Could someone please help with with the sex of my 2 tortoises.  The first one (Monster) is about 9 years old, I re-homed it so not 100% on the age.  The second one (Sherman) is 4 years old.  Monster keeps biting and chasing Sherman and trying to mount and Sherman has recently been showing signs of nesting, climbing about all the time, restless, and digging with back legs in the substrate. Thank you

It looks from the photos that the first photo shows a male and the second a female.