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Butterfly Migration 2018: An update
Rains & Monsoon - October/ November 2018
The month of October had mixed fortune with respect to rains for the
state of Tamil Nadu, with the first week of the month saw widespread rain
over the state. However, the next couple of weeks saw the cyclones on
either side of the land mass moving elsewhere depriving the rain that is
due to TN. Also, the 3 rd week onset of Northeast monsoon got delayed and
conditions favoured only on the last week of October for the commence-
ment of the Monsoon, which finally set on Nov 1 st over TN, but the rains
started arriving from 31 st October. The NE monsoon was however active
only on coastal districts. The intensity of Butterfly Migration was however
noticed only from end of 3 rd week of October from the Eastern Ghats and
Plains to the Western Ghats in their regular and shortest straight-line
routes that they have been using since time unknown and making use of
the favourable wind directions.
To recap of what has happened in September 2018, we have reported that
between September 1st and 15th, migration was reported from Chennai,
Madurai and Salem (Yercaud Hills) and nothing over the Western districts
until September end; they are however under action from October 2018.
Carrying from September movement of Danainae species, the month of October until end of the third week was eventless,
except a stray case of Crows and Emigrants moving from plains to the hills in south of Tamil Nadu. However, the action started
from 19th October, where observation was made when travelling between Dindigul and Madurai highways, where the Tiruma-
la species alone were moving from the direction of Sirumalai hills (which is the Eastern Ghats hills) to the Palani/ Kodai Hills
area direction. This was followed by information from Erode on the next day, i.e. on 20th October that the Tigers and Crows
are on the move from the Eastern Ghats (most likely from the Yercaud– Kolli malai– Pachamalai complex) to the direction of
Coimbatore– Mettupalayam. These were expected to reach the foothills near Coimbatore in a day or two after it is noticed in
Erode.
For the next 3 days (21-23, Oct), the Tigers and Crows were reaching over a wide area, from Ponnuthu to Walayar and lack of
data from Mettupalayam area, was an issue in confirming if they reached the foothills up to Mettupalayam from Ponnuthu.
From the directional prediction, we expect these to reach Anaikatti Hills and The Nilgiris and also Anamalai Tiger Reserve
(ATR). Except for a day (29th Oct), the movement in places and in varying degree have happened until Oct 31st. The
Oddanchathiram– Dharapuram road also witnessed continuous movement of Tigers and Crows towards the Western Ghats
directions. All of these movements have continued until Nov 20th, even after commencement of widespread rain over Tamil
Nadu landmass, signalling the arrival of North-East monsoon from Nov 1st. After the failure of migration in 2016, the last two
years have successfully witnessed the migration movement.
It is not just the Tigers, Crows and Emigrants
which make these migration/ dispersal
movement, there are also other species we
find going with these. In this year, the nota-
ble among them are Brown Awl (which were
actually making a downhill movement in The
Nilgiris), Small Salmon Arab, Pea Blue and
Red Helens. In a few places, Common Band-
ed Peacock, Common Leopard, Common
Mormon and Chocolate Pansy too were ob-
served among the moving specimens.
In the next 3 pages, these information have
been presented in easy to understand graph-
ic forms. In the first infographics, date wise
movement of the species were marked. The
second infographics highlights point of obser-
vation, along with direction and approximate
numbers per species at the point of observa-
tion.
PATTAMPOOCHI
A TNBS MAGAZINE
WINGS 3 VEINS 1
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