Are crocodiles secret fruit-lovers?

Nov 12, 2013 by Jon Tennant, The Conversation
Five-a-day please. Credit: blacktigersdream

Seed dispersal by animals is important for plants to help them occupy new areas of land. Usually bugs, birds, or intrepid kittens do that job. Now we can add crocodiles to that list. A new study reviewed the diets of crocodiles and showed that 13 of 18 species ate fruit of some sort and a wide variety of plants.

Using as a method of is actually a useful form of mutualism – the plants get to spread their genes and animals get a healthy snack. In other reptiles seed dispersal is a well-known activity, although not as well understood as for insects, mammals, birds and even in snakes.

The recent study, published in the Journal of Zoology, shows that for crocodiles, almost a quarter of the fruits consumed were of the "fleshy" kind. However, none of the recordings were of direct observations of fruit eating, so exactly how or why they did is still a bit of a mystery.

Most of the evidence come from dissection of crocodiles' stomachs and their faeces. So there is some chance that these crocodiles are indirect eaters of fruit who feast on fruit-eating animals. But direct observations (see video) have been made many times to believe that they might actually like eating fruits.

Why do it? First researchers that crocodiles learnt this behaviour from alligators in captivity. But the review makes note of observations in the wild. Perhaps it is similar to why dinosaurs consumed stones (gastroliths), to help with grinding food in their stomachs and get a tasty treat in the process. The energy values of fruits are pretty high, so consumption could be for a nutritional benefit.

This video is not supported by your browser at this time.

Perhaps this odd phenomenon might help in part explain why crocodiles are such successful animals. If meat was ever in short supply, they had the capacity to diversify and track down other food sources, from vegetation and grasses.

The study reveals something interesting about the way scientists might operate. Crocodiles are obligate carnivores – their primary diet is meat – and as such, fruits are often classed as anomalous food items when found in their stomach and not considered in a physiological context. This mainstream view may have led to the ignorance that feeding on fruits could help their diet and energy balances.

That the review study picked up so many independent instances of feeding on fruit and having ingested seeds is solid evidence for this. It shows that sometimes stepping back and taking a broad look at evidence can reveal some interesting things.

Explore further: Study examines overlooked role fruit-eating crocodilians may play in forest regeneration

More information: onlinelibrary.wiley.com/doi/10.1111/jzo.12052/abstract

add to favorites email to friend print save as pdf

Related Stories

New evidence for warm-blooded dinosaurs

Jul 18, 2013

University of Adelaide research has shown new evidence that dinosaurs were warm-blooded like birds and mammals, not cold-blooded like reptiles as commonly believed.

Recommended for you

Orchid named after UC Riverside researcher

5 hours ago

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

8 hours ago

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

8 hours ago

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 0

More news stories

Deadly human pathogen Cryptococcus fully sequenced

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...