Q- How do I know who is earning the highest amount of curation reward in Steem?
You can check the daily, monthly curation reward data from Steemdb and also from the Curation Rewards Leaderboard, you will get to know who is on the top in earning Curation rewards.
Go to: https://steemdb.com/
Click on "Curation".
Now you are in the Curation Rewards Leaderboard page, here you can check the daily, monthly data of curation rewards and hence you will get to know the rank of the various curators in terms of earning curation rewards.
In the daily statistics of curation reward data, @ranchorelaxo is on the top with a total of 290.016 SP as the curation reward.
In the monthly statistics of curation reward data, @appreciator is on the top of the list with a total of 8266.366 SP as the curation reward.
Note- The Author/Curation reward split is now 50/50 of the post payout, so both the author and the curator(s) share 50% of the total post payout.