Like most hylid frogs Smilisca is most readily collected and observed when individuals congregate for breeding.
Smilisca breeds primarily in quiet water and reaches its height of breeding activity at times of plentiful rainfall,—usually from May through October. Through most of its range Smilisca baudini breeds in those months, but in some places where abundant rain falls in other seasons, the species breeds at those times. For example, in southern El Petén and northern Alta Verapaz, Guatemala, Smilisca baudini has been found breeding in February and March. The other pond-breeding species (S. cyanosticta, phaeota, and puma) live in regions lacking a prolonged dry season, and possibly they breed throughout the year, but breeding activity seems to be greatest in the rainiest months.
The two stream-breeding species (S. sila and sordida) breed in the dry season when the streams are low and clear, principally in December through April. At high elevations the species sometimes breed in the rainy season; also, individuals sometimes breed in the short dry season (summer canicula) in July and August.
At several localities species have been found breeding at different times of the year: S. baudini in March and July at Chinajá, Guatemala; S. phaeota in April and August at Palmar Sur, Costa Rica; S. puma in February and July at Puerto Viejo, Costa Rica; and S. sila in February, April, and August at El Volcan, Panamá. These observations indicate only that the population breeds at more than one time in the year, but do not provide any evidence on the breeding cycles of the individual frogs. This is one important aspect of the natural history of Smilisca for which we lack data.
All members of the genus Smilisca presumably deposit their eggs in water.
Smilisca baudini usually breeds in temporary rain pools; often these are nothing more than shallow, muddy puddles. In other instances the sites are extensive ditches or large flooded areas (Pl. 8, Fig. 1). This species is an opportunistic breeder, and males gather at any of a wide variety of suitable breeding sites that are formed by torrential rains in the early part of the rainy season. Smilisca baudini nearly always breeds in open pools having bare earthen edges. Frequently congregations of S. baudini are found at such small pools, but are absent from nearby large ponds surrounded by vegetation.
Little is known of the breeding habits of S. cyanosticta, which inhabits humid forests on foothills and lowlands. Apparently its breeding sites are not unlike those of S. phaeota, which usually are pools surrounded by vegetation (Pl. 8, Fig. 2), although sometimes males of S. cyanosticta call from open muddy puddles. In uplands, where standing water is uncommon, this species breeds in quiet pools in streams.