Last year in this period, while walking on a rocky pasture near Ustrine, a small village of the Cres island that faces the western side of the island, in search for the Mediterranean black widow spider (Latrodectus tredecimguttatus), the entomologist Nediljko Landeka and the botanist Slavko Brana spotted here for the first time the endemic species Iris adriatica (Fig.1).
Described for the first time in 1980 by Trinjastic & al. but, it has been validly published only in 2002, with the scientific name Trinajstić ex Mitić. Since then, this endemic species has been found only in the Dalmatian region around the cities of Zadar, Sibenik, Split, Drnis and Unesic and on the islands of Ciovo, Brac, Kornati and Vir.
Iris adriatica´s flowers can be found in early spring (March-April) in mediterranean and sub-mediterranean meadows, within the “Stipo-Salvietum officinals” (a mixture of Stipa grasses and Salvia officinalis) and the “Festuco-Koelerietum splendentis” (a mixture of Festucaand Koeleria splendens grasses) associations as well as in rocky pastures.
Description: Dwarf, rhizomatous plant, perennial but usually leafless in winter. The stem is short (3-5 cm) and the leaves narrow, straight, sometimes sickle shaped, up to 10 cm long, and 0.5-1 cm wide. The flowers, solitary and large at the top of the stem, can be yellow, purple or violet.
Conservation status: Listed as near threatened in the Flora Croatica Red Book. The wild population is decreasing due to succession of the vegetation – the overgrowth of more dominant species (shrubs) due to the reduced utilisation.
The island of Cres (Fig. 1) lies in the Kvarner Gulf, at the Croatian side of the Adriatic sea. Along with Krk, it is the largest Croatian island – both have an area of about 406 km2 . Rich in biodiversity, it hosts about 1300 plant species, many bird and reptilian species, among them various endangered and protected, of which many endemisms.
Tramuntana is the name given to the northern half of Cres; it is also known as the “head of the island” (or, in Latin, “Caput Insulae”). Situated just slightly above the 45th parallel, Tramuntana is widely covered by a dense forest of deciduous trees such as oaks (Quercus pubescens, Qurcus cerris), ashes, hornbeams, elks and chestnuts. Such abundance of trees is favoured by the peculiar climatic conditions, a mixture of continental and Mediterranean – known also as the submediterranean climate.
This area was once mainly used as a pasture and this activity had an important impact in the architecture of the landscape and in the creation of new components of the ecosystem with peculiar microclimates that enriched the primary biodiversity. The inhabitants of Tramuntana practiced agriculture, raised olive trees and forest harvesting in a sustainable way, which ensured an adequate balance between plant and animal species. Sheep (Fig. 2) were important members of the ecosystem because they ensured the maintenance of the grassland in a natural way, and their carcasses were an important food source for the griffon vulture (Gyps fulvus), which inhabits the nearby cliffs. In the last few decades, the amount of sheep drastically decreased, and this led to the decrease of the number of griffon vultures in the island, since sheep are a crucial component of their food chain.
In the same time, the abandonment of the practice of sheep breeding has caused many changes in the vegetation landscape, since the absence of the grazers has allowed the regrowth of the underbrush, made prevalently of Juniperus oxycedrus, Paliurus spina-christi and Crataegus monogyna.
The interior of Tramuntana is mainly covered by forests, however it is possible to see many scattered open patches with small ponds that are an important source of water for the wildlife; there are also many small areas delimited by dry walls where olive trees and old fruit trees still grow; these are excellent pastures for sheep (Fig. 3 and 4).
What caugt my attention is the strong scent that in the whole island begins to spread starting from March, that is released by a big euphorbian species which starts to flower in this period, the Euphorbia characias subsp. Wulfenii (Fig. 5). Typical of the Mediterranean vegetation, this plant can grow up to 180 cm in height. Even though their flowers attract various insect species (Fig. 6 and 7), like all the members of the Euphorbia species, they produce a toxic white sticky sap, which has been used for treating skin excrescences since ancient times.
The following pictures (Fig. 8, 9, and 11) are just an example of the rich biodiversity of Tramuntana. Starting from early spring, a rich bird concert makes a journey in the area particulary pleasent. The forest is espeically rich in song bird species, owls, the hoopoe, the european nightjar, swifts etc. According to curren estimates, of the 136 bird species present in the island of Cres, 65 of them nest in this area. In the whole island there are 32 autochtonous amphibian and reptilian species, among them the common toad (Bufo bufo), the blue-throated keeled lizard (Algyroides nigropunctatus), the common newt (Triturus vulgaris meridionalis), the yellow-bellied toad (Bombina variegata), the agile frog (Rana dalmatina) and the slow worm (Anguis fragilis). One curios thing is that, in the island of Cres and Losinj there are no venomous snakes and still nobody knows the exact reason.
Spring days in the Mediterranean region in May are ideal for observing butterflies and other insects, because during this period most of the plants are in full blossom. Therefore, I try not to miss any potential day for wandering with my dog in search of opportunities for a good picture. During one of these sunny and warm days of May, while trekking on Marlera, I spotted a beautiful sample of Glaucopsyche alexis or, Green-underside Blue, a member of the Lycaenidae family. It was resting on a herbaceous plant, most probably of the Linum genus. However, their life history is accomplished on several members of the Fabaceae family and the larvae are attended by various ant species, as typical for this family of butterflies. This species is widespread and common in many European regions, and it can be easily recognised by the metallic greenish-blue flush on the light-grey hind underside wing. In the specimen on the picture (Photo 1 and 2) it is extended to the edge but in some populations it can be reduced.
Eggs are laid on a flower which will later be eaten by the larvae. The colour of the larvae is variable and depends on the colour of the flower they feed on. It can be greenish, dusky-pink or even bright yellow if they consumed the yellow flowers of Spartium junceum.
Larvae is whitish prior the pupation and at this stage it is attended by various ant species (Lasius, Formica, Myrmica, Camponotus etc.).
At the tip of the Istrian peninsula (Croatia), there is a small peninsula called Cape Kamenjak (Rt Kamenjak), an area of immense beauty which is for good reasons under protection at the level of Protected Landscape. The rugged coastline creates small bays where pebbles and gravels are transported by the waves during windy days. However, most of the coast is rocky, and at the tip forms walls of up to 5m in height (Fig.1).
A stunning view can be seen from the highest point of the peninsula of about 60m, which is created by the crystal blue sea, and the 11 scattered small islands, in one of which dominates a picturesque lighthouse called Porer.
Fig. 2 Porer
Fig. 3 The rugged coastline and the crystal-blue sea
The mediterranean climate of Kamenjak creates the ideal condition for the developement of a rich flora community. In fact, in this small area there are about 500 plant species. Thypical vegetation that can be found here are dry grasslands combined with garrigue and macchia, a degradation stage of an once-existing mediterranean forest.
For nature lovers, spring is the best season to visit. The first flowers appear very early, since the very beginning of February where Croculs biflorus (Fig. 4) emerges first, followed by Romulea bulbocodium, both members of the Liliaceae family. About two weeks later, Ranunculus ficaria will emerge, a small Ranunculaceae with bright yellow flowers and flashy heart shaped leaves. Leaves of this blant ar eadible and vitamin C rich, and are better consumed before flowering; later on, nutrients are realesed for the blooming.
As the days become longer and warmer, more flowers come up. Among numerous yellow Taraxacum sp., the fuxia of Anemone hortensis (Fig. 5) brightens the meadows in April. A close up vew of the inner part of those flowers, formed by the stamens and blue anteras, attracts various insects and sometimes offers a temporary shelter for the nymph stage of green grasshoppers.
Spartium junceum (Fig. 11) and Erica arborea (Fig. 6 and 7) create a spectacular combination in May, when both are in full blossom. However, Erica shows its tiny beautiful flowers already in April.
Fig. 6 Erica arborea
Fig. 7 Erica arborea usually attended by various pollinators
Fig. 8 Cistus incanus
Fig. 9 Cistus monspeliensis
Fig. 10 Macchia with bushes of Cistus monspeliensis