Thursday 28 March 2024

Panthera tigris sondaica: A possible sighting of the 'extinct' Javan Tiger.

Indonesia was once home to three species of Tiger, the Sumatran Tiger, Panthera tigris sumatrae, the Javan Tiger, Panthera tigris sondaica, and the Bali Tiger, Panthera tigris balica. Two of these species  have been declared extinct in the past twenty years, the Javan Tiger in 2008, and the Bali Tiger in 2013, using the International Union for the Conservation of Nature's criteria of not having been observed in more than 30 years; the last confirmed sighting of a Javan Tiger happened in 1976 in Meru Betiri National Park, East Java.

The Javan Tiger was endemic to Java, and in the eighteenth and nineteenth centuries was frequently encountered in lowland forests, thickets, and even gardens on the island. However, it was widely seen as a pest (Tigers will feed on both livestock and Humans), leading to widespread hunting of the species, and its presumed extinction in the last quarter of the twentieth century. The last systematic search for the species deployed 35 camera traps in the Meru Betiri National Park in 1999-2000, but made no observations.

A Javan Tiger observed in Ujung Kulon Nature Reserve (now Ujung Kulon National Park) in 1938. Andries Hoogerwerf/Wikimedia Commons.

Although there have been no confirmed sightings since 1976, rumours of the species' continued existence persist, with numerous unconfirmed sightings, reports of footprints too large to belong to a Leopard, and even reports of attacks on livestock. 

In a paper published in the journal Oryx on 21 March 2024, Wirdateti Wirdateti of the Research Center for Biosystematics and Evolution of the Indonesian National Research and Innovation Agency, Yulianto Yulianto of the Research Center for Applied Zoology of the Indonesian National Research and Innovation Agency, Kalih Raksasewu of the Yayasan Bentang Edukasi Lestari Bogor Foundation, and Bambang Adriyanto of the Cikepuh Wildlife Reserve, describe a possible sighting of a living Javan Tiger, and the results of an investigation which followed it.

On 18 August 2019, Ripi Yanur Fajar, a local resident and conservationist, reported seeing a Javan Tiger close to the village of Cipendeuy in South Sukabumi Forest, West Java, to Kalih Raksasewu, who visited the site the next day, along with Bambang Adriyanto. Ripi Yanur Fajar described the Tiger as having jumped a fence between a village road and a plantation, and examination of this fence by Raksasewu and Adriyanto led to the discovery of a single hair, which could potentially have come from a Tiger.

The hair recovered by Kalih Raksasewu and Bambang Adriyanto from a fence in Cipendeuy Village, West Java. Indonesian National Research and Innovation Agency.

A genetic analysis was subsequently carried out in which DNA from the hair was compared to DNA from Sumatran Tigers, Bengal Tigers, Amur Tigers, Javan Leopards, and a museum specimen of the Javan Tiger, from Museum Zoologicum Bogoriense, collected in 1930. The hair was found to show a 4.2% difference to the Leopard sample, differences of between 3.7% and 4.1% from the Sumatran, Bengal, and Amur Tigers, but only a 0.3%d difference from the Javan Tiger museum specimen.

Wirdateti et al. stop short of claiming that they have proof that the Javan Tiger still exists on the basis of a single hair, but do believe that the hair comes from a member of the species, and that this merits further investigation into the possibility of a surviving population of these Tigers in West Java.

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Dwarf planet 136472 Makemake reaches oposition.

The dwarf planet 136472 Makemake will reach opposition (i.e. be directly opposite the Sun seen from Earth) on Saturday 30 March 2022 at 8.28 pm GMT. This means that it will both be at its closest to the Earth this year, about 51.80 AU (51.80 times the average distance between the Earth and the Sun, or about 7 776 097 000 km), and completely illuminated by the Sun. While it is not visible to the naked eye observer, the planets have phases just like those of the Moon; being further from the Sun than the Earth, 136472 Makemake is 'full' when directly opposite the Sun. The planet will be in the constellation of Coma Berenices and at its highest point in the sky at about midnight local time from anywhere on Earth (this is because the rising and setting of objects in the sky is caused by the Earth's rotation, not the movement of the object). (Even at it's very brightest 136472 Makemake will only have a Magnitude of 17.1, making it almost impossible to see with any but the largest of Earth-based telescopes, and where resolvable it will only be possible to see it as a point of light indistinguishable from a faint star.

The orbit and position of 136472 Makemake (2005 FY9) at 10.00 pm on Monday 28 March 2022. JPL Small Body Database Browser.

136472 Makemake orbits the Sun on an eccentric orbit tilted at an angle of 29.0° to the plane of the Solar System, which takes it from 37.8 AU from the Sun (37.8 times the average distance at which the Earth orbits the Sun) to 52.8 AU from the Sun (52.8 times the average distance at which the Earth orbits the Sun. With an average distance of 45.3 AU, 136472 Makemake completes one orbit around the Sun every 305 years. This means that the planet is almost stationary compared to the faster moving Earth, so that it reaches Opposition only two days earlier each year than the year before, and reaches Solar Conjunction (when it is directly on the opposite side of the Sun to the Earth), roughly six months later.

Hubble Space Telescope image of 136472 Makemake. Mike Brown/NASA.

136472 Makemake was discovered on 31 Match 2005 by a team led by Mike Brown of the Palomar Observatory in California. With a diameter of 1430 km it is considered to be the fourth largest dwarf planet in the Solar System (after 134340 Pluto, 136199 Eris, and 136108 Haumea) as well as the twenty second largest body in the Solar System, excluding the Sun (several moons, including our own, are larger). Makemake is also the second-brightest Kuiper belt object, after Pluto.

The surface of 136472 Makemake appears reddish at visual wavelengths, and spectral analysis suggests that it's surface is covered primarily by methane ice, with large amounts of ethane and tholins as well as smaller amounts of ethylene, acetylene and high-mass alkanes. Notably, nitrogen, although present, is observed at much lower levels than on Pluto and Triton, where it is the most abundant ice. 136472 Makemake apparently lacks any form of atmosphere, although it does have a satellite, S/2015 (136472) 1, which is estimated to be 175 km in diameter and orbits at a distance of at least 25 000 km, with an orbital period of at least 12 days.

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Neotropicomus indicus: A 'South American' Mushroom from India.

The genus Neotropicomus was created in 2022 to include two species of Boletacean Mushrooms from South America, the previously described Xerocomus parvogracili (which became Neotropicomus parvogracili) from Guyana, and a new species, Neotropicomus australis, from the Atlantic Forests of Brazil. The name 'Neotropicomus' refers to the Neotropical Realm, the biological zone which incorporates the tropical biomes of South and Central America and the Caribbean islands, to which region the new genus was thought to be restricted.

In a paper published in the journal Cryptogamie Mycologie on 27 March 2024, Salna Nanu and Arun Kumar of the Department of Botany at the University of Calicut, describe a third species of Neotropicomus from Kerala State in India.

The new species is named Neotropicomus indicus, in reference to its unexpected presence in India. It produces small Mushrooms 20-30 mm across, which are convex when young, but flatten out as they age. The upper surfaces of the Mushrooms are reddish brown, fading to greyish towards the centre. The gills and stipe (stem) are white, with the stipe being 20-40 mm long and 3-4 mm wide.

Neotropicomus indicus, holotype, basidiomata. Nanu & Kumar (2024).

Neotropicomus indicus Mushrooms were found growing solitary in Diptocarp forests in Thiruvananthapuram District. It physically resembles other members of the genus Neotropicomus, and was confirmed as being the sister taxon to the other members of the genus by a genetic analysis.

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Wednesday 27 March 2024

Five dead and five missing in West Java following landslide.

Five people, including two children, have been confirmed dead after a landslide hit the village of Cibenda in West Java, Indonesia, slightly before midnight on Sunday 24 March 2024, with another five still unaccounted for. The landslide is reported to have destroyed about 30 houses, and came after weeks of heavy rain in the area, associated with the onset of the Southwest Monsoon. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall.

Rescue workers searching for missing persons following a landslide which hit the village of Cibenda in West Java, Indonesia, on 24 March 2024. Septianjar Muharam/Xinhua,

Landslides are a common problem in Java, particularly during the two Monsoon seasons, with parts of the island receiving 4000 mm of rain per year. This problem has been made worse as expanding populations has led to people farming higher on hillslopes, in an area where soils tend to be volcanic in action and poorly consolidated (i.e. lack much cohesion), making them more prone to landslides when trees are removed.

Monsoons are tropical sea breezes triggered by heating of the land during the warmer part of the year (summer). Both the land and sea are warmed by the Sun, but the land has a lower ability to absorb heat, radiating it back so that the air above landmasses becomes significantly warmer than that over the sea, causing the air above the land to rise and drawing in water from over the sea; since this has also been warmed it carries a high evaporated water content, and brings with it heavy rainfall. In the tropical dry seasons, the situation is reversed, as the air over the land cools more rapidly with the seasons, leading to warmer air over the sea, and thus breezes moving from the shore to the sea (where air is rising more rapidly) and a drying of the climate.

Diagrammatic representation of wind and rainfall patterns in a tropical monsoon climate. Geosciences/University of Arizona.

Java has two distinct Monsoon Seasons, with a Northeast Monsoon driven by winds from the South China Sea that lasts from November to February and a Southwest Monsoon driven by winds from the southern Indian Ocean from March to October. Such a double Monsoon Season is common close to the equator, where the Sun is highest overhead around the equinoxes and lowest on the horizons around the solstices, making the solstices the coolest part of the year and the equinoxes the hottest.

The winds that drive the Northeast and Southwest Monsoons in Southeast Asia. Mynewshub.

This year the rains in Indonesia and Southeast Asia have been particularly heavy, due to a prevailing el Niño weather-system over the Pacific Ocean, which is typically linked to more extreme weather patterns in Southeast Asia.

The El Niño is the warm phase of a long-term climatic oscillation affecting the southern Pacific, which can influence the climate around the world. The onset of El Niño conditions is marked by a sharp rise in temperature and pressure over the southern Indian Ocean, which then moves eastward over the southern Pacific. This pulls rainfall with it, leading to higher rainfall over the Pacific and lower rainfall over South Asia. This reduced rainfall during the already hot and dry summer leads to soaring temperatures in southern Asia, followed by a rise in rainfall that often causes flooding in the Americas and sometimes Africa. Worryingly climatic predictions for the next century suggest that global warming could lead to more frequent and severe El Niño conditions, extreme weather conditions a common occurrence.

Movements of air masses and changes in precipitation in an El Niño weather system. Fiona Martin/NOAA.

The development of an el Niño weather-system this year is considered particularly alarming by climate scientists, as the world has had several consecutive years in which average global sea-surface temperatures have equalled or slightly surpassed the hottest previous average temperatures recorded, despite the climate being in a la Niña phase. As sea surface temperatures are typically significantly warmer during an el Niño phase than a la Niña phase, the development of such a phase could push temperatures into areas not previously encountered on Earth since Modern Humans first appeared, potentially triggering or accelerating other climatic problems, such as glacial melting, droughts in tropical forests, and changes in ocean circulation, which might in turn take us further into unfamiliar climatic territory.

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Tuesday 26 March 2024

At least six fatalities following Magnitude 6.9 Earthquake beneath East Sepik Province, Papua New Guinea.

The United States Geological Survey recorded a Magnitude 6.9 Earthquake at a depth of 40.2 km,approximately 38 km to the northeast of the town of Ambunti in East Sepik Province, Papua New Guinea, slightly after 6.20 am Local time on Sunday 24 March 2024 (slightly after 8.20 pm on Saturday 23 March GMT). Six people have been confirmed dead following the event,with several more injured, and around a thousand homes damaged or destroyed across the province.

A house in East Sepik Province, Papua New Guinea, damaged by an Earthquake on Sunday 24 March 2024. The area was already suffering from severe flooding. Cyril Tara/ABC.

 The north coast of East Sepik Province is located on the southern margin of the North Bismarck Plate, close to its boundary with the Australian Plate, which underlies most of the Papuan mainland. The North Bismarck Plate is being subducted beneath the Australian Plate along the New Guinea Trench on the north coast of the island. This is not a smooth process, with the rocks sticking together, then moving sharply as the pressure builds up enough to break them apart, which can also lead to Earthquakes in the region.

The approximate location of the 24 March 2024 East Sepik Province Earthquake. USGS.

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