Any assistance, corrections and pointers to other references that can be emailed to me would be most appreciated.

Document last updated and completed 15th May 1998

View eastwards from Antipolo towards Tanay, which lies across the bay at centre-left.

The Sierra Madras and the volcano Mt Banahaw (2,177 m) lie in the distance.

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A list, as best as can be identified, is provided of the Lepidopterous and Coleopterous fauna recorded by the author in the Tanay district, Rizal Province, Luzon Island, The Philippines. It has been compiled during a number of short visits to the area and is likely to be far from complete. However, as it appears that no other work has specifically dealt with this district, this work provides an initial database to expand upon.

Tanay is situated in a rural district 53 km directly east of Manila, Luzon, at 14o 30' 0" N, 121o 17' 0" E, and at an altitude of ~5m A.S.L. The township is presently undergoing rapid expansion as a centre of commerce. Tanay lies on the northern shores of Laguna de Bay, the largest enclosed body of water in The Philippines.

The Tanay area is situated largely at sea level, while the surrounding foothills, being extensions of the main eastern range extending along the length of northern and central Luzon, the Sierra Madras, touch Tanay at its northern and north eastern boundaries. To the east of Tanay a further extension of the Sierra Madra, dominated by Mt Sembrano (743 m A.S.L.), forms a major peninsula projecting southwards into Laguna de Bay.

Tanay lies near the eastern edge of a region which experiences a monsoonal climate, with a wet season from June to October, and a dry season from November to May. The hottest part of the year is during the months of April - June, prior to and at the beginning of the annual "wet" which last until about October. Approximately 10 km to the east of Tanay an imaginary north-south line passing through the town of Mabitac marks the boundary with an equitorial climactic region experiencing rainfall throughout the year.

The district was originally vegetated with monsoonal tropical rainforest, but nearly all of this has been cleared in modern times, particularly since World War II when The Philippines still had 70% of its forest cover intact. Only very small areas of this original habitat remain, some of it being partial regeneration. Such areas are generally confined to the steeper hillsides or in gullies and gorges, such as at Daranak Falls Reserve. The rainforest cover was originally 100% dominated by Dipterocarps.

Until very recently rice fields covered the flat lowlands, but these are being abandoned as urban development progresses along the road link to Manila. Laguna De Bay is very shallow near its shores, and is populated with numerous fish pens. On the nearby lower hillsides, mango, coconut and citrus fruit plantations occur. Large areas of open grassland cover the higher parts of the surrounding hills and mountains. Many of the low hills in the vicinity of Tanay have dense stands of bamboo and weedy Mimosaceae growth, some of which is regeneration or remnant regrowth. To the east of Tanay a forestry regeneration project has revegetated an area entirely with a species of bamboo.

This initial survey should assist in indicating which endemic species appear to be surviving despite the severe habitat modification that has taken place in this district.

The authored surveyed Lepidoptera generally in May, July and August at sites (A), (B) and (C), while site (D) could only be surveyed in May. These four sites were:

(A) Tanay township - various gardens, vacant lots, and remnant or regenerating vegetation growing along property boundaries, in rice padi's, along the Tanay River and environs, and in the cemetery.

(B) Daranak Falls Reserve (administered by Tanay City Council), located in a gorge situated approximately 8 km N.E.E. of Tanay. Remnants of the original rainforest survive in this gorge.

(C) Dalawang Kawayan Hill (Two Tree Hill), approximately 5 km N. of Tanay at an altitude of approximately 800 metres.

(D) Halangnagubat area, approximately 7 km N.N.E. of Tanay. The data site is a property located at ~200 m A.S.L. near the summit of a broad hill.

* = occurs at this site.

NS = not surveyed or sufficiently surveyed for these specific items.

 Fauna List

As expected, the area with the most resemblence to the original forest cover, at Daranak Falls, also had the highest species count, with 60 butterfly species recorded, of which nearly half were not able to be found elsewhere. 

The potential for additional species to be added to be above lists is consered to be highest at Daranak Falls, where the extent of habitat remaining and the available niches that have not been properly surveyed, or surveyed at all, allow for the greatest scope for additions to be made.

Despite the almost total elimination of the original forest cover around the Tanay area, and considering the small areas of forest that remains, being mostly tiny remnant patches along rivers, and the fact that many records were made in areas of scrubby regrowth of a reduced range of plant species, the diversity was surprisingly good, representing about 10% of the recorded Philippine butterfly fauna (Total Philippine spp. 734 per Baltazar, 1990)

At this point, it is considered that it is far too early to make any further conclusions, particularly as regards the distribution pattern of some species, as it is felt that a great deal more survey work needs to be undertaken. Further field research is required to both confirm the above records and to add substantially to them. Additional research sites would also be helpful, and surveys at different times of the year will undoubtedly reveal many more species.

However, some tentative conslusions can be drawn from the existing data. Not unexpectedly, by far the most diverse area for Lepidoptera was Daranak Falls, where there are remnants of the original forest cover surviving around Daranak and the nearby Batlig Falls, and along the sides of the deep gorge these falls are located in. This site is considered most likely where future researchers will find additional species not listed here. Clearly, all effort should be made to preserve such remnant areas from further destruction. This survey is therefore indicitive of the need to conserve whatever remains of the remaining original habitat, even if degraded, as it shows that even degraded areas of remnant forest such as that at Daranak Falls can still support a wide range of butterfly and other insect species.

The next most diverse area was that of Two Tree Hill, and this was aided by some of the species being found only at the summit of a small hill in the area.

The outskirts of Tanay township were much less diverse, but even here a few ubiquitous species appear to be surviving quite well, some of which were not seen elsewhere.

At Daranak Falls this species was observed to fly only in the cool of the early morning, whilst there was still dew on the grass. It flew slowly and low to the ground, and whilst it did not refrain from flying in the open sunshine this would not be for long. The butterfly generally stayed close to and amongst shrubs and other vegetation cover. Common and widespread. Not shown to be endangered.

Baltazar, C.R., An inventory of Philippine Insects, II. Order Lepidoptera (Rhopalocera), University of the Philippines Los Banos, 399pp.

D'Abrera, B. Butterflies of the Oriental Region.

Sakai, K.1996. Flower Beetles. Endless Science Information Vol. 1, 52pp., illus.

Sampaloc 

Curculionidae sp (large, black)

Triodes rhadamantus

Appias nero domitia

Moduza sp. (thespias or mata mata or urdeneta)

Euploea mulciber dufresne

Papilio rumansovia

Cethosia sp.

Euthalia? merta? (may also be a new range record or new subspecies)

Euryphagus lundi