Owls (Strigiformes): Annotated and Illustrated Checklist

371 Pages·2006·19.81 MB·English

by  Friedhelm Weick (Author)

Friedhelm Weick
Owls (Strigiformes) · Annotated and Illustrated Checklist
Eulen (Strigiformes) · Kommentierte und illustrierte Artenliste
Friedhelm Weick
Owls (Strigiformes)
Annotated and Illustrated Checklist
With 63 Illustrations and 23 Color Plates
Friedhelm Weick
Pommernstraße 34
76646 Bruchsal-Untergrombach
Germany
About the Author
Friedhelm Weick was born in Karlsruhe, Germany. For 35 years he worked as a technician
in the construction industry. Throughout this time he painted birds, and since 1965 he has
also been a professional illustrator and wildlife artist. Since 1988 he has been a graphic
designer at the Museum for Natural History in Karlsruhe, a job which entailed painting a
complete range of animals and plants. He illustrated over 120 books, including most vol-
umes of the Handbuch der Vögel Mitteleuropas (1971–1997) and all volumes of Die Vögel Baden-
Württembergs (1987–2006). His work has appeared in all leading wildlife magazines. In
addition, he has published books in his own right, including Birds of Prey of the World, in
collaboration with L.H. Brown, Owls, a Guide to the Owls of the World, in collaboration with
C. König and J.H. Becking and Anmut im Federkleid, in collaboration with O. Kröher.
Library of Congress Control Number: 2006927285
ISBN-10 3-540-35234-1 Springer Berlin Heidelberg New York
ISBN-13 978-3-540-35234-1 Springer Berlin Heidelberg New York
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The use of general descriptive names, registered names, trademarks, etc. in this publication
does not imply, even in the absence of a specific statement, that such names are exempt
from the relevant protective laws and regulations and therefore free for general use.
Editor: Dr. Dieter Czeschlik, Heidelberg, Germany
Desk Editor: Dr. Jutta Lindenborn, Heidelberg, Germany
Cover design: design&production, Heidelberg, Germany
Typesetting: Stasch, Bayreuth, Germany
Production: LE-TEX Jelonek, Schmidt & Vöckler GbR, Leipzig, Germany
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Dedicated to three splendid owl-experts and friends /
Den drei hervorragenden Eulenkennern und Freunden gewidmet:
Dr. h. c. Siegfried Eck †, Dresden, Germany
Dr. Gerrit Paulus Hekstra, Harich, The Netherlands
Professor Dr. Claus König, Ludwigsburg, Germany
Foreword
The owl is a magical creature: it exudes an ambivalent fascination that can
trigger completely antithetical responses. On the one hand, there is something
unsettling about the owl’s soundless flight, eerie call, and nocturnal activity
that can result in its demonization as a messenger of darkness. On the other
hand, however, its masklike visage and seemingly penetrating gaze prove en-
thralling, and this may have contributed to the deification of the owl as the
companion spirit of an omniscient mother earth. In addition, the highly spe-
cialized captor of prey aroused the competitive envy of hunting parties, even
provoking a bit of resentment when they lost out to owls in their hunt for
small game. Moreover, the excrement and pellets (hairballs) they deposited in
barns and church towers contributed to their reputation as undesirables or
even pests. With the overcoming of superstition and suspicion, our relation-
ship with these creatures of the night has now become one of unreserved ad-
miration. They grant us insights into the rich diversity of adaptation to noc-
turnal hunting as well as into sound inventories, brooding biology, and nest-
ling development.
In a complete transformation of what was once a symbol of fear and hatred,
charismatic owls now enjoy an almost singular popularity in large parts of the
population. Whether it be the barn owl, eagle owl, or boreal (Tengmalm’s) owl,
each is well-suited as the flagship species for a biotope and species protection
in keeping with our times. A gratifyingly large number of specialists, ama-
teurs, and enthusiasts are involved in owl protection: creating potential nest-
ing hollows, banding birds, collecting pellets, guarding endangered breeding
areas, or mitigating the risk of electrocution by power poles. The organization
of owl friends on the local, regional, and international level ensures that advi-
sory support and coordination take place at a high level of expertise.
Other friends of owls seek to regenerate owl populations in as natural a way
as possible, whether for resettlement or for securing the continued existence
of highly endangered species. This effort encompasses not only zoos, bird parks,
and special breeding stations, but also those work-intensive rehabilitation cen-
ters in which injured or orphaned owls can be given professional care. All of
these organizations and facilities serve, directly or indirectly, to inform and
enlighten the public and are thus instrumental in ensuring a positive image
for the once so detested “wraiths of the night.” The spectrum of owl-related
hobbies includes nature photography, painting and sculpture, with the
lattermost encompassing the most diverse forms of owl representation. Owls
it appears are highly reluctant to let go of anyone who has fallen into their
clutches.
viii Foreword
This certainly applies to the author of this taxonomic list of owl species.
Deeply impressed by the grace and patterns of behavior of wild animals,
Friedhelm Weick moved from a very different profession to become – about
40 years ago – a painter of animals and an illustrator of textbooks. The begin-
nings of his collections of illustrations and sources from the literature, as well
as his study of museum skins (to obtain an overview of the world of owls) go
back at least 25 years. These activities were considerably boosted by his joint
efforts with Claus König to create the first compendium of the entire order of
Strigiformes (1999). Such tenacious and long-term pursuit of this project un-
doubtedly reflects a profound enthusiasm for owls.
In a time of ever-new media that bombard our senses and constantly seek
to outdo each other in emotional impact, that dazzle us with floods of images,
3-D projections, and virtual reconstructions of long-lost worlds, a systematic
list of a specific group of birds may seem anachronistic and antiquated. And,
in fact, there is no lack of voices that ridicule the outmoded museum work of
classical taxonomists and see no practical value in discussions of the system-
atic classification of organisms. Since academia too did not remain untinged
by this subliminal disdain, the foundations of species information and sys-
tematic classification were largely forced out of research and teaching in the
competitive struggles among the various academic disciplines. If the univer-
sity, however, shirks its responsibility, taxonomy threatens to become an en-
dangered discipline. And this despite the fact that sound knowledge of the
systematic subdifferentiation of organisms represents the essential precondi-
tion for understanding evolutionary processes. In a multifaceted interplay with
geography, ecology, ethology, and genetics, systematics makes it possible to
trace the natural history of populations. This includes the origin and paths of
dissemination of populations, their development through competition and
predation, through changes in climate or shifts in available habitat, and their
isolation and radiation into distinctive forms of adaptation.
Ever since the environmental protection conference in Rio de Janeiro in
1992 (the “Earth Summit”), the catch-all term of “biodiversity” has enjoyed
pervasive use. Even if biodiversity extends the variety of biological phenom-
ena to habitats and landscapes, there is no doubt that diversity of organisms
continues to represent its most important foundation. This lends new weight
to the genealogies of organisms. The majority of developed nations signed the
Biodiversity Treaty, which makes mandatory the protection of the worldwide
diversity of lifeforms. Within the European Union, the concept of “Natura 2000”
is based on this objective. Aside from the “Red Lists” of endangered species,
criteria were also established for Germany for determining responsibility in
the protection of species. Even if these are highly commendable developments,
they nevertheless remain first and foremost a reflection of a troubling process
of extinction, an ever-accelerating disappearance of species caused by a his-
torically unprecedented expansion of human settlement.
Whether projects of research involve questions of evolutionary biology, con-
servation programs for the preservation of the species, or the breeding of eco-
nomically relevant livestock, knowledge and correct taxonomy of “species”
represent the unconditional precondition for all of them. Even if the naming
and categorizing of animate objects is as old as the development of human
language itself, the scientifically grounded definition and differentiation of
particular groups of organisms as a “species” is nonetheless a highly complex
Foreword ix
discipline. And here, apart from objectifiable decision-making criteria, sub-
jective aspects such as worldview, system of social values, or even national
ambitions and political correctness may have a part to play. Moreover, the state
of knowledge regarding global diversity and its diffusion patterns remains
full of gaps.
According to present listings we know of 1.7 million recent species on earth
from the realms of protozoa, fungi, plants, and animals. Approximately 50000
of them are vertebrates, of which 9935 are birds; a good 200 of these, in turn,
are owls. However, since many of the tropical forests have not yet been ex-
plored and may possibly be destroyed by logging operations prior to a species
survey, well-founded speculations reckon with the possibility of up to ten times
as many species.
Early museum taxonomy was only concerned with classificatory systems
for designating and administering the diversity of organisms, and this was
especially true as long as even biologists considered the immutability of cre-
ation as incontrovertible dogma. Ever since Darwin, however, the goal has be-
come more ambitious: to classify species as the basis for reconstructing their
evolutionary history (phylogenesis). A comparative examination of morpho-
logical, physiological, and ethological properties that takes the results of ecol-
ogy and zoogeography into account expects, on the one hand, that all indi-
viduals of a population demonstrating a high level of matching traits can be
brought together as of the same species and, on the other hand, that a high
level of matching traits between heterogeneous populations correlates with a
high degree of kinship between them. Ernst Mayr added, as an essential crite-
rion of differentiation of individual species, the reproductive barrier develop-
ing between them in evolution, which minimizes the risk of interspecies hy-
bridization. Nevertheless, all classic species concepts are confronted by an abun-
dance of convergent forms, which is why they have to place great weight on the
distinction between homologous and analogous traits. Additionally, a com-
parison of traits is frequently insufficient for the systematic differentiation of
subspecies and even less sufficient for assessing higher-level taxa in terms of
their phylogenetic connections.
Ultimately, molecular biology, at the end of the 20th century, has led the way
out of this stagnation on the systematic level in an almost revolutionary man-
ner, for it turned out that very fundamental questions could only be approached
by incorporating modern genetics into the analysis. Above all the structural
analysis of genetic material, of DNA, has revived the discussion of taxonomic
classification and given it back the societal recognition it needs. Since DNA
analysis looks for similarities in genetic material, it is more immune to irrita-
tions arising from convergences in morphology. The goal here goes beyond
the grouping of related species; the effort is to reconstruct as realistically as
possible the process of speciation with its individual branchings of the phylo-
genetic tree. It is even possible to locate such splitting off points in time with
the help of the “molecular clock,” which makes the phylogenetic tree into a
multidimensional construct.
Of all the groups of organisms, the phylogenetic classification of birds is the
most advanced. Currently, recent forms have been arranged into 23 orders,
146 families, and 2141 genera of 9935 species (as of December 2005, according
to zoonomen.net). Spectacular fossil discoveries of recent years, especially from
mesozoic deposits in China, even allow the documentation of the derivation of
x Foreword
birds from feathered, bipedal saurians (of the Sauriurae and Ornithurae fami-
lies). These fossils, of at least 120 million years in age, can already be assigned to
the plovers, loons, petrels, and anserines. Owls have existed for 50–60 million years.
Within the class of birds, owls represent a conspicuously uniform morpho-
logical group. With their usually large and rigidly forward oriented eyes within
the “face” of a large, round, and “neckless” head, with their loose, fleecy plumage
usually in camouflaging colors, and with their broad and compact bodies, it is not
hard for anyone to recognize them as owls. Insofar, however, as the uniform ap-
pearance of owls was selected by a nocturnally active lifeform as predator, this
uniformity of morphological traits made systematic subdifferentiation more dif-
ficult. Given this unity, there was never any controversy regarding the owls as
a uniform group, even though as early as 1840 Nitsch had proposed splitting
them up into a group of barn owls and a group of “typical owls.” There was,
however, a great deal of uncertainty regarding their integration with their next
of kin, as Sibley and Ahlquist (1990) showed in great detail in their historical
survey. On the basis of their similar beak forms, Linnaeus (1758) grouped owls,
as the genus Strix, together with falcons and shrikes (in the Accipitres order).
Baird (1858) was the first to use Strigidae as a family name for nocturnal birds
of prey, in the context of the bird world of North America. Huxley (1867) clas-
sified owls with vultures and secretary birds. Fürbringer (1888) was the first
to dissociate owls from diurnal raptors, incorporating the Striges lineage with
the family Strigidae among the Coraciiformes. Peters (1931) was the first to
recognize owls as an independent order Striges, ranking them among night-
jars, parrots, and cuckoos.
According to Sibley and Ahlquist, the methods of molecular biology made
it possible to partially corroborate these kinship relationships. Nonetheless, in
this interpretation, owls were separated from the Coraciiformes and at the same
time moved closer to the swifts and hummingbirds. DNA analysis requires the
dissociation, once and for all, of nocturnal from diurnal birds of prey. These
authors add a new superorder, Strigimorphae, which includes the Strigiformes
order, with its 319 species in 51 genera. A suborder, Strigi, within the latter,
includes the two owl families, Tytonidae, with its 15 species in 2 genera, and
Strigidae, with its 184 species in 27 genera. As of late, the frogmouths and the
nightjars are also incorporated as suborders within the Strigiformes order.
Within the Strigimorphae superorder, the Strigiformes order is joined by the
turacos (Musophagiformes order).
The systematic list of the owls of the world provided here encompasses
220 species of owls and with the subspecies classification results in 539 taxa.
By providing synonyms, the aim is to clear up the often confusing duplication
found in the designations. (Even today, valid species names are sometimes
assigned twice: Glaucidium passerinum, for instance, designates not only the
Eurasian pygmy owl, but also a blue-blossomed plant in Japan.) This checklist
has been brought up-to-date and already takes the results of genetic analysis
into account. This has led to the splitting up of previous species complexes, as
is especially striking in the case of the genera Otus and Glaucidium. In this
context, Weick names considerably more owl species than do all authors be-
fore him: Peters (1940) cited 141 species, del Hoyo et al. (1999) cited 195, the
World Birds Taxonomic List (zoonomen.net) cites 199, and König et al. (1999)
cited 212. Recently, however, the Global Owl Project actually named 225 owl
species (www.globalowlproject.com/species). The current upheaval in owl sys-
Foreword xi
tematics is documented by countless individual publications. By bringing to-
gether sources that are in part widely dispersed, the succinctly annotated check-
list provided here presents a kind of status report.
It goes without saying that no list can ever be final, since the process of
bringing the classification into line with the findings of evolutionary biology
represent a continuous process of approximation and convergence. On the one
hand, animal forms exist in a continuum of superspecies, species, and subspe-
cies, of ecotype and morph, and in this way the construct of the species con-
cept ultimately originates from a convention, which has no equivalent in real
population dynamics. Thus, in spite of all scientific differentiation criteria,
there remains a large amount of leeway for personal assessments. On the other
hand, the temporal and spatial differentiation of the branchings in the phylo-
genetic tree is much more multifaceted than can be reproduced through the
limitations of rigid classificatory categories (Newton 2003). Furthermore, evo-
lutionary biology has demonstrated that in the course of evolutionary history
a cooperative fusioning of heterogeneous organisms must have repeatedly oc-
curred, which means that individuals at a higher level of organization actually
have emerged from “species conglomerates,” which raises a problem of philo-
sophical theory for the definition of species.
This checklist is neither an identification guide, nor a mere picture book, nor
an owl monograph. By reflecting a high level of scientific expertise and the most
up-to-date research, it provides outstanding support in the handling of scientific
collections and in studies of global biodiversity. But it should also address the
needs of practitioners of scientific species preservation, since global, national, or
regional responsibility for ensuring the continuance of endangered forms fre-
quently first becomes apparent on the basis of taxonomic and geographic dif-
ferentiation. Not least of all, this list can support scientific conservation and
breeding programs, whose contribution to species preservation is largely de-
pendent on knowledge of the systematic subclassification of the animals bred.
I too would like to support this intention to the best of my abilities.
St. Oswald, Germany
January 2006
Dr. Wolfgang Scherzinger
Zoologist in Bavarian Forest National Park