Create Seamless Loop Video of White Birds (No Background)

I need custom HD video loops of natural white doves flying, to be projected on the wall of a sukkah.
The video must show only the birds — no background, no scenery, no glow. Everything other than the birds must be true black (RGB 0,0,0) so nothing else projects.

Requirements:
• Format: MP4 (H.264), 1920×1080, silent (no audio).
• Clips:
1. ~2 min — Single dove, slow/relaxing flight, left↔right, varying height/size.
2. ~2 min — Small group (2–4 birds).
3. ~2 min — Larger flock sweeping across.
4. (Optional) ~6 min combined loop of all 3.
• Look & feel: Natural white birds (not cartoon). Slow, graceful, relaxing flight. Mix of closer/larger and smaller/distant passes.
• Looping: Seamless — video must play continuously without visible jumps.
• Preview: Deliver a 30-second Bird_Test_Preview.mp4 first (smaller 720p file) to check speed, size, and motion before final renders.
• Playback environment: USB → media player → projector (≈4000 ANSI lumens). Needs to run continuously for 7 days.

Deliverables:
• 3 individual MP4 files (~2 min each).
• 1 combined MP4 file (~6 min).
• 1 preview file (~30 s).