Karine Aigner / Biologist Clara Cooper-Mullin (left) and her colleague Olivia DaRugna. Clara is holding a Hermit thrush (Catharus guttatus), as part of her study into the migration behaviour of birds that use the isl...

Karine Aigner / Biologist blowing on the breast of a Hermit thrush (Catharus guttatus) in order to separate feathers to see how much fat the bird has gained. Fat gain is important for migratory birds as they use a lo...

Karine Aigner / Biologist about to harness Hermit thrush (Catharus guttatus) with nano-transmitter. Block island, Rhode Island, USA.

Karine Aigner / Wax worms are portioned out by weight as biologist studying Hermit thrush (Catharus guttatus). The food is weighed out to test how much food it takes for the birds to fatten adequately before migratio...

Karine Aigner / Hermit thrush (Catharus guttatus) captive during scientific study, with a wax worm. This bird is part of a study about weight gain, diet and condition prior to migration. Once the thrush has reached i...

Karine Aigner / Biologists researching song birds, weighing and banding birds caught in mist nets. Here birds are kept in breathable fabric bags while they are waiting to be examined. Block island, Rhode Island, US...

Karine Aigner / Woman releasing a Hermit thrush (Catharus guttatus) from a mist net. Block island, Rhode Island, USA.

Karine Aigner / Hermit thrush (Catharus guttatus) caught in a mist net. Block island, Rhode Island, USA.

Karine Aigner / Biologist harnessing a Hermit thrush (Catharus guttatus) with nano-transmitter. Block island, Rhode Island, USA.

Karine Aigner / Hermit thrush (Catharus guttatus) wearing a barely visible nano-transmitter. Block island, Rhode Island, USA.

Karine Aigner / Hermit Thrush (Catharus guttatus) held in hand before release - wearing a barely visible nano-transmitter. Block island, Rhode Island, USA.

Karine Aigner / Golden-crowned kinglet (Regulus satrapa) in a mist net. Block island, Rhode Island, USA.