Birds in Flight during Raya Holiday

My lifer Red-wattled Lapwings (Vanellus indicus). size=32cm
Exif: 1/8000s |  ISO 640 | f/5.6 | 400mm | Exp bias 0 step.

Testing Canon EOS 5D Mark iv and 400mm f5.6 L lens for birds in flight photography during recent Hari Raya holiday.
I set the camera at 61-points Automatic Selection AF, AV mode, AI servo and high speed continuous shutter, and just fired 7fps at any passing birds.

Unlike egret or eagle, these birds are small 20cm (Asian Glossy Starling) to 32cm (Red-wattled lapwings), and moving very fast.
With overcast weather, I have to push up the ISO to 4000. Shooting against the sky,  need to compensate the exposure to +1 to +2 to bring up the birds details.
Most of the birds fly laterally to the sunlight, except for Oriole, when the sun is at my back 

Asian Glossy Starling (Aplonis panayensis), size=20cm
Exif: 1/6400s | ISO 1600 | f/ 5.6 | 400mm | Exp bias +1

Jungle Myna (Acridotheres fuscus), size=24cm
Exif: 1/8000s | ISO 1600 | f/5.6 | 400mm | Exp bias  +1 step

Jungle Myna carrying  nesting material.
Exif:  1/8000s | ISO 4000 | f/5.6 | 400mm

Oriental Magpie-Robin (Copsychus saularis), size=19cm
Exif: 1/4000s | ISO 1600 | f/5.6 | 400mm | Exp Bias +1.3 step

Yellow-vented Bulbul (Pycnonotus goiavier), size=20cm
Exif: 1/4000s  | ISO 640 | f/5.6 | 400mm | Exp bias +1 step

Common Myna (Acridotheres tristis), size=25cm

Black-naped Oriole (Oriolus chinensis), size =27cm
Exif:  1/6400s | ISO 640 | f/5.6 | 400mm | Exp bias 0 step
All the pic are shoot handheld.