DOCSLIB.ORG

(144) Reactions of Some Passerine Birds to a Stuffed Cuckoo. Ii. A

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
(144) Reactions of Some Passerine Birds to a Stuffed Cuckoo. Ii. A (144) REACTIONS OF SOME PASSERINE BIRDS TO A STUFFED CUCKOO. II. A DETAILED STUDY OF THE WILLOW-WARBLER. BY GEORGE EDWARDS, ERIC HOSKING AND STUART SMITH IN a previous paper {British Birds, Vol. xlii, pp. 13-19) we described the reactions of various small passerine birds to a stuffed Cuckoo (Cuculus canorus) placed in their nesting territories. These experiments, which were exploratory in nature, raised a number of interesting problems, and it became evident that if we were to obtain answers to certain of them, it would be necessary to give close study to a single species during the whole of the breeding period. We chose for this study the Willow-Warbler (Phylloscopus trochilus) because it is a common bird whose nest is not very difficult to find, and one which reacts strongly to a stuffed Cuckoo. It can be shown mathematically that if one assumes a probability of at least 0.05 (one in twenty) to be desirable, then at least 10 experiments on one species must be carried out to obtain significant results from which sound deductions can be made. Altogether we found, and did experiments at, 14 nests of the Willow-Warbler, whilst in addition, experiments were tried in 6 territories of cock birds of this species, from the day of their arrival in mid-April until the beginning of nest construction. The results relating to the period of territory formation, therefore, are not so significant as those obtained at the nests. During this intensive study we attempted, among other things, to answer the following questions :— (a) What effect has the stage reached in the breeding cycle on the reactions of the birds ? (b) Has any particular part of the Cuckoo a specially high signifi­ cance in evoking attack ? (c) Is the Cuckoo " recognized " as such by the Willow-Warblers, and can they differentiate one dummy from another? These questions, and the experimental data obtained during their elucidation, are dealt with below. (a) Effect of stage reached in breeding cycle. It is convenient to divide the breeding cycle into four periods, namely, (i) from the arrival of the cock birds to the start of nest construction ; (ii) the period including nest-construction, clutch- completion, and incubation ; (iii) the period during which the brood is in the nest; and (iv) the post-fledging period. (i) The first cock Willow-Warblers arrived in their territories in the North Cheshire area in mid-April, and experiments were started on the day of their arrival. There were two cocks singing vigorously on the 13th, three on the 14th, and five on the 18th. The sixth did not VOL. XLIII.] REACTIONS TO A STUFFED CUCKOO. 145 arrive until April 24th. The method of experimentation at this stage was to use stuffed Cuckoos specially prepared for us in which a stout wire protruded through the belly. This wire was thrust down the hollow inside of a 10 foot bamboo cane, and the Cuckoo could then be lifted nearly 20 feet into the tree in which a bird might be singing. Animation could be give to the Cuckoo by slightly rotating the cane in either direction. The birds reacted at once to this, even though an observer held the cane in his hand, but once a bird's attention had been drawn by such methods to the Cuckoo, the cane was normally thrust into the ground and reactions observed from a distance. In general, during this period, the following may be taken to summarize average reaction to the dummy, though there were individual variations between different cocks. The results are based on 42 hours of watching and experimenting in the six territories. Immediately on arrival and for a period afterwards (which is variable and which probably corresponds to that before the hens arrive) the cock Willow-Warblers respond to the Cuckoo by posturing at it with " flicking " wings and very loud and sustained song. Occasonally the chittering " chee-chee " note, which is such a feature of later display, is used against the dummy, but not at all frequently. On no single occasion was an actual attack made on the dummy, the chief features being a close approach and vigorous and sustained singing. As soon as a hen bird arrived and one of the cocks had paired with her, reaction of that cock to the Cuckoo diminished quickly. In two instances, paired cock Willow-Warblers ceased altogether to react to the Cuckoo, although they continued to sing in their territories and attack other Willow-Warblers which ven­ tured in. Reaction to the Cuckoo during territory formation, seems strongest in the region of the song-post, but thereafter it is strongest in the area of the nest. It seems probable that during this stage when the cock birds are forming their territories, the Cuckoo has no very great " valence " for the Willow-Warbler, and that reaction to it may take place more because of the high general level of aggressive potential within the birds, than from specific reaction to the dummy as a Cuckoo. Cock birds which were merely passing through on migration did not react to the Cuckoo at all, although they sang whilst resting in areas as yet untenanted by other Willow-Warblers. Thus in one case, the behaviour of a cock bird which was singing in one area puzzled us at first because, whenever the Cuckoo was presented to it, the bird flew away to a distance. Next day, however, this bird had disappeared and was evidently a passing migrant. (ii) Experiments were conducted at three nests during the build­ ing stage, at four nests during laying and incubation of the eggs, and at seven nests with young in various stages of development. In only one case were the three stages of building, laying and incu­ bation, and rearing of the young, investigated consecutively at 146 BRITISH BIRDS. [VOL. XLIII. one and the same nest, since at two of the three nests found in the building stage, the experiments resulted in the birds abandoning the nest before it was completed. This desertion of nests at the building stage, if experiments are attempted, was also noted by Lack to occur with three Robins (Erithacus rubecula), (Life of the Robin, Witherby, London, 1943). It should be noted, however, that in the case of the nest at which experiments were carried out through all three stages, the reaction at any one stage duplicated exactly that obtained at other nests at which only one, or sometimes two stages were investigated. The general picture, allowing for small individual variations from pair to pair, is fairly constantly as follows. During the nest- building period the Willow-Warbler reacts to the Cuckoo with chittering and wing-flicking, but not with an attack. At one nest, completed externally but not lined, a stuffed Cuckoo placed in a bush a yard above the nest evoked loud chittering and wing-shaking from the pair. This brought in other Willow-Warblers until there were six birds of this species in the small bush, all demonstrating against the Cuckoo. There was no attack, however, although occa­ sionally two of the cocks would sing a snatch of song and then attack one another. While the six birds were in the bush, a live Cuckoo came to a tree 20 yards away and called. Two of the Willow-Warblers then left the bush and flew to the tree, where they chittered and demon­ strated against the live Cuckoo. Later, this nest was deserted, as was one other at which experiments were done during the building stage. As soon as egg-laying starts, reaction to the Cuckoo becomes more violent. At a nest with four fresh eggs of an incomplete clutch, the hen bird returned soon after a dummy Cuckoo had been placed just above the nest. She demonstrated by chittering and flicking her wings, but did not attack. When the cock arrived three minutes later, he attacked at once and the hen joined in, and the combined attack was violent enough to knock over the dummy. After incubation has started, violent attack by both birds of the pair is general, and accompanied by the usual chittering and wing- flicking. (iii) With young in the nest, reaction to the Cuckoo is immediate, violent, and sustained, and does not seem to vary with the degree of development of the young. (iv) In the post-fledging period, experimental work is difficult and uncertain, especially after the young have scattered, but at two nests at which we were able to experiment on the day the young were leaving, or had just left, the nest, the adult birds persisted in attacking the Cuckoo so long as the young remained near to the site of the nest. On the following day, however, when the young were more scattered, the adults no longer attacked the Cuckoo, even though it was placed in its previous position immediately over the VOL. XLIII.] REACTIONS TO A STUFFED CUCKOO. 147 nest. The young were by this time scattered over a radius of about 20 yards from the nest-site, and the adult birds merely chittered at the Cuckoo and flicked their wings. This marked diminution in aggressive behaviour after the young are well clear of the nest duplicates what we observed at a Nightin­ gale's {Luscinia megarhyncha) nest, where violent attack on a dummy ceased quickly a few minutes after the young had scattered into the undergrowth around the nest. Although violent attacks on the Cuckoo occur in the area imme­ diately surrounding the nest during the incubation and fledging periods, the cock Willow-Warblers will react to the Cuckoo by clutter­ ing and wing-flicking at any point within their territories.
Load more

Recommended publications
  • Red-Winged Blackbirds: I. Age-Related Epaulet Color Changes in Captive Females1
    Copyright © 1980 Ohio Acad. Sci. 0030-0950/80/0005-0232 $2.00/0 RED-WINGED BLACKBIRDS: I. AGE-RELATED EPAULET COLOR CHANGES IN CAPTIVE FEMALES1 MILDRED MISKIMEN, Put-in-Bay, OH 43456 Abstract. Twenty-four female red-winged blackbirds (Agelaius phoeniceus) were trapped when juveniles and held captive during 3.5 years of observation. Color changes in upper secondary coverts (epaulets) of wings occurred at the time of the late-summer molt of the birds' first and second years. About 84% of birds had dilute rust epaulets after their first molt; 16% had orange. After the molt of the second year, 100% of the birds acquired bright rust or orange epaulets. Thus, outside of the later-summer molting period, females with orange, rust or red epaulets would by chance be 86% after-second-year birds and 14% second year birds. Observations of females caught in fall banding operations supported these findings; 10% of 109 birds in their first winter had bright rust or orange epaulets, and 90% had dilute rust epaulets. OHIO J. SCI. 80(5): 232, 1980 Plumages of red-winged blackbirds uncertainty of the age estimates. Both have been well documented since the be- Francis and Dolbeer could have inter- ginning of this century with classical preted their results with more confidence works by Dwight (1900) and Ridgeway if they had been reasonably certain of the (1902) and more recent work by Meanley ages of the birds they studied. The same and Bond (1970). Emphasis has been on principle could apply to other studies male plumage, especially regarding the recorded in the literature.
    [Show full text]
  • Miles, William Thomas Stead (2010) Ecology, Behaviour and Predator- Prey Interactions of Great Skuas and Leach's Storm-Petrels at St Kilda
    Miles, William Thomas Stead (2010) Ecology, behaviour and predator- prey interactions of Great Skuas and Leach's Storm-petrels at St Kilda. PhD thesis. http://theses.gla.ac.uk/2297/ Copyright and moral rights for this thesis are retained by the author A copy can be downloaded for personal non-commercial research or study, without prior permission or charge This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the Author The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the Author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given Glasgow Theses Service http://theses.gla.ac.uk/ [email protected] Ecology, behaviour and predator-prey interactions of Great Skuas and Leach’s Storm-petrels at St Kilda W. T. S. Miles Submitted for the degree of Doctor of Philosophy to the Faculty of Biomedical and Life Sciences, University of Glasgow June 2010 For Alison & Patrick Margaret & Gurney, Edna & Dennis 1 …after sunset, a first shadowy bird would appear circling over the ruins, seen intermittently because of its wide circuit in the thickening light. The fast jerky flight seemed feather-light, to have a buoyant butterfly aimlessness. Another appeared, and another. Island Going (1949 ): Leach’s Petrel 2 Declaration I declare that the work described in this thesis is of my own composition and has been carried out entirely by myself unless otherwise cited or acknowledged.
    [Show full text]
  • The Cuckoo Sheds New Light on the Scientific Mystery of Bird Migration 20 November 2015
    The cuckoo sheds new light on the scientific mystery of bird migration 20 November 2015 Evolution and Climate at the University of Copenhagen led the study with the use of miniature satellite tracking technology. In an experiment, 11 adult cuckoos were relocated from Denmark to Spain just before their winter migration to Africa was about to begin. When the birds were released more than 1,000 km away from their well-known migration route, they navigated towards the different stopover areas used along their normal route. "The release site was completely unknown to the cuckoos, yet they had no trouble finding their way back to their normal migratory route. Interestingly though, they aimed for different targets on the route, which we do not consider random. This individual and flexible choice in navigation indicates an ability to assess advantages and disadvantages of different routes, probably based on their health, age, experience or even personality traits. They evaluate their own condition and adjust their reaction to it, displaying a complicated behavior which we were able to document for the first time in migratory birds", says postdoc Mikkel Willemoes from the Center for Macroecology, Evolution and Climate at the University of Copenhagen. Previously, in 2014, the Center also led a study mapping the complete cuckoo migration route from Satellite technology has made it possible for the first Denmark to Africa. Here they discovered that time to track the complete migration of a relocated during autumn the birds make stopovers in different species and reveal individual responses. Credit: Mikkel areas across Europe and Africa.
    [Show full text]
  • The Migration Strategy, Diet & Foraging Ecology of a Small
    The Migration Strategy, Diet & Foraging Ecology of a Small Seabird in a Changing Environment Renata Jorge Medeiros Mirra September 2010 Thesis submitted for the degree of Doctor of Philosophy, Cardiff School of Biosciences, Cardiff University UMI Number: U516649 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. Dissertation Publishing UMI U516649 Published by ProQuest LLC 2013. Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 Declarations & Statements DECLARATION This work has not previously been accepted in substance for any degree and is not concurrently submitted in candidature for any degree. Signed j K>X).Vr>^. (candidate) Date: 30/09/2010 STATEMENT 1 This thasjs is being submitted in partial fulfillment of the requirements for the degree o f ..................... (insertMCh, MD, MPhil, PhD etc, as appropriate) Signed . .Ate .^(candidate) Date: 30/09/2010 STATEMENT 2 This thesis is the result of my own independent work/investigation, except where otherwise stated. Other sources are acknowledgedjjy explicit references. Signe .. (candidate) Date: 30/09/2010 STATEMENT 3 I hereby give consent for my thesis, if accepted, to be available for photocopying and for inter-library loan, and for the title and summary to be made available to outside organisations.
    [Show full text]
  • Why So Many Kinds of Passerine Birds?
    Letters • Why so many kinds of passerine birds? Raikow and Bledsoe (2000), in em- Slud 1976). It is unreasonable to assume the list of possible reasons for passerine bracing the null model of Slowinski that there is no underlying biological rea- success, but I would place more empha- and Guyer (1989a, 1989b), may perhaps son for this pattern and for the major sis on it than he did. be said literally to have added nothing turnover in avifaunas in the Northern It is difficult to discuss the nest-bufld- to the Kst of suggestions for why there are Hemisphere in favor of passerines after ing capabilities of passerines without re- so many species of passerine birds. When the Oligocène. sorting to anthropomorphisms such as Raikow (1986) addressed this problem Reproductive adaptations presumably "clever" or "ingenious." Is it not mar- previously and could find no key mor- made the holometabolous insects velous, however, that a highly special- phological adaptations to explain the di- (Coleóptera, Díptera, Hymenoptera, ized aerial feeder such as a cliff swallow versity of Passeriformes, the so-called Lepidoptera, and so on) the dominant (Hirundo pyrrhonota), with tiny, weak songbirds or perching birds, he despaired clade of organisms on earth. Likewise, it bill and feet, can fashion a complex nest and suggested that the problem may be appears that reproductive adaptations, out of gobs of mud fastened to a flat, only "an accident of classificatory his- not morphology, are responsible for the vertical surface? What adjective suffices tory," which brought on a storm of protest dominance of passerine birds over other to describe the nest of tailorbirds {Systematic Zoology 37: 68-76; 41: 242- orders of birds.
    [Show full text]
  • A Baraminological Analysis of the Land Fowl (Class Aves, Order Galliformes)
    Galliform Baraminology 1 Running Head: GALLIFORM BARAMINOLOGY A Baraminological Analysis of the Land Fowl (Class Aves, Order Galliformes) Michelle McConnachie A Senior Thesis submitted in partial fulfillment of the requirements for graduation in the Honors Program Liberty University Spring 2007 Galliform Baraminology 2 Acceptance of Senior Honors Thesis This Senior Honors Thesis is accepted in partial fulfillment of the requirements for graduation from the Honors Program of Liberty University. ______________________________ Timothy R. Brophy, Ph.D. Chairman of Thesis ______________________________ Marcus R. Ross, Ph.D. Committee Member ______________________________ Harvey D. Hartman, Th.D. Committee Member ______________________________ Judy R. Sandlin, Ph.D. Assistant Honors Program Director ______________________________ Date Galliform Baraminology 3 Acknowledgements I would like to thank my Lord and Savior, Jesus Christ, without Whom I would not have had the opportunity of being at this institution or producing this thesis. I would also like to thank my entire committee including Dr. Timothy Brophy, Dr. Marcus Ross, Dr. Harvey Hartman, and Dr. Judy Sandlin. I would especially like to thank Dr. Brophy who patiently guided me through the entire research and writing process and put in many hours working with me on this thesis. Finally, I would like to thank my family for their interest in this project and Robby Mullis for his constant encouragement. Galliform Baraminology 4 Abstract This study investigates the number of galliform bird holobaramins. Criteria used to determine the members of any given holobaramin included a biblical word analysis, statistical baraminology, and hybridization. The biblical search yielded limited biosystematic information; however, since it is a necessary and useful part of baraminology research it is both included and discussed.
    [Show full text]
  • The Relationships of the Starlings (Sturnidae: Sturnini) and the Mockingbirds (Sturnidae: Mimini)
    THE RELATIONSHIPS OF THE STARLINGS (STURNIDAE: STURNINI) AND THE MOCKINGBIRDS (STURNIDAE: MIMINI) CHARLESG. SIBLEYAND JON E. AHLQUIST Departmentof Biologyand PeabodyMuseum of Natural History,Yale University, New Haven, Connecticut 06511 USA ABSTRACT.--OldWorld starlingshave been thought to be related to crowsand their allies, to weaverbirds, or to New World troupials. New World mockingbirdsand thrashershave usually been placed near the thrushesand/or wrens. DNA-DNA hybridization data indi- cated that starlingsand mockingbirdsare more closelyrelated to each other than either is to any other living taxon. Some avian systematistsdoubted this conclusion.Therefore, a more extensiveDNA hybridizationstudy was conducted,and a successfulsearch was made for other evidence of the relationshipbetween starlingsand mockingbirds.The resultssup- port our original conclusionthat the two groupsdiverged from a commonancestor in the late Oligoceneor early Miocene, about 23-28 million yearsago, and that their relationship may be expressedin our passerineclassification, based on DNA comparisons,by placing them as sistertribes in the Family Sturnidae,Superfamily Turdoidea, Parvorder Muscicapae, Suborder Passeres.Their next nearest relatives are the members of the Turdidae, including the typical thrushes,erithacine chats,and muscicapineflycatchers. Received 15 March 1983, acceptedI November1983. STARLINGS are confined to the Old World, dine thrushesinclude Turdus,Catharus, Hylocich- mockingbirdsand thrashersto the New World. la, Zootheraand Myadestes.d) Cinclusis
    [Show full text]
  • Passerines: Perching Birds
    3.9 Orders 9: Passerines – perching birds - Atlas of Birds uncorrected proofs 3.9 Atlas of Birds - Uncorrected proofs Copyrighted Material Passerines: Perching Birds he Passeriformes is by far the largest order of birds, comprising close to 6,000 P Size of order Cardinal virtues Insect-eating voyager Multi-purpose passerine Tspecies. Known loosely as “perching birds”, its members differ from other Number of species in order The Northern or Common Cardinal (Cardinalis cardinalis) The Common Redstart (Phoenicurus phoenicurus) was The Common Magpie (Pica pica) belongs to the crow family orders in various fine anatomical details, and are themselves divided into suborders. Percentage of total bird species belongs to the cardinal family (Cardinalidae) of passerines. once thought to be a member of the thrush family (Corvidae), which includes many of the larger passerines. In simple terms, however, and with a few exceptions, passerines can be described Like the various tanagers, grosbeaks and other members (Turdidae), but is now known to belong to the Old World Like many crows, it is a generalist, with a robust bill adapted of this diverse group, it has a thick, strong bill adapted to flycatchers (Muscicapidae). Its narrow bill is adapted to to feeding on anything from small animals to eggs, carrion, as small birds that sing. feeding on seeds and fruit. Males, from whose vivid red eating insects, and like many insect-eaters that breed in insects, and grain. Crows are among the most intelligent of The word passerine derives from the Latin passer, for sparrow, and indeed a sparrow plumage the family is named, are much more colourful northern Europe and Asia, this species migrates to Sub- birds, and this species is the only non-mammal ever to have is a typical passerine.
    [Show full text]
  • Dinosaur Incubation Periods Directly Determined from Growth-Line Counts in Embryonic Teeth Show Reptilian-Grade Development
    Dinosaur incubation periods directly determined from growth-line counts in embryonic teeth show reptilian-grade development Gregory M. Ericksona,1, Darla K. Zelenitskyb, David Ian Kaya, and Mark A. Norellc aDepartment of Biological Science, Florida State University, Tallahassee, FL 32306-4295; bDepartment of Geoscience, University of Calgary, Calgary, AB, Canada T2N 1N4; and cDivision of Paleontology, American Museum of Natural History, New York, NY 10024 Edited by Neil H. Shubin, University of Chicago, Chicago, IL, and approved December 1, 2016 (received for review August 17, 2016) Birds stand out from other egg-laying amniotes by producing anatomical, behavioral and eggshell attributes of birds related to relatively small numbers of large eggs with very short incubation reproduction [e.g., medullary bone (32), brooding (33–36), egg- periods (average 11–85 d). This aspect promotes high survivorship shell with multiple structural layers (37, 38), pigmented eggs (39), by limiting exposure to predation and environmental perturba- asymmetric eggs (19, 40, 41), and monoautochronic egg pro- tion, allows for larger more fit young, and facilitates rapid attain- duction (19, 40)] trace back to their dinosaurian ancestry (42). For ment of adult size. Birds are living dinosaurs; their rapid development such reasons, rapid avian incubation has generally been assumed has been considered to reflect the primitive dinosaurian condition. throughout Dinosauria (43–45). Here, nonavian dinosaurian incubation periods in both small and Incubation period estimates using regressions of typical avian large ornithischian taxa are empirically determined through growth- values relative to egg mass range from 45 to 80 d across the line counts in embryonic teeth.
    [Show full text]
  • The Relationships of the Hoatzin
    THE AUK A QUARTERLY JOURNAL OF ORNITHOLOGY Vo•,. 90 J^NU^R¾1973 NO. 1 THE RELATIONSHIPS OF THE HOATZIN CH^R•,ESG. Sm•,E¾^N•) JON E. AHLQmST THE taxonomicposition of the Hoatzin (Opisthocomushoazin) of South Americahas long been one of the mostdebated problems in avian system- atics. It hasusually been placed in the Galliformes,but someauthors have allied it with the African turacos(Cuculiformes: Musophagidae), the pigeons(Columbidae), or the rails (Rallidae), and othershave placedit in its own monotypicorder. The Hoatzin occursin riparianvegetation alongthe streamsof the Orinocoand Amazonriver drainagesin northern SouthAmerica. It is a slenderbird, about 25 inchesin lengthand generally brownishin color, somewhatresembling a chachalaca(Cracidae). The smallhead bears a ragged,bristly, reddish-browncrest and the bare facial skin is bright blue. As is apparentfrom the Frontispiece,the Hoatzin is actuallymost like the smallerGuira Cuckoo(G. guira) in coloration;in fact, the two speciesare remarkablysimilar, except in size. This paperreviews the taxonomichistory of the Hoatzinand presents newevidence from a studyof the egg-whiteproteins indicating that the resemblanceto Guira is due to a closerelationship, not merelyto con- vergenceor coincidence.The correctposition of the Hoatzinis as a genus withinthe neotropicalsubfamily Crotophaginae (Cuculidae) and its dosest relativesare Guira and Crotophaga.The longassociation with the Gal- liformes,we believe,was based upon little morethan the prejudiceestab- lishedby the originaldescription as Phasianushoazin (Mi•ller 1776) and the inabilityof subsequentworkers to interprettheir anatomicaldata. The link to the Musophagidaeseems to be basedupon the commonpossession of a numberof anatomicalcharacters (see Verheyen 1956), the vegetarian diets, poor flying ability, generalproportions, and similar size. In the turacosand in the Hoatzin the younghave wing clawsand clamberabout near the nest before they can fly.
    [Show full text]
  • USE of the EXTANT PHYLOGENETIC BRACKET (EPB) CONCEPT in RECONSTRUCTING the DINOSAUR RESPIRATORY Systel\1
    293 USE OF THE EXTANT PHYLOGENETIC BRACKET (EPB) CONCEPT IN RECONSTRUCTING THE DINOSAUR RESPIRATORY SYSTEl\1. NORTON, James M., University of New England, 11 Hill's Beach Road, Biddeford, ME 04005, U.S.A. The EPB concept was developed to provide a framework for inferring soft tissue structures in extinct animals and is applied here to a characterization of the dinosaur respiratory apparatus. The recognized EPB for dinosaurs consists of crocodilians and modern birds, and the respiratory systems of these animals appear to be quite different. Crocodilians have complex multicamerallungs fixed within the thorax, with main intrapulmonary bronchi that communicate with three rows of air chambers. The lungs are ventilated in a tidal pattern by changes in thoracic volume produced primarily by piston-like motions of the liver and abdominal organs. In contrast, the avian respiratory system is separated into rigid lungs for gas exchange and air sacs that serve as a bello~vs-like ventilatory apparatus providing relatively constant, unidirectional air flow through the gas exchange regions. The underlying structural affinity of these apparently dissimilar lung types is demonstrable through a comparative study of their embryology. The avian system represents an embryological fusion of crocodilian-type lateral chambers originating at different points along the intrapulmonary bronchus to form parabronchi. An accompanying expansion of other chambers forms the air sacs. In this EPB analysis, the bracket node (shared by crocodilians, dinosaurs, and birds) would therefore possess a multicameral, crocodilian-type lung. The outgroup node (shared by dinosaurs and birds) would possess a relatively rigid, fixed-volume parabronchial lung with associated air sacs, similar to the paleopulmo possessed by all modern birds.
    [Show full text]
  • Birds of Dinosaur Valley State Park: a Field Checklist
    TEXAS PARKS AND WILDLIFE BIRDS OF DINOSAUR VALLEY S T A T E P A R K A FIELD CHECKLIST 2017 Cover: Illustration of Golden-cheeked Warbler by Clemente Guzman III. INTRODUCTION inosaur Valley State Park, on the Lampasas Cutplain in Somervell County, contains 1,597 acres, nearly half of which is covered D in evergreen Ashe juniper woodlands. This large area of cedar brake on hilly terrain is dissected by several drainages which empty into the Paluxy River — the park’s primary watercourse. One of these tributary drainages, Denio Creek, contains habitat which harbors one of the most sought-after birds in the park, the Golden-cheeked Warbler. The visiting birder should look for this warbler between late March and late June along the Denio Creek and Ridge Trails. While searching for the warbler, expect to find Black-chinned Hummingbirds, Bewick’s Wrens (year-round), Blue-gray Gnatcatchers, Black-and-white Warblers, and Field Sparrows (year-round). Lesser Goldfinches and House Finches can sometimes be found in the park, especially during spring and summer along the Denio Creek Trail. Please stay on the trail so as not to disturb the breeding cycle of our Texas specialties. Perhaps a third of Dinosaur Valley consists of a large fairly open grassland where live oak, yucca, prickly pear and a diversity of shrubby growth predominate. In summer, this habitat is home for Scissor-tailed Flycatchers, orioles, and Rufous-crowned Sparrows. If you’re lucky, you might find a Bell’s Vireo in a dense shrubby thicket. On spring and summer evenings, listen for Common Poorwills along Farm Road 1007 as it winds along the park’s western border.
    [Show full text]