The Amazon rainforest and all her wildlife vs 300,000 U.S. army troops (1960s)

300K Us army troops from 1960s drop in the Amazon rainforest to take control over it and kill any animal that get in the way

Privileges:

Supplies are shipped to the troops in the rainforest
50k extra troops to replace the dead
The troops can build bases and dugouts
Medics, Machine gunners and sniper will be available
Arty shells are available
Door Gunners support is available

Rules:

No Airstrikes
No Nukes
No Tanks
No armored vehicles

Who wins?