I live in dandora area two where birds behaviour seems to be alway amazing me as a birder.
On 3rd march 2012,as from 4:30pm i had yellow wagtails flying over me watching from my balcony,it was starting to be dark that early evening because there was heavy clouds the whole of NW and SW(cloud cover 90%),SE and NE was clear and the cloud cover was about 25% stretched low in the far east skies.all this keeness was brought by a question do yellow wagtails at night? because it was just starting to be dark the sunlight was blocked by the heavy clouds in west.
Even with this slight darkness with my binoculars first i could identify the species but not races then counting was easier because they were flying low right over buildings i eximated about 163 birds passing in groups of 10-20 birds all moving to the same direction north.these groups kept on passing until around 5:12pm,
while still watching them pass i note that some how they were pass over the same buildings or some distance away but through the same are,they seemed to move in a straight forward flight no corners and they were calling or contacting each other.
Then i had a question in my mind,could this be a passage in their memory?my reasoning came from previous migration of the same species on the same same passage in the previous migrations, which are two different migrations the spring and autum migration.
First i saw them in late feb 2010 in spring migration and in november 2011 in autum.In these two migration i just watched them pass from the same balcony to north and to south this time is to north,i never thought these area was a passage of the yellow wagtails until some days ago when they passed in this  same area.

Apart from these species also eurasian bee-eaters pass in their group and at these times its different,difference in speed they are abit faster and doesn't have stop over atleast here they ones stoped.also in this migration they also have defined directions north to south and viseversa.
Another migration i've seen here is that of raptors,like Common buzzards,steppe eagle,booted eagles,black kites(migrant,last spotted in nov 2011).This migration is different from that of the wagtails and bee-eaters they come from western headed east high up in the sky.
White storks too pass here not all the time or maybe i do miss them.
Barn swallows come here in their hundreds because of the dandora dumpsite.

I was wondering are these clear or enough evidence to show that dandora could be a migration passage,and other thing,yellow wagtails migrate a number of races together and feed in same grounds here in africa how do they migrate and split on their way back to their respective countries or breeding grounds? I would like to understand that from birders its a mistery to me.