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

• 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 
• 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 
• 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 (2015)
  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 (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 48 (1) (2014) pp.13-14
  ISSN: 0030-6053 eISSN: 1365-3008
  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, 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, 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 
• 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
  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 
• 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) 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 

Other publications

• 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

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