CAR Holds Hordes of Varied, Small Mammals


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CORDILLERA ADMINISTRATIVE REGION — A fifteen years study, started in 2000, ended in 2016 and revealed this June in the scientific journal “Frontiers of Biogeography,” has proven the Cordillera Administrative Region (CAR) highlands is still the frontier of entire Luzon which has been hiding for centuries an assemblage of unique and small animal species.

Unmatched in terms of span and scale, the study was a toilsome task and the Filipino and American scientists who engaged in the study were evidently amazed by their findings.  The never thought it would take fifteen years to finish it.

And they discovered something immensely satisfying: Just as they have discovered CAR the remaining backwoods where varied small mammals can be found; Luzon could be hiding the world’s highest cluster of unique animal species.

The study has placed the Philippines as one of only 17 megadiverse countries on the map for it holds 70 per cent of the world’s plant and animal species.

In CAR, the scientists discovered various species of cloud rats and several species of earthworm mice restricted to a single mountain or mountain range – and that is in Mount Amuyao in Barlig, Mountain Province, Mount Bali-it in Kalinga, and Mount Pulag in Benguet and all in Central Cordillera.

These cloud rats found endemic in Benguet and earthworm mice found in the other CAR provinces are non-volant, or they are incapable of flight or   exist only in a very peculiar and particular place. Taking them out of their natural habitat will mean death for them.

These species could hardly adapt if wrenched from their natural place of existence.

There were two species of cloud rats discovered in the Cordillera in 2014, in the midst of the study and these were scientifically named, “Musseromys inopinatus,” and “Musseromys beneficus.”

These two new cloud rat species add to the list of five cloud rat species in CAR unearthed in 2000, scientifically called “Batomys granti;” “Carpomys melanuros;” “Carpomys phaeurus;” “Crateromys shadenbergi, and;” “Batomys dentatus.”

At the same year of 2000, the mixed Filipino-American scientists stumbled on three earthworm mice species, which they scientifically named “Sorycomys Kalinga;” “Archboldomys maximus, and;” “Sorycomys montanus.”

In the case of the cloud rat, it can be recalled that it was in the 1880’s when the so-called giant cloud rat was discovered in Mount Pulag. After such discovery it was then viewed that there was no more species of cloud rat.

Such view was wrong. By 1900, this perception changed abruptly when a field research conducted by a scientist named Alfred Russel Wallace  conducted in a study  Mount Data that implied a far deeper history of fauna than anticipated, the study noted.

In the long study, the scientists found out Mount Amuyao holds the highest percentage of species present at 67 per cent eight species; Mount Pulag has 63 per cent of five species and Mount Bali-it at 56 per cent of five species.

To investigate further these patterns, the scientists sampled small mammal existence on three mountains in Central Cordillera that provided them evaluation of variation along mountain ranges in general.

And they came out with the finding that, as with smaller mountains, species richness and levels of endemism (by virtue of nativeness) are low at the low elevations but increase greatly up by 1,600 meters up.

Taken in that context, Mount Pulag is 2,922 meters high, Mount Amuyao is 2,702 meters high and Mount Bali-it is 1,950 meters high.

“Up to eight species that are endemic to the Central Cordillera are present at many high-elevation localities and the endemics make up 50 per cent to 70 per cent of the high elevation fauna,” the scientists wrote in the study.

All of the scientists came from the Biodiversity Management Bureau (formerly Protected Areas and Wildlife Bureau) of the Department of Environment and Natural Resources (DENR-CAR), National Museum of the Philippines, University of the Philippines, Silliman University, Conservation International- Philippines, Haribon Foundation, CAR provincial and local government units and the people of each study sites who offered their hard work, hospitality and friendship.

Financial support to the study was shouldered by the United States National Science Foundation, Macarthur Foundation, the Grainger Foundation, the Field’s Museum’s Ellen Thorne Smith and Marshall Field Fund, the Barbara Brown Fund for Mammal Research and the Negaunee Foundation.

The study was conducted in accordance with Philippine laws and regulations regarding intensive field research on wild mammals.

From 2000 to 2012, the scientists conducted standardized and detailed trapping and surveys of small non-flying mammals along elevational transects at 17 intensively samples sites in Luzon. This endeavor involved 37 months of field work by teams of six to eight scientists and undertaken during the relatively dry months.

Survey of long continuous land strips extended from lowest elevation with remaining forest, usually beginning in patchwork of mixed agricultural and regenerating low elevation forest at 400 to 800 meters elevation and proceeding to near the tops of the highest mountain peaks.

Individual sampling areas were spaced at elevational intervals at 200-300 meters, depending on  local circumstances, with at least 600-night traps at each elevation.

Traps of several designs and used for the cloud rats and earthworm mice have been deposited with the Philippine Museum of Natural History and the National Museum of the Philippines.

All of the news species discovered since 2000 are members of two new group species, “based on calibrated molecular phylogenies,” the study pointed out, meaning, realigned, microscopic evaluation of evolution.

In this case, the study pointed out that the cloud rats which are arboreal, herbivorous rodents are called so because evolution has created them to survive only in cloud forests and the earthworm mice are so-called because these only consume earthworms and nothing else.

To further investigate the patterns of specie existence, the study widened its scope on eleven mountains in Luzon and found increase in diversity of native small mammals specifically along elevated gradients.

In the Sierra Madre Mountains, which is also adjacent to Cordillera, the study discovered two species of earthworm mice scientifically named these “Apomys iridensis” and “Apomys karst.”

And the study was able to uncover a lone cloud rat specie in the deep and mossy recesses of Sierra Madre and scientifically distinguished it as “Musseromys annacuao.”

These new data on cloud rats and earthworm mice have important implication in conservation, the study stressed, for it shifts understanding of pattern of process to protect areas of endemism, which should underpin national, regional and local conservation programs.

“Concern about individual species that suffer from any source of threat can result in active management only when those species are known to exist and their distribution and basic ecology is documented,” the study emphasized.

In the course of the fifteen years of study, the scientists discovered 28 new species of mammals in Luzon, breaking wide open a previously unsuspected mammalian diversity in CAR and the rest of Luzon.

It was for the above reason that the study concluded that, “Any study of geographic patterns of biodiversity, whether for conceptual or practical conservation purposes, must be viewed with skepticism unless it is solidly grounded in thorough intensive field surveys that are coupled with equally intensive studies on morphology and genetics that produce reliable information on diversity of mammals.”

Species richness is the most fundamental measure of biodiversity. From this starting point, the scientists emphasized in the study, pattern and process of evolution are based, where conservation priorities are inferred.