| Literature DB >> 32953073 |
Pema Dendup1,2, Tatyana Humle2, Damber Bista3, Ugyen Penjor4,5, Choki Lham1, Jigme Gyeltshen1.
Abstract
Understanding the influence of anthropogenic disturbances on species' habitat use and distribution is critical to conservation managers in planning effective conservation strategies and mitigating the impact of development. Few studies have focused on the Himalayan red panda (Ailurus fulgens) in Bhutan. This study aimed to assess the habitat requirements and threats to this endangered species in the Khamaed subdistrict of the Jigme Dorji National Park, Bhutan. We employed a transect walk and plot-sampling survey design across two seasons, that is, winter and spring. In total, we surveyed 84 × 50 m radius circular plots along 51 km of existing trails within a 25.4 km2 study area. At 500 m intervals, we established plots at random distances and direction from the trail. We recorded direct sightings (n = 2) and indirect signs (n = 14), such as droppings and footprints as evidence of red panda presence within an altitudinal range of 2,414-3,618 m. We also noted 21 tree and 12 understory species within plots with red panda evidence; the dominant tree species was the Himalayan hemlock (Tsuga dumosa) and the Asian barberry (Berberis asiatica) as an understory species. Red panda presence showed a significant positive association with distance to water sources and fir forests. Plant disturbance and infrastructure, such as power transmission lines, were identified as prominent anthropogenic threats in the study area. Based on our findings, we recommend the development and implementation of local forest management plans, livestock intensification programs, and strict application of environmental impact assessment regulations to promote the conservation of the red panda in the region.Entities:
Keywords: Environment Impact Assessment; anthropogenic activities; habitat disturbances; habitat use; red panda; water source
Year: 2020 PMID: 32953073 PMCID: PMC7487235 DOI: 10.1002/ece3.6632
Source DB: PubMed Journal: Ecol Evol ISSN: 2045-7758 Impact factor: 2.912
Figure 1Red panda (Ailurus fulgens) photographed in Jigme Dorji National Park (Photograph: Sonam Dorji, JDNP)
Figure 2Location of the study site: (a) protected area network of Bhutan, with dark green areas representing protected areas and light green areas biological corridors, (b) Jigme Dorji National Park with its 14 subdistricts. Khamaed highlighted in yellow is one of the 14 subdistricts where the study was carried out (c) Study area with sampling plots within Khamaed subdistrict. Red and green features show the sampling plots with red panda presence and absence signs, respectively
Habitat, vegetation, and disturbance variables recorded in each different plot
| Variables | Unit of measurement | Plot size | Method/Instrument used |
|---|---|---|---|
| Geographical Location | Degree Minute Second | 50 m radius | GPS (Garmin eTrex Vista HCx) |
| Altitude | meter | 50 m radius | Altimeter |
| Aspect | East, West, North, South, southeast, southwest, northeast, northwest | 50 m radius | Suunto Compass |
| Slope | Degree | 50 m radius | Suunto Clinometer |
| Poaching signs | Yes/No | 50 m radius | Visual |
| Landslides | Yes/No | 50 m radius | Visual |
| Livestock | Yes/No | 50 m radius | Visual |
| Timber and NWFP harvesting | Yes/No | 50 m radius | Visual |
| Plant disturbance (lopping/girdling) | Yes/No | 50 m radius | Visual |
| Dead bamboos | Yes/No | 50 m radius | Visual |
| Infrastructures | Yes/No | 50 m radius | Visual |
| Fallen logs and stumps | Numbers | 50 m radius | Visual and Count |
| Distance to the nearest water source | meter | 50 m radius | Measuring Tape |
| Habitat type | Fir, CBL, Mixed conifer | 50 m radius | Visual |
| Tree species | Numbers | 10 × 10 meter | Visual and Count |
| Tree diameter at breast height (DBH) | cm | 10 × 10 meter | Diameter Tape |
| Canopy cover | % | 10 × 10 meter | Densitometer |
| Understory species | Numbers | 4 × 4 m | Visual and Count |
| Bamboo cover | % | 4 × 4 m | Visual estimation |
| Shrub cover | % | 4 × 4 m | Visual estimation |
| Herb cover | % | 1 × 1 m | Visual estimation |
Results of the multicollinearity between the variables using variance inflation factor
| Variables | Variance Inflation Factor |
|---|---|
| Elevation | 1.52 |
| Slope | 1.31 |
| Distance to water | 1.26 |
| Number of fallen logs | 1.39 |
| Number of understories | 1.31 |
| Ground cover | 1.43 |
| Canopy cover | 1.26 |
| Bamboo cover | 1.35 |
| Dead bamboo | 1.47 |
| Landslide | 1.20 |
| Predator | 1.21 |
| Plant disturbances | 1.42 |
| Livestock | 1.45 |
| Infrastructure | 1.46 |
Summary of model‐specific logistic regression (binomial distribution) models showing, degrees of freedom, AICc, ∆AICc, and model weight for habitat covariates influencing red panda habitat use in the study site
| Model |
| AICc | ∆AICc | Model weight |
|---|---|---|---|---|
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| 6 | 69.45 | 0.00 | 0.21 |
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| 6 | 69.45 | 0.00 | 0.21 |
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| 6 | 69.45 | 0.00 | 0.21 |
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| 7 | 69.45 | 0.00 | 0.21 |
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| 5 | 70.00 | 0.55 | 0.16 |
Covariates: Wat, distance to the nearest water source; MCF, mixed conifer forest; Fir, fir forest; CBL, cool broadleaf forest; Und, number of understory species; Can, proportion of canopy cover
Summary of the model‐average coefficients and standard errors (SE) from GLM to predict covariates influencing red panda habitat use
| Estimate | SE | 2.5% | 97.5% | |
|---|---|---|---|---|
| Intercept | −2.600 | 0.638 | −3.871 | −1.328 |
| Cool broadleaf forest | −0.449 | 3.315 | −6.967 | 6.068 |
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| Canopy cover | −1.440 | 0.757 | −2.946 | 0.066 |
| Number of understory species | −2.644 | 1.590 | −5.810 | 0.522 |
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| Mixed conifer forest | −3.961 | 2.927 | −9.733 | 1.810 |
The significant variables, whereby the confidence intervals do not cross zero, are bolded
Summary of logistic regression (binomial distribution) models indicating degrees of freedom, AICc, ∆AICc, and model weight for disturbance covariates influencing red panda habitat use in the study site
| Model |
| AICc | ∆AICc | Model weight | |
|---|---|---|---|---|---|
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| 6 | 81.4 | 0 | 0.337 | |
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| 6 | 82.2 | 0.77 | 0.229 | |
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| 6 | 82.5 | 1.05 | 0.199 | |
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| 7 | 83.8 | 2.33 | 0.105 | |
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| 6 | 85.2 | 3.8 | 0.05 | |
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| 8 | 86.1 | 4.67 | 0.033 | |
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| 6 | 86.5 | 5.11 | 0.026 | |
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| 5 | 87 | 5.6 | 0.021 | |
Covariates: Dea, dead bamboo; Fal, fallen log; Inf, infrastructure; Lan, landslide; Liv, livestock; Pla, plant disturbance; Pre, predator
Summary of the model‐average coefficients and standard errors (SE) from the GLM analysis of the influence of disturbance covariates on red panda habitat use
| Estimate | SE | 2.50% | 97.50% | |
|---|---|---|---|---|
| (Intercept) | −1.134 | 0.446 | −2.078 | −0.305 |
| Landslide | −17.084 | 1,495.325 | NA | 125.513 |
| Predator | −1.048 | 1.201 | −4.150 | 0.965 |
| Fallen log | 0.756 | 0.677 | −0.619 | 2.082 |
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Bolded are the coefficient estimates where the confidence intervals do not cross zero and the variables that are hence significant.