Effects of visitor disturbance on tetrapod vertebrates in the Horton Plains National Park, Sri Lanka

Main Article Content

D.M.T. Dhananjani
W.A.D. Mahaulpatha


Effect of visitor disturbances on tetrapod vertebrates was studied from December 2017 to October 2018 in the Horton Plains National Park (HPNP), which is one of the world’s best nature reserves and a popular tourist destination of Sri Lanka. Roads and nature trails with cloud forest, aquatic and grasslands habitats inside the HPNP were selected to compare the effect of visitor disturbances. Three 100 meter fixed length line transects were marked along the roads and the nature trails in each habitat. Vehicle noise was measured using sound meter software. Visitor activities that cause disturbance included road kills, photography, trampling and animal feeding. Amphibian and reptile road kills were higher compared to other tetrapod road kills during vacation periods. Behavioral response of species to visitor disturbances included avoidance, habituation and attraction. When the vehicle noise range was from 63±2.11 dB to 69±2.11 dB, habituation behavior was displayed. When the vehicle noise range increased to the range of 70±4.71 dB to 88±4.71 dB, avoidance behavior was displayed. Animals display a propensity to habituation behavior compared to avoidance behavior when vehicle speed was less than 30 kmh/hr. The results of this study can be used to integrate with the future visitor, park and wildlife management practices of the park.  

Article Details



Amarakoon, A.M.R.K., E.S. Nathanael & A de Silva (2010). The pattern of reptiles killed by road traffic on the Anuradhapura-Mihintale Road, Sri Lanka. Lyriocephalus 7: 81–88.

Andersen, R., J.D. Linnell & R. Langvatn (1996). Short term behavioral and physiological response of moose Alces alces to military disturbance in Norway. Biological Conservation 7(2): 169–176. https://doi.org/10.1016/0006-3207(96)00004-3

Barber, J.R., K.R. Crooks & K.M. Fristrup (2010). The costs of chronic noise exposure for terrestrial organisms. Trends in Ecology & Evolution 25(3): 180–189 https://doi.org/10.1016/j.tree.2009.08.002

Bernardino Jr, F.S. & G.H Dalrymple (1992). Seasonal activity and road mortality of the snakes of the Pa-hay-okee wetlands of Everglades National Park, USA. Biological Conservation 62(2): 71–75. https://doi.org/10.1016/j.tree.2009.08.002

Bechet, A., J.F. Giroux & G. Gauthier (2004). The effects of disturbance on behaviour, habitat use and energy of spring staging snow geese. Journal of Applied Ecology 41(4): 689–700. https://doi.org/10.1111/j.0021-8901.2004.00928.x

Boyle, S.A. & F.B. Samson (1985). Effects of non-consumptive recreation on wildlife: a review. Wildlife Society Bulletin 13(2): 110–116.

Brumm, H. &, H. Slabbekoorn (2005). Acoustic communication in noise. Advances in the Study of Behavior 35: 151–209. https://doi.org/10.1016/S0065-3454(05)35004-2

Coffin, A.W. (2007). From roadkill to road ecology: a review of the ecological effects of roads. Journal of transport Geography 15(5): 396–406. https://doi.org/10.1016/j.jtrangeo.2006.11.006

Collins, S. (2004). Vocal fighting and flirting: the functions of birdsong, pp. 49–79. In: Marler, P., & H. Slabbekoorn (eds.). Nature’s Music: The Science of Birdsong. Elsevier publisher, 513 pp.

De Alwis, S.A.U., P. N. Dayawansa, B.M.P. Singhakumara, D. Weerakoon & M.R. Wijesinghe (2007). Biodiversity Baseline Survey: Horton Plains National Park. Sri Lanka Protected Areas Management and Wildlife Conservation Project (PAM &WCP/ CONSULT/02/BDBS), Department of Wildlife Conservation, Ministry of Environment and Natural Resources, Colombo, 40 pp.

Dharmarathne, W.D.S.C. (2018). Foraging Ecology and Habitat Utilization of Sri Lanka Dull-blue Flycatcher (Eumyias sordidus) in the Horton Plains National Park. MPhil Thesis. University of Sri Jayewardenepura.

Fahrig, L., J.H. Pedlar, S.E. Pope, P.D. Taylor & J.F. Wegner (1995). Effect of road traffic on amphibian density. Biological Conservation 73(3): 177–182. https://doi.org/10.1016/0006-3207(94)00102-V

Forman, R.T. & L.E. Alexander (1998). Roads and their major ecological effects. Annual Review of Ecology and Systematics 29(1): 207–231. https://doi.org/10.1146/annurev.ecolsys.29.1.207

Forman, R.T., D. Sperling, J.A. Bissonette, A.P. Clevenge , C.D. Cutshall, V.H. Dale, L. Fahrig, R.L. France, K. Heanue, C.R. Goldman, K. Heanue, J. Jones, F. Swanson, T. Turrentine & T.C. Winter (2003). Road Ecology: Science and Solutions. Island Press, 504 pp.

Gill, J.A., W.J. Sutherland & A.R. Watkinson (1996). A method to quantify the effects of human disturbance on animal populations. Journal of Applied Ecology 33(4): 786–792. https://doi.org/10.2307/JAE.2404948

Green, R. & M. Giese (2004). Negative effects of wildlife tourism on wildlife. Wildlife tourism: Impacts, management and planning. Wildlife Tourism Research Report Series-No. 5., 205 pp.

Hanna, D., G. Blouin-Demers, D.R. Wilson & D.J. Mennill (2011). Anthropogenic noise affects song structure in red-winged blackbirds (Agelaius phoeniceus). Journal of Experimental Biology 214(21): 3549–3556. https://doi.org/10.1242/jeb.060194

Karunarathna, D.M.S., S. Henkanaththegedara, A.A. Amarasinghe & A. de Silva (2013). Impact of vehicular traffic on herpetofaunal mortality in a Savanna Forest, Eastern Sri Lanka. Taprobanica 5(2): 111–119. https://doi.org/10.4038/tapro.v5i2.6284

Keerthrirathna, W.L.R. (2017). Habitat preference and microhabitat utilization of Cophotics ceylanica (Peter, 1861) in Horton Plains National Park, Sri Lanka, BSc Thesis, University of Sri Jayewardenepura.

Klein, M.L. (1993). Waterbird behavioral responses to human disturbances. Wildlife Society Bulletin 21(1): 31–39.

Knight, R.L. & D.N. Cole (1995). Wildlife responses to recreationists, pp. 51–69. In: Knight, R.L. & D.N. Cole (eds.). Wildlife and Recreationists: Coexistence through Management and Research. Island Press, Washington, DC, 389 pp.

Kline, N.C. & D.E. Swann (1998). Quantifying wildlife road mortality in Saguaro National Park, pp. 23–31. Proceedings of the 5th International Conference on Wildlife Ecology and Transportation (ICOWET 1998) Florida Department of Transportation US Department of Transportation US Forest Service Defenders of Wildlife. February 9–12. Academic Press.

Laurance, W.F., M. Goosem & S.G. Laurance (2009). Impacts of roads and linear clearings on tropical forests. Trends in Ecology & Evolution 24(12): 659–669. https://doi.org/10.1016/j.tree.2009.06.009

Lemelin, R.H. & E.C. Wiersma (2007). Perceptions of polar bear tourists: a qualitative analysis. Human Dimensions of Wildlife 12(1): 45–52. https://doi.org/10.1080/10871200601107890

Maduwage, K.P. & A. Silva (2003). Snakes killed on the roads of the gardens of the University of Peradeniya. Loris 23: 22–24.

Marler, P. (2004). Bird calls: a cornucopia for communication, pp. 132–177. In: Marler, P. & H. Slabbekoorn (eds.). Nature’s Music: The Science of Birdsong. Academic Press, 504 pp.

Mazerolle, M.J., M. Huot & M. Gravel (2005). Behavior of amphibians on the road in response to car traffic. Herpetologica 61(4): 380–388. https://doi.org/10.1655/04-79.1

Miller, S.G., R.L. Knight & C.K. Miller (1998). Influence of recreational trails on breeding bird communities. Ecological Applications 8(1): 162–169. https://doi.org/10.1890/1051-0761(1998)008[0162:IORTOB]2.0.CO;2

Morley, E.L., G. Jones & A.N. Radford (2014). The importance of invertebrates when considering the impacts of anthropogenic noise. Proceedings of the Royal Society B: Biological Sciences 281(1776): 2013–2683. https://doi.org/10.1098/rspb.2013.2683

Myers, N., R.A. Mittermeier, C.G. Mittermeier, G.A. Da Fonseca & J. Kent (2000). Biodiversity hotspots for conservation priorities. Nature 403(6772): 85. https://doi.org/10.1038/35002501

Newsome, D., S.A. Moore & R.K. Dowling (2012). Natural Area Tourism: Ecology, Impacts and Management. Channel View Publications, xxi + 457 pp.

Parris, K.M. & A. Schneider (2009). Impacts of traffic noise and traffic volume on birds of roadside habitats. Ecology and Society 14(1): 1–23. https://doi.org/10.1371/0063349

Poster, C., B.A. Harrington & M. Lavine (1992). The impact of human disturbance on shorebirds at a migration staging area. Biological Conservation 60(2): 115–126. https://doi.org/10.1016/0006-3207(92)91162-L

Rathnayake, R.M.W. (2015). How does ‘crowding’ affect visitor satisfaction at the Horton Plains National Park in Sri Lanka. Tourism Management Perspectives 16: 129–138. https://doi.org/10.1016/j.tmp.2015.07.018

Reijnen, R., R. Foppen, C.T. Braak & J. Thissen (1995). The effects of car traffic on breeding bird populations in woodland. III. Reduction of density in relation to the proximity of main roads. Journal of Applied Ecology 32(1): 187–202. https://doi.org/10.2307/2404428

Senevirathna, H.M.M.C. & P.K.P. Perera (2013). Wildlife viewing preferences of visitors to Sri Lanka’s national parks: Implications for visitor management and sustainable tourism planning. Journal of Tropical Forestry and Environment 3(2): 1–10. https://doi.org/10.31357/jtfe.v3i2.1838.g955

Slabbekoorn, H. & M. Peet (2003). Ecology: birds sing at a higher pitch in urban noise. Nature 424(6946): 267–268. https://doi.org/10.1038/424267a

Stockwell, C.A., G.C. Bateman & J. Berger (1991). Conflicts in national parks: a case study of helicopters and bighorn sheep time budgets at the Grand Canyon. Biological Conservation 56(3): 317–328. https://doi.org/10.1016/0006-3207(91)90064-G

Stone, E. (2000). Separating the noise from the noise: A finding in support of the “Niche Hypothesis,” that birds are influenced by human-induced noise in natural habitats. Anthrozoös 13(4): 225–231. https://doi.org/10.2752/089279300786999680

Tershy, B.R., D. Breese & D.A. Croll (1997). Human perturbations and conservation strategies for San Pedro Mártir Island, Islas del Golfo de California Reserve, México. Environmental Conservation 24(3): 261–270. https://doi.org/10.1017/S0376892997000349

Valentine, P. & A. Birtles (2004). Wildlife watching, pp. 15–34. In: Higginbottom, K. (ed.). Wildlife Tourism: Impacts, Management and Planning. Common Ground, Altona, 277 pp.

Verzijden, M.N., E.A.P. Ripmeester, V.R. Ohms, P. Snelderwaard & H. Slabbekoorn (2010). Immediate spectral flexibility in singing chiffchaffs during experimental exposure to highway noise. Journal of Experimental Biology 213(15): 2575–2581. https://doi.org/10.1242/jeb.038299