A short distance inside the Playacar entrance off 10 Avenida, the small Aviario Xaman-Ha (Paseo Xaman Ha s/n, tel. 984/873-0330, www.aviarioxamanha.com [1], 9 a.m.–5 p.m. daily, US$25 adult, children under 12 free) bird sanctuary is home, or a stopover, for more than 60 species of tropical birds, including toucans, flamingos, cormorants, and parrots.
Some birds are in enclosures, but many are not, and a stone path meanders through the leafy grounds. Unfortunately, the admission price is ridiculously inflated and keeps getting higher.
If you do go, be sure to bring bug repellent.
Links:
[1] http://www.aviarioxamanha.com