Pangolins are one of the least studied mammal groups (Willcox et al., Reference Willcox, Nash, Trageser, Kim, Hywood and Connelly2019; Heighton & Gaubert, Reference Heighton and Gaubert2021). For example, reliable population estimates are lacking for any of the eight species, and the ranging behaviours of wild individuals remain largely unknown. These knowledge gaps reflect their biology and atyptical morphology, as well as their low population densities, which limit survey encounters (including via camera traps). Their varied habits, from fossorial to arboreal and nocturnal to diurnal, make them difficult to observe; their scales impede the use of off-the-shelf telemetry devices; and their wide size range, from the c. 1.5 kg white-bellied pangolin Phataginus tricuspis to the c. 30 kg giant pangolin Smutsia gigantea, necessitates different tracking devices. Nonetheless, telemetry has yielded valuable insights for some Asian and much bigger African pangolin species. For example, researchers have used telemetry to track the welfare and behaviour of rehabilitated and free-ranging ground pangolins Smutsia temminckii (Carroll et al., Reference Carroll, Harvey-Carroll, Trivella and Connelly2024; Harvey-Carroll et al., Reference Harvey-Carroll, Carroll, Trivella and Connelly2024), monitor the activity and reproduction of the Chinese pangolin Manis pentadactyla (Sun et al., Reference Sun, Pei and Wu2021; Huang et al., Reference Huang, Shen, Zhang, Cheng, Xie and Zheng2025), and estimate the home range and activity patterns of the Sunda pangolin Manis javanica (Gray et al., Reference Gray, Van Le, Nguyen, Cau, Van Nguyen and Van Pham2023).

Among African species, the white-bellied and black-bellied Phataginus tetradactyla pangolins are perhaps the least studied, yet they are also the most heavily hunted and trafficked across West and Central Africa, as indicated by hunter offtake and seizure records (Ingram et al., Reference Ingram, Coad, Abernethy, Maisels, Stokes and Bobo2018; Emogor et al., Reference Emogor, Ingram, Coad, Worthington, Dunn and Imong2021). They are categorized as Endangered (Pietersen et al., Reference Pietersen, Moumbolou, Ingram, Soewu, Jansen and Sodeinde2016) and Vulnerable (Ingram et al., Reference Ingram, Shirley, Pietersen, Godwill Ichu, Sodeinde and Moumbolou2019), respectively, on the IUCN Red List of Threatened Species. Multiple efforts, including ours, have attempted to study Phataginus spp. species using telemetry (Assovi, Reference Assovi2020; Emogor, Reference Emogor2022; Zanvo, Reference Zanvo2024, Reference Zanvo2025). However, most have struggled to generate data suitable for ecological inference, largely because existing tracking devices are incompatible with the species; for example, these species need lightweight tags that can function for several weeks without the need for recapture.

Here, we report the challenges and occasional successes we encountered while using telemetry to study the ranging and feeding ecology of the white-bellied pangolin. Although we report our fieldwork experiences, we do not present formal ecological findings, as collecting robust data proved difficult. Instead, we share insights from 24 months of fieldwork (with direct field and equipment costs of at least USD 10,000) to guide and inform future research on the species. Although our study focused on the white-bellied pangolin, these recommendations are also likely applicable to the black-bellied pangolin, given their similar body size and habitat requirements.

We attempted to track pangolins in the Oban Division of Cross River National Park from February 2020 to March 2022. Oban, a 3,000 km² moist tropical forest, represents typical habitat for Phataginus spp. across their range (note they also occupy forest–savannah mosaics and riparian forests). Our study site was selected in consultation with park rangers, who reported frequent encounters with both free-ranging pangolins and individuals confiscated from hunters. Field searches were conducted for c. 6 hours per night, with greater effort during the darkest hours (hunters noted that pangolins are more active around the new moon and that eyeshine detection is easier under these conditions). We also focused our surveys during the drier months, when pangolins are reportedly more active. Our main search strategy involved sitting quietly for 15–30 min and listening for rustling movements before scanning with headlamps to locate individuals. We averaged c. one pangolin detection every 7 nights during the dry season.

When captured, we fitted pangolins with either a VHF transmitter (we had five units of RI-2B Holohil, 15 g, USD 150/unit), a GPS tag (four e-obs Bird Solar tag, 15 g, USD 1,300/unit), or both, attached via screws and bolts to the tip of a central scale around the tail base, following methods outlined by Sun et al. (Reference Sun, Pei and Lin2019), with a thin metal plate placed between the drilled scale and the pangolin’s body to prevent injury. We only tagged adult pangolins, which were captured by hand when encountered on the forest floor and identified by a body mass > 1 kg and the presence of rough-edged scales. Tag selection was guided by consultations with wildlife telemetry manufacturers and researchers using telemetry to study pangolins (particularly Phataginus), with small telemetry size (15–30 g) and ease of attachment on the species as key criteria. However, we could not find an existing GPS tag attachment design suitable for Phataginus, so we modified the e-obs bird tag by adding a 2 mm metal plate with two holes at each end to enable secure attachment. The modified tags were subsequently tested to ensure the addition of the metal plate did not interfere with signal transmission (Plate 1).

Plate 1

(a) A white-bellied pangolin Phataginus tricuspis fitted with a modified GPS tag, (b) one equipped with a modified VHF tag (b), and another with a GPS tag and using ultraviolet-reflective paint, which lasted c. 3 days (c). Photographs: (a) Alex Moore, (b) Edet Etim and (c) Charles Emogor.

Plate 1 Long description

Panel A: A white-bellied pangolin Phataginus tricuspis is shown climbing a tree trunk. The pangolin has a modified GPS tag attached to its scales. Panel B: A pangolin is being handled by gloved hands. The pangolin is equipped with a modified VHF tag. Panel C: A pangolin is seen in a dark, forested environment illuminated with ultraviolet light. The pangolin has ultraviolet-reflective paint applied to its scales.

VHF transmitters were fitted on the first five adult individuals we found, allowing us to manually record their locations using a handheld GPS (Plate 1). Because only a single receiver was available, we did not use triangulation to locate tagged pangolins; instead, we relied on changes in signal strength (beep intensity) to infer proximity to individuals. However, we obtained only a few coordinates, and in most cases it was impossible to identify the exact location of the individual, resulting in a location error of up to 100 m. This low success was mainly because of the dense forest vegetation, which prevented approaching the pangolin without alerting it. To address these issues, we later switched to solar-powered GPS units that store finer-scale location and activity data for later download (Plate 1). We selected solar-powered tags because they are lightweight and allowed us to assess whether the pangolins’ arboreal behaviour would expose the tags to sufficient sunlight to enhance their operational longevity. Although GPS tags reduced manual tracking challenges, their short battery life limited data collection (a fully charged battery lasted 3–4 days when set to provide one fix every 3 hours). The longest record we obtained spanned 7 days for a tag set to provide one fix every 6 hours (Fig 1). Furthermore, despite their arboreal habits, white-bellied pangolins’ nocturnal activity and shaded resting sites during the day (in burrows, based on our experience) prevented effective solar charging.

Fig. 1

One week (3–9 March 2022) of GPS tracking data showing accelerometer output (top) and movement trajectory (bottom; the red line in the bottom left is a scalebar representing 100 m) of a white-bellied pangolin Phataginus tricuspis in Nigeria’s Cross River National Park. For the top panel, the lines show acceleration data along the three orthogonal axes of the tag: the x-axis (red) representing acceleration along one horizontal axis (e.g. forward-backward or side-to-side), the y-axis (green) representing acceleration along the second horizontal axis, perpendicular to x, and the z-axis (blue) representing acceleration along the vertical axis, often aligned with up-down movement and gravity. Brown vertical lines spanning the accelerometer data panel separate the data into individual days. Based on the movement trajectory, the tagged pangolin appeared to cover 1 km. The straight line likely results from few fixes being taken and saved as a result of delays in the tag transmitting data to the satellite.

To aid data collection and tag retrieval, we deployed camera traps (Browning Patriot, Browning, USA) near locations we previously sighted pangolins, and around ant and termite mounds and decaying wood. Although camera traps helped identify search areas, encounter rates were low (1–2 pangolins per camera per month), making the results of little use for ecological analysis. We also marked one pangolin with non-toxic UV-reflective paint (Starglow clear UV paint with protective topcoat, GLOWTEC, UK), which was visible only under an ultraviolet flashlight and not under regular torchlight, thereby reducing the risk of detection by hunters (Plate 1). This facilitated short-range tracking (50–80 m) with a UV flashlight, but the paint lasted only c. 3 days. While the paint is non-toxic and was applied sparingly to external scales, and no immediate adverse effects were observed during routine monitoring (for 4 hours), we cannot rule out potential behavioural or ecological effects, including increased detectability to other animals. We therefore recommend that any future use of this approach be preceded by prolonged post-application monitoring, ideally conducted on rehabilitated pangolins temporarily held in captivity, where close behavioural observation and welfare assessment are possible.

Our only notable success came when we paired VHF and GPS tags: VHF tracking enabled us to locate individuals and replace or retrieve GPS tags, and the latter provided fine-scale movement and activity data. However, even when pairing the tags, we struggled to gather robust data, as the limited battery life of the GPS units required frequent maintenance, which meant weekly encounters with tagged individuals, increasing stress on the animals and potentially altering their behaviour.

Based on our experience, we recommend caution in seeking to use telemetry on Phataginus spp. It is not impossible to obtain ecologically meaningful data with current technology, but trying to do so demands substantially greater time, effort, funding, and animal handling than is typically feasible. Ultimately, the development of bespoke telemetry devices tailored to Phataginus biology would address many of these challenges, and we urge funders and technologists to prioritize such innovations. In particular, we recommend lightweight tags (≤ 3% of average adult body mass, with consideration given to the gravitational forces exerted during movement; Wilson et al., Reference Wilson, Rose, Gunner, Holton, Marks and Bennett2021), and an extended battery life of at least 1 month, capable of providing at least 6–12 location fixes per day. In terms of size, the tags must be compact enough to sit comfortably on the dorsal scales without protruding excessively, so as not to impede movement, including climbing and burrowing. To prevent scale breakage, particularly during burrowing, tags should include a flexible attachment strip (c. 5 cm long) through which nuts are secured to attach the tag to the pangolin. Guidance on animal welfare and ethics, which should also be considered when designing telemetry for Phataginus spp., is provided by Harvey-Carroll et al. (Reference Harvey-Carroll, Carroll, Trivella and Connelly2025) and Soulsbury et al. (Reference Soulsbury, Gray, Smith, Braithwaite, Cotter and Elwood2020).