WILD LIFE WATERING HOLE - WEST BALI NATIONAL PARK (Part 1) - English Translation

 WILDLIFE WALLOWS

Hery Kusumanegara, Ketut Widiantara, Putu Mertameyasa, Kukuh Damai and Maman

Translator : Amien Rais (Former IPB Student)

The dry season is synonymous with hot air. The cool air of the rainy season has disappeared. The color of leaves begins to turn yellow, dominating the forest vegetation. Fallen leaves on the ground are brown, then dry covering the soil. For tree vegetation in the conservation forest of West Bali National Park (TNBB) this is a normal seasonal cycle.

The blast of cool air turning into hot air makes the leaf canopy cover in the forest more open. Sunlight is able to penetrate directly to the ground. The soil becomes dry and even cracked on soils with clay texture. On sandy soils, it makes sand grains fly around.

Trees remain standing upright. Leaves are still visible, even on the ground surface. Hotter air currents can be felt. Day and night still alternate in the Forest Area.

It seems something is missing?

What is missing?  

The answer is active water wallows (freshwater).  

Is that true? 

The dry season causes water in the West Bali National Park (TNBB) Forest area to begin to decrease and even disappear at certain points. Water wallows dry up. The bottom soil of the wallows appears cracked due to drying. There is no longer any surface water flow filling the wallows. There is no more rainwater that can be collected by the wallows. It means there is no more addition of water volume in the wallows before the rainy season arrives. No wildlife tracks, which are usually seen around the wallows when water is present wallows are visible.

Figure 1.         A small wallow at an elevation above 100 meters in Grid M6 that is no longer filled with water. Photo: June 11, 2028 – TNBB Document.

Where are the wallows located?

In the West Bali National Park (TNBB) nature conservation area there are many wallows. Have all wallows in the TNBB area dried up in the dry season? The totally dry wallows are small wallows. Their size is less than 10 square meters and they are located at altitude, namely above 50 meters. Wallows of this size hold water from surface water flows that are not main flows. The depth when fully filled with water is usually only around 20 cm.

Figure 2. Photos at the large wallows show water still retained in the main basin as well as small surrounding basins. The grass also remains green. Photo: August 11, 2026 – BTNBB Document.

Smart Patrol August 10 – 14, 2026 still found freshwater wallows in the lowlands around Cekik with a size of more than 100 square meters. In the rainy season, this wallow can be 500 square meters in size with a maximum depth of 100 cm. Currently, the condition of the wallow basin is not fully filled with freshwater. Or it shows that the water volume has decreased. The wallow soils around the water are still moist and wet. Animal tracks such as wild boar (Sus scrofa), deer (Rusa timorensis), barking deer (Muntiacus muntjak) and even jungle fowl (Gallus sp), are clearly imprinted. Large trees with their dense leaf canopies provide shade. The wallow is protected from direct exposure to sunlight. This reduces evaporation. The cover of banyan trees (Ficus sp), buta-buta (Excoecaria agallocha) and gebang (Corypha utan) dominates this area. Grass (Gramineae) is still green around the wallow.

 The wallow in Tegalbunder (Figure 1) is a wallow with an elevation of several cm above sea level at the highest tide that is still active in the dry season (August 2026). The savanna field is still green. The basin area of Gilimanuk Bay (Grid J7) bordering the mangrove, the grass is also green and growing lush (Figure 2). In this area on the mangrove mud section, tracks of monkeys (Macaca fascicularis), wild boar to deer were found. Even in the mud basins in the mangrove area also become wallows for boars and salt-licking places for deer.

Figure 3. A water wallow in the Tegalbunder savanna. Photo taken on August 13, 2026 – TNBB Document.

Who are the users of the wallows?

The users of wallows in the TNBB area are wildlife. Ranging from insects to large mammals. Insects that are often encountered are butterflies (order Lepidoptera), dragonflies (order Odonata), and bees (Apis sp). Monitor lizards (Varanus sp), lizards (Suborder Lacertilia or Sauria) and snakes (Suborder Serpentes) represent reptiles that are often found around wallows. All aves, both birds and jungle fowl, gather in the area around wallows. Aves often use trees in the wallow area as a place to "perch" and even as a place to live/nest.

The main users of wallows in the TNBB area are large mammals such as Wild Boar, Deer, Barking Deer, Giant Squirrel (Ratufa bicolor), Treeshrew (Order Scandentia), Long-tailed Macaque (MEP), and Langur (Trachypithecus auratus). They leave traces in the form of footprints when utilizing the wallows.

Special note. The users of wallows in the TNBB area are not only wildlife. Domesticated animals such as cattle (Bos domesticus) are found grazing in the savanna where there are wallows. Why does this happen? It will be discussed on another occasion.

Why wallows?

Wildlife utilize wallows in the TNBB area for: 1). Drinking. In addition to being fulfilled from the water contained in the food material eaten, wildlife requires direct water intake into its body. To avoid dehydration, considering that the body of biological creatures mostly consists of water.; 2) Cooling the body temperature of wildlife. Birds also submerge (soak) in the wallow water. Mammals such as pigs like to submerge themselves in wallows. Submerging temporarily in water functions to lower the body temperature of wildlife.; 3) Wallow mud can function as skin care especially for animals with no fur to sparse fur, such as pigs. The purpose is to prevent cracked skin.; 4) Repelling insects or parasites. I have never seen deer wallowing in wallows except to drink. To reach the water in the wallow, deer's legs often have to enter the wallow. Even to the point of leaving footprints. The soles of the feet will be covered with wallow mud. This is suspected to prevent parasites and hoof disease. Similar function as skin care; 5) Camouflage. The body of wild boar covered with dried mud helps to disguise it from predators such as Python Snakes.; 6) Relaxation. Soaking in a wallow is the same as Rusa timorensis crossing from Menjangan Island to Brumbun and vice versa, which is to make muscles relax.; 6) Salt licking. To meet the need for salt minerals (alkali) in the body, Rusa timorensis are seen visiting brackish water wallows around the mangrove.

Wallows are mini wetlands

The wallows inside the West Bali National Park (TNBB) area are wetlands. These wallow wetlands are highly influenced by the season. In the rainy season, the wallows are full of water. In the dry season, the water in the wallows decreases and even dries up. Freshwater material is a characteristic feature of purely terrestrial wallows. 

        The wallows in the mangrove area are highly influenced by the tides. The wallows in the mangrove can be seen during low tide. Water basins are often imprinted on the edge of the mangrove near the mainland. This means the wallows are only filled during the highest tide. These wallows are very productive (used) during the dry season, when the wallows on land dry up. The material is brackish to saline water.

Figure 4. Shows the role of the wallows in maintaining the ground surface with a dominance of grass that remains green. The presence of this grass is evidence that the soil in this savanna remains moist due to the presence of freshwater. Freshwater gathers in the wallows, and some of it remains tightly bound to the soil which is utilized by the grass to stay alive.

Figure 4. Mini wetland in Grid J7 Tegalbunder – West Bali National Park. Photo August 13, 2026 – TNBB Document.