Kos (April 2025)

The third largest island in the Dodecanese, Kos lies in the Aegean sea in a somewhat rectangular shape with a hook-shaped peninsula on its western edge. Its position is anything but isolated; surrounded by the islands of Kalymnos, Pserimos, Nisyros, and Gyali, countless small islets including Nera, Safonidi and Plati, and additionally close to two projections of the Turkish mainland. Kos is situated in a fascinating geographical area, with Turkey in the east visible from much of the island. It is fairly low-lying, with two small mountains; the highest of these is Mount Dikaion, standing at 846m, while Mount Simpatro (430m) follows the southern edge of the island. Staying in Kos town for part of our trip then out towards Therma for the latter, most of our locations were around the north; even on a relatively small island, it is difficult to fit everything into a limited timeframe, so we left much of the southern half of the island unvisited.

To anticipate the reptile and amphibian fauna of the island I looked primarily at the relatively recent Update on the herpetofauna of the Dodecanese Archipelago (Greece) (Cattaneo et al. 2020), which teased a number of sumptuous species; sand boas, worm lizards, worm snakes… In addition, only a handful of fairly common shieldbugs had been recorded from Kos itself, but a few scattered reports from nearby Turkey and some of the other Dodecanese islands suggested that Kos very likely played host to some more unusual species as well.

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LOCATION: Kos Town and surroundings

Within the numerous ruins which are around virtually every corner of Kos town, small forests of yellow and white flowers supported a generous diversity of bees, wasps, flies, beetles and bugs, although parts which seemed to be overgrown were gradually starting to be strimmed down. Regulating the numbers of all of these insects were numerous species of spider, a community largely dominated by salticids and ‘trash-line’ spiders Cyclosa (probably C. sierrae).

Above: Cyclosa, and some bugs: Macroscytus brunneus, Calocoris nemoralis, leafhopper, Cyphostethus tristriatus, Cercopis intermedia

Above: 14-spot Ladybird (Propylea quatuordecimpunctata), 10-spot Ladybird (Adalia decempunctata), Cryptocephalus (probably rugicollis) Graptostethus servus

It was here that we saw the first agamas (Laudakia stellio), chunky grey-brown lizards with rough-looking scales who ruled over the walls and crevices. If you approached them to take their photograph they would nod their heads rapidly (presumably exerting their dominance) but as soon as you were too close for comfort would shimmy into cracks between the rocks. There always seemed to be one quite dominant animal on any one rocky outcrop or old wall, who could frequently be seen chasing off smaller individuals between stints basking at the very top of the rock.

I was rather sad to find my first ever Black Rat (Rattus rattus) lying dead on a footpath in the Hellenistic Gymnasium, with no obvious injuries apart from a little blood on its small hands – perhaps a victim of poison, or a local cat. However, I was grateful for the chance to see one at very close quarters, as they do look rather different to the more familiar Brown Rat. Their ears are large and rounded, and their faces seem ever so slightly more elongate, giving them the appearance of a very oversized mouse. While they can be black, this one was a sort of brindled light brown with a few dark hairs interspersed. This is, of course, the species made famous in Europe for carrying the plague, and eventually was largely replaced in the UK by the Brown Rat.

Probably the most common reptile around these urban areas, moreso in the peripheries where there was a lower density of cats, was the Snake-eyed Lizard (Ophisops elegans), a small and rather nippy species which once sufficiently warmed you generally only heard briefly as it whipped out of sight. These take the place of wall lizards, of which there are none on Kos.

Above: more animals and plants of this area: Limnobium, Tassel Hyacinth (Muscari comosum), Cataglyphis nodus, Green Underside Blue (Glaucopsyche alexis), Rayless Chamomile (Anthemis rigida), Capnodis tenebricosa

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LOCATION: Psalidi Wetlands & Therma

The reservoir and eco-reserve path at the Psalidi Wetlands and the adjoining beach were especially productive. We found that the best time to visit was extremely early in the morning, before dawn, when the sun hadn’t yet risen across the small stretch of sea over the Turkish mountains.

Above: Green Toad (Bufotes viridis)

On one of the occasions we conducted a sunrise visit, groups of small fish had been driven very close to shore by something. The ‘something’ that had driven them in could have been anything from the favourable tide to predators. We saw a small pod of dolphins far out in the middle of the strait, slowly and lazily tracking from left to right, and slightly closer to us the water was occasionally breached with incredible speed and ferocity by what can only have been tuna; leaping in brief but graceful arcs with muscular, inflexible bodies propelled by scythe-shaped tails. On several occasions small fish leapt from the water and seemed to travel an unnatural distance before entering it again – we never got a good enough look to see whether these were flying fish or not.

It was here that I found a peculiar fly which at first glance I took to be a greenbottle, but upon closer inspection had the most beautiful sapphire blue eyes, which didn’t get picked up too well by the camera. It was an interesting thing up close; not quite a greenbottle with such a bristly pronotum and long splayed legs, but also not right for a hoverfly, which had been my other initial guess. Greenbottle turned out to be closer, as the fly was indeed an Oestroidea, of the genus Rhyncomya. This post on Dipterist’s Forum indicates that four species are known from Greece, but I don’t have the skills or resources to identify mine yet.

The fascinating life history of Rhyncomya was highlighted in a very recent paper (March 2025) in which the larvae socially and chemically integrated with termite nests by mimicking the termites themselves, with markings and projections on the larva’s bottom looking like the head end of a termite. Larvae that were already known to do this didn’t appear to have been properly identified before, so this paper matches the mysterious larvae with the family Rhiniinae.

Above: Aegaeobuthus gibbosus

Above: Dahl's Whip Snake (Platyceps najadum) - the only blurry photo I was able to get before it lived up to its name and disappeared!

I also found two great shieldbugs in this area, which I was very happy about. The first was Stenozygum coloratum, a beautifully harlequin-patterned species, and the other was Geotomus ciliatitylus. Both species on the same day (from the same car park) was a result!

The following day, we walked down to Therma beach from the ‘end of the road’ car park. This was a very interesting area and I was sorry to have only visited once, as it had a lot of promise for interesting and under-recorded (or unrecorded) species. We saw a dead Cat Snake (Telescopus fallax) quite close to the car park, a rare opportunity to see this nocturnal species at fairly close range; records of cat snakes from the island are quite scarce. The geology was very volcanic-looking, with dramatic looking slumps of dark, loose stony material with lighter, harder rocks protruding through from beneath (more info). There were two small, deep-looking cave shafts which went into the rock, for quite some distance. I went up to take a closer look, but didn’t attempt to go inside – while the larger one could have accommodated a crouching person, it looked as though there was a wagtail nesting inside. Outside was a mummified goat, a testament to the dry, desiccating conditions.

We did go down onto the beach and dip our hands into the thermal pools, which run at about 45-50 degrees and are pretty hot. They smell slightly sulphurous. They are apparently the result of neighbouring volcanic activity on Nisyros, although the exact geology of the area encompassing Kos is complex.

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LOCATION: Central Kos hills and mountains

In the hills of the island we frequently found tortoises, munching their way through bushels of wildflowers and rolling about like small 4x4s. Kos hosts the Greek or Spur-thighed tortoise (Testudo graeca), which was by far the most conspicuous tortoise of the three species I have seen so far. They were large and very dark overall, with not as much yellow and orange as the Hermann’s. They could be best observed in the afternoon and early evening, when they returned to their burrows – the impression was that they had a burrow (or at least a shallow hole or depression) that was used regularly to rest in, and on one occasion we found two individuals resting together in a small sheltered bush. When they are immobile they’re surprisingly difficult to see. In the meadows and groves there were numerous little criss-crossed paths which looked as though they marked well used trackways. They were absolutely charming.

I missed a small but interesting 'target species' on one tortoise: the tortoise tick Hyalomma aegyptium, which I only saw after reviewing the photos.

The environment is very unusual-looking, with different rock types overlaying one another; particularly in the Dikeos mountain area and to the north-east, there is a rather striking combination of sedimentary material and limestone. It is perhaps these differing rock types that create peculiar blankets of lowland meadow before the more upland pine starts, cropped by goats and dotted with the occasional large boulder.

Here everybody found a number of unusual species, including an ant-cricket (Myrmecophilus sp) and an owlfly larva (Bubopsis sp.), also in an ants nest, a genus which I was excited to finally see alive and in the wild.

Above: small staphylinids (Pselaphinae) with some hydrophilids(?)

Above: Horvathiolus superbus, Staria lunata, Nebria testacea, buprestid

Above: Neoasterolepisma sp.

Above: another strange beetle we saw in this area was a rather long-legged dung beetle, Pseudotrematodes frivaldszkyi, which was 'galloping' across the ground using pairs of legs at once and dragging the back pair, as opposed to an alternating walk. Some dung beetles are known to do this (more info) which may help with stabilising vision when walking over uneven surfaces.

Above: Worm Snake (Xerotyphlops vermicularis)

We passed a suitably overgrown patch of ground at the side of the road next to a small reservoir or lake. Tom saw, but failed to photograph or catch, a large sheltopusik. The lake was quite prettily designed, with some islands and even a small boat in there, but it was rather compensated for by the strong stench of death wafting over the sides to assail you; this was the result of several dead geese and a dead cat floating in the water, being gradually disembowelled by a platoon of large terrapins (several Trachemys and what was probably an adult Mauremys rivulata). Despite the rancid water, litter and pollutants, the terrapins looked incredibly healthy and happy. Each to their own, I suppose.

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LOCATION: Palio Pyli

Pyli castle was the end destination of a wiggly drive through the hills and mountains around the centre of Kos. The castle and surrounding ruins date back to the 11th century, and sits at an altitude of about 300 metres (more info).

There are two primary walks that can be taken directly up the hill from the road; the left-hand fork is relatively flat and winds around the hill, while the right-hand path goes up an incline to the castle and adjoining Ottoman baths. Amazingly, most of the way up the hill a little taverna is perched, which we were informed by a local will make ‘whatever you want’. I didn’t end up going, although while walking the stony route to the top I could hear muffled music and voices through the trees. To reach the very top of the hill for the castle and view is even steeper, a hard to see offshoot of the uphill path. For us it felt a little laborious on a warm evening, but the ever-present goats were more than comfortable trotting nimbly up and down the ruins at the very top of the hill.

Above: Jackdaw (Corvus monedula soemmerringii), goat, Egyptian Locust (Anacridium aegyptium), some sort of Trifolium(?), and as-yet unidentified flowers poking through.

There were more Snake-eyed Lizards here than I’d seen anywhere else, and they were quite bold too, sitting out and allowing themselves to be photographed rather than scuttling off into the undergrowth. This was very useful for being able to see their strange unlidded eyes.

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LOCATION: Igroviotopos Alikis – Salt Lake

We of course managed to fit in an evening at the lagoon, best known for its large numbers of flamingos (which can be seen with binoculars all the way from Pyli castle!) but also featuring an unusual sandy dune habitat.

I could have spent all day lying on the floor observing small bugs between the plants poking through the sand. There was a huge number of interesting species. I managed to see several new and exciting shieldbugs here, including Microporus nigrita, Byrsinus sp. and at least one Sciocoris sp., as well as more common species such as Codophila varia.

Above: Microporus nigrita (first three photos) Byrsinus sp. (bottom right)

Above: Codophila varia (and interrupted by a Tentyria sp.) coreid, and Sciocoris

Small, fast-running tenebrionids weaved between larger and more cumbersome Erodius orientalis, which endlessly pursued organic matter to feed on between the dry, shifting micro-dunes.

The most interesting species we saw at this site was probably Lertha ledereri, a rather uncommon species distributed in Turkey and some of the eastern Greek islands. It was a large, beautiful and delicate-looking neuropteran, with a pair of ornate ‘spoons’ on the end of long wing-threads. The species can be found flying at night as well as during the day (more info).

Above: Lertha ledereri

Other insects from the dunes (above) included many grasshoppers, a single small Onthophagus sp. (taurus?) and a beautiful bristletail with an unusual 'saddleback' marking - Silvestrichilis sp.

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LOCATION: Zia

We took another evening trip to Zia, and took a leisurely walk up the path that eventually leads to Mount Dikaion, passing through the beautifully picturesque little town, outwards past little olive groves and fenced-in goats. There was a different and interesting fauna here, with these little meadows dominated by large numbers of Eastern Festoon (Allancastria cerisyi), a species I had never seen as an adult before.

Despite these numbers, it was curious that we didn’t notice much Aristolochia, their foodplant, although doubtless there had to be enough somewhere nearby to support the population. The landscape, while not far-reaching, offered mesmerising views up into the mountain, white limestone with the dark contrast of pines, and the occasional spring green of the kermes oak. The warbling of a single blackbird to a backdrop of gentle goat bells was a supremely relaxing experience.

Under some rocks was a curious little spider with a rather rounded appearance. We at first mistook it for an Eresus, but could find no species that it closely resembled. After a bit of further diving into the recorded spiders in Greece and Turkey, it was revealed to be a palp-footed spider, Palpimanus, a predator of other spiders, particularly salticids (of which there seemed to be a plentiful supply).

Above: Palpimanus and potential prey, Philaeus chrysops

Above: Melaphe vestita (probably)

The highlight of this little excursion was undoubtedly a Turkish Worm Lizard (Blanus strauchii) an unexpected find towards the end of our trip but a very welcome one. For some reason, I expected worm lizards to feel somewhat hard and scaly (like a skink) but in fact it was rather soft and almost velvety, a continuous tube of muscle with tiny eyes reduced to little more than a light-sensitive smudge underneath a scale.

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LOCATION: Asklepion meadow

Fairly close to the Asklepion itself, which is worth a visit, we stopped at a small meadow grown in with flowers and with a small agricultural path, which we followed for only a few tens of metres. There was no need to walk particularly far, as every square inch seemed to be overflowing with unusual insects, and the air was filled with the flight of festoons. I was amazed to find a mating pair of the uncommon shieldbug Derula flavoguttata, which I was sure I would eventually see in France (where the highest concentration of records are) and not in Greece, where it seems much rarer.

Above: D. flavoguttata

Above: Steatoda paykulliana, Scolopendra cingulata, Carabus coriaceus, Xylena sp. caterpillar

Above: an ant mimicking jumping spider, perhaps Leptorchestes?

Another meadow, much further up in the mountains near the church of Panagia Agios Dimitros and close to the semi-ruined village nearby, was just as productive as the lower meadow, situated under the olive groves and humming with bees and beetles. Here I found Stagonomus amoenus, a pair in cop, feeding on a giant lamiaceae alongside many bees, including possibly Habropoda tarsata(?)

We lifted a suitably-placed board among some long grass and discovered something which was small, pink and somewhat worm-like, but this was no worm lizard or worm snake… it was a baby shrew! It can’t have been more than a few days old – its eyes were still closed and it was making small, nearly inaudible squeaks. We put the board gently back pronto, as the parent would doubtless be back for it within moments. I’m unsure what species of shrews are found on Kos, as we saw only this infant and another dead adult which I did not closely examine. On iNaturalist, there are no shrews recorded from the immediate surroundings of Kos, but further afield produces Güldenstädt's Shrew (Crocidura gueldenstaedtii) and Pygmy White-toothed Shrew (Suncus etruscus), while a search of papers revealed Crocidura suaveolens recorded from Kasos and Astipalaia.

At a different spot, even more remote, Tom found a palpigrade, which we had only ever encountered once before, in a cave on Madeira. The genus Eukoenenia (to which this one most likely belonged) has several representatives in Greece, but as with many small and delicate species there was no way we could positively identify this one from photographs alone.

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LOCATION: Plaka Forest

On our way back to the airport, we stopped off briefly in Plaka Forest, just past Antimachia, a dry pine woodland with an understorey of rhododendron. Sadly, the introduction of enormous numbers of peacocks and cats has probably put paid to most life that may have had the potential to live in the woodland – with the exception of a few woodlice, there was virtually nothing in the primary clearing.

On the way back we stopped by the side of the road with the hope of seeing something slightly more native. Here, I found an interesting spider, moving with incredible rapidity among the stems of various plants and grasses. It had rather good velvet ant markings, although I haven’t identified the species yet.

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Kos made a lasting impression in more ways than one, as I discovered the day after getting back when I looked in the mirror and found a big fat tick attached to my neck. However, this in no way dampened an immensely enjoyable trip crammed with interesting wildlife and offering tantalising glimpses into the environments of mountains, forests, and meadows.

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Shieldbugs:

• Byrsinus sp.

• Codophila varia

• Carpocoris mediterraneus mediterraneus

• Derula flavoguttata

• Geotomus ciliatitylus

• Graphosoma italicum

• Graphosoma semipunctatum

• Microporus nigrita

• Sciocoris sp.

• Stagonomus amoenus

Other invertebrate highlights

• Eastern Festoon (Allancastria cerisyi)

• Eukoenenia sp.

• Lertha ledereri

• Palpimanus sp.

• Pseudotrematodes frivaldszkyi

• Rhyncomya sp.

Reptiles and amphibians

• Agama (Laudakia stellio)

• Balkan Terrapin (Mauremys rivulata)

• Cat Snake (Telescopus fallax)

• Copper Skink (Ablepharus kitaibelii)

• Dahl’s Whip-snake (Platyceps najadum)

• Green Lizard (Lacerta diplochondrodes)

• Green Toad (Bufotes viridis)

• Large Whip-snake (Dolichophis jugularis)

• Ocellated Skink (Chalcides ocellatus)

• Sheltopusik (Pseudopus apodus) dead only

• Snake-eyed Lizard (Ophisops elegans)

• Spur-thighed Tortoise (Testudo graeca)

• Trachemys sp.

• Turkish Worm Lizard (Blanus strauchii)

• Worm Snake (Xerotyphlops vermicularis)