SEAVR 2023: 005‐006
ISSN: 2424‐8525
Date of publication: 25 January 2023
Hosted online by ecologyasia.com

Interspecific amplexus of Rhinella marina (Linnaeus, 1758) and Polypedates
leucomystax (Gravenhorst, 1829) on Mindoro Island, Philippines
Michaela S. WEBB & Przemysław ZDUNEK
teamleader@pawikanpatrol.com (Webb), zdunek.komodo@gmail.com (Zdunek)

Observer: Michaela S. Webb.
Photograph by: Michaela S. Webb.
Subjects identified by: Przemysław Zdunek.
Location: Munting Buhangin, Barangay Udalo, Municipality of Abra de Ilog, Occidental Mindoro, Philippines.
(13.4775°N, 120.816944°E; WGS 84)
Elevation: 26 metres ASL.
Habitat: Sparsely populated residential area near the coast; private house with garden.
Date and time: 12 July 2014, 22:52 hrs.
Identity of subjects:i) Cane Toad, Rhinella marina (Amphibia: Anura: Bufonidae).
ii) Common Southeast Asian Tree Frog / Four‐lined Tree Frog, Polypedates leucomystax(Amphibia: Anura: Rhacophoridae).
Description of record:
An interspecific amplexus was observed between a male Polypedates leucomystax and a female Rhinella marina(Fig.1). The individuals were sitting on a floor mat inside the door frame and remained motionless for several
minutes before hopping down three steps and disappearing into the garden.

Figure 1. Polypedates leucomystax (above) and Rhinella marina (below).

5© Michaela S. Webb

Remarks:
The female Cane Toad (which are much bigger than males) was identified based on (i) large, triangular, swollen
parotid glands, (ii) cranial ridges are well‐developed, and (iii) skin with irregularly scattered warts (Somaweera etal., 2018). Rhinella marina is an introduced species in the Philippines (Diesmos et al. 2006).
The Common Southeast Asian Tree Frog (Polypedates leucomystax) (assumed to be male) was identified based on(i) slightly built, (ii) snout pointed, (iii) lacks raised warts/tubercles on back, (iv) fingers and toes with circular discs,(v) toes fully webbed except on toe 4, (vi) lateral face darker than dorsal and (vii) a prominent dark stripe extends
from the snout, through the eye, above he tympanum and past the neck (Somaweera, 2020).
Whilst the Cane Toad is frequently observed within Barangay Udalo and throughout the seasons, the Common
Southeast Asian Tree Frog is less abundant but are more likely to be encountered during the wet season. We haveobserved that the local population of the latter has noticeably increased in past years due to the installation ofbirdbaths at a height of 1 meter above the ground. Both eggs and tadpoles have been observed in these containers.
This type of interspecies event is not uncommon in many countries (Serrano et al., 2022) even in the Philippines(Lorenzo & Ralubit, 2019; Flores et al., 2022). The exact causes and mechanisms of misdirected amplexus are still
unclear, it is possible that the high abundance of heterospecific males and the low abundance of same‐species
males may have an impact (Hettyey and Pearman, 2003). To the best of our knowledge, this is the first observationof interspecific amplexus between a native and an introduced species on Mindoro Island.
References:
Diesmos, A.C., Diesmos, M.L., Brown, R.M. (2006). Status and Distribution of Alien Invasive Frogs in the Philippines.
Journal of Environmental Science and Management 9 (2): 41‐53.
Flores, A.B.A., Pantorill, R.R., and Nuneza, O.M. (2022). Interspecific amplexus between Kalophrynus sinensis (Peters1867) and Pulchrana grandocula (Taylor 1920) in Rogongon, Iligan City, Philippines. Southeast Asia Vertebrate
Records 2020: 028‐029.
Hettyey, A., Pearman, P.B. (2003). Social environment and reproductive interference affect reproductive success inthe frog Rana latastei. Behavioral Ecology 14(2): 294–300.
Lorenzo II, A. N., & Ralubit, N. D. C. (2019). Interspecific amplexus between Ingerophrynus philippinicus andMegophrys ligayae on Palawan Island, Philippines. Southeast Asia Vertebrate Records 2019: 074‐075.
Serrano, F.C., Díaz‐Ricaurte, J.C., and Martins, M. (2022). Finding love in a hopeless place: A global database of
misdirected amplexus in anurans. Ecology: e3737.
Somaweera, R. (2020). A naturalist's guide to the Reptiles & Amphibians of Bali. John Beaufoy publishing 2ndedition. 64 pp.
Somaweera, R., Azis, A., Resa, E., Panggur, M., Saverinus, D., and Muga, K. (2018). Amphibians and Reptiles ofKomodo National Park. Aaranya Wildlife Odysseys. 17 pp.

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