Question: Is it only bird song you're interested in or other animals "calls" as well?

Rupert Marshall answered on 15 Mar 2017:

That’s a good question because it gets to the heart of being a scientist. I am interested in animal communication. I mainly study bird song because it is easy to record and easy to study: we can see pictures of songs and measure things like how high, how low and how long they are – have a look at this example on my profile:

Scientists choose the animal which bests help them answer their questions. Even though I mainly study birds, I study only a few. I study great tits, like the ones you see in gardens because they have a simple song made of simple whistle sounds. This makes it easy to see if they are singing higher or lower in noisy towns. But I also study dialects – how songs change between different fields. To do this I study a bird called the corn bunting which sings in very precise dialects.

When I first started out I moved from birds to study barking geckos. I was still studying animal calls but from a reptile. These creatures come to the entrance of their burrows in the evening and bark. They live in the Namib Desert, in southwestern Africa and bark like birds do, to defend their little bit of territory. You can see and listen to one here (click the top picture)
http://www.pachydactylus.com/pages/english/ptenopus/ptenopus-kochi.php

Lots of animals use sound to communicate, from lions to dogs, to mice to fish. I am interested in the basic ideas that are behind how and why animals do what they do. I just happen to mainly study birds. And they do sound nice to humans too which is a bonus