Animals will usually be wary of the camera, and often it’ll take a few hours – or even a succession of days – for them to get used to it. What’s more, the sound of the shutter might scare them off. It helps if they can get used to the sound, so fire it a few times when they’re nearby. Hopefully they’ll feel more comfortable hearing the sound when they come up close to the camera. Alternatively, you can dull the sound of the shutter by turning on Live View, but it’ll slow down your shooting rate.