News from the Western Ghats again, rather their ‘sky islands’ or mountains tops isolated from each other by surrounding lowlands.
Scientists from the National Centre for Biological Sciences (NCBS), Bangalore, report in Molecular Ecology that bird species that live in fragmented populations within sky islands were connected in the past, but are now disconnected, thanks to increasing forest destruction.
NCBS says “continued fragmentation could lead to small disconnected populations, and possibly extinction.”
The conclusions are based on a study on shortwings, small, insect-eating birds endemic to high-altitude ‘shola’ forests of Western Ghats. The birds were already living in patchy, isolated populations in the sky islands. Now, additional pressures of deforestation and commercial plantations in the Ghats are further fragmenting the shortwings populations.
The NCBS scientists studied the genetic material of 218 shortwing samples. Birds on either side of natural barriers in the Western Ghats were genetically different. Additionally, birds in forests fragmented by human activity also showed genetically different patterns. “Fragmentation is hindering the birds’ movements across human habitats like plantations,” NCBS says.
The genetic sampling results were corroborated by computer simulation studies. The combo of genetic analysis and computer simulations helped the scientists gather extensive information on species biology and vulnerability to habitat fragmentation, which would not have been possible through field-based studies alone, according to NCBS.