The G-cat

Revisiting Piñata Island

Every now and then, my gaming habits tend to take a bit of a wander down memory lane. Of late, that means cracking out one of my classic faves – the life simulation and “collectathon” Viva Piñata by Rare. Originally released in 2006, with successor (expanded version, essentially) Viva Piñata: Trouble in Paradise released in 2008, the game essentially involves creating a lavish garden to attract wild piñata-like animals. Although a little light on plot, the main goal is to entice these wild creatures (Wilds) to stay in your garden (becoming Residents), to later be sent off to parties across the globe. Trouble in Paradise boasts a roster of 88 different species of Piñatas to collect, as well as a variety of fruiting trees, plants, and flowers to grow.

As you might expect, I have a lot of love for a game that essentially involves discovering and collecting animals like an ecological kleptomaniac (yes, hello Pokémon). But playing it again from the perspective of a trained ecologist brings a few curious questions to mind – the most pressing of which is “how diverse is Viva Piñata, anyway?”. This incredibly abstract topic is the focus of today’s adventures, so let’s get taxonomical!

Piñata biodiversity

For the comparison, I started by collecting taxonomical information (or best guesses thereof) for all the different species. This involved simply taking the animal each piñata is based on and determining which phylum, class, order, and family the real species belongs to. I avoided including genera and species specifically as many of the piñata animals are rather generic (“dragonfly” could mean any number of species!) – in fact, determining which family some piñatas belong to was difficult or impossible. Two exceptions were not included in this database – the yeti species Jeli (I’m sure a cryptozoologist will come barging in with taxonomic suggestions any minute) and the unicorn Chewnicorn (which could probably have been considered a highly divergent equine).

The first thing I decided to look at was the overall diversity of Piñata Island. I used the taxonomic delineations (phylum, class and order) for the majority of the cast to construct a dendrogram using the dendextend package in R. This very neatly summed up the piñata diversity into taxonomic categories. As you can see, mammals and birds are well-represented in the game, making up a total of 59 (~67%) of all piñata species, compared to only four amphibians (~4.5%). It’s worth noting that some species – such as the divergent Shellybean (the sole member of the phylum Mollusca)– were not included as dendrograms can’t handle missing data (e.g. no ‘Class’ for a species).

But to dive into the diversity of Viva Piñata a little more, I decided to do a series of comparisons to real biodiversity. In essence, I looked at the relative number of (described) species at the phylum, class and order level and compared these to the cast of Viva Piñata – what I wanted to see was how well the diversity of the game matched real biodiversity. These statistics were somewhat opportunistically taken from various sites (predominantly Wikipedia), so naturally there is some margin of error around them (although for the purposes of this blog, so long as they’re in an order of magnitude correct we should be fine).

Essentially, I tried to predict how many piñatas per group should exist if they were randomly selected based on biodiversity (e.g. if one phylum contains 50% of all species, then 50% of piñatas should be members of that phylum). I assumed that the total number of piñatas in the game was constant (88). I wanted to know: what types of animals were under-represented? Which ones were over-represented? What groups were missing entirely?

Comparing phyla

For comparisons at the phylum level, I compared the piñata species to each of the 31 phyla in the kingdom Animalia. As you can see in the bar plot below, the phylum Chordata (which includes all vertebrates [fish, amphibians, reptiles, birds, mammals], as well as tunicates) is very well represented in Viva Piñata, but actually makes up a relatively small amount of real biodiversity. In reality, the phylum Arthropoda dominates the biodiversity landscape, making up more than 80% of all described species (>1 million species)! Remember that this is also based on described species only, which likely underestimates arthropod diversity compared to other macro-organisms such as mammals.

For Viva Piñata to represent the immense diversity of Arthropoda, the cast should include 72 arthropod piñatas (60 more than there currently are). Most of these could be taken from Chordata, which should have four piñatas (instead of the 72 currently). The game could also use a brachiopod (similar to a mollusc), a cnidarian (e.g. jellyfish, corals, anemone), an echinoderm (sea star), a couple more molluscs and a platyhelminth (flatworm) to better capture real-world biodiversity. Of course, many of these would be difficult to implement in an entirely terrestrial game, depending on how biologically realistic you’d like to be (I mean, sea stars can walk a little bit?).

Comparing classes

Given that there are a total of 107 classes within the kingdom Animalia, and that many of these would not reasonably feature in Viva Piñata (i.e. completely aquatic or microscopic organisms), I reduced the comparison down to 23 more realistic classes. As with the above comparisons, birds (Aves) and mammals (Mammalia) are very well represented in Viva Piñata, along with a handful of insects and reptiles. However, Insecta absolutely dominates real biodiversity, making up 76% of the species in these classes (which would correspond to 67 piñatas). In fact, insects make up so much biodiversity that to be fair to relative biodiversity, Viva Piñata should actually feature no mammals (0.4%), no amphibians (0.5%), one reptile (0.6%) and one bird (0.7%). It should also feature a couple more arachnids (five more), a couple more gastropods (snails, etc; five more) and another Malacostraca species (crabs, lobsters, shrimp, etc.), as well as a species of Adenophorea (nematodes), Diplopoda (millipedes) and Polychaeta (bristle worms).

Comparing orders

Even more so than with classes, I needed to whittle down from the 440 – 450 (some debate around that number) orders in Animalia. So, for this level of comparison, I only considered those which had at least one Piñata species in them already (which, as you could probably tell from above, is missing plenty of things!). One of the first things you may notice is the difference between breadth and depth of biodiversity – Viva Piñata features animals in 34 different orders, but with most having few (one) species. However, real biodiversity is so dominated by orders of Insecta that very few orders would actually be represented in the game – particularly, Coleoptera (beetles), Diptera (flies), Hymenoptera (wasps, bees) and Lepidoptera (butterflies and moths) contain inordinate numbers of species. In fact, the 400,000 described species of beetles comprise around 40% of all insects and 25% of all known animals. Let that sink in – one in every four animals is a beetle!

For Viva Piñata, a representative cast would only feature nine orders, with the aforementioned insect ones each containing at least 11 piñatas (37 in the case of Coleoptera). There should also be four piñatas in Araneae (spiders) and one piñata each in Decapoda (‘ten-footed crustaceans’ such as lobsters and prawns), Squamata (the largest order of reptiles), Passeriformes (songbirds) and Odonata (dragonflies). All those mammals in Viva Piñata – especially the many animals in Artiodactyla (even-toed hooved animals; ten species) and Carnivora (carnivores; 12 species) – would not even feature a single representative under this strategy.

So, what was the point of all that?

There wasn’t really one, sorry! I guess if there’s any particular point to make, it’s to appreciate the sheer diversity of invertebrate life. Like many derivations of real biological diversity (in fantasy, media, gaming), there is an inherent bias towards what we call ‘charismatic megafauna’ – large animals that we can more easily relate to such as mammals and birds. But they barely rate a mention in the true diversity of species on the planet, and although some may consider insects and spiders gross their amazing diversity underpins so many ecosystems around the world. With that, I leave you with an iconic quote:

The Creator, if He exists, has an inordinate fondness for beetles.

J.B.S Haldane