Six weeks into COVID lockdown, and still not posted a new ape!
Here goes:

From the Central African Republic, showing the endangered Coquerel's sifaka, a lemur from Madagascar, and on the stamp, the almost critically endangered crested macaque from Sulawesi.
The 4stamp MS shows Sykes monkey, as yet of Least concern;the Vulnerable East Javan langur;the mandrill, also Vulnerable; and the critically endangered Black and white lemur.