Native and invasive alien anuran species in urbanized areas in Davao City, Philippines, with preliminary study of feeding biology

Abstract

This article presents the anuran species in urbanized areas, diet overlaps between native and invasive alien anuran species, and its implications on conservation and ecological health in urban environment. Visual encounter technique following the road as a transect was done to determine the diversity of anurans, and stomach content extraction was employed to analyze its diet composition. Results revealed a very low anuran diversity (Shannon-Weiner; 1.165), which is dominated by invasive alien anuran species. Jackknife 1 species richness estimator indicated that 77-100% of the anuran species in the area were already detected which includes three invasive; Rhinella marina (Linnaeus, 1758), Kaloula pulchra Gray, 1831, Hoplobatrachus rugulosus (Wiegmann, 1834), and two natives; Polypedates leucomystax (Gravenhorst, 1829), Limnonectes leytensis (Boettger, 1893). Additionally, assessing the diet of 33 randomly selected anuran samples revealed that Formicidae dominated their food item. Invasive anurans also showed more diverse diet composition compared to native frogs, in which diet overlaps were observed. In conclusion, the study supports the idea that urbanization decreases anuran diversity and supports the dominance of invasive anurans which compete for food with their native and endemic counterparts. Additionally, it is important to manage invasive anurans that dominates urban ecosystem which might affect the native and endemic species in the area and possibly in nearby pristine environment. 

Keywords

• diet composition
• diversity
• frogs
• invasive alien species
• roadkills
• urban environments

References

1. [1] Vershinin, V. L., Vershinina, S. D., Berzin, D. L., Zmeeva, D. V., & Kinev, A. V. (2015). Long-term observation of amphibian populations inhabiting urban and forested areas in Yekaterinburg, Russia. Scientific data, 2, 150018.
2. [2] Mazgajska, J. & Mazgajski, T.D. (2010). Amphibians of Poland's Urban Areas. Preface. Museum and Institute of Zoology, PAS.
3. [3] Hoefer, A. M. & Starrs, D. (2016) One pond fits all? Frogs as an indicator of urban wetland health. Final Report to Upper Murrumbidgee Waterwatch. Ginninderra Catchment Group, Canberra.
4. [4] Forman, R. T., & Alexander, L. E. (1998). Roads and their major ecological effects. Annual review of ecology and systematics, 29(1), 207-231.
5. [5] Andrews, K. M., Gibbons, J. W., Jochimsen, D. M., & Mitchell, J. (2008). Ecological effects of roads on amphibians and reptiles: a literature review. Herpetological Conservation, 3, 121-143.
6. [6] Beebee, T. J. (2013). Effects of road mortality and mitigation measures on amphibian populations. Conservation Biology, 27(4), 657-668. 4
7. [7] Duff, J. P., Colvile, K., Foster, J., & Dumphreys, N. (2011). Mass mortality of great crested newts (Triturus cristatus) on ground treated with road salt. Veterinary Record, 168(10), 282-282.
8. [8] Johansson, M., Primmer, C. R., Sahlsten, J., & Merilä, J. (2005). The influence of landscape structure on occurrence, abundance and genetic diversity of the common frog, Rana temporaria. Global Change Biology, 11(10), 1664-1679.

9. [9] Mazerolle, M. J. (2004). Amphibian road mortality in response to nightly variations in traffic intensity. Herpetologica, 60(1), 45-53.
10. [10] Sillero, N. (2008). Amphibian mortality levels on Spanish country roads: descriptive and spatial analysis. Amphibia- Reptilia, 29(3), 337-347.
11. [11] Eksilmez, H., Altunışık, A., & Özdemir, N. (2017). The Herpetofauna of Karçal Mountains (Artvin/Turkey). Biological Diversity and Conservation 10(1), 1-5.
12. [12] Diesmos, A.C., Watters, J.L., Huron, N.A., Davis, D.R., Alcala, A.C., Crombie, R.I., Afuang, L.E., Gee-Das, G., Sison, R.V., Sanguila, M.B. and Penrod, M.L. (2015). Amphibians of the Philippines, part I: checklist of the species. Proceedings of the California Academy of Sciences, 62(20), pp.457-539.
13. [13] Diesmos, A. C., & Brown, R. M. (2011). Diversity, biogeography, and conservation of Philippine amphibians. In Biology and Conservation of Tropical Asian Amphibians. Proceedings of the Conference ‘‘Biology of the Amphibians in the Sunda Region, South east Asia.’’Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, Malaysia (pp. 26-49).
14. [14] Yap, C.H. (2015). Diet of five common anurans found in disturbed areas in northern peninsular Malaysia (dissertation) Universiti Sains Malaysia.
15. [15] Philippine Statistics Office (2010). Urban Barangays in the Philippines [Internet]. Available from https://psa.gov.ph/content/urban-barangays-philippinesbased2010-cph
16. [16] Marzluff, J. M., Bowman, R., & Donnelly, R. (2001). A historical perspective on urban bird research: trends, terms, and approaches. In Avian ecology and conservation in an urbanizing world (pp. 1-17). Springer, Boston, MA.
17. [17] Philippine Statistics Authority (2015). Total Population by Province, City, Municipality and Barangay: as of August 1,2015 [Internet]. Available from https://www.psa.gov.ph/sites/default/files/attachments/hsd/pressrelease/R12.xlsx
18. [18] Alcala, A.C., Brown, W.C. (1998). Philippine amphibians. An Illustrated Field Guide. Bookmark. Inc, Makati City, Philippines.
19. [19] Colwell, R.K. (2013) EstimateS: Statistical estimation of species richness and shared species from samples. Version 9.1.0. http://purl. oclc. org/estimates.
20. [20] Hammer, Ø., Harper, D.A.T., Ryan, P.D. (2001). PAST: Paleontological statistics software package for education and data analysis. Palaeontologia Electronica, 4(1):9pp. http://palaeo-electronica.org/2001_1/past/issue1_01.htm
21. [21] Santos, E. M., Almeida, A. V., & Vasconcelos, S. D. (2004). Feeding habits of six anuran (Amphibia: Anura) species in a rainforest fragment in Northeastern Brazil. Iheringia. Série Zoologia, 94(4), 433-438.
22. [22] McKinney, M. L. (2002). Urbanization, Biodiversity, and Conservation. The impacts of urbanization on native species are poorly studied, but educating a highly urbanized human population about these impacts can greatly improve species conservation in all ecosystems. Bioscience, 52(10), 883-890.
23. [23] Parris, K.M., 2006. Urban amphibian assemblages as metacommunities. Journal of Animal Ecology, 75(3), 757-764.
24. [24] Zhang, W., Li, B., Shu, X., Pei, E., Yuan, X., Sun, Y., Wang, T. and Wang, Z. (2016). Responses of anuran communities to rapid urban growth in Shanghai, China. Urban Forestry & Urban Greening 20, 365-374.
25. [25] Pillsbury, F. C., & Miller, J. R. (2008). Habitat and landscape characteristics underlying anuran community structure along an urban–rural gradient. Ecological Applications, 18(5), 1107-1118.
26. [26] Kouamé, N. G., Ofori-Boateng, C., Adum, G. B., Gourène, G., & Rödel, M. O. (2015). The anuran fauna of a West African urban area. Amphibian & Reptile Conservation, 9(2), 1-14.
27. [27] Ferreira, R. B., Silva-Soares, T., & Rödder, D. (2010). Amphibians of Vitória, an urban area in south-eastern Brazil: first approximation. Salamandra, 46(4), 187-196.
28. [28] Delima, E.M.M., Ates, F.B., Ibañez, J.C. (2006). Species composition and microhabitats of frogs within Arakan Valley Conservation Area, Cotabato, Mindanao Island, Philippines. BANWA, 3, 16-30.
29. [29] Matos, C., Sillero, N., & Argaña, E. (2012). Spatial analysis of amphibian road mortality levels in northern Portugal country roads. Amphibia-Reptilia, 33(3-4), 469-483.
30. [30] Carr, L. W., & Fahrig, L. (2001). Effect of road traffic on two amphibian species of differing vagility. Conservation Biology, 15(4), 1071-1078.
31. [31] Ates, F.B., Palafox, D.B., Cabelin, V.L.D., Delima, E.M.M. (2007) Diet Composition of Six Anuran Species (Amphibia: Anura) in Terminalia Forest, Mindanao Island, Philippines. BANWA Archives, 4(2), 7-20.
32. [32] Almeria, M. L., & Nuñeza, O. M. (2013). Diet of seven anuran species (Amphibia: Anura) in Agusan Marsh, Mindanao, Philippines. Animal Biology & Animal Husbandry, 5(1), 116-126.
33. [33] Toft, C. A. (1981). Feeding ecology of Panamanian litter anurans: patterns in diet and foraging mode. Journal of herpetology, 139-144.
34. [34] Apayor-Ynot, C.L., Tan, S.N., Kamyll, N. (2007). Diet of Cane Toads (Rhinella marina) collected from areas adjacent to human dwellings in Davao City, Philippines. Imperial Journal of Interdisciplinary Research, 3 (11), 640-642.
35. [35] Anderson, A. M., Haukos, D. A., & Anderson, J. T. (1999). Diet composition of three anurans from the Playa Wetlands of Northwest Texas. Copeia, 515-520.
36. [36] Greenlees, M. J., Brown, G. P., Webb, J. K., Phillips, B. L., & Shine, R. (2006). Effects of an invasive anuran [the cane toad (Bufo marinus)] on the invertebrate fauna of a tropical Australian floodplain. Animal Conservation, 9(4), 431-438.
37. [37] Greenlees, M. J., Brown, G. P., Webb, J. K., Phillips, B. L., & Shine, R. (2007). Do invasive cane toads (Chaunus marinus) compete with Australian frogs (Cyclorana australis)?. Austral Ecology, 32(8), 900-907.
38. [38] Shine, R. (2010). The ecological impact of invasive cane toads (Bufo marinus) in Australia. The Quarterly Review of Biology, 85(3), 253-291.
39. [39] Janvic, M., The Philippine Star. (2019). No proof frogs, toads effective vs mosquitoes. Available at https://www.philstar.com/nation/2019/09/01/1948009/no-proof-frogs-toads-effective-vsmosquitoes# XE1zYvSAMEB9j1S8.99.