Quote:
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The largest proportion of fruits (81%) was removed by frugivorous seed dispersers, especially by bats at nighttime.
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Spatial and temporal effects on seed dispersal a... [Integr Zool. 2012] - PubMed - NCBI
Do bats eat and pass the seeds? Eat and regurgitate? Or eat only the pulp?
I would certainly expect that bats sometimes do all three, depending on the bat and the fruit, and it sounds as though that's correct:
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Eight hundred and fifty-four (854) fecal samples and 169 samples from fruit parts and seeds discarded by bats beneath feeding roosts were analyzed.
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Also, piles of pulp and seed parts regurgitated during bat feeding (Handley et al. 1991) were found at resting or sleeping perches in hollow trees, underneath foliage and in leaf-tents used by bats of tribe Stenodermatini y (Timm 1987).
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Revista de BiologĂ*a Tropical - Food niche overlap among neotropical frugivorous bats in Costa Rica
(That article is about new-world bats and numerous different fruits, not including any bananas.)
Then there's this:
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During their feeding, these frugivores swallow small seeds and so disperse them in their feces great distances from the mother tree. When fruits are too large to be eaten rapidly, frugivores typically carry them off to distant trees where they can feed safely, thus dispersing even large seeds tens to hundreds of feet away.
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I focused on the cape fig, a tree species that commonly grew along the edge of the gallery forest and was one of the first "forest" trees to invade the savanna zones as soon as fires were reduced.
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When feeding, the bats stuffed their mouths to bulging, then slowly and methodically chewed the mass, swallowing only the easily digested juices and many seeds. When finished, they spat out a compressed mass of fiber, including some seeds, which I called a rejecta pellet. During their frequent flights, they left the walls peppered with seed-filled fecal splotches, resembling those I found on the plastic collecting sheets in the savanna.
From these observations I could identify three categories of seeds: those that remained untouched in the fruit, those that had been masticated but spat out in the rejecta pellet, and those that had passed through the gut and showed up in the feces. To test the effect of the bats' treatment of the seeds, I collected hundreds of seeds from ripe fruits, rejecta pellets, and feces and placed them on moist blotting paper to germinate. Fecal seeds were the first to germinate. After only six days, more than 50% had sprouted, and it took only a few more days before all the seeds had germinated. Seeds from rejecta pellets took a little longer (14 days for 50% germination) and only 75% germinated. In contrast, no more than 10% of seeds I extracted from ripe fruits ever germinated--even after 89 days.
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On Fruits, Seeds, and Bats
It seems obvious that if there are a few huge seeds the seeds would be discarded, whereas a fruit with many small seeds would be eaten seeds and all. And if the pulp separates easily from the seeds, that should mean that the seeds are discarded, whereas seeds tightly attached to the pulp would be passed. Banana seeds seem big to me, and it looks in pictures as though the pulp would come off fairly easily. So I'm still guessing that they don't go through the bats' (or other animals') digestive tracts.