During the Antarctic summer female Weddell seals congregate in colonies along the Antarctic coastline to give birth to a pup, nursing it from body reserves. Advancements in 3D photogrammetry have provided a unique opportunity to quantify costs of reproduction for these females. Using mass measurements derived from photographs we can assess how Weddell seal mothers energetic investment changes with age. This will improve our knowledge of an important life history strategy of the Weddell seal.