1. Light level geolocation Michael Sumner PhD. candidate

2. Summary Light level geolocation –Light data –Environmental data –Behavioural model Summarizing behaviour of multiple animals Calibrating tags

3. Tracking vertebrates southern elephant seal (male 5yo) Photo: J. van den Hoff, AAD Archival tag –Light level –pressure (depth) –temperature –Archived on board

4. Light levels and solar elevation Kingston, Tasmania April 2003 Time GMT 10 PM 8 AM 6 PM 2 AM 10 AM 8 AM 4 PM Local time LONGITUDE time of noon in GMT LATITUDE length of day vs. night LATITUDE difference in length of day versus night

5. Effect of longitude on expected light Effect of latitude on expected light Locations for predicted light levels DAWN

6. Light data – with solar elevation in Hobart (different y-scale)

7. Light data – choosing “twilight”

8. Real light data – diving elephant seal

11. Parameters to estimate – lon, lat, and light attenuation

13. Location estimates Storing series of estimates for animal “tracks”

14. Calibrating light tags