Occurrence and temporal activity pattern of Burmese Red Serow (Capricornis rubidus, Bovidae) in Baraiyadhala National Park, Bangladesh: insights from a camera trapping study

1 Introduction

Burmese Red Serow (Capricornis rubidus) is a confirmed resident in China, India, Myanmar and has a doubtful occurrence in Bangladesh as per IUCN global Red List assessment (Shepherd 2022). However, the national Red List of Bangladesh assessed only one species of serow which is Red Serow alias C. rubidus (IUCN Bangladesh 2015). There are about four to seven species of serows distributed over eastern and southeastern Asia and still there are disputes regarding classification and distribution of these ungulates across their range (Chen et al. 2019; Grubb 2005; Mori et al. 2019).

Despite controversy over the serow species’ classification, a recent molecular phylogenetic analysis of the Capricornis genus indicates that the serow species found in Bangladesh is possibly the Red Serow (C. rubidus) (Mori et al. 2019). However, it is speculated that more than one species of serow could inhabit Bangladesh. The Red Serow is a globally vulnerable bovid (Shepherd 2022) and very little is known about its population status, behavioral ecology, and habitat use pattern in most of the countries that make up its range. Bangladesh is no exception, and so far, it has only handful and sporadic appearances from mixed evergreen forests of the Chittagong Hill Tracts and the mixed evergreen forests of transboundary northeastern regions and is regarded as nationally endangered species (IUCN Bangladesh 2015; Khan 2018).

In recent times, with the advancement of camera trapping studies, there have been few reports of Red Serows from northeast region and Chittagong Hill Tracts. However, our understanding of its overall population, activity pattern, habitat use pattern with other sympatric species, and threats is still very limited. In this study, we did not attempt to address the issues with serow classification; rather, we reported on a population that had not been studied before in order to precise its relative abundance, activity patterns and co-occurrence with other ungulates.

2 Materials and methods

2.1 Study area

Baraiyadhala National Park (BNP) (22°42′53.47″N and 91°38′20.17″E) (Figure 1) is a stretch of 2933.61 ha mixed evergreen forest with scattered bamboo and bushy areas situated under Chittagong North Forest Division. This protected forest is ecologically diverse because of steep and undulating terrain with many waterfalls and hilly streams (Harun-ur-Rashid et al. 2018; Hasan et al. 2021; Karim and Ahsan 2016). Most of the streams are seasonal and dry up during the winter season. The climatic condition is tropical moist, and rainfall is frequent and heavy during the monsoon ranging between 115.2 and 561.1 mm with the total rainfall 1891 mm. The average maximum annual temperature was 31.50 °C and the minimum 20.67 °C. 29 mammalian species belonging to 26 genera, 17 families and 9 orders were recorded from this national park (Karim and Ahsan 2016). However, the presence of Dhole (Cuon alpinus), Bengal Fox (Vulpes bengalensis), Asiatic Brush-tailed Porcupine (Atherurus macrourus) and Indian Hare (Lepus nigricollis) was reported based on the local knowledge. A recently conducted camera trap study found 27 mammalian species from BNP (Kamrul Hasan pers. comm).

Figure 1:

Study area and camera trap sites, indicating camera trap sites with Burmese Red Serow detection and sites where serows were not detected.

3 Results

We obtained 25 serow events captured from 11 spatially distinct locations with an effort of 2793 camera trap nights (Figure 2). Four female and 11 male serows were recognized from the photographs however, it was not certain which sexes the other ten individuals belonged to. All detections consisted of a single serow, apart from two incidents that entailed two individuals. About 65 % of detections (15 events) were in steep hilly habitats and the rest were in forest floor.

Figure 2:

Camera trapped photo of Red Serow from the study area. The top image depicts an adult and a juvenile, and the bottom image is of an adult male.

The RAI of serow was 0.89, while the RAI of Barking Deer and Wild Boar was 9.92 and 5.01 respectively. The Burmese Red Serow appeared to be nocturnal and showed peak temporal activities after the dusk. Barking Deer and Wild Boar did not show any specific temporal preferences (Figure 3).

Figure 3:

Temporal activity pattern and overlap estimates for focal species Burmese Red Serow and sympatric Barking Deer and Wild Boar.

In terms of overlapping temporal activity with two sympatric artiodactyls, Burmese Red Serow showed moderate overlap with both the Barking Deer (∆1 = 0.59; CI: 0.31–0.63) and Wild Boar (∆1 = 0.62; CI: 0.57–0.90) (Figure 3).

A total of 308 individual events of anthropogenic activities (categorized as villagers, tourists, poachers, livestock, and pet animals) were captured. Tourists have the higher RAI (4.8) followed by villagers (3.9) and poachers (1.7).

4 Discussion

Camera trapping studies provide valuable information on poorly studied cryptic, threatened, and sympatric wildlife species (Chen et al. 2019; Li et al. 2022; Singh et al. 2022; Zakir et al. 2020). This study for the first time reveals the country’s strongholds for Burmese Red Serow with vital insights on spatial and temporal activity pattern with sympatric artiodactyls in Baraiyadhala National Park. For taking conservation action and monitoring future changes, it is critical to know spatial as well as ecological information of a threatened species (Singh et al. 2022). Our study confirmed at least 25 individuals of Burmese Red Serow from BNP. The small number of detections (RAI = 0.82) of the Red Serow suggests that this species likely occurs at a low density in the study area. The local community people living nearby, and national park officials also reported similar perceptions on the occurrence of this species. Our camera trapped photos identified 49 individual poachers, which indicates intense hunting pressures for wildlife in this area. We speculated that Barking Deer, Serow, Wild Boar, Jungle Fowls, and pheasants are some of the targeted species.

Red Serow’s preferred nocturnal active period in our study site which was consistent with results obtained from Mt. Gaoligong National Nature Reserve, Yunnan Province, China (Chen et al. 2019). Aligned with other studies (Bhattacharya et al. 2012; Kobayashi and Takatsuki 2012; Liu et al. 2013; Seki and Hayama 2021) our results confirmed that the studied serows co-exist with other ungulates (Wild Boar and Barking Deer) by showing moderate temporal activity overlap in the study site. Such comparative studies of sympatric species are crucial in understanding co-evolutionary behavioural adaptations, activity pattern (Chen et al. 2019; Seki and Hayama 2021), niche separation (Feeroz 2012; Zhou et al. 2014), diet (Zhou et al. 2014) and foraging preference (Schweiger et al. 2015; Sugimoto et al. 2016), predator avoidance (Kittle et al. 2008), competition and other coexistence mechanisms.

Although our study was confined to the BNP, we propose conducting a comparable investigation in adjoining Hazarikhill Wildlife Sanctuary, which has long been recognized as a serow habitat by local people and forest department staffs but has yet to initiate a systematic camera trapping study. Baraiyadhala National Park (2933.61 ha) and adjacent Hazarikhill Wildlife Sanctuary (1177.53 ha), Sitakunda Ecopark and Botanical Garden (808 ha) altogether can be considered as a wider landscape for conserving existing wildlife, specially serow population. Since the ecological state in this area is favorable for serows, strict hunting restrictions, community awareness and restoration programs to improve the denuded forests could be worthwhile as initial efforts.