ADDITIONAL INFORMATION ON THE LAST ARTICLE
On 30th /March/2012 at 7:34 am (Cloud Cover 70%, cool). 
While still on bed I heard Eurasian bee eaten calling out. Immediately as any bird would react to rare calls of the birds that are special, I woke up and just over the flats there were Eurasian bee eaters busy hunting bees from a Groton tree that is flowering near the started flying around the tress and often they started flying on a head and higher this time the is group of 16 birds was not in more of non stop and direct flight as one's I had seen, they seemed to be just moving around catching insects around the area then after 20 minutes they disappeared behind  buildings and I could just hear calls in a distance as they moved  further.

Next day 31st /March/2012 4:30 pm (cloud cover 50%, cool) 
I went for a walk a walking distance from home to the railway areas which is like on the lower side of my area, the area is cultivated both sides of the railway and big companies are along the railway on the left side when headed to town and there is a river along on the left side, its patchy grassland and some wet areas along the river.
This day I sat down under a shade of a wall and in front there is a hill garbage burning, some second after I sat down, my attention was caught by the calls of yellow wagtails, the ones I could see they were atleast 12 all walking on the ground some on the hill and more were walking around the garbage, this was a lesson on what this species feed on even do they exploit much or what the alternative areas they would visit, with a lot of dumping in Nairobi and the surrounding would be good places they could also find food such as flies in dumping areas.
I had more time to watch them and just observed as some came just some steps from me chasing insects the calls were many even in the small planted areas surrounding the dumped place, these added more chances of watching and listening longer.
I had seen them few days earlier but I had not seen them on the ground, this reminded me of the days I saw them flying over the flats and buildings kin my area in the evenings so I became more eager I gave to watch them until when the dark will start to come in. As the time moved on, around 6:15 I was more conscious of any unusual behavior to me mostly on their movements, this when is saw one bird flying away making "preew" calls and was followed immediately by 6 more birds and they caught up with it and flew together at this time the calls were more intense but birds were camouflaged in the grass so I could just see few birds around than many calls I heard coming from all over in the grasses.
After every 5-8 minutes another group flew out of the grasses and this groups ranged from 5-15 birds and that I didn't understand is that before the whole numbers of groups that flew there was a bird that kind of gave a "go" sign by calling more faster than the normal call they were calling and then almost immediately a group follows behind altogether. This was an answer of the small groups of yellow wagtails that pass over my area in the evenings.
This point where I was watching this birds it was at the lower side of my area you can see my house on the other side of the river. The building just starts right at the edge of the wetland vegetation. So watching this groups fly it was easy to see the direction of they head. By 7:00 pm 6 groups had flown off and all the birds were gone and there was no calls around.
That night, I thought of this wagtails and the dumping sites and I came up with an idea of checking out on things in a totally different area which was the Dandora dumping site which is on the northern side of the Dandora. The dumping site is a big because if the main dumping site of Nairobi by (NCC) Nairobi City Council. 

On 1st /March/2012 11:20 am 
I just walk to the dumping site and the first thing I had was site covers a really big area hundreds of acres, so I just walk inside some metres inside, the marabou strokes, sacred ibises, house sparrow, cattle egrets, speckled pigeons were in the area as usual but also big numbers of yellow wagtails were all over the garbage on the roads inside hunting flies and flying around short distances this was like major feeding area, this was just a small area I walked comparing with the size of the whole dumping area and yellow wagtails were everywhere then I wondered how many wagtail could be around hundreds. I walked for about 1:40 minute and could notice different races of the yellow wagtails.

2nd /April/2012 7:30 am (70% cloud cover, cold).
This morning was a good one, I woke up early as 6:05 and decided to walk to the balcony and watch the skies early in the morning and also I expected to see a beautiful sunrise but the clouds were heavy on the east so I couldn't even see the sun shooting up it was dark, and the  clouds were not only heavy on the east put from my observation point it was almost all cover heavily with clouds around the skies expect an opening that was not clear with light but there was enough light to look around the whole area, hardly we get midst around here and so its always easy to see around when there is some light. This time I had my binoculars with me and I could see herons coming back home to a tall eucalyptus near my home. To feed their young one's with fish and some lizards. Then over behind the tree first one falcon appeared moving north east and it was an Amur falcon, then this was so interesting because I had  not seen one before here. Some how I have this tendency of watching birds in move until they disappear and so it happened with this falcon until it disappeared in my binoculars in far east in clouds.

2MIN: After it disappeared another group of 5 falcons came from the same direction following same direction which was so fascinating. This wasn't over, behind them in a distance a Eurasian Roller also followed in the same path and this was so great with it flying under this light of the sun that had just started to appear from the gap in the clouds so the top features were so shiny when it moved.
In the same flight as this falcons and in the end it went in clouds to the east and couldn't be seen again.
Birding here has started being more interesting with this wonderful passing by here.

Good luck birders.