6 months ago
2
About a week back, successful mid-November, researchers astatine Bengaluru-based ATREE were alerted to information transmitted from a tiny 9.5 gm transmitter connected to the backmost of a bird. The Pallid Harrier, geo-tagged by them, has reached its roosting crushed successful Tirunelveli, each the mode from Kazakhstan.
Harriers, winged migrants from Central Asia, person started visiting India, flying astir 5,000 km successful hunt of grasslands.
The Harrier Watch Project, a semipermanent task founded by researchers T. Ganesh and Prashanth M.B., has been monitoring the six harrier taxon that get successful India successful winter, with the purpose of monitoring the raptors and their grassland habitats and assessing the interaction of nonaccomplishment of grasslands connected the species.
Roosting connected the crushed
“Did you cognize Madiwala water was a roosting tract for Western Marsh Harriers?” asks Arjun Kannan, a PhD pupil who works with the project, citing a survey published successful 2010 by Ashok Verma.
Among the wintertime visitors to India are Western Marsh Harriers, Montagu’s Harrier, Pallid Harrier, Hen Harrier, Pied Harrier, and Eastern Marsh Harriers. Unlike galore different birds, they roost connected the crushed among gangly grasses and truthful marque grasslands their habitats.
“We person mapped their roosting sites spanning Western India to South India. We’ve besides tagged a fewer to recognize their migration,” said Mr. Kannan.
Starting successful 2016, the ATREE squad has truthful acold tagged astir 20 harriers- 8 Pallid Harriers and 12 Montagu’s Harriers- from roosting sites successful Tal Chhapar successful Rajasthan, Nannaj successful Maharashtra, and Tirunelveli successful Tamil Nadu.
Around the Himalayas
The birds, which breed successful Central Asia, travel to the Indian sub-continent successful winter. Owing to physiological reasons, they don’t transverse implicit the Himalayas, but alert astir it. This detour migration which takes astir 25 days means an further formation way of 1,500 km approximately, compared to crossing implicit the Himalayas. By March, they commencement flying to Central Asia again, crossing Pakistan, Afghanistan, Uzbekistan, and Tajikistan to scope Kazakhstan.
“Interestingly, the birds, en way to India, halt implicit for a fewer days astatine the Thar godforsaken bordering India and Pakistan. They don’t bash the aforesaid portion flying backmost to Kazakhstan. We deliberation it is due to the fact that erstwhile they alert to India, it is conscionable aft the monsoon, and therefore, there’ll beryllium a batch of lush greenish grass available. It could besides beryllium that the birds are fatigued much arsenic they are flying post-breeding,” said Mr. Kannan.
Declining numbers
The task information shows that the fig of harriers has been consistently declining successful the roosting sites, portion immoderate of the roosting sites person simply ceased to exist, acknowledgment to the alteration successful onshore usage patterns.
“Madiwala utilized to beryllium a roosting site. Hesaraghatta is different important one. In examination to the 80 to 90 harriers that erstwhile utilized to beryllium spotted there, we saw lone 8 determination the different day. In the spot wherever the roosts were, a batch of trees person been planted successful the past fewer years. Given that determination is lone a tiny spot remaining for grazing, determination is besides the occupation of over-grazing. Most of the writer is precise abbreviated now,” said Mr. Kannan.
According to him, Harriers are important mobile links for effect dispersal betwixt grassland patches. The IUCN has categorised Pallid Harriers arsenic adjacent threatened, and according to the State of India’s Birds reports, Montagu’s Harriers and Pallid Harriers person declined by astir 50% compared to pre-2000s assessments.
Grass onshore conservation
During the project, the researchers besides observed that the nonaccomplishment of grassland screen was affecting the location scope sizes of the harriers, forcing them to determination astir much successful hunt of prey and suitable habitat.
“They walk a batch of vigor flying astir the upland ranges. Sight fidelity is different important diagnostic of harriers. It has been observed that they travel backmost to the nonstop aforesaid spot each year. So, erstwhile the way oregon the roosting sites get threatened, it becomes a interest arsenic to however the taxon is going to fare successful the agelong term,” said Mr. Kannan.
“Harriers are raptors, birds of prey. If they tin beryllium considered arsenic flagships to conserve grasslands, past we volition besides beryllium conserving a batch of different grassland taxon similar the Lesser florican that are critically endangered and are not arsenic charismatic,” helium adds.
