We are seeing many more birds come into the wildlife rehab covered in a sticky substance that won't come off. I found out it is a repellant called polybutylene. It comes in a form that can be sprayed and it does more than repel, it's been quite deadly for the small birds who have come in contact with it.
If you have a wildlife rehab group in your area, you may want to ask them to share info about this with their followers. This stuff leads to a pretty awful death for wildlife.
I found more info on our own HSUS page about pigeons, but same goes for all birds:
NEVER use polybutylene gel. Sticky gel repellents made from polybutene can harm all birds and any animal that comes in contact with it. The HSUS strongly recommends that these dangerous repellents be avoided at all costs. The feathers of any bird who comes into contact with the dense, sticky gel will become damaged, interfering with their ability to fly and to stay water-proofed.
These gel repellents are not selective. Other birds are likely to land on the gel, get stuck, and die a slow death. The polybutene gels are particularly harmful to smaller species.
