Dr Michela Balestri

Wildlife trade, both legal and illegal, is increasingly recognized as a key factor in the rise of emerging viral infectious diseases, and this is especially apparent in Asia, where large numbers of wildlife are openly offered for sale in bird markets. We here focus on the risk of Psittacosis becoming a zoonotic disease in the wildlife markets of Java and Bali, Indonesia. Psittacosis is particularly prevalent in parrots (hence the name), and the trade in parrots was instrumental in the Great Parrot Fever Pandemic in 1929/1930. Between 2014 and 2023, we conducted 176 surveys of 14 bird markets, during which we recorded 4446 largely wild-caught parrots for sale. On average, each market had nine genera on offer, and the diversity of genera increased with the increasing presence of parrots (up to 16 genera). For most of the bird markets during each survey, parrots from different genera and originating from different parts of the world, were offered for sale alongside each other. Genera offered for sale together did not cluster into natural (geographic) groups. We found no temporal difference in the sale of parrots. We conclude that the omnipresence of wild-caught parrots from various geographic regions in large numbers within the same bird markets increases the risk that psittacosis is present and that this poses a real risk for the zoonotic spread of avian chlamydiosis to humans.

The main objective of environmental education is to promote pro-environmental behaviors; increasing knowledge and understanding are the first steps. Active learning plays a crucial role in increasing engagement levels and achieving positive behavioral development. We aimed to evaluate the effectiveness of a wildlife-friendly farming curriculum, including active learning, presented to 223 students aged 13–15 years from ten middle schools in Garut Regency, Indonesia, from June to September 2019. Using pre- and post-questionnaires, we found that knowledge retention and understanding increased if students completed an exercise that involved an active discussion with parents and if the class was engaged (monitored via WhatsApp groups) in an active learning experiment. Key concepts regarding wildlife-friendly farming, such as mutual benefits for wildlife and humans, the provision of ecosystem services by animals, and the use of organic farming, were more frequent if students discussed the program with parents or if they were engaged during the experiment. We found evidence that student engagement via active learning increased knowledge retention and understanding of wildlife-friendly farming. Similar approaches should be used to promote wildlife-friendly farming approaches from even younger ages and should be tested with other projects aimed at producing pro-environmental behaviors.

Edge effects result from interactions between adjacent habitats, which can modify abiotic and biotic conditions and produce various negative effects on biodiversity. Given the high degree of forest fragmentation in Madagascar, understanding lemur responses to edges is a conservation priority. We aim to determine the depth of edge influence in a continuous low-land rainforest of south-eastern Madagascar and identify the response of six lemur species. We surveyed lemur abundance along nine 1 km transects from May 2015 to July 2016 totaling 112.2 km of survey effort during the day and 88.5 km at night. We characterized the habitat structure via 33 plots centered along the line transects. We used Generalized Additive Models and Generalized Linear Models to test the effect of distance from the forest edge on vegetation parameters and animal encounter rates. Edge effect on the vegetation structure can be detected up to around 100 m in terms of tree diversity and density. We found a negative edge response for Madame Fleurette’s sportive lemurs (Lepilemur fleuretae) and collared brown lemurs (Eulemur collaris), and a positive edge response for Anosy mouse lemurs (Microcebus tanosi), Southern bamboo lemurs (Hapalemur meridionalis) and Southern woolly lemurs (Avahi meridionalis). Since around half of the forested areas in Madagascar are within 100 m of forest edge, taking into account edge effect is vital when producing estimates of population sizes and informing conservation management.

Among mammals, the order Primates is exceptional in having a high taxonomic richness in which the taxa are arboreal, semiterrestrial, or terrestrial. Although habitual terrestriality is pervasive among the apes and African and Asian monkeys (catarrhines), it is largely absent among monkeys of the Americas (platyrrhines), as well as galagos, lemurs, and lorises (strepsirrhines), which are mostly arboreal. Numerous ecological drivers and species-specific factors are suggested to set the conditions for an evolutionary shift from arboreality to terrestriality, and current environmental conditions may provide analogous scenarios to those transitional periods. Therefore, we investigated predominantly arboreal, diurnal primate genera from the Americas and Madagascar that lack fully terrestrial taxa, to determine whether ecological drivers (habitat canopy cover, predation risk, maximum temperature, precipitation, primate species richness, human population density, and distance to roads) or species-specific traits (body mass, group size, and degree of frugivory) associate with increased terrestriality. We collated 150,961 observation hours across 2,227 months from 47 species at 20 sites in Madagascar and 48 sites in the Americas. Multiple factors were associated with ground use in these otherwise arboreal species, including increased temperature, a decrease in canopy cover, a dietary shift away from frugivory, and larger group size. These factors mostly explain intraspecific differences in terrestriality. As humanity modifies habitats and causes climate change, our results suggest that species already inhabiting hot, sparsely canopied sites, and exhibiting more generalized diets, are more likely to shift toward greater ground use.

Volunteer tourists, often foreigners, collect essential data in wildlife conservation projects worldwide. Due to the COVID-19 pandemic, international tourism activities reduced drastically, forcing many conservation projects to shut down. Using a nine-year (2013–2021) case study in Indonesia, we examine how local and foreign tourists construct the meaning of their volunteer experiences in the light of COVID-19. We aim to highlight the potential benefits of local volunteer tourism to face the travel limitations posed by COVID-19, and to show an example of how conservation projects can overcome the challenges of the current and potential future pandemics. We recruited 117 volunteers (49 Indonesians, 68 foreign; 73 females, 44 males; mean age: 24.2 ± SD 4.7) that collected 50.8% of the total amount of data collected by the project over the same period. Of the 117 volunteers, 81 of them (38 Indonesians, 43 foreigners) filled in a feedback form at the end of their stay. Via logistic regressions, we found that Indonesian volunteers declared more positive feedback on the logistics at the research station (p = 0.047). Via Bayesian structural equation models, we found that Indonesian volunteers reported significantly more frequently than foreign volunteers that they learned new skills (89% Credible Interval = 0.017–0.351) and that they gained personal wisdom, growth and maturity (89% Credible Interval = 0.891–1.003) from the volunteer experience. The volunteer program evolved from being 100% foreign volunteers in 2013 to 100% Indonesian volunteers by 2020 at the peak of the pandemic, which helped maintain the continuity of the research and conservation activities. We presented the positive implications of shifting towards local volunteer tourists in a long-term conservation project. We suggest that promoting local volunteer tourism through training new generations of nationals in conservation projects is key to guarantee the persistence of such initiatives in the post-COVID-19 Era.

The activity patterns of mammals depend on environmental changes (e.g., moon luminosity, food availability, weather) and endogenous rhythms. Behavioral observations are traditionally used to estimate the activity patterns of animals, but low visibility and the cryptic nature of some species entail that, in certain conditions, the animal is visible only for around 60% of the time. Recent advances in technology allow automatic data collection on the activity levels of animals. We used five years of data collected via accelerometers to understand how moon luminosity, seasonality, sex, and weather conditions influence the activity levels of the nocturnal and cryptic Javan slow loris. We collected 9589 h on six females and 7354 h on six males. Via Generalized Additive Mixed Models, we found that lorises are lunarphobic; they reduce activity levels during cold nights, they have higher activity levels when the relative humidity is close to 100%, and they have high peaks of activity between December and February and between June and August. The activity levels are thus influenced by avoidance of predators, food availability, consumption of insects and nectar, physiological, and behavioral adaptations to cold temperatures and energy requirements during reproductive stages. We highlight the importance of using bio-loggers for cryptic animals as with behavioral observations only, and the observer might underestimate active behaviors and overestimate inactivity.

Non-formal, yet educative, activities such as science festivals can positively influence the public regarding their attitude towards Science, Technology, Engineering and Math (STEM) subjects and students’ willingness to pursue STEM-related careers. We evaluate the changes made to adapt the Oxford Brookes Science Bazaar, a science festival that has been delivered face-to-face since 2008, to a virtual format in 2021 due to the COVID-19 pandemic. The online festival included 28 pre-recorded and 12 live activities of different types (hands-on, demonstration, games, lectures, podcasts, virtual tours). Hands-on activities and virtual tours had the highest number of unique viewers, while lectures and podcasts were the least watched. The videos were watched also after the advertised date of the festival and reached a broader audience than the physical events. The number of participants, the holding time, and the proportion of people who filled the feedback forms, however, were lower in the online than the physical events. STEM organisations should consider hybrid events, with both virtual and in-person contents, to reach a broader audience and to create more inclusive events. We provide recommendations on how to maximise the benefit of virtual formats, including expanding blended virtual activities to reach a wider variety of age groups.

Pollination services, from both wild and managed populations of insect pollinators, have degraded as a result of agricultural intensification. Whilst 75% of economically important crops depend on insect pollinators for cultivation, 40% of insect pollinator species are threatened with extinction. Pollination services must be preserved if there is to be enough food for a global population whose demand is expected to double, if not triple, by 2050. Pollinator diversity and pollinator efficiency have been found to increase as a result of wildlife-friendly farming practices (i.e., natural chemicals and fertilizers and agroforestry). We evaluated the presence of insect pollinators in 42 coffee home gardens in West Java, Indonesia. Via generalized linear mixed models, we found that number of visitor species (β = 0.418 ± SE 0.194, p = 0.031) and visitation time (β = 0.845 ± SE 0.308, p = 0.006) decreased as farms were more intensely managed, (i.e., used chemical pesticides), compared to fields using organic practices. As knowledge of pollination services is widespread amongst smallholder farmers in Indonesia and beyond due to the long-held tradition of beekeeping, these results will add to their existing knowledge and empower farmers to enhance resources for pollinator species through agroforestry and natural pest management. Although we found significant differences in pollination services provided in intensely managed and wildlife-friendly farms, chemical use can affect farms far beyond a particular area of production. Therefore, pollinator conservation must be applied at a landscape level and involve all stakeholders, including farmers, when making effective policies.

Accelerometers offer unique opportunities to study the behaviour of cryptic animals but require validation to show their accuracy in identifying behaviours. This validation is often undertaken in captivity before use in the wild. While zoos provide important opportunities for trial field techniques, they must consider the welfare and health of the individuals in their care and researchers must opt for the least invasive techniques. We used positive reinforcement training to attach and detach a collar with an accelerometer to an individual Bengal slow loris (Nycticebus bengalensis) at the Shaldon Wildlife Trust, U.K. This allowed us to collect accelerometer data at different periods between January–June 2020 and January–February 2021, totalling 42 h of data with corresponding video for validation. Of these data, we selected 54 min where ten behaviours were present and ran a random forest model. We needed 39 15-min sessions to train the animal to wear/remove the collar. The accelerometer data had an accuracy of 80.7 ± SD 9.9% in predicting the behaviours, with 99.8% accuracy in predicting resting, and a lower accuracy (but still >75% for all of them apart from suspensory walk) for the different types of locomotion and feeding behaviours. This training and validation technique can be used in similar species and shows the importance of working with zoos for in situ conservation (e.g., validation of field techniques).

Complex agroforestry systems can host similar biodiversity levels to adjacent continuous forests and can offer important ecosystem services for wildlife. Species inhabiting adjacent forests, as well as species that prefer agroforestry systems, can benefit from this habitat matrix. It is necessary, however, to understand the species-specific adaptability to such a complex matrix. Indonesia is a biodiversity hotspot and hosts many endemic species that are threatened with extinction. Its human population relies heavily on agriculture, meaning that finding a balance between crop productivity and biodiversity is key for the long-term sustainability of local communities and wildlife. We aim to determine the influence of the presence of shade trees and distance to the forest on the detection rates of wildlife in coffee home gardens. In West Java, Indonesia, we monitored 23 gardens between April 2018 and March 2021 via camera traps, totalling 3856 days of monitoring in shade-grown and 3338 days in sun-exposed gardens. We also collected data in the nearby montane rainforest, totalling 1183 days of monitoring. We used Generalized Additive Models to estimate the influence of shade cover and distance to the forest on the detection rates of wildlife. The Sunda leopard cat Prionailurus javanensis was found more frequently in shade-grown gardens and used both the forest and agroforest matrix. Wild boars Sus scrofa mostly occurred in gardens adjacent to the forest, while barred buttonquails Turnix suscitator were associated with gardens far (>1 km) from the forest. Several species (civets Viverricula indica and Paradoxus musangus javanicus, Horsfield’s treeshrew Tupaia javanica, Javan ferret badger Melogale orientalis, Javan mongoose Herpestes javanicus) were not influenced by shade cover and distance to the forest, suggesting they are well adapted to the agroforestry system. Still, species of high conservation importance, such as Javan leopard Panthera pardus melas, Sunda porcupine Hystrix javanica, and grizzled langur Presbytis comata, were present in the forest but not in the agroforest, suggesting that the replacement of the forest by the agroforestry matrix is still detrimental. Nevertheless, it is important to maintain the complexity of the agroforestry system and connectivity with the neighbouring continuous forest to favour the long-term sustainability of this environment and the conservation of endemic species.

Traditional socio-ecological models consider that folivorous primates experience limited feeding competition due to the low quality, high abundance, and even distribution of leaves. Evidence from several folivorous species that experience similar constraints to frugivores does not support this hypothesis. The sympatric lemur genera Avahi (Indriidae) and Lepilemur (Lepilemuridae) are good models to understand how food availability constrains folivores since they are both nocturnal, folivorous, and have a comparable body mass. Here we investigate how two nocturnal folivorous primates, Avahi meridionalis and Lepilemur fleuretae, living in the lowland rain forest of Tsitongambarika, South-East Madagascar, partition their dietary niche and are influenced by seasonality of young leaves. To account for food availability, we collected annual phenological data on 769 trees from 200 species. We also collected behavioural data on 5 individuals per lemur species from August 2015 to July 2016 via continuous focal sampling. We found the phenological profile to be seasonal with peaks of leaf flushing, flowering, and fruiting occurring in the austral summer. The two species showed limited dietary overlap (37% rich period, 6% lean period), and A. meridionalis showed higher feeding time and longer daily distances travelled during the rich  period. L. fleuretae showed a dietary shift during the lean period, relying more on mature leaves (73.3% during the lean period, 13.5% during the rich period) but maintaining similar activity levels between seasons. The time spent feeding on food items by A. meridionalis was positively correlated with the nitrogen content and negatively correlated with polyphenols in food items during the rich period. We highlighted a clear effect of the seasonality of young leaves on the diet, nutritional content, activity patterns, and daily distances travelled by two folivorous species, which can be linked to nutrient balancing and time-minimising versus energy-maximising strategies.

Agroforestry systems have been recognised as a possible refuge for biodiversity especially when bordering intact landscapes. The intensification of crop management to increase yields is usually associated with a reduction of shade trees and heavy use of chemicals, typically correlated with a decrease in biodiversity. The relationship between intensity of crop management and biodiversity, however, is not clear-cut and is dependent on environmental and geographical differences. We assessed the influence of different shade cover, shade tree richness, richness of other crops, distance from the forest, and use of chemicals on the diversity, richness and abundance of butterflies, a bioindicator in coffee home gardens. We collected data in 42 coffee home gardens in West Java, Indonesia, via Pollard transects, totalling 15.1 km (July-August 2019 and July-August 2020). We found 54 species of butterflies in the gardens. Via Generalised Additive Mixed Models, we found that the use of chemicals negatively influenced the abundance (p = 0.001) and richness (p = 0.039) of butterflies, while shade tree richness positively influenced the abundance (p

Indonesia is at the epicenter of the Asian Songbird Crisis, i.e., the recognition that the cage bird trade has a devastating impact on numerous imperiled bird species in Asia. The Javan pied starling Gracupica jalla, only in the last five years recognized as distinct from the pied starlings of mainland Southeast Asia, has been declared extinct the wild in 2021. Up until the 1980s, it used to be one of the most common open countryside birds on the islands of Java and Bali, Indonesia. From the early 2000s onwards, the species is commercially bred to meet the demand from the domestic cagebird trade. We conducted 280 market surveys in 25 bird markets in Java and Bali between April 2014 and March 2020, with 15 markets being surveyed at least six times. We recorded 24,358 Javan pied starlings, making it one of the most commonly observed birds in the markets. We established that, conservatively, around 40% of the birds in the market were sold within one week and used this to estimate that at a minimum ~80,000 Javan pied starlings are sold in the bird markets on Java and Bali. The latter represents a monetary value of USD5.2 million. We showed that prices were low in the 1980s, when all birds were sourced from the wild. It became more varied and differentiated in the 2000s when a combination of now expensive wild-caught and cheaper captive-bred birds were offered for sale, and prices stabilized in the 2010s when most, if not all birds were commercially captive-bred. Javan pied starlings are not protected under Indonesian law, and there are no linked-up conservation efforts in place to re-establish a wild population on the islands, although small-scale releases do take place.

There is an urgent need for a global transition to sustainable and wildlife-friendly farming systems that provide social and economic equity and protect ecosystem services on which agriculture depends. Java is home to 60% of Indonesia’s population and harbors many endemic species; thus, managing agriculture alongside human well-being and biodiversity is vital. Within a community of ~400 coffee farmers in the province of West Java, we assessed the steps to develop a wildlife-friendly program until reaching certification between February 2019 and October 2020. We adopted an adaptive management approach that included developing common objectives through a process of stakeholder consultation and co-learning. We firstly investigated via interviews the expectations and the issues encountered by 25 farmers who converted to organic production in 2016. Their main expectations were an increase in income and an increase in coffee quality, while they had issues mainly in finding high quality fertilizers, reducing pests, and increasing productivity. We used this information to establish a problem-solving plan for the transition to community-wide wildlife-friendly practices. As part of the adaptive evaluation, we assessed the quality of coffee plantations before and after the implementation of coproduced actions. The quality of coffee significantly improved after our interventions to reduce the coffee berry borer, especially in the fields that started as inorganic and converted to organic. We uncovered additional issues to meet the standards for certification, including banning hunting and trapping activities and increasing coffee quality for international export. We describe the coproduced actions (agroforestry, conservation education, local law, organic alternatives) and phases of the program and discuss the potential barriers. We provide novel evidence of adaptive management framework successfully used to implement management actions and reach shared goals.

1. Elevation gradients correlate with changes in several environmental conditions and are known to be related to animal abundance. Animals in regions with a naturally limited extent of lowland rainforest are expected to have evolved adaptations to intermediate elevations that provided a stable environment during their evolution.
2. Since the lowland rainforest of Madagascar has a limited extent and suffers from increasing anthropogenic pressure, it is essential to understand how well species tolerate intermediate and high elevations. In this study, we aim to quantify the relationship between lemur abundance and elevation in the eastern rainforest of Madagascar.
3. We correlated abundance data on 26 lemur species (10 genera), including 492 records from 26 studies, with elevation. We analysed the consistency of correlations across species with a meta‐analytical approach. We controlled for species’ body mass, elevational range and median elevation. We then ran generalised linear mixed models to determine whether lemur abundance was related to elevation, body mass, plant productivity and anthropogenic disturbance.
4. Overall, the abundance of lemur species in Malagasy rainforests was negatively correlated with elevation, and species occupying broader elevational ranges showed stronger correlations. Body mass was not related to species’ tolerance of high elevations. Even though several lemur species are able to occupy the entire elevation gradient, the few remaining patches of lowland rainforests host lemur species at greater abundances than other sites. Abundance across species was negatively related to body mass, elevation and seasonality in plant productivity and positively related to plant productivity.
5. Despite the ecological flexibility of many lemur species, the remnant patches of lowland rainforests host the highest levels of lemur abundance and are key to lemur conservation. It is crucial to preserve this priority habitat both for biodiversity conservation and for our understanding of lemur adaptations.

Time is considered a resource in limited supply, and temporal niche separation is one of the most common strategies that allow ecologically similar species to live in sympatry. Mechanisms of temporal niche separation are understudied especially in cryptic animals due to logistical problems in gathering adequate data. Using high-frequency accelerometers attached to radio-collars, we investigated whether the ecologically similar lemurs Avahi meridionalis and Lepilemur fleuretae in the lowland rainforest of Tsitongambarika, south-eastern Madagascar, show temporal niche separation. Accelerometers stored data with a frequency of 1 Hz for a total of 71 days on three individuals of A. meridionalis and three individuals of L. fleuretae. We extrapolated motor activity patterns via the unsupervised learning algorithm expectation maximisation and validated the results with systematic behavioural observations. Avahi meridionalis showed peaks of activity at twilights with low but consistent activity during the day, while L. fleuretae exhibited more activity in the central hours of the night. Both lemur species had their activity pattern entrained by photoperiodic variations. The pair-living A. meridionalis was found to be lunarphilic while the solitary-living L. fleuretae was lunarphobic. We suggest that these activity differences were advantageous to minimise feeding competition, as an anti-predator strategy, and/or for dietary-related benefits. These findings demonstrate a fine-tuned temporal partitioning in sympatric, ecologically similar lemur species and support the idea that an activity spread over the 24-h, defined here as cathemerality sensu lato, is more common than previously thought in lemurs.

Significance statement

Ecologically similar species may exhibit temporal niche partitioning and separate their peaks of activity when co-occurring in an area. We show for the first time that the mainly nocturnal genus Avahi can exhibit high crepuscular activity with low but consistent bouts of activity (up to 44.6% of daily activity) during the day. We defined this activity as cathemerality sensu lato as opposed to the cathemerality sensu stricto observed in Eulemur sp. We suggest that this flexible activity may be advantageous for the species to minimise feeding competition and predatory pressure, and/or to provide dietary-related benefits. This finding in the secondary nocturnal genus Avahi supports the idea that activity patterns in lemurs are graded and traditional categorisations are inadequate.