Hope you can help? I read this short story, possibly in a science fiction anthology from the 70's. Now I'm struggling to remember the author and the title of the story and I'd like to use it as reference as it is a great metaphor for immigration.
What I remember is a story about the character being a part of an invasion team where they struggle to reach the enemy. In fact never coming into contact, being hampered by poor visibility and having to constantly struggle against hedges and thickets of plant life that slowed down their progress. At some point they all lose consciousness and when recovering discover they have transformed into beings with a seal like pelt covering. They have been turned native by the environment itself.
There are other previous invaders but they too have been transformed in the same way. Now, the planet is getting too crowded and they need to begin plans for invasion themselves.