Eyes in the sky How drones are helping animal rights campaigners

Inexpensive and easy to use, they are proving invaluable for activists monitoring illegal fishing, hunting and deforestation - as well as keeping tabs on zoos and aquariums

- Laura Trethewey

Late last year, UrgentSeas received an anonymous tip from a former employee at the Miami Seaquarium about animal tanks away from public view. The advocacy group went to investigate.

In November, the group posted a short clip of what it found by flying a drone over the property: an elderly manatee living alone in a decaying private pool. Within a month, the clip had been watched millions of times and the outcry had grown so intense that the US Fish and Wildlife Service moved the manatee, Romeo, to a sanctuary.

Over the past decade, drones have become irreplaceable tools in activist and conservation circles. In 2013, the animal rights group Peta launched a drone campaign tracking illegal bowhunting in Massachusetts.

Since then, drones have been used to record factory farm pollution in the American midwest, sea lice outbreaks in Icelandic salmon pens, and deforestation in the Brazilian Amazon. Drones are popular because they're relatively cheap, easy to use and extend a person's range in difficult or inaccessible terrain. They also provide a bird's-eye view of the scale of an issue, such as an oil spill or illegal logging.

When it comes to marine mammal captivity, the aerial perspective can be invaluable, exposing the cramped conditions and the constrained life for the animals inside the tanks.

In some cases, the drones capture the secret lives of animals hidden from view. "This is the footage people need to see to realise how cruel captivity really is," said the drone pilot who shot the footage at the Miami Seaquarium, who prefers to remain anonymous.