@chia told me to look for a rare frog at night around the grounds of the Hotel Bouganvilla in San Jose, the Blue-sided Tree Frog (Agalychnis annae). Chia has some shots at:
http://www.inaturalist.org/observations/1374384
So, I went out last evening after dark to see if I could find it. It was very windy and that may have hampered my efforts, but in any event I was not successful in spite of carefully checking the outside water pools for an hour. I did find several leopard frogs, which I believe are Lithobates taylori which Chia also has shots of at:
http://www.inaturalist.org/observations/791308

Hotel Bouganvilla
San Jose, Costa Rica
13 February 2016
9.9817
-84.0786
3940 ft elevation