The sinking ark: a new look at the problem of disappearing species.

14 Pages·2003·1.18 MB·English

REVIEWS
EDITED BY WALTER BOCK
The sinking ark: a new look at the problem of disappearing species.--Norman Myers. 1979.
New York, PergamonP ress. xiii + 307 pp. $9.9$.--The problem of disappearings peciesi s an urgent
one for ornithologistsa nd other biologists,f or both selfisha nd altruistic reasonst hat are all too plain. In
these circumstances we can each choose whether to become involved or to remain detached, but no one
should be ignorant of the crisis. The causeso f extinction, the economicsa nd politics of preservation, and
the size and configurationo f nature reservesa re all topicst hat must receivep rofessionacl onsideration
of the highestq uality. This is why a numbero f us lookedf orward to the publicationo f a book like "The
Sinking Ark," and why its failure is a seriouss etbackf or the causeo f speciesc onservation.
"The Sinking Ark" is a shallow, silly, and confusedb ook which does only one thing effectively: it
dramatizes the magnitude of the present mass extinction of species.I questionn either Myers' statistics
nor his guesses(a lthoughi t would be nice if they were more clearly differentiatedf rom one another);
anyone should be able to see that ecosystemsa nd speciesa re disappearingf ast, perhaps a great deal
faster than Myers' much-quotedg uesso f one speciesp er day. But oncet his problem has been delineated,
"The Sinking Ark" becomesi ndistinguishablef rom the "Titanic."
From the beginning, the author wants us to know that he is an expert and a professional.I t is
"switched-on scientists, not 'case-hardened eco-nuts'" who are now issuing the warnings, and he makes
plain that he is one of the former group. Yet in spite of this indication of his professionalismI, confess
that I cannot make headso r tails of Myers' geneticsa nd evolution. Maybe I misseds omethingt hat
readers of The Auk will understand, so I quote:
To date, electrophoresiso ffers only partial and approximatem easureso f geneticv ariability. But as
the technique is refined, it may prove useful to conservationistsw ho agonize over whether to allocate
funds towards saving speciesX while implicitly consignings peciesY and Z to oblivion. Already
electrophoresish as revealed that the average polymorphisma nd heterozygocity... for plants is 17
percent, for invertebrates 13.4, for man 6.7, for vertebratesi n general 6.6, for reptiles 5, and for
birds less than 5. Least variability appears among polar-region species... an intermediate amount
amongt emperate-zones peciesa, nd the greatestd egreea mongt ropical speciesT. hese findingst end
to confirm that the tropical rainforests,w ith their plethora of plant and insects pecies,d eservet o be
at the top of the conservationist'ss hoppingl ist.
So much for birds, so much for Canada, Scotland, and Argentina. I think I know how Dr. Myers has
confusedh eterozygosity,p olymorphism, variability (at many levels), and speciesd iversity in order to
make his strange value judgment, but no matter. Let's go on.
There are abundant good reasonsw hy whales deservet he best efforts of conservationists.
whales' longevity and low reproductive rates mean that it takes decadesf or one generation to give
way to another. In turn, this means that whales' scopet o respondt o environmental changesv ia
selectionp ressuresa nd adaptive variations(cid:127)the forerunner processeso f speciation--is more limited
than for almost any other form of life, except for similar higher animals such as elephants and
rhinos, also man. So for purposeso f evolutionary processesth at lead to new speciesa nd greater
geneticd iversity, whales have little to offer as comparedw ith virtually all other of earth's stock of
species.
So much for whales. But let's go on to the inevitable conclusion.
If conservationp ostulatesth e maintenanceo f geneticv ariety as a leadingr ationalef or preservation
of species,s hould we not lend a helping hand to the evolutionary processesfo r insects,a long the
lines of what we have been doing for dogsa nd their breeds?
I lookedl ong and hard for somes ign in all of this that Myers is playing a harmlessl ittle joke on the
reader--but, alas, he seemsq uite serious.W hat bothers me most about this weird perversiono f Dar-
winian theory is the obvious ulterior motive behind it: I can use genetics,e volution, and ecologyt o tell
you which speciess hould live and which must die, Myers implies. A kind of global eugenicsi s crawling
out of the woodwork here, and this strikesm e as more evil and more dangerouse ven than the extinction
that is now goingo n. The speciesth at are savedw ill be selectedb y expertso n the basiso f their "utilitarian
benefits."B ut what experti s there who can calculatet he net utilitarian benefitt o humanity of any species
(integrated over the time that humans and that speciesh ave left to coexisto n the planet)? Who knows
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the consequencest,h e plusesa nd the minuses,o f keeping or losinga ny species?N ot I, and certainly not
Norman Myers.
Before describingw hat I believe to be the central defectso f this book, I want to note several lesserb ut
nonethelessi rritating biases. First, for Myers, the only biome-type that really seems to count is the
tropical moist forest. I also love and appreciatet hesef orests;I was in one just a few days before writing
this review. And I am aware of their peril. But they occupyo nly a few percent of the earth's surface---
there are other ecosystemse qually deservingo f our concern.T o equate speciesd iversity with preservation
value makes no sense,b iologically or otherwise. Alaskan tundra and Idaho trout streams are just as
important to keep intact. Every major climatic and altitudinal zone, every soil type, and every regional
aquatic systemm ust continue to have available a fair sample of the plants and animals that evolved
there. Nothing less will do. After all, we are not about to recolonizea ravaged temperate zone desert
with speciest hat we have saved in any tropical moist forest.
Myers gives four "country profiles" in his book; in three the dominant natural ecosystemis tropical
moist forest (the fourth is also tropical). Even so, for all his preoccupation with this ecosystem,h e does
not always seem on familiar ground. In his six-paged iscussiono f Costa Rica, for example, he doesn ot
once mention the serious effect of banana cultivation on the moist forests of both the Caribbean and
Pacific slopes.
A secondm inor criticism is that Myers seemsr eluctant to share the limelight in the text with people
whosei deas he is using. The philosophicali mplicationso f the idea of conservingt he smallpoxv irus are
discussed,b ut Bernard Dixon's original and fascinating paper on this subject is not cited. A whole
chapter is based largely on the ideas of Garrett Hardin and he is quoted directly, but I do not recall
seeingh is name mentioned except in the footnotesa t the back of the book. Worse yet, Myers tends to
slight the other side of controversials ubjects:i n citing Martin and Wright's classica nd well-balanced
work on Pleistocenee xtinctions,t he climatic change hypothesisi s relegated, without discussiont, o the
status of a minor factor.
But there are more significantf laws in the book. Although it hardly seemsp ossible,M yers does not
seem to have grasped the fundamental cause of modern extinctions. Leopold Kohr, who inspired E. F.
Schumacher,s aid it clearly in his brilliant book, "The Breakdown of Nations," publishedn early a quarter
of a century ago: "Bigness, or oversize, is really much more than just a social problem. It appears to be
the one and only problem permeating all creation. Wherever somethingi s wrong, something is too big."
How true this is of speciese xtinctions.T here is the oversizedh uman population, to be sure;a nd Myers
knows that. But even more important is the oversizedt echnologyt hat can consume1 00,000 ha of rain
forest at a gulp, that can changet he pH of the rainfall of a continent, that can releasem illions of tons
of deadly and durable chemicalsi nto the environment, and that can plan the rearrangement and usually
the degradation of the ecosystemso f whole nations.
What is Myers' solution to the problem of shifting cultivators in rain forests?G ive them "intensive"
agriculture (with its monocultures,f ertilizers, massivei rrigation and water diversion systems,h erbicides,
and insecticidess) o that they will leave the forest alone. Tax the multinationals for conservationp rograms,
regulate them, educate them (but don't hurt them), so that the massivep ower they wield, their global
oversize,h as no bad effectso n rare species.G et the seedc ompanies( nearly all owned by multinationals
now) to preserveg eneticv ariety and diversity. Develop biomassf uels on a grand scale( despitet he fact
that each gallon of corn-basede thanol for gasoholc ausest he losso f more than 100 poundso f topsoil).
Get Americanst o give up unnecessarym edicalo perations,t o stop drinking too much, and to stop wasting
food, and we can use the "$100 billion" saved each year to preserves pecies.H e even sayst hat "there is
no basicc onflictb etweent he economici nterestso f developingc ountriesa nd thoseo f developedc ountries."
Businessa nd growth as usual, but do it nicely.
It is Myers' refusal to comet o grips with the nature and ecologicalc onsequenceosf bignesst hat causes
this kind of silliness.I n his preface he notest hat his book was underwritten, in part, by the Rockefeller
Brothers Fund. I doubt that they have found cause to regret their investment.
Finally, the basicd efecto f "The SinkingA rk" is that it has no moral underpinningsA. s Aldo Leopold
and Charles Elton have pointed out, there are better, tougher reasonsf or saving speciest han to keep
them for exploitation. Myers claims to be a hard-nosed, "switched-on," scientific and economic realist.
But is it realistic to believe that the cure for canceri s growing somewherea round the next bend of the
Rio Negro, and that Volkswagen can be taxed, cajoled, and enlightenedi nto saving the pristine rain
forest it owns?I s it realistic to behave as if everything on this planet were meant to serve our ends--to
believet hat we both can and shouldf igure out which speciesw e can afford to throw away?A sorry kind
of realism, I think, but no better than one can expectt o result from a mixture of bad morality and bad
ecology.--DAvID EHRENFELD.
January 1981] Reviews 201
Conservation biology: an evolutionary ecological perspective.--Michael E. S0ul(cid:127) and Bruce
A. Wilcox (Eds.). 1979. Sunderland, MassachusettsS, inauer Associates,I nc. 395 pp. $14.9 5. --The
strength of this volume is mixed. The weak sectionsa re those chapters in Parts I (Ecological Principles
of Conservation,4 chapters)a nd II (The Consequenceos f Insularization, 5 chapters)t hat deal with the
application of island biogeographya nd ecologicalt heory to conservationp roblems. Part III (Captive
Propagationa nd Conservation,5 chapters)i s excellenta nd containss omef ascinatingi nformation on the
technologya nd problemso f breedinge ndangereds peciesin zoos. Part IV (Exploitation and Preservation,
4 chapters)i s also strong and reviews large-scalep reservation( African wildlife and rain forests)a nd the
details of management, and closesw ith a call for change by Ehrlich.
The volume beginsw ith a foreword by Thomas Lovejoy of the World Wildlife Fund, who reviews the
destruction of our planet and argues that becauseo f this the demands on sciencea re large. Ehrlich, in
the closingc hapter, is closert o the truth: conservationh as very little to do with sciencea nd very much
to do with economics,p olitics, and sociology.A nd Ehrlich is right that unlesst here are fundamental
changesi n the way societyv iews its relationship to Earth nothing else really matters. In the introductory
chapter Soulfia nd Wilcox review conservationb iology and conclude,a mong other things, that "conser-
vation biology, strictly speaking, does not include the subject of economics."T his revelation would be
of interest to native Africans such as the Ik who are now nearly extinct as a result of their exclusionf rom
their former hunting grounds, now the Kidepo Reserve (see Coe, Chapter 16). The editors continue
reviewing conservationb iology and are obvious supporterso f the application of island biogeography
(called insular ecologyb y Wilcox) to the planning and designo f refuges.T he editors and several of the
contributors refer to some deleterious effects of isolation (extinction, inbreeding, etc.). I certainly sensed
a deleteriouse ffect of isolation while attending the conference,a nd it was isolation from reality. This
feelingw as particularlys trongw hile I was sittingi n an air-conditionedb uildingw ith other white middle-
classb iologistsu rging nations located in the tropics to set aside huge areas for the preservationo f the
natural environment.
Another sort of isolationc haracterizedt he papersb y Diamond, Wilcox, and Terborgh and Blair. Here
the isolation was from standard scientific method in Popper's sense:t hat is, if an idea is not held up to
possiblef alsification it is not science.T o hear them speak and to read the contributionso ne would think
that the ideas they proposedw ere not controversial.S imberloff (in press,J . Biogeography)h as already
commentedo n this but I would only point out that another way of looking at island biogeographya nd
conservationd esign can be found in Abele and Connor (1979, Proc. First Conf. on Sci. Res. in the
National Parks, Vol. I: 89-94, R. M. Linn, Ed.). It is somewhat disturbing that this paper, or any
opposingv iewpoint, for that matter, was not cited despite the facts that (a) the editors had a copy of it
before the conference,a nd (b) I presentedp art of the paper at the conferencea s the introduction to a
workshopo n the designo f nature reserves.R egardlesso f which view is correct, it is hardly in the spirit
of scientifice nquiry to protect an idea from challenge.
In chapters 2 and 5 Gilbert and Foster point out that a reserve must include successionasl tages, and
both authorsa rgue for managedd isturbance.E isenberga dds that mature tropical evergreenf orestsd o
not support as high a diversity of mammals as a mosaic of mixed secondg rowth and tropical evergreen.
Preservesa re obviously going to require some management.
Franklin, Soulb, and Goodman make some very specifics uggestionsc oncerningt he population sizes,
genetics, and management of population growth. Franklin's commentst hat the effective population size
should not be less than 50 for the short term and should be 500 for the long term bear directly on
Eisenberg'sd ata, which suggestt hat most large mammals in Wilpattu Park have populationsb elow this
value. Soulb provides additional information on the genetic diversity of small populations and, despite
some disclaimers, recognizest he tenuous assumptionso f the models. Goodman, with a very interesting
example, provides details on managing populations under conditionso f encouragedg rowth or culling.
The third sectiond eals with captive propagationa nd conservation.T he sectionb eginsw ith an overview
by Conway, who points out that nearly one-twelfth of the specieso f birds and one-sixtho f the mammals
have been recently bred in zoos. He further reviews the four possiblef unctionst hat captive-breds tocks
couldf ulfill. Someo f theseh ave beens uccessfubl, ut the costi s fairly high and there hasb eeni nadequate
support at best. Senner reviews a model of inbreeding depressioni n small closedp opulations and finds
that the result is almost always extinction.H is recommendationesc hot hoseo f Franklin and SoulS:t o
avoid founders that are inbred and caution against an unbalanced sex ratio. Benirschke, Lasley, and
Ryder presenta fascinating report on the technologyo f captive propagation, including using endocrine
studies to sex individuals and karyotyping individuals of the same "species"p rior to mating attempts.
The chromosomed ata are of much wider interestt han captive propagation.T hey concludeo ptimistically
concerning the availability of the necessaryb iomedical technology, but suggestt hat zoos can serve as a
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last refuge for only a small number of vanishing species.K leiman emphasizest he many complexitieso f
sociobiologya s it relates to captive propagation. These can include the processo f mate selection that
results from intense fighting, infanticide, the need for extended family groups in some species,a nd
suppressiono f mating by male dominance. She also points out the need for zoost o publish their failures
as well as their successesIt. is difficult to avoid a certain amount of pessimismh ere. Earlier chapters
have made a number of important recommendationsc oncerningg roup sizea nd inbreeding,f or example.
Yet it is apparent from Kleiman's work that it is going to be difficult to satisfy the sociobiological
requirementso f somes peciesa nd at the samet ime avoid the problemsa ssociatedw ith small populations.
Campbell reviews reintroduction of captively-bred animals into the natural habitat. He cautionst hat the
few successfuiln troductions,s uch as the European bison, ibex, and chamois,s houldn ot overshadowt he
numerous problems, particularly those of economics.C ampbell points out that the Peregrine Falcon
program has already cost one million dollars and will probably run to 4 or 5 million dollars if it is
maintained for another 10 or 15 years. While this may seemo utrageoust o somet axpayers, it is a small
amountc omparedt o the costi nvolvedi n the restorationo f historics tructuresa, s mentionedb y Campbell.
Ten problems associatedw ith reintroduction are summarized, ranging from permits and laws to the
chauvinistica ttitude of Welsh nationalistsw ho opposedt he reintroductiono f the rosy marsh moth into
England.
The fourth section deals with exploitation and preservation. Coe begins this section with a detailed
review of African wildlife resources.H e reviews the use of game ranches and the relationship of Africans
to their wildlife, especiallya s a sourceo f protein. I find it difficult to be sympathetic to conservationists
who ignore Coe's recommendation that national parks and reserves be relevant to the lives of rural
Africans who live in the area. A "vehicleso nly" policy of parks can't help but antagonizet he very people
whose cooperation is vital to the survival of the park. Is the extinction of the Ik tribe less serioust han
the loss of another species?W hitmore deals with tropical rain forests of the world. He begins with the
astonishings tatistict hat rain forestsh ave disappeareda t the rate of 21 ha per minute between 1964 and
1973. I would suspectt hat the rate has probably doubled since 1973. It is easyt o agree with Whitmore
that "adequate" (= large and representative) sampleso f virgin rain forest should be preserved, but the
biological, social, and economic complexities of doing this in the nations where the forests are located
appear overwhelming. Pyle deals briefly with the management of reserves, and his conclusionc an be
summarized in his own words(cid:127)"The emphasisi s on practicum." Despite the glowing optimism of "insular
ecologists"t he specific problems of management have much to do with everyday activities such as
vandalism, pollution, and legal challenges, and virtually nothing to do with extinction coefficientst hat
have half-times of thousandso f years. These everyday problemsw ill have done their damagel ong before
the long-term effects of insularization are felt, claims to the contrary notwithstanding. As already men-
tioned, Ehrlich, in the closing chapter, argues that nothing short of radical changesi n the behavior of
the world's societies will save the Earth. He is right.--LAWRENCE G. ABELE.
Character variation and evolution of sibling species in the Erapidonax dlfficilis-flaves-
cens complex (Aves: Tyrannidae).--Ned K. Johnson.1 980. University of California Publicationsi n
Zoology, Vol. 112. Berkeley, University of California Press. x + 154 pp., 39 text figures + 3 plates.
$9.50.--Picture a beginningg raduate student, eager to selecta researchp roject that will make a mark,
about to examine the contents of specimen casesi n a university museum. If by chance the first case
contained tyrannid flycatchers,a nd if, due to continuing misfortune, the first drawers opened were those
containing specieso f Empidonax, most likely our student would quietly closet he case, thank the curator,
and selecta researchp roject in the physiologyo f chickens.M ost memberso f Empidonax are remarkably
similar in size, shape, color, and foraging behavior, in fact so much so that some are interspecifically
territorial to a degree.
To the seasoneds ystematist,h owever, the Empidonax groupp resentsa number of intriguingp roblems.
The genusi s rich in setso f superspeciesA. number of speciesh ave remained allopatric long after the
completiono f geographics peciation.N ed Johnsonh as taken on this group, and in the present volume
setso ut to examinet he early stagesi n the evolutiono f morphologicallyv ery similar species,t he Western
Flycatcher (E. difficilis) and the Yellowish Flycatcher (E. fiavescens). The development of isolating
mechanismsin the formation of sibling species,a nd the relationshipb etweenm orphologicals tability and
isolating mechanisms,a re also examined. The analysisi s based on morphologicalm easurementsf rom
1,284 bird skins and on 5,032 sonagramso f 208 individual songs.F ieldwork began in 1964 and continued
through 1970.
As with many papers emanating from the Museum of Vertebrate Zoology that appear in the University
January 1981] Reviews 203
of California Publications in Zoology series, one gets a lot of basic biology along with information more
central to the systematict heme. Johnsonp rovidesa comparativet reatment of distribution, abundance,
and habitat requirementso f the populationsa nd speciesb eing studied. Each specieso f Empidonax is
reported to occupya distinctiveh abitat for nesting.
An analysis of character correlationsi ndicated that some skin and song characters were redundant, so
the character set was reduced to minimize redundancies. The correlation matrix was presumably on the
total sample of males (females were not so treated), but it could have been on locality means. This
distinctioni s important, but the statemento f methodsi s silent on this issue.
Comparison of the sexess howed that males tend to be larger than females in most characters. Greater
sexual dimorphism was found for E. difficilis than for E. fiavescens.
There were greater coefficientso f variation for bill characters than for wing and tail measurements,
a pattern found for many other avian species.W hy bill size should be more variable than wing and tail
size is puzzling, and a few authors have theorized about this. Rothstein (1973 Amer. Natur. 107: 796-
799), for example, speculatedt hat becauseo f variation in food, bill dimensionsa re subject to more
extreme yearly shiftsi n directionals election,r esultingi n the accumulationo f greater variability. Johnson
believest his is not the entire story, and pointso ut that wing sizei n aerial foragersi s tied to food gathering
and therefore ought to show greater variability than it does. Actually, this is not a particularly good
counterargumentb ecausee ven in highly aerial foragers, such as swifts, it is difficult to accept the idea
that the wing is more of a "feeding structure" than in any other bird. No one yet has a good explanation
for the characterv ariability sequence.P rocessesm ore closelyt ied to the physicala spectso f growth and
developmentm ay be responsible.
In tests involving relative variability of individual characterst here are no differencesb etween the
sexes, between E. difficilis and E. fiavescens, nor between E. difficilis and E. hammondi. Overall
comparisons,h owever, suggestt hat E. harnrnondii s more variable than E. fiavescens, which is more
variable than E. difficilis. Mention is made of other theories concerningv ariability and whether or not
the Ernpidonax data agree. The data are not adequate, however, to develop any of these ideas success-
fully.
Each mensural, color, and song character was examined by an analysiso f variance proceduret hat
grouped setso f statisticallyn onsignificantl ocality samples.T his, coupledw ith the clear graphic presen-
tation on range maps, makes it easy to look for broad clines as well as abrupt steps, and even allows
comparisono f specificp airs of locality samples. Some of the clearest clines are seen with color (e.g.,
purity of breast color), while other characterss how seesawp atterns of variation. Song is the basis for
believing that E. difficilis and E. fiavescens are separate biological species.T he advertising songso f
both speciesd iffer in obvious ways and are presumedt o serve as premating isolatingm echanisms.S ong
traits were measuredf rom sonagramsa nd patternst ested by analysiso f variance.
Multivariate analysisw as also used. Presumablyb ecausec ompleted ata were lacking for all samples,
five separate data sets were analyzed: one of 10 samples of male E. difficilis with 22 mensural, color,
and song characters;t wo based on 22 size and color characterso f 22 sampleso f males and 19 samples
of femaleso f E. difficilis; and two basedo n 22 size and color characterso f 49 sampleso f malesa nd 42
sampleso f femaleso f E. difficilis and E. fiavescensc ombined.T wo multivariate proceduresw ere used,
principal componentsa nalysiso f correlation matrices based on locality means, and cluster analysiso f
taxonomic distances,a lso calculatedo n locality means. The preferred statistical procedurew ould have
been canonicalv ariates analysisb ecausei t examinesa mong-populationd ifferencesr elative to within-
group differences.N onetheless,J ohnson'sa nalysisd oesy ield interpretable results. In both the principal
componentsa nd cluster analysist here are clumps of samplest hat are distinguishable,a nd the overall
impressioni s that the statisticala nalysism irrors the geographicp ositiono f samplesa nd combinesp op-
ulations accordingt o relationshipss uggestedb y the existing subspeciesO. ne of the problemsw ith five
separated ata setsa nd two methodso f analysisi s that specificc omparisonso ften do not match or are not
replicablef rom one test to the next. This indicateso ne of the main difficultiesi n interpretingt oo literally
the resultso f single statisticalt ests in systematicsb, ut, taken together, a biologicallyr ealistic picture
emerges.
Zoneso f contactb etweenE . d. difficilis, the coastals ubspeciesa,n d E. difficilis hellmayri, an interior
subspeciesc, ame under scrutiny via discriminant function analysis. A single function made up of size
and color characters,a nd another basedo n componentso f advertisings ong,w ere calculatedt o maximally
separatet he two races. The geographicallyin termediates amplec ame out morphologicallya nd vocally
intermediate, with a broader range of variation than either of the two "pure" samples. This not only
seemedt o demonstratei ntegration, but increasedv ariability due to hybridization, recombination,a nd
backcrossinga s well.
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Of all the characterse xamined, clear clinal variation existsi n very few. Most vary in a seesawf ashion,
and Johnson'sa ttempt to explain this by climate and ecologicalc orrelatesi s admittedly limited by a lack
of data. It seems that a variety of selective factors may be acting on different suites of characters. To
unravel the selective forces will be difficult.
Johnsons ubjectively identified concordancea mong characters. "Whole complexeso f features change
more or less simultaneously over fairly narrow and well defined zones" (p. 102). The major regions with
minimal geographicv ariation within them are: the Channel Islands, Pacific Coast, Rocky Mountains to
central Oaxaca, nuclear Central America, and Costa Rica to Panama. There are also zoneso f abrupt
character change between these regions, specificallyb etween the southwesternC alifornia coast and the
Channel Islands, along the crest of the Cascade Mountains, in north Mexico, at the Isthmus of Tehuan-
tepec, and in the Nicaraguan depression. Generally, size and habitat choice vary concordantly, with
strong gradients over short distances. Vocal characters change more gradually. No generalization was
possiblef or color.
The geographicv ariation analysiss upportst he subspeciesa lready establishedf or both species.J ohnson
expressesa ssurancet hat the trinomial systems hould remain intact for this group. Two setso f subspecies
are believed to be "megasubspecies,"s ubspeciesp resumably approaching species status. The view is
supportedt hat E. difficilis and E. fiavescensa re truly allopatrici n their breedingd istribution,b ut that
the two are distinct biological species.
To conclude,J ohnsonp resentsa hypotheticals chemef or evolution in Empidonax. In StageI there is
rapid morphologicalc haracterd ivergenceb etweent wo sibling populations,w ith much slower changei n
vocalizations.I n StageI I allopatric divergencec ontinuesf or morphology,p hysiology,a nd color, and is
paralled by divergence in song. Following a brief period of parapatry, sympatry between closer elatives
may occur, and here, in Stage III, divergence in vocalizationsc atchesu p to divergence in physical traits,
and both increasea t a greater rate than in Stage II. Several speciesp airs are plotted to show their position
in this scheme. The model seems useful. One concern is that I do not know what to make of the fact that
two subspecieso f one species( E. cl. difficilis and E. cl. hellmayri) are farther along at the parapatry-
sympatry border (Stage III), while two subspecieso f different species( E. difficilis occidentalis and E.
fiavescenss alvinii) are still in late allopatry phase (Stage II). One minor criticism is that Johnsonl abels
one of the axes in his speciationg raph "rate of characterc hange," when it shouldr ead simply "character
change"o r "degreeo f divergence."T he modeld epictsa bsolutec hangeo r divergence,n ot the rate of that
change, at least in my interpretation.
Johnson'ss tudy has eliminated most of the taxonomic confusion about this group. It has been an
interestingc hallenget hat has been met by the author'ss olid understandingo f the biology of Empidonax
flycatchers,b y multivariate morphometricsa, nd by an extensivea nalysiso f vocalizations,a ll followed
by good sense.--DENNIS M. POWER.
Avian orientation and navigation.--Klaus $chmidt-Koenig. 1979. London, Academic Press. x +
180 pp., 84 figures. $26.50.--During the last decade the increase in studies of avian orientation and
navigation has been dramatic. This is particularly true for studieso f avian navigation in homing pigeons.
Schmidt-Koenigh as been very active in this field, and most of his researchh as concentratedo n various
aspectso f pigeon homing. In addition, he has been instrumental in planning and coeditingt he proceedings
of two international symposiao n animal migration, orientation, and navigation; one in 1970 at Wallops
Island, Virginia, and the other at Tubingen, West Germany in 1977. In this volume Schmidt-Koenig
providesa concisea nd authoritative summary of most of the studieso f avian orientation and navigation
that have been publishedt o date, particularly thosei n the last decade.
The volume is divided into nine chapters. The first gives a much abbreviated introduction (8 pages)
to bird migration, and the secondc oversb riefly (13 pages)s omeo f the major techniquesu sed in studying
bird migration in the field (field-glasso bservations, radar, and radio tracking). The third (42 pages) is
devoted to laboratory studieso f the basic and integrated sensoryc apabilitieso f birds that may be used
in orientationa nd navigationa s well as the orientationo f cagedb irds, and in the fourth chapter, Schmidt-
Koenig allocates 12 pagest o the experimentalf ieldwork with wild birds (e.g. displacemente xperiments,
establishmento f breeding and wintering ranges). The fifth chapter is the longest in the book (55 pages)
and not surprisinglyc overs homing experimentsw ith pigeons. The hypotheses,t heories, and concepts
that have been advanced to explain how birds might navigate are discussedin chapter 6 (13 pages),a nd
chapter 7 is a 1-pagec onclusion.T he eighth chapter containsa brief and very valuable summary of all
the precedingc haptersa nd sectionsi n the book. The final chapter is only 1¬ pagesl ong and explains
January1 981] Reviews 205
the use of circular or two-dimensionals tatisticsi n the volume. The bibliographyi s excellenta nd up-to-
date, and a 4-page index concludest he volume.
The chapter devoted to laboratory studiesi ncludest he recent findingst hat pigeonsa re sensitivet o
ambientp ressurec hangesi,n frasoundo, dors,p olarizedl ight, ultravioletl ight, and magnetismT. he sun,
star, and magneticc ompasseuss edi n orientationa re also discusseda, nd Schmidt-Koenigl,i ke many
others,f eel that the compassems ay be hierarchicallya rranged,t hat is, that the basic compassm ay be
the magneticc ompassa nd the sun and star compasseasr e alignedo r calibratedr elative to the magnetic
one. Even if this is so, the term "hierarchical"i s not really appropriate and may be misleadingt o those
familiar with hierarchicalt heory. The compasseasr e alternativesa nd dependo n the availability of the
appropriatec ue. As Schmidt-Koenige mphasizesa, ll three are establishedo ntogeneticalliyn different
ways and operated ifferently with respectt o vision and time compensation.
In reviewingt he hypotheseos f arian navigation,S chmidt-Koenigc oncludesth at there is no experi-
mentals upportf or the hypothesitsh at a grid of isoclineso f Coriolisf orcea nd the verticalc omponenot f
the geomagneticfi eld is usedf or navigation. The theorieso f sun, star, and inertial navigationa re dis-
crediteds imilarly. Olfactoryn avigationi n pigeonsh as somee xperimentasl upport,b ut conflictingr esults
exist. Vector "navigation"i nvolving direction and distancei nformation is supportedb y experimental
resultsa nd may explain how birds-of-the-yeaar ccomplishth eir first autumn migration,b ut the utility of
this concepti n bird navigation is limited.
The original Kramer concepto f map and compassi s still the basic frame of referencei n avian navi-
gation studies, and although much is known about the compassesb irds use in orientation, virtually
nothing is known about the map component.C onsequentlyw, e still do not really know how birds
navigatea nd homea fter displacementot an unknownl ocation.I t is perhapsti me to examinec ritically
and revise the conceptualizationo f navigation in birds in terms of map and compassc omponents.
Althought he booki s well written and illustratedit containsa few typographicaelr rors( e.g. Waltschko
insteado f Wiltschkoo n pagev , severeli nsteado f severalo n page2 1, and Clemson,N . C. insteado f
Clemson,S .C. on pages1 59a nd 175). Schmidt-Koenigh asd onea n exceptionallyfi ne job of summarizing
the abundant and complex information that characterizest he rapidly growing area of arian orientation
and navigationr esearch.I t is a pity that the book costss o much, becauseit shouldb e on the bookshelf
of every avian biologist.--SIDNE¾ A. GAUTHREAIJX,J R.
Birds of the British Lower Eocene.--C. J. O. Harrison and C. A. Walker. 1977. Tertiary Re-
searchS pecialP aperN umber3 . London,T he Tertiary ResearchG roup. 52 pp. Birds of the British
Upper Eoeene.--C. J. O. Harrison and C. A. Walker. 1976. ZoologicaJl ournalo f the Linnean Society
59: 323-351.--Colin J. O. Harrison and Cyril A. Walker have coauthoreda t least 20 papers in avian
paleontologys ince 1970. Harrison has been sole author on a similar number of paleontologicalp apers
during the same period. To date there has been no critical publishedr eview of their publications,a nd
an assessmenot f the merits of thesep apersi s warranted. Although the presentr eview will focuso nly on
two papers concerningt he Eocene avifauna of Britain, the remarks below are equally applicable in
concept to other studieso f fossil birds published by these authors.
BecauseL ydekker (1891, Cat. Fossil Birds Brit. Mus. (Nat. Hist.), London) was the last author to
review the Eocene fossil birds of Britain in a comprehensivem anner, Harrison and Walker's research
is timely and ought to be a significanti mprovement in our knowledge of Eocene birds. After short
introductionsa nd listso f taxa involved, both papersp roceedw ith systematicd escriptionsa nd diagnoses
of the fossils,f ollowedb y a brief discussion(1 977) or no discussiona t all (1976). The basico rganization
of these paperss eemst o be logical, but one is soonf rustrated by the brevity or completel ack of in-
terpretive information, and by the failure of Harrison and Walker to discusst he biological significance
of their findings. They do not place the various taxa in any kind of evolutionary context. There are
seldom even statementss uch as, "This is the earliest known fossil of the Hydrobatidae." Only once is
referencem ade to the geologyo f the depositsf rom which the fossil birds were collected. There is no
indication of the nature of the stratigraphic data that accompanye ach specimen,a lthough one might
expectt hat precises tratigraphici nformation would be lacking for the majority of specimensm, any of
which were obtained from a variety of collectorsm ore than a century ago. Furthermore, Harrison and
Walker never discusso r give referencet o the associatedfl ora or fauna of their fossils ites.S uchi nformation
exists and must be readily available at the British Museum. Thus, no attempt is made to relate the
Eocene birds of Britain to the environment in which they lived.
Each speciesa ccounti s divided into subsectionss uch as "Diagnosis,"" Material," "Occurrence,"" De-
206 Reviews [Auk,V ol. 98
scriptions," "Measurements," and "Comments." Synonymiesa re provided for previously describedt axa,
and etymologiesa re given for newly named taxa. In these two papers alone, Harrison and Walker have
named 2 new families, 14 new genera, and 18 new speciesf rom lower Eocene deposits,a nd 7 new genera
and speciesf rom upper Eocenel ocalities. They begin the systematics ectiono f their lower Eocene paper
with the descriptiono f Marinavis longirostrisa s a new family, genus, and specieso f supposedp rocel~
lariiform affinities, the species being based on three scraps of a bill and an extremely fragmentary
carpometacarpus. Their "diagnosis" of the Marinavidae (p. 6) does not mention any other family of
Procellariiformes, so it is impossible to determine how the Marinavidae resembleso r differs from other
memberso f the order. Even if Marinavis possessedo nly characterst hat were clearly procellariiform in
nature, the available material would simply be inadequate for the establishmento f new taxa. Harrison
and Walker's admission of the presencei n Marinavis of characters that are suggestiveo f the Pelecani-
formes and the Laridae, as well as others not found in any of the modern taxa considered,m akes their
ordinal assignmente ven more suspect. They designate a rostral hook as a paratype of Marinavis, but
go on to say (1977: 8) that "the rostral hook and carpometacarpusm ight be referable to either order
[Procellariiformeso r Pelecaniformes]."T hey provide no justification at all for referring the carpometa-
carpus even to the order Procellariiformes, much less to their newly erected Marinavidae. The treatment
of Marinavis can be cited further as an example of three characteristic features of Harrison and Walker's
work: 1) the complete or nearly complete failure to mention which living speciesw ere used in their
osteologicalc omparisons;2 ) the use of "descriptions"t hat are extremely lengthy and redundant, partic-
ularly when accompaniedb y an illustration;3 ) the unjustified referral of a fossilf ragment to a taxon that
is otherwise based solely on a different skeletal element (which may be equally fragmentary and unin-
formative).
The description of Precursor (1977: 24), a new genus of supposed charadriiform relationship and
possiblya glareolid,s uffersf rom many of the samec onceptuapl roblemsa s that of Marinavis and contains
additional kinds of errors as well. Harrison and Walker create three new specieso f Precursor: parvus,
based on the distal end of a humerus and a paratypical proximal end of a humerus; magnus, based on
the distal end of a tarsometatarsuso nly; and litorum, based only on the distal end of a humerus. All
three holotypes are illustrated in Plate 6, with parvus enlarged 5 x, magnus enlarged 3x, and litorum
enlarged 2 x. Direct comparison of the illustrations of parvus and litorum (both based on distal ends of
humeri) is rendered nearly impossible by their separation on opposite sides of the tarsometatarsi of
magnus and by the use of such different size scales.V irtually no comparable measurementsa re given for
these humeri, so once again it is very difficult to compare the two specimensd irectly. Early in the
"description" of each supposeds pecieso f Precursor is found the ubiquitous and frustrating statement
alluding to the "good condition" of the fragment in question, despite its many flaws that are then
described. Of P. parvus they say (p. 25), "... well-preserved but the palmar aspect of the condylesh as
been worn away and there is slight damage to the anconal tips of the ectepicondylea nd entepicondyle";
of P. magnus (p. 26), "... in a very good state of preservation, but lacking the trochlea for the fourth
digit and proximally broken a little before the metatarsal facet"; of P. litorum (p. 26), "... in a good
state of preservation but the ectepicondylar ridge is eroded." I am not at all convinced that any of the
specimenso f Precursor are members of the Charadriiformes, much less the Glareolidae. A conclusive
judgement on this matter requires better specimens.
The photographso f Precursor in Plate 6, mentioneda bove, do not stand alone in being misleadingo r
incorrect. Plate 1: A-E illustrates Primodroma bournei, a new genus and specieso f storm-petrel whose
name does not appear in the caption becausel ine 5 is reproduced twice: once in line 1, and then in its
correct place. One thus gets the initial impressiont hat the humerus of Primodroma belongst o Pseudo-
dontornis, which is misspelled in line 5. Parvigyps praecox, a new genus and specieso f Accipitridae,
appears in Plate 7: D-J, and not Plate 7: D-H as stated on p. 31. The holotype tarsometatarsuso f
Argillipes aurorum appears in Plate 7 and is therefore isolated from the tarsometatarsi of the other
putative galliforms that are shown in Plate 8. Plate 8: E illustrates the humerus of Argillipes aurorum
and not Argillornis longipennis, as claimed on p. 20.
The main difference between the late Eocene study of Harrison and Walker (1976) and the 1977 paper
is the younger age and the smaller size of the avifauna in the former. The same conceptual errors are
evident throughout, and the reader is oncea gain given few cluesa s to why a particular fossilw as assigned
to order or family. The descriptiono f Colymboidesa nglicusL ydekker 1891, occupies1 « pages,y et says
little that is not obtainable from the photographs in Plate 1. Statements such as (p. 327), "The bone
[humerus]w idens at the distal end..." are applicablet o birds in generala nd are of no value in defining
taxa. The synonymiesin Harrison and Walker (1976) are inadequate and inconsistent.P ublication dates
are not given in the synonymieso f Colymboidesa nglicus or Piscator tenuirostris. The authorsa lso omit
January 1981] Reviews 207
any of the volumes of Brodkorb's Catalogue of Fossil Birds in the Literature Cited, despite using Brod-
korb's name in certain of the synonymies.
They describeH owardia eous as a new genus and specieso f Anatidae (p. 337), but the generic name
Howardia is preoccupied, being only one of no fewer than four preoccupied generic names already
proposed by Harrison and Walker. In addition, Howardia is based on a single piece of sternum so
fragmentary that it cannot possiblyb e accurately identified and diagnosed. When fossilsa re so damaged
that identification even at the ordinal level is impossibleo r highly speculative, what knowledge is gained
by describingt heses pecimensa s new generaa nd species?It is evidently Harrison and Walker's philosophy
that every fragmentary fossil can and should be identified and given a name, as though the naming of
new taxa were an end in itself. In pursuit of their philosophy,t hey have comet o regard a paleontological
specieso f bird as being constitutedb y a singlee nd of a bone insteado f an entire skeleton.L ittle attempt
is made to refer elementso f both the wing and leg to the same taxon, the result being a wild proliferation
of new names. Of the 25 new speciesn amed in their two Eocenep apers, only three have elementsf rom
both the pectoral and pelvic assemblagesa ssignedt o them. This taxonomic treatment has in effect made
holotypes of the majority of early Tertiary fossil birds in the British Museum. Even when they do refer
more than one element to a single species,t his is often done arbitrarily and with little justification.
The naming of completely undiagnostic fossils would be less disturbing if most of their potentially
diagnostic specimensw ere at least assignedt o the correct order. From an examination of Harrison and
Walker's figures and descriptions,O lson and Feduccia (1979, Proc. Biol. Soc. Washington 92: 494-497)
have determined three of Harrison and Walker's new genera (Parvicuculus, Procuculus, and Primoscens)
to have been incorrectly assignedt o order. After examining the actual specimensin volved, I am in full
agreement with Olson and Feduccia. The description of an unassociated,d amaged Eocene fossil as a
new speciesi n a modern family, just becausei t is reminiscent of one end of one bone in that family, is
not a valid practice in other subfieldso f paleontology,a nd avian paleontologys hould not be an exception.
Olson (1977, Smithsonian Contrib. Paleobiol. No. 35) has pointed out that Limnofregata, a primitive
frigatebird from the lower Eocene of Wyoming, could be safely referred to the Fregatidae only after
studying the entire skeleton. Familial misidentificationsc ould easily have arisen had only isolated ele-
ments of its skeleton been found, becausec ertain bones of Lirnnofregata have characterso f other higher
taxa. The fact that most early Tertiary birds cannot be diagnosedf rom single elements is sufficient to
invalidate many of the systematicc onclusionso f Harrison and Walker; the majority of their newly named
taxa from the Eocene of Britain can only be regarded as "Aves, incertae sedis."
In summary, the paleontology of Harrison and Walker consistso f the application of names to what
are usually undiagnostico r misidentifiedb ones, without considerationo f their geologicalo r biological
context. The inadequated iagnosesa nd unhelpful descriptionsc ontain many nomenclatorial,t ypograph-
ical, and grammatical errors. Their publicationsa re reminiscento f the 19th century preceptse xercised
by such workers as R. W. Shufeldt and C. W. DeVis. The correction of the past errors of these and
other authors has been an important duty of avian paleontologistsi n the 20th century. Unfortunately,
it appears that such remedial work is not only unfinished, but is being made increasingly necessary,t hus
impeding the genuine progesst hat has been made in avian paleontology in the past few decades. For
someone with sufficient knowledge of avian osteology to make his own assessments,t he photographs in
Harrison and Walker's papers are of interest in that they illustrate specimensn ot figured elsewherea nd
not necessarilya vailable for personal inspectiona t the British Museum (Natural History). I would have
to advise anyone else simply to ignore these publications.--D^vID W. STEADMAN.
Biog(cid:127)ographie et (cid:127)eologie.--J. Blondel. 1979. Paris, Masson. x + 173 pp., 47 figures, numerous
tables. Paper. 130 French francs.--For about 17 years now Jacques Blondel, who is a senior research
worker with the Centre National de la RechercheS cientifique (CNRS) and a professora t the Technical
and Scientific University of Languedoc in Montpellier, France, has carried out detailed and long-term
investigationso n the structure of bird communitiesi n Mediterranean France and elsewhere. In this book
Blondel not only summarizes his own studies and those of his coworkers, but, more importantly, inte-
grates this work within the broader field of community ecology and geographicale cology. The result is
a remarkable volume, small in size but rich in ideas and examples,a nd especiallyv aluable in its detailed
attempt at a synthesiso f modern theory and extensive,o ften original field data.
Blondel approachesh is subject fully within the framework of what he calls MacArthur and Wilson's
paradigm. But instead of dwelling upon already existing theory or developing more theory through
further mathematical refinements, Blondel resolutely tries to see to what extent predictions from theory
can be verified after careful measurements of crucial parameters in nature.
208 Reviews [Auk, Vol. 98
The book is divided into five chapters. In the first (The Diagnosis of Distribution Patterns), the various
levels of integration that one can use to approach the study of specifico r community distribution patterns
are discussedB. londel recognizesfi ve levels: continental, regional, sectorial, biotope, and samplings ite.
For each level he explainsp roblemso f definition and of analysiso f diversity, usinga s the major example
his own work in southern France, especially his distributional studies on Mount Ventoux. The second
chapter (Composition and Structure of Communities) analyzes richness, abundance, and diversity of
communities. Note that Blondel distinguishest wo kinds of "communities," called respectivelyi n French
cornrnunaut(cid:127) and peuplernent. The first correspondst o the biocenosis,t he second to the community in
English language publications. In chapter three (Strategieso f Use of Ecological Space and Community
Regulation), Blondel discussesc ausal factors of community distribution and structure. In the fourth
chapter (Ecological Successionsa nd EcosystemD evelopment) are examined the factors that contribute
to community dynamics over time, with detailed examples from the long-term successions tudies carried
out by C. Ferry and B. Frochot on forest avifaunas in Burgundy, and from the gradient analysesb y
Blondel himself in Mediterranean avifaunas. In the last chapter (Insular Communities) the problems of
richness, diversity, structure, turnover, and adaptive strategies are analyzed with special reference to
Blondel's own studies (with coworkers B. Frochot and P. Isenmann) of avian communities in mainland
France and the island of Corsica.
All the major questionsb eing currently debated are discussedi n this book, including among others
niche breadth, niche width, niche overlap, alpha, beta, and gamma diversities, stability, habitat selection,
r- and K-selection, and turnover. In spite of the occasionalu ncritical acceptance of some theoretical
ideaso r researchr esults,w hich sometimesm ars the originalityo f the work, this book seemst o me to be
one of the best statementso f the current state of geographicale cologya nd community ecologya vailable
in any language. Besidest he examplesf rom work by the French schoolo f avian ecologistsw, ith which
English-speaking workers are unfortunately largely unfamiliar, Blondel's book has the further merit of
also integrating other European with American studies. If it had Been written in English instead of
French, this volume would have been perfect for the series of "Monographs in Population Biology"
published by Princeton University Press;i t would be well worth having this book translated into English
and republished.--Fr, ANqOlSV UILLEUMIER.
Neural mechanisms of behavior in the pigeon.--A. M. Granda and J. H. Maxwell (Eds.). 1979.
New York, Plenum Press. xvi + 436 pp. $42.50.--The past 25 years have witnesseda resurgenceo f
studies in comparative neurobiology, characterized by an emphasiso n brain-behavior reiationships and
involving a combination of anatomical, physiological, and behavioral techniques. Because they offer a
rich repertoire of species-typicabl ehaviorsc ombinedw ith a remarkable assortmento f learning abilities,
birds have been among the most commons ubjectsf or such studies. Our knowledgeo f avian neuroanat-
omy and sensoryp hysiologyi s expanding rapidly, and we can begin to discern the outlines of some of
the neural mechanismsu nderlying eating and drinking, vocalization, aggressiveb ehavior, orientation,
reproductive behavior, and perceptual processesin birds. A broad and authoritative review of this work
would therefore be welcomedb y the general reader, even at the price of this book. Unfortunately, the
presentv olume is not such a review, despitei ts title. It reflects,i nstead, the proceedingso f a conference
devotedp rimarily to the study of visual processes";V isual mechanismso f behavior in the pigeon"w ould
thus be a more appropriate title. Like all conferencep roceedings,i t suffers from a certain arbitrariness
of inclusion( Keeton's chapter on navigation; Boord and Karten's review of anatomy of the vestibular
system) and exclusion (e.g. interocular transfer). Its focus on a single species,w hile reflecting the state
of the field, further limits its usefulnessf or the generalist,a nd a chapter on Columbiform taxonomy is
so perfunctory as to be uselesst o either the specialist or generalist.
These necessaryc aveatsd isposedo f, the book's many specializedv irtues should be noted. The bulk
of the book is devoted to visual psychophysics,p articularly the psychophysicso f color vision, with a
subsidiary emphasis on the role of retinal oil droplets. These chapters are of interest not only for their
substantive content but becauset hey illustrate the variety and sophisticationo f the behavioral procedures
available for the experimental analysiso f the sensoryw orld of birds. A secondm ajor group of papers
deals with the anatomy and physiologyo f central visual structures, their possibleh omologiesw ith mam-
malian structures, and their presumedr ole in various aspectso f visual perception. They contain two very
clear messagesf or the comparative neurobiologist.F irst, there is a surprising degree of similarity in the
organizationa nd function of visual structuresi n birds and mammals, but the differencesm ay be quite
illuminating. Second, even "simple" perceptual processes(e .g. optomotor reflexes)a re likely to reflect
widely distributed central neural processes.