Part VI: Outdoor Terrarium Exhibits
The open-air terrarium complex comprised a series of exhibits which, for all intents and purposes, were areas of the surrounding mountainside which had been separated off from one another and adapted to suit the needs of the inhabitants of each exhibit; this applied to all of the exhibits within this area with the exception of the first two, which had obviously been added at a later point than the main complex and as such were built outwards from the surrounding rock walls. The bulk of these terrariums were located along one side of a small and pleasant courtyard of sorts, from which it was possible to look downhill over the zoo and across the valley to the surrounding city and alpine landscape; as with Alpenzoo Innsbruck as a whole, this courtyard was well-placed to receive sunlight throughout the day, and as a result there were many wild lizards running back and forth along the ground and surrounding walls.
The first enclosure we reached - which as already noted was seemingly a later addition to the exhibit complex as a whole - was a large and very pleasant-looking terrarium containing
Western Montpellier Snake(Malpolon monspessulanus). This comprised a lifetick taxon for both Helly and myself, and after a short period of time observing the exhibit we were able to locate one of the inhabitants; we found the Montpellier Snake to be a particularly interesting-looking species, and rather larger than expected. This taxon is notable as one of a handful of ophiophagic snake species native to Europe, along with the closely-related Smooth Snake, and is also mildly venomous - although due to the rear-fanged nature of the species, along with the small size of the fangs, human envenomations are rare.
The terrarium itself comprised a variety of small shrubs and bushes, of the sort one would find on the lower reaches of a mountainside, dotted with various rocks and boulders, and with a gravel substrate surrounding the main body of the display; the terrarium as a whole was lined with dry-stone walling, with further vegetation growing from the sides. As such, I felt this terrarium was very well-designed; the look and feel of the exhibit fit very well with the overall "feel" of Alpenzoo Innsbruck which I have already commented on, and closely replicated the appearance of the Mediterranean mountainside habitat in which the taxon in question can be found. This, along with the large size of the terrarium as a whole and the open-air location of the exhibit, perfectly positioned to receive a large amount of natural light, meant that this was an extremely good exhibit, and one well-suited to the needs of the inhabitants. It is worth mentioning here that the educational signage within this area was particularly good; each display contained a distribution map for the species at hand, along with information on their life-cycle, diet, habitat and more specific anatomical information such as average size and weight. Moreover, there were also copious amounts of more general educational signposting; for instance, alongside the sign discussing the Western Montpellier Snake there was also a sign discussing the particular anatomical adaptations within the skull and dentition differentiating vipers from rear-fanged colubrids, along with the difference between the dentition of venomous colubrids and that of their venom-less kin.
The next terrarium we reached - the only one in the overall complex which was not open-air, and as noted seemingly added to the complex at a later point - contained
Ladder Snake (
Rhinechis scalaris); this was, like the preceding species, a lifetick taxon for both Helly and myself, and was very attractive looking. The exhibit comprised a mass of dry branches, twigs and logs, interspersed with fresh vegetation towards the floor of the terrarium, with the walls lined by boulders and rocks. Although somewhat smaller than the preceding exhibit, and much more akin to the sort of exhibit one would see in a mainstream collection, it was still a rather good enclosure for the taxon in question in my opinion; the inhabitants had plenty of scope for movement and - due to how thick the branches and vegetation within were in places - could readily escape from view if they so wished.
We next reached the main body of the open-air terrarium complex; a row of six exhibits which, as already noted, were constructed into the side of the mountain slope. The first of these contained
Ocellated Lizard(Timon lepidus) ; we had seen this taxon at Wilhelma the previous day, of course, but it was quite satisfying to note how visible the inhabitants of this exhibit were as they basked in the direct sunlight, allowing us significantly better views of the species than we had previously achieved. The sunlight and close range at which we were able to view the inhabitants of the terrarium made it clear just how large and strikingly-coloured this taxon is when compared to related species; as chance would have it, whilst we were viewing this exhibit a wild Wall Lizard made itself visible on the ground next to us, allowing a direct comparison! The exhibit itself was thickly planted with scrubby vegetation of the sort that would be found in the Mediterranean foothills of the Alps - the area which comprises the northeastern limits of the range of this taxon - dotted with large rocks and boulders among a sandy gravel substrate towards the front of the exhibit, very much akin to the terrarium already discussed for Western Montpellier Snake; however, this exhibit was perhaps a little larger. As with the aforementioned exhibit, I felt that this terrarium was very well-designed, and excellent in terms of how well it met the needs of the inhabitants given the wide range of basking opportunities along with areas of vegetation where they could shelter from extremes of temperature and escape view if desired.
The next terrarium we reached was a mixed exhibit displaying
Viperine Water Snake (
Natrix maura) and
Aesculapian Snake (
Zamenis longissimus); in general design and layout it was quite close in appearance to the preceding exhibit for Ocellated Lizard, although the front of the terrarium was marked by a large and relatively deep pool, with rock shelves and branches allowing easy access in and out of the water. To our significant pleasure, we spotted several hatchlings of the Viperine Water Snake swimming around in the pool area at the front of the terrarium, along with a few within the land area of the exhibit, with perhaps a dozen individuals visible in total. Moreover, adults of both species present within the exhibit were visible, primarily in and around the thick vegetation at the rear of the terrarium.
Again, both of the species within this exhibit had been seen by ourselves at Wilhelma a day previously, but the view available at Alpenzoo Innsbruck was significantly better; I was particularly pleased to get a good view of the Aesculapian Snake given the fact that the majority of individuals I had seen up to this point had been wild individuals glimpsed from afar at London Zoo. Considering the semi-aquatic nature of the Viperine Water Snake, I felt that this exhibit was particularly well-suited to this taxon, and also served the needs of the Aesculapian Snake rather well; once again, I also was rather pleased with the appearance of the exhibit as a whole, and how well it fit with the "feel" of the collection as a whole.
Immediately next to this exhibit, there was another mixed-species terrarium; this one held both
Dice Snake (
Natrix tessellata) and
European Grass Snake (
Natrix natrix natrix). Not only are these both very attractive-looking species - the former representing yet another taxon which I had first saw at Wilhelma the day previously, whilst the latter is a species I have seen on a handful of occasions in the wild, back in the United Kingdom - but it is worth noting here that a particular highlight of the open-air terrarium complex under discussion is that, between this exhibit and the preceding one, it displays all three undisputed members of the genus
Natrix, the only absent taxon being the possibly-invalid
Natrix megalocephala - which as a native of the Caucasus does not fall within the geographic remit of Alpenzoo in any case. In general design, this exhibit was not too dissimilar to its neighbours; like the preceding terrarium, the front of the exhibit was filled by a large and relatively deep pool, whilst the land area was split between scrubby areas of vegetation and piles of dead twigs, branches and logs. However, this exhibit contained far less vegetation as a whole than the preceding ones had, giving a bit more of an upland mountain-stream feel; this would not be strictly accurate for the optimum habitat of the taxa in question, but did fit well with the overall mountain habitat theme of the collection as a whole.
Nonetheless, the exhibit was large and well-suited to the needs of the inhabitants, given the semi-aquatic nature of members of this genus, and despite the less-extensive vegetation in this terrarium there was still plenty of scope for the inhabitants to escape view, both within the logpile to the right-hand side of the exhibit and into the vegetation towards the left-hand side.
The next terrarium we reached comprised a mixed-exhibit for
Nose-horned Viper (
Vipera ammodytes ammodytes) and
Asp Viper (
Vipera aspis, one which I had particularly looked forward to seeing prior to our visit to Alpenzoo Innsbruck; whilst I have been fortunate enough to see Nose-horned Viper on a number of occasions, including at Wilhelma a day previously, given how seldom I have the opportunity to view venomous snakes within the United Kingdom it is always worth appreciating those opportunities that do present themselves. Moreover, the Asp Viper represented a lifetick taxon for both Helly and myself, and a rather appealing one at that.
Within the exhibit, we could readily see at least three or four Nose-horned Viper, and perhaps a dozen Asp Viper - many of which were basking together en-masse, whilst one or two stragglers of both species were moving around the terrarium away from the main body of the inhabitants. Another highlight of this exhibit, it rather goes without saying, was the ability to directly compare the appearance of two members of the same genus; as was highlighted by the excellent informational signage at this exhibit, which also detailed the range, diet and habitat of each taxon, the Nose-horned Viper was significantly larger than the Asp Viper, and as the name would suggest possessed a prominent "horn" comprised of several fused scales which emerged just above the rostral scale whilst the Asp Viper merely possessed a distinct upturn at the tip of the snout.
As was made clear by further educational signage at this exhibit, this represented something of a midpoint between the "horn" of the Nose-horned Viper and the entirely flattened snout of the closely-related Northern Viper or European Adder.
The terrarium itself was extremely good, replicating a rocky Alpine mountainside very well; much of the exhibit comprised large rocks and boulders, dotted with scrubby vegetation and wildflowers, and distinctly sloping uphill. As such it closely resembled the natural habitat of both of the taxa found within, was very attractive to the eye and was very well-suited to the needs of the inhabitants.
Immediately next to this exhibit, there was a terrarium displaying
Northern Viper (
Vipera berus berus), a species which I have been fortunate enough to view on a number of occasions in the wild; however given the aforementioned rarity of seeing captive venomous snakes, along with the presence of congeneric taxa in the neighbouring exhibit, it was particularly interesting to see the species here. I was particularly pleased to note that at least one of the individuals held within was a melanistic-morph; although this is quite a common mutation within the species, it is one which I had previously never been fortunate enough to see. I was quite amused, and surprised, to note that this exhibit also seemed to contain a wild
Common Toad (
Bufo bufo), which had presumably entered the terrarium through a crack in the wall, or perhaps having climbed the exterior borders and fallen into the exhibit from above. Given the diet of the Northern Viper, I suspect that this individual was unlikely to remain in the exhibit for long, one way or another! This terrarium was, broadly speaking, akin to a hybrid between the one which had immediately preceded it and the exhibit for Aesculapian Snake and Viperine Water Snake; like the former it primarily contained large areas of rocks and boulders broken up by scrubby vegetation, whilst like the latter it also contained a pool towards the front of the exhibit, albeit rather more shallow than the one in aforesaid enclosure.
In general "feel" this exhibit very much gave the impression of a mountain stream flowing through an area of scrubby heathland, very much the ideal habitat for the taxon contained within as I know from personal experience. As such, I thought this terrarium was - as had been the case with every exhibit within this complex - excellent and very well-designed both for the purposes of animal welfare and creating an attractive display. Alongside this terrarium, there was a particularly interesting piece of informational signage discussing the differences in appearance between the superficially similar and non-venomous Smooth Snake, and the venomous Northern Viper.
The final terrarium within this area comprised a mixed exhibit for
Alpine Newt (
Ichthyosaura alpestris alpestris) and
Viviparous Lizard (
Zootoca vivipara); these are two species with which I am reasonably familiar, have seen the latter taxon literally dozens of times in the wild within the United Kingdom, and having searched - without success - for the former taxon in known locations within the north of England which contain introduced populations. This exhibit, perhaps unsurprisingly given the taxa in question, was by far the one which contained the largest amount of water in comparison to land area; as a rough estimate only a quarter of the exhibit at the rear of the terrarium comprised dry land, with the remainder comprising a deep pool at the front. However, the land area - which primarily contained scrubby vegetation and dead wood - was supplemented by several outcroppings of rock which formed part of the drystone wall at the rear of the terrarium. The most interesting aspect of this particular exhibit, much like the previously-discussed terrarium containing Ocellated Lizard, was the ability to get a visual comparison between Viviparous Lizard and Wall Lizard, as a result of the numerous wild individuals of latter basking throughout the annexe on walls and bushes; although wild individuals of the former were also present, as they had been elsewhere in the collection, the latter was by far the most commonplace in the grounds of Alpenzoo Innsbruck.
Along with the terrariums which made up the main focus of this annexe, there was one final display which is worthy of particular discussion; a few metres from the row of terrariums, in a portion of the courtyard which stood in direct sunlight, there was a large exhibit showing the different temperatures of varying rock/vegetation/soil, comprising a stone and brick cylinder perhaps five feet tall, topped with several different kinds of rock and bushes, and studded with electronic thermometers. These displayed the temperature of each form of material present within the display, including a cave area which - according to the label on one of the thermometers - was a metre below the surface. This was supplemented by a poster behind, which discussed the way in which reptiles and amphibians will bask in sunlight to warm up, and move to cooler areas if they overheat, and as such are able to thermoregulate despite their endothermic nature. I felt that this was a truly excellent piece of educational material, one of the best I had ever seen at a zoological collection, a judgement which was very much supplemented by the fact that we observed several Wall Lizards and Sand Lizards actually making use of this display to bask!
Having viewed the entirety of the open-air terrarium area, we made our way back downhill in order to rejoin the main footpath through the collection; however, given the quality of these exhibits we resolved to revisit them later in the day, if time and weather permitted.
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