Pineapples, guavas, mangos, Martin Denny playing tangos
"Well, the way that started was that part of my training was how to make a small group sound larger than it really was. So I would use a lot of different percussive effects, and then I started collecting instruments from the South Seas and from the Orient, also from Latin America. The music became a quasi-mix of music from the South Pacific, the Orient and South America. We were always experimenting, and trying out new ideas. Of course, that's when we added the birdcalls on 'Quiet Village.'"
This article about Future Bible Heroes clears up the story about the band's formation, which happened when Merritt and Chris Ewen "...were drawn together by their appreciation of exotica by masters like Martin Denny, members of the electronic vanguard such as Enoch Light, and musical masterminds such as Lindsey Buckingham."
Like Denny, Merritt has a fondness for collecting musical instruments (see the 69 Love Songs instrument list for evidence of this), which is mentioned by Claudia Gonson in this article for Sound on Sound:
"Stephin has really been involved in collecting and using exotic and interesting and weird instruments," explains Claudia. "Chris, too, has not only collected cool instruments, but become sort of a connoisseur of '50s and '60s technology from the earliest days of electronic production. So when you hear the beginning of a song like 'Doris Daytheearthstoodstill', which is like a looped bubble, basically, you think about Enoch Light, or Martin Denny and the earliest stages of making music with electronic things, and there's a kind of integrity. There's a real artistry to it."
"Quiet Village" was composed by Les Baxter, another huge figure in the exotica scene, but Martin Denny's version (complete with birdcalls and frog sounds) was the one that made it into a hit. Regarding the frog sounds, as the story goes, when Denny's band played in Hawaii in 1956 at the Shell Bar, which featured an amphibiously-populated pond near the stage, frogs would croak along with the music. The band thought that these flourishes matched well with their sound, so they incorporated the croaking sounds (recreated using a guiro) into their songs. The first version is from Denny's debut album for Liberty Records, entitled Exotica and released in 1957. The second version is from the 1969 album Exotic Moog, and although it was released under the Martin Denny name, Denny doesn't actually play on it. Still, it's a great version, blending electronics with exotica in a way that I think Merritt and Ewen would approve.
Martin Denny - "Quiet Village" (1969)