SEAVR 2019: 028‐030
ISSN : 2424‐8525
Date of publication: 07 February 2019
Hosted online by ecologyasia.com

The Greenhouse Frog (Eleutherodactylus planirostris)in the diet of the Brown Shrike in the Philippines
Maria Katrina C. CONSTANTINO & Emerson Y. Sy
mcanlas@ateneo.edu (Constantino), emersonsy@gmail.com (Sy)Observer: Maria Katrina C. Constantino.
Photographs by: Maria Katrina C. Constantino.
Subjects identified by: Emerson Y. Sy, Maria Katrina C. Constantino.
Location: Quezon City, National Capital Region, Luzon Island, Philippines.
Elevation: 48 metres.
Habitat: Residential garden within a highly‐populated urban city.
Date and time: 21 January 2017, 07:38 hrs
Identity of subjects:i) Greenhouse Frog, Eleutherodactylus planirostris (Amphibia: Anura: Eleutherodactylidae).
ii) Brown Shrike, Lanius cristatus (Aves: Passeriformes: Laniidae).

Fig. 1.

© Maria Katrina C. Constantino

Description of record: A Brown Shrike was observed surveying actively for potential prey from a perch 1.5 metersfrom the ground in the early morning after sunrise. It swooped down to the ground, which was covered bygarden leaf litter, and caught its prey. It then flew to a potted citrus plant, impaled the prey on a long thorn andflew off again, to perch in the canopy of a nearby tree.

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Around half an hour after photographing the impaled small frog (Fig. 1), the bird came back for its prey andstarted tearing the flesh into smaller pieces with its beak, starting with the limbs, whilst using the thorn to anchor
the frog for leverage. The smaller pieces were swallowed whole. After consuming a small amount, the shrike flew
off again, leaving the remains of the frog still impaled (Fig. 2). When the plant was checked three hours later, theentire frog had been consumed.

Fig. 2.

© Maria Katrina C. Constantino

Remarks: The frog was identified as Eleutherodactylus planirostris based on (i) its small size (ca. 20mm snout‐ventlength), (ii) two light brown‐coloured dorsolateral stripes, (iii) head as broad as body and (iv) toes which are
slender and long without webbing (Olson et al., 2012). It is an introduced species in the Philippines and iscurrently known to occur on the following islands: Cebu, Luzon, Mactan, Mindanao, Negros and Palawan (Ducaoet al., 2017; Sy, 2017a, Sy 2017b).
The Brown Shrike is a small bird found throughout the Philippines. It is a common and abundant migrantoccupying all types of habitats. Although most individuals arrive during August or September and depart by May,
it has been reported throughout the year (Kennedy et al., 2000). It is very aggressive and territorial, often
observed chasing off other birds. It has a loud, sharp rattling call but also a pleasant melodious song. It perches
conspicuously while it hunts for its prey which typically includes insects and small vertebrates. The bird is known
to impale its prey on a sharp branch, thorn or even man‐made structures such as barbed wire. The prey is theneaten immediately or is left impaled on the plant to be eaten throughout the duration of the day.
Invertebrates, frogs, lizards, snakes, birds, and mammals are known to predate on the Greenhouse Frog, both inits natural and in its introduced range. This note provides the first known predator of the introduced Greenhouse
Frog in the Philippines.
References:Ducao, L.A., Ducao, T.J., Peralta, S.A. Peralta, & Sy, E.Y. (2017). Geographic distribution: Eleutherodactylus
planirostris (Greenhouse Frog): Philippines, Mindanao Island, Bukidnon Province. Herpetological Review 48(3):583.
Kennedy, R.S., Gonzales, P.C., Dickinson, E.C., Miranda, H.C. Jr., & Fisher, T.H. (2000). A guide to the birds of thePhilippines. Oxford University Press, Oxford, UK.

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Olson, C.A., Beard, K.H., & Pitt, W.C. (2018). Biology and impacts of Pacific Island invasive species. 8.
Eleutherodactylus planirostris, the Greenhouse Frog (Anura: Eleutherodactylidae). Pacific Science 66(3):255‐270.
Sy, E.Y. (2017a). Geographic distribution: Eleutherodactylus planirostris (Greenhouse Frog): Philippines, Mactan
Island, Cebu Province. Herpetological Review 48(3): 583.
Sy, E.Y. (2017b). Geographic distribution: Eleutherodactylus planirostris (Greenhouse Frog): Philippines, Palawan
Island. Herpetological Review 48(3): 583.

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