The archive contains nature notebooks, correspondence and research papers collected over Michael Thompson's lifetime, including papers from his school-age species collecting trips to Israel and Lebanon. 

In 2017, both parts of the archive were gifted to the Borthwick by the Yorkshire Museums Trust who had held them since the death of Michael Thompson in 2011. 

The six boxes of papers are accessible by appointment in our reading room.

The papers document the decades-long study of the species and environment of both York and further afield. 

Included in the archive are five boxes of mammal recording data, correspondence and personal papers including papers relating to the establishment of the Yorkshire Mammal Group by Michael Thompson and others in 1970.

A large portion of the records contain Thompson's groundbreaking and internationally significant study of Pipistrelle bats in the Vale of York, representing the first attempt at understanding and recording the lifecycle of the female Pipistrelle.