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Stray dogs excreting litter on the street or in elevated areas have a purpose after all. They foretell that rain is coming.
Researchers from the Mariano Marcos State University in Batac, Ilocos Norte led by Evangeline S. Galacgac and Criselda M. Balisacan confirmed this to be 100 percent true based on their study done in this province in 2002-2003.
The study was monitored by the Los Baños-based Philippine Council for Agriculture, Forestry and Natural Resources Research and Development of the Department of Science and Technology (PCARRD-DOST).
The researchers explained that dogs have a keen sense of smell and hearing. They can feel frequencies as high as 35,000 vibrations per second. When rain develops, the density of air decreases, as the moist air displaces the dry air. This drop in air density produces sound. Since sound waves travel farther in moist air, dogs can actually hear and even smell the coming of rain much more ahead than humans. Anticipation of the coming rain causes the dogs to become restless, stimulating them to excrete waste.
The study validated and verified that there is truth to the weather lore by our forefathers and old folks who through years of observation have associated natural phenomena such as the unusual behavior of plants and animals, lunar corona or ring around the moon, giant sea waves, and sea roars with adverse weather and climate changes. This weather lore may not always be 100 percent accurate, but they were found consistent with modern forecasting methods used by the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA).
The study proved that animal behaviors were correct in predicting an upcoming rain. Plaintive cuckoo utters "peet-to-peet" five to six times; dragonflies and Himalayan swiftlets fly low.
Birds and flying insects are very sensitive to changes in atmospheric conditions such as change in air pressure. They can also detect infrasound with frequency as low as 0.05 hertz. Infrasound travels at long distances as far as thousands of kilometers via the wind, and travels even farther in moist air. Thus, like dogs, birds can hear the approaching rain very much ahead than humans.
Birds and insects fly low when rain is about to come because as air absorbs more moisture, signaling an impending rain, the birds' feathers become soggy and heavy, causing them to fly with difficulty at higher altitudes.
The birds' chirps indicate their emotional state. When they feel fine their chirps indicate joy and sense of well-being. But when they are nervous, they make a different sound to release their nervous energy. This is true when the plaintive cuckoo utters "peet-to-peet" when it is cloudy and rainy.
Other animal and plant behaviors foretell the onset of the rainy season. The lesser coucal, another kind of cuckoo, makes a mournful "kok-kok" sound; armies of ants move out from their underground habitats to other places; the herons migrate to the mountains; frogs in swamps croak; "siniguelas" fruits shed. These were proven true by the study. (Maria Teresa S. Agarrado, S&T Media Service) |
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