'Reason for Hope'

Reintroduction of the Northern  Bald Ibis in Europe


Bairlein et al.

Bairlein F, Fritz J, Scope A, Schwendenwein I, Stanclova G, van Dijk G, Meijer HAJ, Verhulst S & Dittami J 2015.

Energy Expenditure and Metabolic Changes of Free-Flying Migrating Northern Bald Ibis.


Migratory birds can perform extraordinarily long flights during migration but the physiological processes that make these feats possible have only recently come into focus. It has generally been assumed that flight has high energetic and physiological costs and that the ability to perform long-distance flights was contingent on the evolution of extraordinary physical adaptations to undertake the journey. 

read more


Fritz & Unsöld

Fritz J & Unsöld M 2015.

Internationaler Artenschutz im Kontext der IUCN Reintroduction Guidelines: Argumente zur Wiederansiedlung des Waldrapps.

Vogelwarte 53, 2015: 157 – 168

Seit bald 14 Jahren beschäftigen wir uns mit dem Waldrapp Geronticus eremita, einer charismatischen Ibisart mit extravagantem Aussehen. Das „Waldrappteam“ (www.waldrapp.eu) formierte sich 2002 als private Initiative unter Mitwirkung von zahlreichen Volontären und mit diverser Unterstützung durch eine zunehmende Anzahl von Institutionen wie Zoos und Universitäten im In- und Ausland. 

read more


Voelkl et al.

Voelkl B, Portugal SJ, Unsöld M, Wilson AM & Fritz J 2015.

Matching times of leading and following suggest cooperation through direct reciprocity during V-formation flight in ibis.

Proceedings of the National Academy of Sciences

One conspicuous feature of several larger bird species is their annual migration in V-shaped or echelon formation. When birds are flying in these formations, energy savings can be achieved by using the aerodynamic up-wash produced by the preceding bird. As the leading bird in a formation cannot profit from this up-wash, a social dilemma arises around the question of who is going to fly in front?

read more


Portugal et al.

Portugal SJ, Hubel TY, Fritz J, Heese S, Trobe D, Voelkl B, Hailes S, Wilson AM & Usherwood JR 2014.

Upwash exploitation and downwash avoidance by flap phasing in ibis formation flight.

Nature, 505, 399-402

Many species travel in highly organized groups. The most quoted function of these configurations is to reduce energy expenditure and enhance locomotory performance of individuals in the assemblage. The distinctive V formation of bird flocks has long intrigued researchers and continues to attract both scientific and popular attention.

read more


Serra et al.

Serra G, Lindsell JA, Peske L, Fritz J, Bowden, CGR, Bruschini C, Welch G, Tavares J & Wondafrash M. 2014.

Accounting for the low survival of the Critically Endangered northern bald ibis Geronticus eremita on a major migratory flyway.

Oryx, 1-9

The poor survival rate of immature northern bald ibises Geronticus eremita during their first years spent outside the natal site is driving the last known wild colony of the migratory eastern population to extinction. To inform emergency conservation action for this Critically Endangered species we investigated the distribution range and behaviour of immature birds in passage and wintering areas, and the threats to which they are subject. 

read more