'Reason for Hope'

Reintroduction of the Northern  Bald Ibis in Europe

Fritz et al. 2020


Fritz J, Eberhard B, Esterer C, Goenner B, Trobe D, Unsöld M, Voelkl B, Wehner H & Scope A (2020)

Biologging is suspect to cause corneal opacity in two populations of wild living Northern Bald Ibises.

Avian Research 11, 38 (2020). https://doi.org/10.1186/s40657-020-00223-8

In this paper, we present evidence that biologging is strongly correlated with eye irritation, suggesting a causal relationship with obvious impairing effects for the affected individuals. A migratory population of Northern Bald Ibises (Geronticus eremita) is reintroduced in Europe, in the course of a LIFE+ project (LIFE Northern Bald Ibis). Since 2016, an increasing amount of birds were equipped with solar-powered devices, fixed on the upper back, as this is the more sun-exposed position. From 2016 to 2018, a total of 25 birds were affected by an opacity in the cornea of one eye (unilateral corneal opacity; UCO), with varying intensity up to blindness. However, only birds carrying a device on the upper back were affected (2017 up to 70% of this group). In contrasts, none of the birds which carried devices on the lower back ever showed UCO symptoms.

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Fritz et al. 2019


Fritz J, Unsoeld M & Voelkl B (2019)

Back into European Wildlife: The Reintroduction of the Northern Bald Ibis (Geronticus eremita)

Bookchapter in: Scientific Foundations of Zoos and Aquariums: Their Role in Conservation and Research (Kaufman AB, Bashaw M, Maple T Edtrs.), Cambridge University Press; ISBN 978-1-316-64865-0. DOI: 10.1017/9781108183147.014

August 26, 2015, 09:40: in the morning after a cold night, the sun warms up and removes the last patches of fog. We are at the airfield of Mauterndorf in the Austrian Alps at 1,100 m above sea level; a team of 14 people and 31 juvenile northern bald ibis. Despite the wonderful surroundings, our mood is rather depressed. Our aim is to lead the group of ibis across the Alps to northern Italy.

Two hours ago, two microlight aircrafts started at the airfield, each with a human foster parent in the back seat. At the beginning, the birds followed them willingly, as we expected them to do. But after ten minutes, the birds headed back to the airfield.

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Wirtz et al. 2018


Wirtz, S., Böhm, C., Fritz, J., Kotrschal, K., Veith, M. & Hochkirch A (2018)

Optimizing the genetic management of reintroduction projects: genetic population structure of the captive Northern bald ibis population.

Conservation Genetics 19/ 4: 853–864. DOI: 10.1007/s10592-018-1059-6

Many threatened species are bred in captivity for conservation purposes and some of these programmes aim at future reintroduction. The Northern Bald Ibis, Geronticus eremita, is a Critically Endangered bird species, with recently only one population remaining in the wild (Morocco, Souss Massa region). During the last two decades, two breeding programs for reintroduction have been started (in Austria and Spain). As the genetic constitution of the founding population can have strong effects on reintroduction success, we studied the genetic diversity of the two source populations for reintroduction (‘Waldrappteam’ and ‘Proyecto eremita’) as well as the European zoo population (all individuals held ex situ) by genotyping 642 individuals at 15 microsatellite loci.

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Voekl B & Fritz J 2017


Voekl B & Fritz J (2017)

Relation between travel strategy and social organization of migrating birds with special consideration of formation flight in the Northern Bald Ibis.

Philosophical Transactions of the Royal Society B 372: 20160235. http://dx.doi.org/10.1098/rstb.2016.0235.

A considerable proportion of the world’s bird species undertake seasonal long distance migrations. These journeys are energetically demanding. Two major behavioural means to reduce energy expenditure have been suggested: the use of thermal uplifts for a soaring-gliding migration style and travelling in echelon or V-shaped formation. Both strategies have immediate consequences for the social organization of the birds as they either cause large aggregations or require travelling in small and stable groups. Here, we first discuss those consequences, and second present an analysis of formation flight in a flock of Northern Bald Ibis on their first southbound migration.

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Stanclova et al. 2017


Stanclova G, Schwendenwein I, Merkel O, Kenner L, Dittami J, Fritz J & Scope A (2017)

The effect of flights on hematologic parameters in Northern Bald Ibises (Geronticus eremita).

Journal of Zoo and Wildlife Medicine 48(4): 1154–1164

Under the project of ‘‘Human-Led Migration,’’ the authors had the unique opportunity to accompany hand-raised Northern Bald Iibises (NBIs; Geronticus eremita) during migration, which occurred in stages from Bavaria, Germany, to southern Tuscany, Italy. The aim of this study was to investigate the immediate effects of flight, with respect to flight duration, and the more delayed recovery effects on hematologic variables. A total of 31 birds were sampled. Blood samples were taken immediately before takeoff, after landing, and 1 day after the flight. The data show that the decrease of tWBC is mainly caused by the lymphocyte fraction and that NBIs need more than 1 day to reverse the postflight changes in some hematologic values.

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Sperger et al. 2017


Sperger C, Heller A, Voelkl B & Fritz J (2017)

Flight strategies of migrating Northern Bald Ibises: Analysis of GPS data during human-led migration flights.

AGIT ‒ Journal für Angewandte Geoinformatik, 3-2017

In the past, studying birds in free flight has been extremely difficult, though recently developed technologies, e.g. small and light GNSS-data loggers, allow gaining new insights into the behaviour and flight strategies of birds. As logger weight is still a limiting factor and battery size dictates the number of positional fixes, knowledge of species-specific flight strategies is still restricted. During a human led migration of fourteen juvenile northern bald ibis in 2014 we could, for the first time, record a complete GNSS dataset from all flock members over a four day migration from Salzburg to Tuscany. Data were collected by Waldrappteam, in the course of an EU-LIFE+ project. The following paper analyses this dataset. The aim of this paper is to show the different flight strategies of migratory birds and furthermore the capabilities and limitations of the used GPS-modules for the study of free-flying birds.

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Fritz et al. 2017


Fritz, J., Kramer, R., Hoffmann, W., Trobe, D. & Unsöld, M. (2017)

Back into the wild: establishing a migratory Northern bald ibis Geronticus eremita population in Europe.

International Zoo Yearbook 51: 107–123; DOI: 10.1111/izy.12163

From the perspective of zoological institutions reintroduction projects offer many possibilities to link conservation and research programmes. An example of the multi-layered and diverse contributions that zoological institutions in general and, specifically, Vienna Zoo, Austria, can make is the reintroduction of the Northern Bald Ibis Geronticus eremita in Central Europe. The involvement of zoological institutions ranges from the provision of eggs or birds for release trials, to financial and advocacy support, including with government agencies and non-governmental organizations. Through involvement at a steering level at the coordinative association ‘Förderverein Waldrappteam’ and as a partner in the EU LIFE+ reintroduction project, Vienna Zoo directly contributes to the shape of the reintroduction project for this Critically Endangered species and provides much more than technical and infrastructural support.

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Bairlein et al. 2015


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.

PLOS ONE 10(9): e0134433

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. 

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Fritz & Unsöld 2015


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. 

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Voelkl et al. 2015


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 112/7: 2115–2120

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?

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Portugal et al. 2014


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.

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Serra et al. 2014


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, 49: 312-320

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. 

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Fritz J. 2020


Fritz J. 2020

Zweite Chance für das Überleben in freier Wildbahn sichern

ProntoPro Blog

Dr. Johannes Fritz ist Biologe und selbständiger Unternehmer. Der 52-Jährige arbeitet – im Auftrag eines Fördervereins – vorwiegend im Europäischen Artenschutzprojekt zur Wiederansiedlung des Waldrapps. Was sich hinter „menschengeführter Migration von Zugvögeln“ verbirgt, welchen technischen Probleme es dabei zu meistern gilt und wie schwierig die Auswilderung der Ibisart ist, erzählt Johannes anschaulich im folgenden Interview.

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