that suggest these comprise distinct taxa. Arctocebus ranges from Nigeria and Cameroon in the north to Gabon and Congo in the south, whilst Perodicticus is more widespread, having a combined distribution that encompasses a large portion of central and western Africa. Despite this large range, only nine surveys with any substantial effort have been published in the last twenty years from only five range countries; two re-ported new taxa (P. p. stockleyi and P. p. juju). Although not included in abundance counts,pottos frequently appear in bushmeat reports throughout their range, suggesting this is a realthreat to this cryptic, easy-to-catch primate. Despite an almost complete dearth of knowledgeabout these taxa, all perodicticine taxa are listed on the IUCN Red List of Threatened Species as Least Concern, with, contradictorily, only the reasonably studied P. p. stockleyi as Data Deficient. The situation of these primates is mirrored in zoos. No Arctocebus are kept in European zoos, with only 17 Perodicticus in ISIS institutions. Their taxonomy is uncertain, breeding rates are poor and infant mortality is high. Clearly the perodictines offer an open frontier for both in situ and ex situ studies. We certainly do not have the data to assess their conservation status yet.

  Website 

Membership of professional bodies

• Primate Society of Great Britain
• International Primatological Society
• European Federation of Primatology
• IUCN/SSC Primate Specialist Group

Consultancy

Online trade in nocturnal primates

Further information

Education

• PhD Primate Conservation, Oxford Brookes University
• MSc Primate Conservation, Oxford Brookes University
• BSc Animal Science, Nottingham Trent University
• FdSc Wildlife Conservation, Nottingham Trent University

 

 

 

Further information

https://www.researchgate.net/profile/Magdalena_Svensson