Many birds (probably most) possess some homing ability. Many crocodiles (general sense) also possess strong homing ability over 100s of kilometers in several cases. In the case of some crocodiles there is a bit of a paradox. The saltwater crocs have spread from all the way from
India to Australia via sea; yet, they home over long distances. However, ironically both depend on the same ability of efficient navigation at sea and by rivers using favorable water currents to their advantage. When the current is favorable they use it to drive their travel at
rates of up to 20km per day over several days. One croc homed by covering 411 km in 20 days. In birds a major aspect of the homing capacity appears to be magnetic sense. But when the current is not favorable they dive down and wait or come a shore if close to a bank/shore.
In American crocs putting strong magnets on their heads before release in a distant site is anecdotally reported to prevent homing. This suggests that the ancestral archosaur was capable of homing in using a magnetic sense. However, it is not clear if the magnetic sense is all
there is to homing (birds are said to also use stars and smell, though to what extent is unclear). It is also not clear how this magnetic sense is translated into navigation. Birds tend to take the shortest paths which they can going by air so the initial orientation is key.
At least in migratory birds they sweep their head in peculiar way so that their eyes ``see the geomagnetic field'' before taking off.The crocs however do not have that luxury in terms of a straight path but seem to optimize path for available waterways. The Taittirīya-śruti seems
to have cryptic statement which might be one of the first records of an unusual sense that birds use to see ``something'' on the earth.

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with manasataramgini

manasataramgini Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @blog_supplement

3 Dec
I came across some rather interesting work by a certain zoologist Müller from Basel who did meticulous experiments with homing in dogs that to my knowledge have never been repeated. He made several interesting observations: 1. Based on their behavior he classified the dogs into
3 ranks that in principle might have corresponded to their place in the ancestral wolf-pack state. Dominant curs αs; middle ranked βs and low-ranked submissive ωs. He found that only αs and high βs were able to home successfully.This is keeping with earlier observations with army
dogs that only some of them home. It suggests that keeping home range is important for αs. ωs tended to find street dog companions if available or human dwellings. 2. He found that the homers went through an initial phase of orientation at the unknown release site. Once that was
Read 6 tweets
29 Nov
There was discussion on cannabis legalization where 1 side felt it was safer than smoking tobacco& the other it was triggering mental illness& dangerous behavior. Just posting some stuff which is mostly common knowledge but apparently those in that argument did not seem to know
Just parking that bAlabodhana here in case some1 else is interested. 1st for some anatomical background: There is this part of the mammalian brain shown in red in the below pic where much of the action that concerns us happens. It's called the striatum. There is a key signaling
pathway that occurs in the neurons in that structure mediated by a neurotransmitter called dopamine shown below. It is type of compound called catecholamine (if you recall you school chem you will see those groups). It signals between neurons by bind a receptor which is on the
Read 9 tweets
28 Nov
The growing Cases of people of European/West Asian ancestry claiming to be First Americans or of African descent. This seems to illustrate 1 of the contradictions of liberal (mostly North American) identity crisis. The simultaneous insistence & denial of the centrality of race
It laterally impinges on an oft discussed (heatedly) modern identity problem in the Hindu world too -- i.e. that of varNa by birth vs temperament. In our opinion (as mentioned before) it is good to not go the whole hog along either branch of the decision tree but accept a bit of
a superposition. The genetics of tribes, lineages etc keep changing with admixture -- a reality of human existence -- hence, hanging your identity purely on a "mine is bigger" attitude is not the best thing. On the other hand just genetics does not correlate strictly with the
Read 6 tweets
27 Nov
Sometime before the 800s a shAkta text under a tAthAgatan garb known as the Arya-shrI-mahAdevI-vyAkaraNa was transmitted to the Tibetans. In it the cosmic buddha of sukhAvatI vyUha declared that the H goddess mahAdevI would become a future buddha & called upon the saMgha& others
to worship her with a 108 names. One has to ask if it was a missionary ploy on part of the bauddha-s to appropriate mahAdevI or whether they simply could not avoid the growing H influence and had to simply accommodate it saying it was being sanctioned by the cosmic buddha.
A version of the text in Sanskrit is found in the famous Gilgit manuscripts & was already present by the gupta. Along with the bauddha material the Gilgit manuscripts also contains a fragment of the shaiva tumburu-chaturbhaginI tantra; we shall touch upon that later. The mahAdevI
Read 7 tweets
24 Nov
Good recitation of 5.23.3/4 of the atri-s. Note the peculiar nambUtiri transform n->L: revan -> revaL. It features the peculiar phrase vR^iktabarhiSh meaning twisted grass used in the ritual. This phrase has an interesting distribution in the RV:
counts of vR^iktabarhiSh
maNDala 1 ... 5
maNDala 3 ... 3
maNDala 5 ... 3
maNDala 6 ... 1
maNDala 8 ... 11
maNDala 9 ... 1
maNDala 10 ... 2
clearly the kANva-s have a much greater propensity to us this phrase than others. Then
vaishvAmitra-s & atri-s. Even in maNDala 1 of the 5, 1 is by the vaishvAmitra madhuChandas & 4 are by kANva-s include the founder of the clan kaNva himself. Thus totally the kANva-s have 15; vaishvAmitra-s 4 thereafter. Thus, the twisted grass though universal among v1s today
Read 4 tweets
24 Nov
In earlier saiddhAntika tradition the iconography of tumburu feature him in company of the 7 mAtR^ikA-s. This is contrast to his own root tantra-s of the vAmasrotas where he is presented with the 4 sister goddesses: the chaturbhaginI Here is the account from vairochana's manual:
The two surviving Nepalian manuscripts of the manual showing tumburu with the first 3 mAtR^i-s. He is shown with a tiger hide contrary to the text and without a trident. tumburu in this configuration is widely misidentified as "vINAdhara-vIrabhadra".
Here is the Bhanpura tumburu which matches the prescriptions in the manual including the trident and snake.
Read 4 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us on Twitter!

:(