Some Recent and not-so Recent Bird Papers

["Jaime A. Headden" <qilongia@yahoo.com>]

  I am looking for any help in getting these papers, largely involved with
finding correlations to evolving and losing flight in birds, and one personal
ref on the beak of parrots, which probably has nothing to do with flight
evolution/loss. I also realize with the discussion of Archie's place in avian
evolution, these papers may be of interest, some rather new and directly
relevant to loss of flight, to others involved in the discussion. Perhaps they
will allow us to explicitly test what features only show up when flight is
_lost_, rather than evolving from some other condition as an exaptation, a
system that has hitherto been only cursorily referenced, as Tim noted, in the
prey-catching to flight model of Ostrom.

http://www3.interscience.wiley.com/cgi-bin/abstract/109920448/ABSTRACT

  Livezey, B.C. 2005. Morphological corollaries and ecological
   implications of flightlessness in the kakapo (Psittaciformes:
   *Strigops habroptilus*). _Journal of Morphology_
   213(1):105-145.

Abstract:
  "The morphological corollaries of flightlessness of the kakapo
   (*Strigops habroptilus*) have been studied using skin
   specimens, skeletons, and pectoral dissection of an anatomical
   specimen. These have been compared with the closely related,
   flighted kea (*Nestor notabilis*), and secondarily with other
   Psittaciformes and the convergent hoatzin (Cuculiformes:
   *Opisthocomus hoazin*). *S. habroptilus* is the most massive
   and sexually dimorphic psittaciform in the world, and has the
   smallest relative wing size of any parrot. Alar pterylography
   of *S. habroptilus* is similar to that of other parrots, but
   remiges of the species are shorter, comparatively rounded, show
   less asymmetry of vanes, and have fewer interlocking barbules
   distally. *S. habroptilus* shows peculiarities of the sternum
   (vestigial carina, shortened spina externa), coracoid (elongate
   processus lateralis, enlarged angle with scapula), and humerus
   (prominent tuberculum ventrale, undercut crista bicipitalis).
   Pectoral skeletal dimensions of *S. habroptilus* are smaller
   than those of *N. notabilis*, whereas the reverse is true for
   pelvic dimensions. Most skeletal dimensions of *S. habroptilus*
   are more variable (within sexes) than those of *N. notabilis*.
   Proximal wing elements are disproportionately long and distal
   elements disproportionately short in *S. habroptilus*. The legs
   of *S. habroptilus* are characterized by disproportionately
   long femora and disproportionately short tarsometatarsi.
   Distinctive features of the pectoral musculature of *S.
   habroptilus* include a greatly reduced Mm. pectoralis thoracica
   and supracoracoideus, the absence of a distinct proximal muscle
   belly of M. propatagialis tendo longus, an extensive M.
   cucullaris capitis clavicularis associated with a voluminous
   crop, and an essentially tendinous M. sternocoracoideus.
   Relative to mean body mass, all dimensions of the antebrachial,
   carpometacarpal, digital, and patagial muscles are smaller in
   *S. habroptilus* than in *N. notabilis*. These aspects are
   compared to those of other flightless birds. Discussed are
   implications of flightlessness and associated large body size
   of *S. habroptilus* for issues of thermodynamics, metabolism,
   activity patterns, digestive anatomy, diet, reproduction, and
   insularity."

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http://www.springerlink.com/(bsodee452cybtdvkeasx2v45)/app/home/contribution.asp?referrer=parent&backto=issue,2,5;journal,27,53;linkingpublicationresults,1:100160,1

  Cubo, J. and W. Arthur. 2000. Patterns of correlated character
   evolution in flightless birds: a phylogenetic approach.
   _Evolutionary Ecology_ 14(8):693-702.

Abstract:
  "Given a robust phylogeny for a particular higher taxon, it is
   possible to map the evolution of various character changes onto
   the phylogeny and study the extent to which they co-occur. Of
   particular interest are the questions of (a) whether particular
   morphological changes tend to accompany changes in ecology or
   behaviour to which they bear a functional relationship and (b)
   whether changes in those "primary" morphological characters
   tend to be associated with correlated changes in other aspects
   of morphology, as would be expected given the high level of
   morphological integration that characterizes most organisms.
   Here we report a study of this kind, looking at morphological
   correlates of the evolution of flightlessness in birds, and
   using the concentrated changes test to determine whether
   associations are significant. We find that pectoral reduction,
   pelvic enlargement and changes in skull morphology
   significantly co-occur, and that these are usually achieved
   through heterochrony rather than other kinds of developmental
   reprogramming."

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http://www.journals.royalsoc.ac.uk/(ycz4due0wgltqz55s0gons45)/app/home/contribution.asp?referrer=parent&backto=issue,21,37;journal,51,211;linkingpublicationresults,1:102024,1

  Nudds, R. L.; G. J. Dyke & J. M. V. Rayner. 2004. Forelimb
   proportions and the evolutionary radiation of Neornithes.
   _Proceedings of the Royal Society: Biological Sciences_ 271
   (supp. 5):324-327

Abstract:
  "Analysis of a comprehensive dataset demonstrates that the
   brachial index (BI = humerus length/ulna length) of modern
   birds (Neornithes) varies significantly between clades at all
   taxonomic levels, yet is strongly correlated with recent
   phylogenetic hypotheses. Variance in BI at the infraclass level
   is low, but increases rapidly during the proposed major
   radiation of neornithines in the Palaeocene and Eocene.
   Although a BI of greater than 1 is primitive for Neornithes,
   more basal groups of Mesozoic birds (Confuciusornithidae and
   some members of the diverse Enantiornithidae) had BIs
   comparable with those of 'higher' modern clades. It is possible
   that occupation of ecological niches by these Mesozoic clades
   precluded the divergence of some groups of neornithines until
   after the Cretaceous-Tertiary boundary. We suggest that with
   further analysis and data collection the relationships between
   flight behaviour, ecology and BI can be determined. Hence, BI
   may provide a useful tool for characterizing the ecology of
   fossil birds."

--

  Okay, this last one is really just about me....

  Tokita M. 2003. The skull development of parrots with special
   reference to the emergence of a morphologically unique
   cranio-facial hinge. _Zoological Sciences_ 20(6):749-58.

Abstract:
  "The order Psittaciformes (parrots) has unique morphological
   features in the head that are evolutionarily novel. To better
   understand the unique evolution of the head in parrots, the
   developmental pattern of the skull of the budgerigar
   (*Melopsittacus undulatus*) was initially described on the
   basis of transparent skeletal specimens. Although the
   fundamental pattern of the skull development of birds is
   conserved in parrots, some differences were observed between
   parrots and other groups of birds. In parrots, the vacuity in
   the interorbital septum did not emerge throughout ontogeny, in
   contrast to other lineages of birds, for example Galliformes
   and Coliiformes. This feature seems to be concerned with the
   attachment of the unique jaw muscle of parrots, M.
   ethmomandibularis, to the interorbital septum. In spite of a
   prokinetic skull, the cranio-facial hinge of parrots was
   brought about by secondary transformation of dermal bones
   unlike that of birds with a standard prokinetic skull (e.g.
   Corvus) in which the nasal-frontal suture directly becomes a
   hinge of bending. To further understand the evolution of
   "pseudoprokinesis" in parrots, the construction of a robust
   avian phylogeny is desired. The parrot-specific suborbital arch
   and cranio-facial hinge are not seen until birds leave the nest
   and can feed themselves. In conclusion, these structures are
   considered to be essential for eating hard and/or large meals."

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http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=228617

  Iwaniuk, A. N.; J. E. Nelson; H. F. James; & S. L. Olson. 2004.
   A comparative test of the correlated evolution of
   flightlessness and relative brain size in birds. _Journal of
   Zoology_ 263:317-327.

Abstract:
  "Secondary flightlessness has evolved independently many times
   in birds. Morphological changes in the pectoral girdle and
   flight feathers and changes in body size have been associated
   with the evolution of flightlessness, and it has also been
   suggested that flightless birds have relatively small brains.
   We therefore tested whether flightlessness is related to
   changes in relative brain size. Relative brain size was
   compared between volant and flightless species using both
   conventional statistics and modern comparative methods within
   nine taxonomic groups. No significant difference was found
   between flightless and volant species in six of these groups,
   regardless of whether body mass or tibiotarsal measurements
   were used as estimates of body size. Species with relatively
   smaller brains compared with their volant relatives were the
   great auk *Pinguinus impennis*, the kakapo *Strigops
   habroptilus* and some species of penguin. Thus, we found no
   evidence of a general correlation between the evolution of
   secondary flightlessness and the evolution of relatively small
   brains in birds. This suggests that neural requirements are not
   significantly different between flightless and volant species,
   although our methods may have overlooked subtle neurological
   changes that do not result in markedly different endocranial
   volumes."

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http://www.springerlink.com/(q4ikfp552maproai5ibwmm55)/app/home/contribution.asp?referrer=parent&backto=issue,6,6;journal,32,439;linkingpublicationresults,1:400492,1

  Quin, T. H. & J. J. Baumel. 1990. The digital tendon locking
   mechanism of the avian foot (Aves). _Zoomorphology_
   109(5):281-293.

Summary:
  "Representatives of all avian orders were studied in order to
   establish that the tendon-locking mechanism (TLM), consisting
   of local specialization of the flexor tendons and the adjacent
   portion of the flexor tendon sheath, is by no means rare, but
   rather, constitutes the prevalent condition in a large majority
   of the avian species sampled. The areas of tubercles on the
   tendons and the adjacent sheath plications intermesh with one
   another thereby forming a true tendon-locking mechanism that
   maintains the distal and other interphalangeal joints of the
   digits in the flexed position. The TLM seems to function not
   only in perching, but in a wide variety of other activities of
   the avian foot including swimming, wading, prey-grasping,
   clinging, hanging, and tree climbing. The basic structural
   components of the mechanism are remarkably similar in the
   divergent avian groups adapted for these activities.
   Ultrastructural detail of the TLM was studied by means of
   scanning and transmission electron microscopy. Interdigital
   variation in distribution of the TLM in all of the digits of
   individuals were made as were comparisons of the interspecific
   distribution of the TLM. An analysis of the biomechanics
   involved in engaging the elements of the TLM and how they
   produce locking of the flexed joints of the digits includes a
   consideration of the roles of the podothecal pads, ungual
   flexor processes, and the elastic flexor and extensor ligaments
   of the toes. The components of the TLM are differentiated in
   early fetal development establishing that the TLM components
   are not acquired adventitiously in response to such factors as
   posthatching mechanical stresses."

  Cheers,

Jaime A. Headden

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


                
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