The Whiskered Tern (Chlidonias hybrida) occurs widely across the world in Africa, Europe, Asia and Australia. It is rare in Germany and only breeds in Mecklenburg-Western Pomerania and Saxony-Anhalt. Evidence of breeding was also recently reported in Brandenburg. In other parts of the world, however, this Chlidonia tern is the most common of the genus.
Even in the breeding plumage, Chlidonia terns are not always easy to distinguish from one another or from some of the smaller Sterna terns. This is all the more true if the breeding plumage has not yet developed or the species has moulted into non-breeding plumage. I find the Chlidonia terns to be particularly tricky in non-breeding plumage, especially in the first calendar year, when they have lost their conspicuous young plumage, the plumage is a mixture of molten (light) and old (dark) feathers and the contrasting drawing of the magnificent dress is far from being developed.
I have therefore tried to get as much information as possible for the best possible identification of the species of young Chlidonia terns.
Many identification guidesbooks emphasize the differences in physique. The best book is definitely still the (English) Helm Identification Guides “Terns” by Klaus Malling Olsen from December 1994. It is now sold as an antiquarian bookshop at a significantly higher price than it was then in the store and has Continue reading ID immature Chlidonia’s terns→
Im Nordosten Polens, etwa 200 Kilometer nordöstlich von Warschau, erstreckt sich eine einmalige Sumpflandschaft, die von vielen deutschen Tierfotografen inzwischen nicht mehr vernachlässigt wird. Der Biebrza-Nationalpark liegt zwar eigentlich nicht gleich vor unserer Haustür, doch stellt er für etliche Arten die westlichste Verbreitungsgrenze dar. So kann man an der Biebrza nach wie vor viele in Europa sonst schwierig zu sehende Arten wie Doppelschnepfe, Seggenrohrsänger oder Schreiadler relativ leicht sehen. Mit dem Auto schafft man die Fahrt an einem Tag. Von Berlin führt die Route über die A2 und dann ab Frankfurt/Oder weiter nach Poznan-Warschau-Bialystok.
Der Biebrza-Nationalpark, der „Europäische Amazonas” schützt ein riesiges Flußsystem mit ausgedehnten Feuchtwiesen, Wasserflächen, Sümpfen und Auwäldern. Der Park hat eine Größe von etwa 60.000 Hektar. Geprägt wird das Gebiet von dem Biebrza-Becken, einem außergewöhnlich weitläufigen Continue reading Vogelfotografie im Biebrza-Nationalpark im Frühjahr→
Bird richness on the northern shore of the Caspian Sea is amazing. Caspian Sea is counted the largest inland body of water in the world. More than 100 rivers provide inflow to the Caspian, with the Volga River being the largest. Pristine floodplain forests, flooded grasslands to the horizon, eagles on almost every tree. A trip to the lowlands south of Astrakhan in southern Russia is not easy due to the distances and border formalities. But the only alternative is a trip to the Danube delta. To ease preparation, it was decided to participate in a guided trip in the first half of May 1998 to Volga delta. After that, the trip continued to the hill – lakes region and the feather grass steppe and the semi-desert north-west of Astrakhan.
Today saw a remarkable influx of White-winged Tern, Chlidonias leucopterus, in several parts of northern Germany. Observations were recorded from the Seeburger See (lake) near Goettingen (1 indiv.), from the Wedeler Marsch near Pinneberg (13 indiv.), from the Winsener Marsch near Winsen an der Luhe (2 indiv.), from the Sulzdorfer Wiek on the islands of Fehmarn (3 indiv.), from the Okeraue near Braunschweig (1 indiv.), from the “Langes Moor” near Cuxhaven and a maximum of 252 indiv. from Dreye (a southern suburb of Bremen in Niedersachsen.
Mid of may is generally a good time to see White-winged Terns. In the evening of May, 14th of 2007 more than 200 individuals of these terns flew over the nature reserve “Streng”. Sometimes the terns picked in front of the observation tower in short hovering flights insects from the reed bed. In the meantime other White-winged Terns flew over the meadows where they were seen in company with Gulls, Common Black-headed Gull (Larus ridibundus). Remarkably, only one Black Tern, Chlidonias niger, mixed among the many White-winged Tern.
Looking at field guides like „ Collins Bird Guide“ from Peter Grant, Dan Zetterstrom, Lars Svenson and Killian Mullarney the ID look quite simple. But even in the breeding plumage Chlidonias – or Marsh – Terns can cause some headache identifying in the field. Then even the Whiskered Tern (Chlidonias hybridus) can be confused with the Black Tern (Chlidonias niger) especially if seen in poor light facing the sun when both terns look remarkably dark.
A remarkable fact is, that the scientific name arises from Whiskered Tern´s similarities in appearance to the Black Tern but also to the (more whitish) Sterna – Terns.
To distinguish Black Tern (Chlidonias niger) and the 3rd member of the genus, the White-winged Tern (Chlidonias leucopterus) is even more sophisticated. The wings do not always look decidedly white – as the name suggests. Often the upper parts of the wings do not look so much brighter than in the Black Tern. On the other hand a good deal of black is shown in the underwing-coverts. Hence the black & white contrast of the underwings might be the best criterion to distinguish flying White-winged Tern from Black Tern in the field.
In flight, all these terns appear slim – less so the Whiskered Tern. The wing-beats are full and dynamic, and flight is often erratic as they descend to the surface for food. Chlidonias – or Marsh – Terns do not dive for fish, but forage on the wing picking up items at or near the water’s surface or catching insects in flight. They mainly eat insects and fish as well as amphibians. The feeding habit is quite unlike Continue reading Identifcation of flying Chlidonias Terns in breeding plumage→
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