Provided photo of  Max Calderan during  his journey walking the Tropic of Cancer ,  340 km ,  from the border of Oman to KSA

Credit Mauro Grigollo *** Local Caption ***  max_calderan_credits Mauro Grigollo (8).jpg
Explorer Max Calderan during his journey along the Tropic of Cancer. Around 337 km of the length of the notional line that forms the Tropic is in the UAE. Courtesy Mauro Grigollo

Discoveries by enthusiasts are helping build a comprehensive picture of the UAE's natural history