Q2 2020 – Stay Home (but don’t forget to take your camera along!)

As SARS-CoV-2 spoiled our Mediterranean travel plans in spring 2020, we spent a lot of time in our local playground called the “Eifel”, the name of the German part of the Ardennes mountain complex. This hilly area is characterized by cool, humid sub-Atlantic climate. Compared to the Mediterranean, biodiversity in Western Germany is quite low, as this area has been an arctic tundra only some 12k years ago. In the postglacial era, in particular mobile and flexible species were able to expand their distribution range northwards. Poor north, rich south! However, local geology has generated a diversified habitat patchwork in our area:

The higher altitudes (up to 700 m) are covered with mountainous woodlands and meadows. These hills consist of some 400 million year old Devonian silicate rock with rather acidic soil.
Interspersed in between the silicate rock, some limestone troughs are home for xerophilic species.
The deep river valleys with their particularly warm local climate are habitat even for some sub-Mediterranean species.

In consequence of this habitat variety, the area has been identified as one of the 30 German hotspots within the national biodiversity strategy (see detailed map: https://biologischevielfalt.bfn.de/fileadmin/NBS/documents/Bundesprogramm/2_Hotspots/Detailkarten/hotspots14.pdf).

Our area with the places which can be reached within about 30 minutes. On the left, the Belgian border (which was a hard border, during lockdown) is marked in yellow; top right, the Rhein river can be seen, the meanders bottom right are the Mosel river.

With regard to lizards, it has to be mentioned that our area is populated by only three Lacertid species (Lacerta agilis, Podarcis muralis, Zootoca vivipara). Hence, a generalist approach including insects and plants seems more appropriate to give an impression of the local nature. As each time has its highlights, our picture galleries below are structured by months.

April - sunny days and frosty nights

April is the time when first spring flowers come up despite of the meadows frequently being covered by hoarfrost in the morning. It was exciting to watch nature subsequently re-emerging after winter.

1. High altitudes

The higher altitudes of our area are populated by only two repitle species: Zootoca vivipara and Anguis fragilis. Both species give birth to fully developed juveniles - laying eggs seems no good idea in this rough climate! The heathlands on acidic soil have their own flora with some atlantic species reaching their eastern distribution limit in our area.

No doubt, it's spring! (Anemone nemorosa)

Zootoca vivipara basking on dry leaves, which warm up rapidly in the sun.

Vinca minor is one of the first pollen sources for insects. Like its relative, the Mediterranean Nerium oleander, it belongs to the dogbane family.

A forest pond - the rock in front consists of Tertiary silicate, which emerged after silica poured into loose sand.

...and the frogs as well (Rana temporaria)

The heathland still looks like winter, but the lizards can already be observed basking:

Zootoca vivipara: A rather dark specimen

Narcissus pseudonarcissus, an Atlantic species which reaches its eastern distribution in our area.

Fritillaria meleagris, another sub-Atlantic species, occurs in two colour morphs.

Geum rivale frequently can be found, as indicated by its Latin name, at the shores of creeks.

Genista pilosa, one of five Genista species in our area.

Oxalis acetosella with striking pinkish colour.

Milvus milvus with prey: Germany has major responsibility for the conservation of this beautiful species, as over 50% of the global population live here.

2. Visiting the limestone areas

The limestone troughs with their warm microclimate are inhabited by 4 reptile species: Besides of Zootoca vivipara and Anguis fragilis, these are Lacerta agilis and Coronella austriaca.

Furthermore, the poor, xeric grasslands, which are used as extensive sheep pastures, are home for interesting spring flowers.

Dry slopes with the early flourishing Prunus spinosa.

Lacerta agilis basking in the grass. This species is widespread in the limestone areas but it occurs in very low densities.

Anguis fragilis, not interested in being photographed.

Globularia bisnagarica, a member of a Mediterranean genus with only one species being native in our area.

The caterpillars of Hamearis lucina feed on Primula plants...

...and here's the food: Primula elatior.

Pulsatilla vulgaris, a member of the Ranunculaceae family, is a very popular spring flower.

The first orchid species which can be seen in our area: Orchis mascula

limestone rocks, overgrown with moss. Such habitats in light forests host a rich flora.

Lathraea squamaria, a parasitic plant which parasites on beech roots.

Anacamptis morio, the second orchid species which can already found in April.

3. Short trip to Ahr Valley

The Ahr river, which runs from central Eifel eastwards to the Rhine river, has digged a steep valley into the silicate rock. The valley slopes have some dry and warm habitats which are inhabited by Podarcis muralis which in Germany occurs in areas with favorable climate, only. The Ahr population is connected with the Wall Lizards from the Rhine valley. It belongs to subspecies brongniardii.

A southern exposed slope of the Ahr valley.

A male watching a female which is searching for food in the loose soil.

Such dry and rocky slopes are perfect habitats for Podarcis muralis.

Amelanchier ovalis: In Germany, this plant occurs in very warm habitats only.

May - dry like summer

In early May, winter was back. Temperatures of -6 °C killed a lot of insects, and plants were damaged. However, nature recovers fast. The following weeks were warm and dry, but, due to permanent drought, vegetation grew extremely slow.

1. Spring in the high altitudes

Nature's creatures have to be tough in an area where frost and snow are still possible in May. Anyhow, this time of the year demonstrates impressively the power of nature with flowers sprouting in the heathlands and numerous insects which seem to appear "over night".

Being less popular than the limestone areas with their amazing vegetation, the heathlands on silicate soil have their own specific flora and fauna. Meanwhile, this habitat type is listed in the European Flora Fauna Habitat Directive (92 /43 /EEC) as "Species-rich Nardus grasslands, on siliceous substrates in mountain areas (and submountain areas , in continental Europe)". The German term for this is "Borstgrasrasen" - for sure one of the coolest words in German language!

Pedicularis sylvativa, a semi-parasitic plant from the Orobanchaceae family. The sharp juice of these plants has been used again head louses in former times (but we do not know, whether this helped).

Ciconia nigra, a shy species which breeds in big forests where it feels undisturbed.

Orobanche rapum-genistae, a parasitic plant which parasites on Cytisus scoparius.

Polygonatum multiflorum, a member of the Asparagaceae family.

Alchemilla vulgaris with dramatic sky. The genus name refers to medieval alchemists, maybe because of their water-repellant leaves which make water drops appear like quisilver.

The roots of Meum athamanticum are used to produce a spicy liqueur.

Viola palustris grows on pour, wet substrates

Saxifraga granulata, a common plant on siliceous meadows

Nardus stricta - the plant from which this type of habitat derived its name (Nardetum strictae)

A grasshopper trying to attract females with its chirping noise.

Copula of Cantharis fusca, a species feeding on other insects.

A parasitic bee of the genus Nomada. It lays its eggs in the nests of other wild bees where their larvae feed on the host larvae.

Megachile sp. - some members of this genus cut pieces of leaves to line their nests.

Cicindela campestris, a fierce predator of small insects and Arachnids.

2. Early summer in the xeric habitats

The limestone habitats and the warm river valleys can be hot like summer already in May. Hence, nature develops much faster compared to the mountain meadows. And a short trip to Ahr valley is always good when you are longing for reptiles.

Orobanche teucrii: Note the leaves of the host Teucrium chamaedrys bottom right.

Coronella austriaca, basking on a dry stone wall in the centre of a village

A beautiful parasitic bee: Melecta luctuosa...

June – Atlantic mix of rain and sun

The spring drought ended in early June and due to frequent rainfalls the landscape turned lush and green. Northern Atlantic summer...

1. highlights of the limestone areas

The limestone troughs in our area are famous for their numerous orchid species - a must for naturalists in early summer. Furthermore, the dolomite rocks of Gerolstein host a population of Podarcis muralis. This is remarkable, as most German populations of this species occur on schist or sandstone, but not on limestone - maybe, because this kind of rock doesn't store the heat very long. Anyway, the Gerolstein population seems to be vital.

This kind of sparse meadows bears an amazingly rich flora.

Ophrys holoserica reaches its northern distribution limit in our area

These annoying hikers frequently photo bomb the orchid shots (Platanthera chlorantha)

A meadow with Phyteuma orbiculare, Trifolium montanum, Gymnadenia conopsea and Listera ovata

What's behind this fence? (Motacilla alba)

Milvus milvus: This protected species is the best weapon to avoid annoying wind parks.

Orobanche caryophyllacea with host (Galium mollugo)

Orobanche elatior with host (Centaurea scabiosa)

Female Podarcis muralis doing some signalling with its foreleg. Some recent studies indicate that this is some kind of anti-predator behavior.

Bee hotel: Campanula trachelium - note the tiny bee in the bottom center, which uses these flowers as a source of food and as a place to sleep at night.

2. Back to the mountain meadows!

Early June is the best time for the higher altitudes: The meadows aren't mowed or grazed by sheep yet and show their rich flora. Even in June, warm temperatures can be interrupted by foggy weather or a cold blowing wind. This rough climate generates a unique, magic atmosphere.

A colorful meadow with Trifolium pratense and Senecio jacobaea (The owners of cattle try to remove this poisonous plant, which is - obviously - a sisyphean undertaking).

Cirsium palustre, an important food source for insects in the poor heathlands

Zootoca vivipara perfectly copes with the rough climate. They prefer wood for basking, as it gets warm quickly in the sun.

Jasione montana: despite of its appearance, this delicate plant belongs to the Campanulaceae family.

Even such poor grasslands with very few flowering plants host an interesting insect fauna:

A meadow with Arnica montana, Dactylorhiza maculata and Pseudorchis albida. The latter one is exteremely rare in our area.

Gyps fulvus doesn't breed in Germany but can sometimes be observed roaming in our area. This group presumably had to take a rest because of bad thermic conditions.

Potentilla palustris grows in oligotrophic swamps

Pyrola rotundifolia, hidden deep in the forest

A species-rich valley pasture (with Platanthera bifolia in front)

Copula of Rutpela maculata on Leucanthemum vulgare

Rutpela maculata and Pachytodes cerambyciformis on Knautia arvensis

Another cool parasitic bee from the genus Coelioxys...

...and its potential host: Megachile willughbiella

Pastures being grazed by sheep sporadically are an important factor to preserve biodiversity.