Your thoughts on this excerpt?

Not realistic enough, but pretty good. I've read about people going through dense jungle before in real life. The people not used to the area take guides along with them who know the way in spite of everything, and they hack branches and shrubs continually to get through and collapse from exhaustion and illness finally when through it. The screeching is probably there. The birds first warn the others that something foreign is coming through. They screech even louder if it's a leopard.