From whatever sources are available to me. 

It's nice to be asked to illustrate a species I've already studied, and may already have my own field sketches or photographic reference.  Also, it's a bonus to work on a species which can be studied at the time of the job, to pop out for a part of the day to see it in the field, return and get to work ‘in the moment'. 

Photography can be an important aid for the illustrator and artist alike.  I take lots of background shots during my walks, very few of which will be useful for any particular commissioned work but occasionally one photo might provide an idea or a piece of habitat reference that can be incorporated into a future piece of work.  

I've used video quite a lot since around 1996.  Not only do I love to capture my own sequences of birds and animals, but video has provided a vital resource in isolating fleeting movements and postures that wouldn't be possible by simply observing, or through my own limited still photography capabilities.  It's possible to discover new information of bird plumage or behaviour by trawling frame-by-frame through sequences of video or digital photography. 

For many bird illustrators, access to museum collections is also a vital aspect of the job.  The demands made upon us to depict very specific plumages for field guides and for birding journals etc, often requires close scrutiny of bird specimens, collected from around the world and prepared for scientific purposes.  The most complete collection in the UK is kept at the British Museum, Tring.  Since 1982 most of my museum research has been spent over many visits to Liverpool Museum.

Dead birds also become available through road casualties, cat kills, or from collisions with windows, etc., and it can be very advantageous to take these opportunities to study, measure, sketch and photograph such casualties. I'll be putting some of my studies here to illustrate how I do this.

I've never been able to clock the hours.  I rarely start and finish a painting without having to attend other works which need to be done, so time spent on one piece may blur into that spent on another during one session.  Neither is it possible for me to divorce time spent out walking or searching for birds or mammals in the field from the actual process of painting at the easel or drawing board.  But in order to answer such a question of how long, then I could say anything from a day or two for a small study, to several weeks for a medium to large piece, which may be spread over as much as one, two or more years. 

Researching a new project often consumes my time and energy to an almost obsessive degree, and it can be these early stages of exploration and composition which take up a large proportion of time.  I do enjoy working quickly and spontaneously, but it seems to be in my nature to strive for a realism or a lifelike quality.  Often, it seems the last ten percent of a painting takes about half of the overall time!

So often, just a simple local walk can provide numerous ideas, such as the sudden appearance of sunlight on an otherwise ordinary object or natural feature.  Ideas are so often planted in the mind to emerge much later when an opportunity arises to pursue it further.