The "harmful misuse" of mobile phone apps that mimic birdsong can stop birds performing important tasks such as feeding their young, experts have said.
Dorset Wildlife Trust said visitors to Brownsea Island were using apps to imitate Nightjar calls to entice birds out so they could photograph them.
The RSPB said birds could be diverted from vital tasks and said people might be "devastated" if they realised.
Hilary Wilson, from developer iSpiny, said the apps were a learning tool.
"We welcome this discussion into the ethics of using recorded songs," she said.
Brownsea Island nature reserve manager Chris Thain said: "Use of these apps is not suitable for nature reserves and can be potentially harmful to sensitive species."
Tony Whitehead, public affairs officer for the RSPB in the South West said: "Repeatedly playing a recording of birdsong or calls to encourage a bird to respond in order to see it or photograph it can divert a territorial bird from other important duties, such as feeding its young.