While flying, migratory birds often form V-like structures.  Since, there is no
obvious leader in the group, it is surprising how and why they self-organize
into this shape.  A recent paper arXiv:cs/0611032 address this question.

You are supposed to review this paper :
1) Define their model
2) Explain basic steps of calculations
3) Explain their results.
4) Do you agree with them ? Any suggestions/modifications ?