Are Ball Pythons Arboreal?

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Ball pythons are not a semi-arboreal species, even though they have been found off the ground. —

The short answer is no, Python regius, the ball or royal python is not an arboreal species, even though it can be found off the ground in some circumstances. But thats not really the question we should be asking. The important question from the herpetoculturists perspective, is whether Python regius enclosure design should provide accommodations for climbing. And the answer to that question is a clear and  unequivocal – it depends.

I’m writing this article in response to an article by that laid out some evidence for the species proclivity for the trees. So the papers referenced in that article are referred to here.

Im not writing this to refute his paper, per se, but to temper some of the misguided conclusions and subsequent design flaws those conclusions produced. I’ve lately seen a whole slew of cages for all pythons that look more suited to small tropical lizards – crowded with plants and branches and crowded even more with poorly considered “clutter” that serves no purpose – as clutter rarely does.

To an extent, the argument is semantic. What is meant by arboreal or semi-arboreal anyway? These are not rigorously defined words after all. What is important is that we design enclosures to meet the species needs as best we can. And for that we look to their natural history.

The snakes in the hobby come from the northern regions of Benin, Togo and Ghana. This is a semi-arid area of thorn scrub and grasslands. But the primary research sited in support of arboreality took place in the tropics of coastal Nigeria …

“The field study was carried out mainly during the wet season of 1997 … in some localities of southeastern Nigeria ….  These localities are characterized by permanently flooded swamp, rain- forest patches surrounded by cultivations of cassava and oil palms, and dryland rainforest patches.” (1)

So not only were the studies carried out in a tropical coastal area, they were done during the rainy season. One can easily imagine many of the snakes in the area took to the trees just to escape the rising waters. 

The second most prominent study presented as evidence for arboreality also took place in coastal, tropical Nigeria. In this study the pythons were radio tracked. The researchers found that the snakes spent every day burrowed into tunnels, emerging only at night to forage etc.

During their active periods males were discovered off the ground about 2.5% of the time. The females were discovered off the ground even less – about 0.5% of the time. That means the for every 200 female ball pythons observed only 1 was off the ground. For every 200 males, only 5 were off the ground. The author of that paper writes, ““However, both sexes were ground-dwelling in the great majority of [radio tracked] fixes” Does this constitute semi-arboreality?

Note that the first study was conducted in the day time exclusively, during the rainy season of a swampy environment. Even so the researchers discovered many snakes, lots of which were off the ground. The second study states that the snakes retreated to burrows during the day and emerge only at night to forage. There is contradictory information that leaves us wondering what fundamental details we are missing. How could one study show the snakes to be diurnal and arboreal while a study geographically close and in the same ecotype show them to be strictly nocturnal and overwhelmingly terrestrial and fossorial?

Was it the high waters of the rainy season driving the snakes into the trees?

The other line of reasoning in the paper suggests that the presence of birds and arboreal mammals in the diet of wild ball pythons proves the snakes are semi-arboreal. The argument is simple enough: “The snakes eat birds, birds live in trees, ergo ball pythons climb trees”.

Except birds live on the ground too – as do at least one of the “arboreal” mammals in their diet. In fact many of the species that are presented as tree dwelling aren’t necessarily. The galago (a tiny and darling primate) is often found very close to the ground: “…they are usually found in bushy vegetation only a few meters (0 to 5 m) off the ground. They can often be seen in the dense vegetation by the roadside and in ditches.” (2)

The bee-eaters … “They form colonies, nesting in burrows tunneled into vertical sandy banks, often at the side of a river or in flat ground. As they mostly live in colonies, large numbers of nest holes may be seen together. “ (3)

The grey parrots : “May (1996) observed that Grey parrots (Psittacus erithacus) in a Congo basin forest engage in extensive ground foraging, possibly ingesting soil as well as plants.” (4)

The Cisticolas, small warblers that are one of the most numerous ball python prey items are not particularly tree dwelling, and in fact occupy a niche close to the ground: 

“A variety of open habitats are occupied. These include wetlands, moist or drier grasslands, open or rocky mountain slopes, and human-modified habitats such as road verges, cultivation, weedy areas or pasture.” (5)

In fact, the one species we can probably assume is not going to be found on the ground were the bats, and those were consumed by female ball pythons only, instead of the “more arboreal” males. So there is something we don’t understand happening here as well.

The point Im making is that we cant work backwards from our conclusions to evidence. Birds in the bellies of ball pythons only proves they eat birds – it doesn’t prove anything about their arboreality. After all, even giant tortoises eat birds, and no one uses that fact to claim they are semi-arboreal!

“Here we present video evidence of a Seychelles giant tortoise (Aldabrachelys gigantea) attacking a tern chick and pursuing it along a log. Finally the tortoise killed the chick and was observed to eat it. Other tortoises in the same area have been seen making similar attacks… (6)

One thing that is consistent across the natural world is a simple notion “Form follows function”. An animal’s shape and other physical characteristics will disclose how the animal behaves in the world. 

The paper suggesting ball pythons semi-arboreality acknowledges this …

“Snake biologist Henry Astley had this to say on the subject: “Coming from my background (snake biomechanics), NOTHING about the ball python morphology is consistent with an animal which “spends all their time in a termite mound. Their skulls have no reinforcement or digging adaptations, their eyes aren’t reduced, they have distinct “necks” (as opposed to the robust “train locomotive” morphology of most burrowers), and have no specialized digging rostral scales. Anyone who claims they spend their whole lives in termite mounds needs to go take a look at Loxocemus and Calabaria to see *real* burrowing morphology, then defend how balls can have the lifestyle claimed with zero morphological adaptations.” 

The same argument can be made in regard to arboreality. Ball pythons have no physical or behavioral characteristics that would suggest they are adapted to an arboreal existence. They have none of the rigid muscularity of the tree boa, they don’t have the big eyes of the boomslangs or other sight hunters, they don’t have the enlarged scales that the mambas and other tree dwellers often display, and they don’t have the strength nor elongated shape that would allow them to span spaces between branches like the typical tree snakes do.

In short, they don’t have the form of an arboreal species because they are not an arboreal species.

So why does this semantic argument matter?

It matters because – in typical social media fashion – the interesting information offered was not taken in context of a broader base of knowledge because there often is no broader base of knowledge. Instead the new information was used by sudden authorities to cudgel the poor ignoramuses that hadn’t had a chance to read the paper yet. So it goes.

But worse, the new information was mis-used as guidance for creating ball python enclosures. The internet now abounds with images of ball python enclosures that are more suited to small tropical lizards or tree frogs than to pudgy pythons from arid flatlands. Vivaria packed with tropical plants, criss-crossed with branches and choked with “clutter” that serves no known purpose are now proudly presented as the latest and greatest creations of the herpetoculture literati.

These designs do not reflect the environments of the ball pythons in the hobby.

So if semi-arboreal enclosure designs arent right for ball pythons, what is? First I want to say clearly that none of this in any way condones the keeping of ball pythons in minimalist plastic tubs. There is nothing that can justify that form of animal abuse.

And there certainly isn’t anything wrong with adding a branch or two to a ball python’s enclosure. It wont hurt and it may provide some additional exercise that these little fatties often need. But packing our vivs with branches shouldn’t be advised, and certainly shouldn’t be insisted upon by the various care sheets floating around. 

Note too that the four walls of a cage often produce unnatural behaviors in our animals. So the many photos we see of captive ball pythons balanced on a branch on a cage dont necessarily depict anything natural. Especially when those four walls do not provide for the subterranean preferences of the animal.

More important is a deep, slightly humid substrate that facilitates burrowing. And a warm overhead incandescent lamp. Also something heavy and rough to aid shedding could be important. A surface layer of dried leaves, grasses or even straw to act as a mulch, help preserve substrate moisture and ensure a good humidity, light / security and temperature gradient and would complete the very basic setup for this species. 

If, in a addition to these basics, a keeper wanted to add plants and climbing options there would be no reason not to, as long as the enclosure was big enough to do so without crowding. The design emphasis however should be exactly what is missing in almost all of the new designs seen today – a deep, loose substrate or other subterranean accommodations with proper humidity and temperatures to reflect the place they spend 90% of their time in nature.

1.) “Luiselli, Luca, and Francesco Maria Angelici. ” Sexual size dimorphism and natural history traits are correlated with intersexual dietary divergence in royal pythons (Python regius) from the rainforests of southeastern Nigeria .” Italian Journal of Zoology 65.2 (1998): 183-185.” – 

2.) (Charles-Dominique, 1977; Napier and Napier, 1967; Nowak, 1997)
https://animaldiversity.org/accounts/Galago_demidoff/

3.) https://en.wikipedia.org/wiki/Bee-eater

4.) Soil-Eating by Grey Parrots in Cameroon: An Answer to Mineral Deficiencies or Toxins in the Diet? https://medium.com/@agreenmoment/soil-eating-by-grey-parrots-in-cameroon-an-answer-to-mineral-deficiencies-or-toxins-in-the-diet-b2ffc60e2fb7

5.) https://en.wikipedia.org/wiki/Cisticola

6.) https://www.sciencedirect.com/science/article/pii/S0960982221009179

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