Durham E-Theses. Social especially agonistic behaviour in the pigeon. Spiteri, Nello, J.

Transcription

1 Durham E-Theses Scial especially agnistic behaviur in the pigen Spiteri, Nell, J. Hw t cite: Spiteri, Nell, J. (1975) Scial especially agnistic behaviur in the pigen, Durham theses, Durham University. Available at Durham E-Theses Online: Use plicy The full-text may be used and/r reprduced, and given t third parties in any frmat r medium, withut prir permissin r charge, fr persnal research r study, educatinal, r nt-fr-prt purpses prvided that: a full bibligraphic reference is made t the riginal surce a link is made t the metadata recrd in Durham E-Theses the full-text is nt changed in any way The full-text must nt be sld in any frmat r medium withut the frmal permissin f the cpyright hlders. Please cnsult the full Durham E-Theses plicy fr further details. Academic Supprt Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-theses.admin@dur.ac.uk Tel:

2 SOCIAL ESPECIALLY AGONISTIC BEHAVIOUR IN THE PIGEON by Nell J. Spiteri A thesis submitted fr the degree f Master f Science in the University f Durham Department f Psychlgy Durham July, 1975

3 ACKNOWLEDGEMENTS I wish t extend my sincere thanks t Prfessr F. V. Smith fr the pprtunity f vgrking in the Department f Psychlgy, and fr the excellent research facilities made available t me. I am deeply grateful t my supervisr. Prf. Dr. Juan Delius, fr stimulating my interest in the field f Ethlgy, and fr his cnstant encuragement during the curse f this study and critical appraisal f the wrk presented. My thanks are due t the fllwing: Drs. Arthur Still, Jhn Findlay and Richard Mrris fr their suggestins, advice and criticism; Mrs. C, Thmpsn fr help with cmputer prgramming; the Technical Staff f this department fr prviding such excellent service, especially Mr. D. Harper (pix)tgraphy). I am als indebted t Dr. Rn Wler, f the Dept. f Zlgy, University f Duriiam, fr the use f the Sngraph and fr valuable discussins n bird vcalisatins; and Mrs. Zena Matthews whi has patiently typed this thesis. Finally, i wuld like t express my warm thanks and gratitude t my parents fr their mral and financial supprt.

4 TO J.D.D.

5 ABSTRACT This study describes the scial behaviur f the pigen, with particular reference t agnistic behaviur. The ethgram, presented In Chapter 2, includes a descriptin f the aggressive, curtship and maintenance behaviur patterns f pigens. A selectin f sngrams f pigen vcalisatins, which shws the diversity f the calls, and their assciatin with the accmpanying behaviur, is presented. The functin and causatin f sme f the behaviur patterns are discussed. In an attempt t investigate the mechanisms invlved In the regulatin f aggressin between cnspeclfic neighburs, the agnistic behaviur shwn by a dminant male pigen, when allwed t interact with a subrdinate male, was recrded ver 10 days (Experiment 1). It was fund that aggressive behaviur shwed a large decrement ver the first tw days. Threatening behaviur became mre evident thereafter. The causal and functinal significance f these and ther agnistic behaviurs are discussed in this cntext. It was shwn that diurnal rhythms did nt affect agnistic behaviur. The effects f ttal scial islatin n agnistic behaviur was investigated in three male pigens (Experiment 2). The results btained d nt suggest a build-up f an "aggressive drive", during the perids in islatin, which Is expressed thrugh the perfrmance f aggressive behaviur after islatin. The pssible effects f islatin n ther agnistic behaviurs are discussed.

6 CONTENTS Acknwledgements Abstract Chapter 1: Chapter 2: INTRODUCTION THE ETHOGRAM 2.1 Intrductin 2.2 Subjects and Methds 2.3 Sund Recrding 2.4 Descriptin f Behaviur 2.5 Behaviur at the nest site 2.6 The Curtship encunters 2.7 The Agnistic encunters 2.8 Sme cmments n the functin and causatin f sme f the behaviur patterns I 3 3 k Chapter 3: EXPERIMENT 1: MALE PIGEONS REGULATION OF AGGRESSION BETWEEN 42 Chapter k: 3.1 Intrductin 3.2 Materials and Methds 3.3 Statistical Analysis 3.k Descriptin f behaviur bserved and recrded during encunters 3.5 Experimental results 3.6 Diurnal rhythm effects n agnistic behaviur Experimental results 3.7 Discussin EXPERIMENT 2: SOME EFFECTS OF SOCIAL ISOLATION ON AGONIST IC BEHAVIOUR k.] Intrductin 64 k.2 Materials, and Methds k.3 Experimental Results k.k Discussin 71 APPENDIX A APPENDIX B APPENDIX C Sex determinatin The MATE Ontgeny f Behaviur

7 APPENDIX D Experiment 1 Data Tables 86 APPENDIX E Experiment 1 Intercrrelatln Tables 93 APPENDIX F Experiment 2 BIBLIOGRAPHY ADDENDUM TO BIBLIOGRAPHY Data Tables and Trend analysis

8 CHAPTER ONE INTRODUCTION This thesis describes the scial behaviur f the pigen (Clumba livia). One class f behaviur is investigated in particular, namely agnistic behaviu r. The pigen is unusually well suited fr behaviural research. It adapts very quickly t a labratry envirnment, breeds well in captivity, and exhibits discrete functinal units f behaviur which are readily and clearly recgnisable by an bserver. Mrever, it has been the subject f investigatin by wrkers such as Levi (19^1) and Whitman (1919), wh have prvided a gd infrmative backgrund abut its behaviur. Althugh the reprductive behaviur f this species has been systematically studied by wrkers such as Fabricius and Janssn (I963), investigatin f the pigen's agnistic behaviur has been neglected. This thesis presents tw experiments which, it is hped, will act as a fundatin fr further investigatin int this class f behaviur. In Chapter 2, I present: first, as cmprehensive a cverage as pssible,f the aggressive, maintenance and curtship (including reprductive) behaviur patterns f pigens, which includes a selectin f sngrams f pigen vcalisatins shwing the diversity f and between the calls. Secnd, a cncise descriptin f the curtship and agnistic encunters in this species; and third, analyses f the pssible causatin and functins f sme f the behaviur patterns described. Previus experimental wrk using fish and mice demnstrated that intraspecific fighting "can vary as a functin f the degree f expsure t aggressive experiences in an therwise cnstant testing envirnment" (Cnnr, 197^). With this in mind, these experiments fllwed tw main trends: (a) Habituatin experiments and (b) Islatin experiments. Chapters 3 and k present an investigatin int the effects f (a) cnstant expsure f a male

9 pigen t a neighburing male cnspecific and (b) scial islatin, n the agnistic behaviur f pigens. Peeke and Ven (1973) suggest that in fish and birds similar mechanisms may be respnsible fr the maintenance f lwered levels f aggressin between territrial neighburs. In Chapter 3, the experiment tests whether male pigens can maintain lwered levels f aggressin ver a perid f days as well as investigating ther agnistic behaviurs. The experimental design ensured that the expected waning and any recvery f aggressive behaviur cannt be attributed t either changes in envirnmental factrs (such as changes in phtperid r territrial neighburs) r the frequency f encunters between pigens. All f these factrs are kept cnstant thrughut the experiment. Chapter 4 describes a brief experiment investigating the effects f ttal scial islatin n, mainly, the agnistic behaviur f male pigens. In this experiment, dminant male pigens previusly placed in islatin fr varying perids f time, are tested individually with a subrdinate male, and their behaviur recrded, it is argued that the behaviurs shwn by the pigens immediately after islatin may reflect pssible changes in their mtivatry r physilgical states brught abut by scial islatin. It is hped that these experiments may thrw sme light n the manner in which "mtivatinal" variables affect intra-specific aggressin, as well as stimulating further research n the agnistic behaviur f pigens.

10 !:TKOG:^A;< 2.1 1ntrGJCtin Even thugh the pigen is ne f standard labratry bird species that are used in behaviural research, it is remarkable thut i cr.iprhneive descriptive catalgue f its behaviur is still lacking. Such a ca:;cl ue is fundamental fr an accurate cmmunicatin a-ng invstigatrs and als fr advanced quantitative behaviural vrark, particularly fr L;-.OGC: wrkars wh need t assess behaviural change even thugh their interests be primarily elsewhere (e.g. physilgists, pharmaclgists, endcrinlgists etc.). The first part f this thesis is intended as a fundatin fr such a catalgue. Whitman (1919), Carpenter (1933), Kcinrth and Hcinrth (194S) and mre recently Fabricius and Janssn (1963), have all described tr.^ curtship and reprductive behaviur f the pigen. Hwever, there has been very little descriptin f the agnistic behaviur encunters and maintenance behaviur in this species, with the exceptin f Gdwin (1555, '967) and Levi (1941). Sme f the agnistic, as well as curtship and maintenance behaviur patterns f-ring dves are very similar t thse f pigens. Miller and Miller (1958) give a synpsis f tha behaviur patterns f ring dves (Streptpelia risria), and mre recently Harwd and Vwles (is67) have described the defensive behaviur f this species; but bth accunts are far frm cmplete. In the fllwing sectin, the behaviur patterns which are assciated with curtship, maintenance and aggressin in the feral pigen, are descridad. Eibl-Eibesfeldt (1970) describes such an inventry f behaviur patterns as an ethgram. As part f the ethgram, a selectin f pigen vcalisatins are presented, chsen t shw diversity within and batv;een pigtns.

11 I Bth Craig (1908) and Beer (1970) indicate the imprtant rle f pigen and dve vcalisatins in Influencing scial behaviur, as a means f cmmunicatin and recgnitin between individuals, and als f species recgnitin. Craig states: "the vice (f pigens) is a means f scial cntrl a means f influencing the behaviur f individuals s as t bring them int c-peratin, ne with anther", and "the yung dves have impressed upn their minds,.,;, the fact f differences (in their vices) between individuals". Several authrs (e,g. Heinrthand Heinrth, 19^9, Fabricius and Janssn, I963, Akerman, 1966a, b) have used nmatpeic renderings f the calls lsely and smetimes, when these are described in cnjunctin with the accmpany!ng behaviur, incrrectly. Sme f the terminlgy used in the fllwing ethgrsm is similar t that used by Delius (1969), and Feekes (1971), but this des nt necessarily imply that I cnsider the relevant behaviur patterns f pigens t be hmlgus with thse f skylarks and Burmese red junglefwl, 2.2 Subjects and Methds The pigens used were f hming stck btained thrugh a lcal dealer, and were hused fr at least fur mnths befre they were used fr bservatin and experimentatin. The pigens were kept in galvanised metal cages measuring ko x ko x. k5 cm,, at a cnstant rm temperature f +21 C, and a lighting schedule f 12 hrs, light : 12 hrs, dark, the lights cming n at 08,00 hurs and switching ff at hurs. Fd and water were given ad libitum. During this acclimatisatin perid the birds became accustmed t handling and bservatin, s that subsequently the bservatin f behaviural data were easily accmplished. All the pigens used were ver ne year f age. Fr the recrding and bservatin f behaviur, a variety f techniques was emplyed: ntatin, tape recrding, vide recrding, ci r.ema tgraphy and still phtgraphy. In rder t bserve and recrd pigen behaviur in

12 varius cntexts, all the pssible pairings between the pictin sexes were used, i.e. male - male, male - female, and female - female pairs. When using male - female encunters fr behaviural bservatins, bth breeding pairs and 'strange' pairs f birds were used. The bservatins were made ver a perid f nine mnths, 2.3 Sund recrding The sund recrdings presented in this study were made with the aid f a Marcniphne mdel 4218 tape recrder (British Radi Crpratin Ltd.) at 3 tape speed f 18 cm, per secnd (the frequency respnse f tlie tape recrder at this speed is 40 - I8OOO Hz,), Fr the purpses f call analysis, cntured sund spectrgrams were made frm the tape recrdings by means f a Sn-graph (Kay Electric C,, Sn-graph type B/65), at a 'narrw band' (45 Hz.) fiiter setting and a 'high shape' circuit. The frequency range cvered was frm 0 t 1 khz., since the calls did nt shw main energies abve 1 khz.; the base-line fr the spectrgrams was a 45 Hz, band. In interpreting the cnturs, the darker cnturs indicate higher energies f a call at that particular frequency. The sn-graph drum-speed was 12.7 cm. per secnd. The vcalisatins f twelve pigens are dented by the prefix P fllwed by their ring number, e.g. P 35 etc. Figure 2,1 is a diagrammatical representatin f a driving call, which includes the Heinrths nmatpeic rendering. Referring back t the figure, ne can see that each individual call is cmpsed f elements, syllables and phrases. The elements are the smallest discernible vcal units in a syllable and ne element r a grup f elements having a fixed arrangment cnstitute ne syllable, A phrase is made up f a grup f syllables. Elements may be spaced ver frequency r time r bth and the tempral interval between elements shuld be less than 0,05 secnds. Inter-phrase spacing can

13 elements phrase % Si E i i I «l "1 ~! syllable j se6s WANG WANG R O O K H O O O O Figure 2,1 A diagrammatic representatin f a driving call (P 17), illustrating the terminlgy used fr sectins f the call. Only the main energies at their respective frequencies within the call are shwn, and cnsequently when determining the tempral Intervals fr the cntured spectrgrams ne must d s frm main energy t main energy. vary, but can be taken t be secnds, and in certain circumstances single syllables can cnstitute a singular phrase.

14 2.k Dsscriptin f Behavi-jr A G G R E S S I V E P E C K I N G : With its beak pen, the pigen pecks at the ppnent, usually grasping areas f the head and neck firmly in its beak and giving vigrus head-shakes. Other areas, such as the wing and back feathers, may be grasped by the attacking bird. Smetimes the dminant pigen will tread n the ppnent's tail and back during intense aggressin, while still grasping the neck in its bill. Aggressive pecking is seen mst frequently during encunters betv;een male pigens, and can lead t-further types f attack. This behaviur als ccurs after a sequence f cpulatins during the pre-incubatin phase f the breeding cycle, when the male pecks at the neck and crwn area f the squatting female quite vigrusly. This may be due t the male being bth sexually and aggressively mtivated (Fabricius and Janssn, 19^3). A G G R E S S I V E I N T E N T I O N PECK: The bird is attentive, the neck is stretched upv;ard and the head is brught sharply frward and dwnward; s that pecking actins are directed at the ppnent's head, althugh cntact seldm ccurs. This behaviur was never seen during encunters between male and fiemale pigens. A G G R E S S I V E B I L L I N G : While bdy-pushing with their wings raised, the pigens peck at each thers' bills and ne bird may grasp the ppnent's bill in his mandibles (Plate la), Bth birds perfrm.tw!sting mvements, ne bird bviusly trying t escape the held f the ther, B O D Y - P ' J S H I N G : During bdy-pushing the wings f bth birds and the nes in clse prximity are brught against each ther (usually while the birds bill aggressively), and the tall is fanned

15 PLATE I 8 A, AGGRESSIVE BILLING B. FEMALE DRIVING ft C. WING AND LEG STRETCH

16 r. ut if nt already s. The pigens then mve arund a cmmn centre with their vylngs still in a raised psitin (Fig, 2,2,3), The lwer breast regin als appears swllen, due t fluffing f the plumage and pssibly t the enlargement f the crp. This regin may serve as sme kind f 'bumper', since this is the area used by the pigens when pushing against each ther. W I N G F L I C K : A sharp mvement f the wing which cnsists f a pwerful dwnward wing beat. The pigen fans ut its tail, raises the wing which is nearest t the ppnent and brings it dwn sharply n t the ther bird; the ther wing is raised nly slightly during wing flicks f lw intensity (in this case, des nt refer t the frequency but t the pwer f the wing beat) (Fig, 2,2,1). As the tw pigens encrach n each ther, v;ing flick intensity (bth the pwer and the frequency) increases, and the nn-flicking wing is raised higher till it Is held at a near vertical psitin during high aggressin, W I N G FEND: When a fleeing bird is being clsely pursued by a dminant male, it may flick upward ne f its wings, usually hitting and thereby warding ff the pursuing bird. Wing fending can be seen when tw birds take up a side-n rientatin t each ther: in this instance, it Is als shwn by the subrdinate bird as a defensive behaviur, and the wing, rather than being flicked backwards, is brught sharply utwards (Fig. 2,2,2), C H A S I N G : The dminant jdigen runs in pursuit f a fleeing ppnent. Smetimes intentin-pecking r pecking actins are perfrmed by the chasing bird. Chasing was nt ften seen, presumably because f the restrictin in space; but it is quite cmmn in the free ranging pigen. During a chase, which incidentally is f sme secnds' duratin, the pursuing

17 Fig. 2.2: (1) Wing flick. Ntice the fanned-ut tall and the raised wing n the side away frm the ppnent. (2) The pigen n the left is shwing wing-fending, while the ne n the right is shwing wing-flicking. Ntice the fanned ut tail in bth birds. (3) Wing raising and bdy pushing. (Diagrams drawn frm phtgraphs)

18 11 bird des nt fan ut its tail nr des it call. F L E E! 1^ G: Past lcmtin away frm a pursuing ppnent. F R E E Z I N G : An alarm behaviur in which all mvement ceases; s that the bird remains mtinless in the same behaviural psture v/hich immediately preceded freezing, in certain circumstances, freezing can be maintained fr a relatively lng perid'f time, and is usually released by audi try stimuli. B 0 W i N G: immediately preceding bwing behaviur, the male pigen is erect, and vibratin f the thrat is nticeable (this vibratin is prbably caused by pre-vcalising mvements f the trachea). The crwn, neci< and back feathers are raised; hwever, the mst nticeable feature f the pre-bwing behaviur is the apparent swelling up f the upper part f the pigen's bdy (the breast, neck arfd head regins), partly due t the feather fluffing f this regin and partly t the swelling up f the crp. As the bird lwers its head, it utters the first tw syllables f the bwing call. The head is raised slightly again (cmpleting the bwing actin), and the remainder f the bwing call is uttered as the head is raised, althugh this is very difficult t determine since sme birds d nt have a very prnunced bwing actin. Nrmally bwing is perfrmed while the bird is walking in a circular directin, alternating clckwise and anti-clckwise (Fig. 2.3, sequence 1-3). When tw male birds cme in clse prximity t each ther, they may bw in a sideways-n psitin, while remaining in the same place. I have termed this as 'SIDE-ON' Bwing. 'FULL-FRONTAL' Bwing can als be seen in this cntext, and in fact is identical t Side-n Bwing except fr the rientatin f the displaying bird, which is facing the ppnent directly.

19

20 14 THE B O W I N G CALL: The bwing call as a sund pattern perceived b' the human ear is quite distinguishable frm the driving call and cnsequently, as the names indicate, the tw calls appear in different cntexts. The bwing call in cnjunctin with bwing behaviur is nrmally directed at cnspecifics whether these are male r female: but as Craig (191^) and thers have nted, it can als be directed tivards human bservers. Depending n the cntext in which bwing behaviur is seen, s t the call may have different functins, depending n whether the situatin requires agnism r curtship. As ne can see in Figures 2.k t 2.6, which shw the bwing calls f several pigens, the calls themselves are highly variable in their frequency and energy structures and tempral patterning: they d nt shw the structured patterning f driving calls. Such individual variatin In the bwing calls f pigens wuld tend t supprt a hypthesis that these vcalisatins may serve as Identificatin calls fr individua1 birds. It is interesting t nte that mature female pigens rarely prduce this call and when they d, it is f a higher pitch and lwer amplitude than a male call. The nly time females bw-call with any srt f regularity is when they are three t five mnths f age, befre the nset f sexual maturity. D R I V I N G : At the nset f Driving, the bird Is erect and has Its neck, crwn and back feathers ruffled. The tall is fanned ut and is in cntact with the substrate; s that a brushing nise is prduced when the pigen mves. The male bird is lking directly at the female pigen keeping its beak at a negative angle t the hrizntal. As the head is lwered, the bird utters a call which may be described nmatpelca1ly as 'wang-wang-kr', which Is quite distinct frm a bwing call (see Figures 2.10 t 2.1^). Thrughut the calling f the phrase, the bird raises Its head again, s that it is fully erect at the end f the call as described abve (see als Fig. 2.17). The male pigen may jump r step n t the female's

21 (a) mm I (c) l!l8 sees. TIME 2.36 Fig. 2.k (a) P 15. Bwing call, (b) P 3k. Bwing call, (c) P 28 Bwing call. (A small editing errr in C).

22 0. 1- f Aw - g n 0 /.Osecs. TIME 20 Fig. 2.5 (a) P 30. Bwing call. (b) P 28. Bwing call. (c) P 31. Bwing call. Ntice the different frequency/energy structures fr the three pigens.

23 %t4.ast; 1.15 sees TIME s«cs TIME 13 (ii) (c) /./5 sees TIME 2.3 Fig. 2j6 Bwing calls. (A) P 13. (B) P 20. (C) i: P 35. ii: P 26.

24 15 tail, and the behaviural sequence is repeated (see Fig, 2.3, sequence-6-8). Driving can result as a direct transitin frm the Bwing behaviur and ne is again referred t Fig. 2.3, sequence 3"7. During a Driving sequence in male-female encutners, the male bird may remain quite statinary, althugh perfrming all the actins which are characteristic f the Driving behaviur. This is termed 'FULL-FRONTAL' Driving (cf. Full-Frntal Bwing). Treading n the ther bird's tail by the dminant pigen, whether it takes place during male-male r male-female encunters during Driving sequences, is quite cmmn, A frm f driving is shwn by sme females after cpulatin: bth wings are lwered s that the primaries are very near t the grund, and the tail is lwered and fanned ut, as in the male driving display; but the bdy is kept in the hrizntal plane (Plate IB), While adpting this psture the female rushes abut withut any apparent rientatin, smetimes bumping I nt the male bi rd, D R I V I N G CALL: Driving calls shw mre tempral structuring than bwing calls, s that whereas the latter shw sme tempral patterning between calls (at least as perceived by the human auditry and, in spectrgraphic analysis, visual systems) as well as frequency patterning within calls, the frmer shw tempral patterning mainly wi'thin calls., and smetimes als between calls. Hwever, the tempral separatin between the nset f successive vcalisatins seems t be very irregular, and detailed tempral analysis is required befre any further inferences can be made. Driving calls are accmpanied by driving - a behaviur which is nrmally assciated with curtship and the frmatin and maintenance f pa Ir-bnds. The nmatpeic rendering f a driving call, as given in Fig. 2.1, is nt quite crrect. A driving call sunds mre like 'wang-wang-krr'; but since driving calls themselves can vary an appreciable amunt in their tempral

25 1.0 _L_ 2.0 (a) 0.75 sees. TIME 1.5 Fig. 2.7 P 1. Sequence f calls shwing the transitin frm bwing calls t driving calls, (a) Bwing calls, (b) intermediate r extended bwing call, (c) and (d) Driving calls. Ntice in (d) the increased tempral patterning f the call.

26 ip25 sees. 2:05 (a) (b) r I (c) lss sees. TIME 1.3 Fig, 2.8 P 13. Sequence f calls shwing the transitin frm bwing calls t driving calls, (a) Bwing calls, (b) Intermediate call, (c) and (d) Driving calls.

27 I (a) 0 f (b) a Uj 0_ f (c) SI (d) P sees. TIME 1.6 Fig 2 9 P 36. Sequence f calls shwing the transitin frm bwing calls t driving calls, (a) Bwing call, (b) intermediate call, (c) and (d) Driving calls. Ntice the prgressive change in the frequency and tempral patterning f the ca 11 s.

28 IS f'v. >.. a Uj f fx' (d) P sees. TIME 1.6 Fig P.15I Driving calls. Ntice in (a) and (b) an increase in the frequency f the calls, half way thrugh the end phrases, cupled with a decrease in the energy (r ampli tude).

29 (a) _ f (b) a 0_ f (c) 0. I 0.6 sees. TIME (d) 1.6 P 26 Fig P 26, (a) - (d) Driving calls.

30 0 0 a 0 P /5 sees. TIME 113 Fig P 15. (a) - (d) Driving calls,

31 0 S5? 0 (b) 0 a UJ E 0 J i sees. TIME Fig P 13. (a) - (d) Driving calls.

32 0_ f E CL r m. 0_ 0.8 Sfc?cs 1.6 TIME Fig. 2.1i+ P 36. (a) - (d) Driving calls.

33 1.08 sees (a) I' a Ui 0_ r ifali^p sees. TIME 17 Fig P 17. Sequence f calls shwing the transitin frm a call t driving call, (a) far left: a call fllwed by a bwing call, (b) and (c) intermediate calls, (d) Driving call. Again, ntice the change In the frequency/ energy structure and tempral patterning f the calls.

34 0.975 sees. / /5 sees. TIME Fig P 26. Sequence f calls shwing the transitin frm a call t driving call, (a) far left: a call fllwed by bwing call, (b) Bwing calls, (c) intermediate call, (d) Driving cal1.

35 TIME 0-95 sees Fig. 2,17 Shws the relative c-rdinatin between a driving call and driving behaviur. The actual extensin f the neck and the rapid pening and clsing f the syrinx may be respnsible fr the stuttering effect in the structure f a driving call. patterni ng.vesjdecial 1y: during transi tins frm bwing t driving, an 'ideal' call was chsen in rder t illustrate the patterning f a driving call as ppsed t a bwing call. By using slw-mtin vide analysis, a relative c-rdinatin between the cmpnents f driving behaviur and the structure and tempral patterning within driving calls can be shwn t exist (Fig. 2.17). The stuttering effect in the call is prbably prduced by the elngatin f the neck in cnjunctin with a rapid pening and clsing f the syrinx; while the amplificatin f the call depends n the extent t which the crp is inflated. It has already been shwn that a driving call is relatively mre

36 17 structured and cntains mre terripral patterning within It than a bwing call; but the tw types f calls are nt s dissimilar in the transitins frm ne type *" call t the ther (Figs. 2.7 t 2.9) ccur with accmpanying transitins frm ne behaviur t the ther (Fig. 2.3). Since driving behaviur can be cnsidered a curtship behaviur, the accmpanying vcalisatii must have different functins t the bwing calls. Differences are evident nt nly between the bwing and driving calls themselves but als betv/een the calls f different pigens. Individual differences in bwing and driving calls may be partly respnsible fr individual recgnitin between pigens e.g. in recgnising adjacently territrial neighburs etc, N O D D I N G : The bird lwers its head s that the beak is pinting verticalb dwnwards and then raises its head again. This actin is repeated several times in successin. One gets the impressin that Ndding during male-male encunters is Incmplete in its actin; but this is nt a clear-cut difference. W I N G V I B R A T I O N : This behaviur is seen during bth male-male and male-female encunters. Generally shwn by the subrdinate male in male-male encunters, the wing nearer t the ppnent is vibrated, while the bird is in an upright psitin with its neck feathers ruffled. Wing Vibratin is als shwn by the male at a prspective nest site; hwever, this behaviur may be perfrmed at ther sites in the cage and nt necessarily by the male bird. During wing vibratin at the nest site, the pigen lies In an blique psitin, head dwnwards and tail raised (althugh smetimes the tail Is lwered and placed flat against the substrate), making quite a large angle with the hrizntal. The wing nearest t the female bird Is vibrated (but bth v/ings are smetimes vibrated). Other behaviurs appearing in cnjunctin with wing vibratin are ndding and the "A" call.

37 8 The frmer behaviur in cnjunctin vi'< th wing vibratin is nrmally seen in agnistic situatins while the latter in curtship situatins ("nest demnstratin"); but transitin frm ne behaviur t anther is cmmn. N I B B L I N G : This behaviur ccurs thrughut the preening buts fllwin cpulatin and als during nest demnstratin by the male (ref. Nibbling at the nest site). in the frmer instance, the female stands quite mtinless while the male nibbles, rather than bill-cmbs, her neck and crwn feathers (Plate IIA) cncentrating at times in the regin arund the eyes. Including the cere arund the female's bill; and this almst always leads t begging by the male, B E G G I N G : One bird pecks at the bill, cere r the feathers arund the base f the bill (Plate MB). Begging by the male bird was nticeable when the female cruched. On the ther hand begging by the female v/as seen t ccur during the preening buts after cpulatin. This behaviur lks very similar t the begging shwn by squabs. B I L L I N G : Fllwing begging, the male pens its beak and swells up its crp. At the same time the female inserts her bill int the male's muth (Plates IIC S- D). As the male perfrms twisting actins, ne can ntice mvement f the crp wing t the regurgitatin f the fd, which is immediately swallwed by the female. Althugh it seems that the female pigen als perfrms these twisting actins, vide analysis shwed that the female nly fllws the actins f the male bird, the nly actins she des being relatively unprnunced, and are brught abut by her swallwing the regurgitated fd. C R O U C H! NG: The female stands mtinless in a huddled psitin, after being given a few pecks by the male (Plate!VD). The

38 19 male may preen himself while the female is still cruching, and he may subsequently shw begging In respnse t cruching by the female. S Q U A T T! NG: The female lwers her head, usually directly t ne side away frm the male, while raising a slightly fanned ut tail; at this stage the anal regin mves in and ut, and the wings are kept clse t the sides (Plate IMA), As the male appraches the wings are mved slightly away frm the sides. M O U N T I N G : is achieved when the male jumps n t the back f the female pigen. T R E A D I N G: The male bird flds its wings and treads with Its feet, while resting his tail n the female's tail. The male generally psitins his feet partly n the arc f the wing and partly n the female's back (Plate I I I B). Durl-ng treading the female brings her v/ings Int a hrizntal plane. C O P U L A T I O N : The male fans ut his tail and bends it while pushing the female's tail t ne side; the male then bends the lwer part f his abdmen inwards under the female, s that clacal cntact can be achieved, and perfrms very fast, thrusting mvements ensuring clacal cntact (Plate IMC). These very fast thrusting actins unbalance the male, which then dismunts. The female lwers her tail, raises her head and smetimes pseud-drives. The male shwed squatting If the female preened his back althugh the female shwed n intentin f munting the male (Plates ME S- F). Cpulatins were interspersed with lng buts f preening and ther maintenance activities,

39 PLATE n 20 A. NIBBLINQ B. BE66ING C. BlUINC (i)i D. BILLING (li) E. WLE SaUATTING F. PREENING BY FEMALE DURING HALE SQUAT

40 PLATE III 21 A. SQUATTING B. MOUNTING 1 C. COPULATION

41 PUT IV PRCBItIS C. BOTH Vtlt STRETCH CRWCHI E. auffihs F. FOOT PECKIM

42 D I S P L A C E M E N T P R E E N I N G : The pigen turns its head backwards and smetimes tuches r bill-cmbs the scapulars very rapidly. Gdwin (1956) suggests that the pigen places its bill between Its bdy and the scapulars while Fabrlcius and Janssn (19^3) say that the scapulars are tuched. In fact, the pigen may r may nt tuch the scapulars and smetimes the bill is nt even lwered that far, resulting in an incmplete actin, unlike preening where the pigen bill-cmbs the scapulars. 1 have als seen displacement preening dwn the side f the breast in several birds and In sme instances this type f preening resembled head rubbing against the side f the breast, HEAD R U B B I N G : The head Is turned backwards as in displacement preening, but instead the head is lwered sideways and the side nearest t the bdy is rubbed quickly frward. This rubbing actin Is repeated tv; r three times (Plate IVA), The pssible functinal significance f head rubbing will be'discussed later, FOOT S T O M P I N G : A very rapid, alternating stepping actin f the feet during which the bird remains m re r less in the same place,-but may at times mve slightly backwards. Ft stmping was seen in bth agnistic and curtship situatins, between Intervals f fighting, and between successive sequences f cpulatins, respectively. FOOT P E C K I N G : The pigen pecks at Its ft r feet, thereby remving any lse particles f matter. Occasinally the ft is raised t meet the bill (Plate IVF). Ft pecking is mst frequent during the time the bird is multing, since the skin arund the feet als slughs ff and the pigen usually pecks at the lse skin, remving it frm its feet.

43 P R E E N I N G : was prbably the mst cmmn activity bserved. The feathers are dravvn thrugh the bill with very fast, unidirectinal mvements (bi11-cmbing). Several bdy areas are preened thrughut a preening but: neck, breast, abdminal and back preening require n descriptin. Fr wingbw preening, the wing is brught slightly utward and frward giving a skewed appearance - the primaries are preened by drawing each feather separately thrugh the bill, starting at the base f the feather and drawing it utward. Fr wingface preening the wing is mved utward nly very slightly and apprached frm abve. Fr tailcvers and tail preening the bird turns its head backwards and stretches its neck: the tail is fanned ut and brught frwards tv^ards the head. The bird begins by preening the tailcvers but then prgresses t the tail feathers themselves. These are preened in a similar fashin t the wing primaries: the bird preens the base and then bill-cmbs each feather separately, bringing it frward in an arc (Plate ivb). Preening f each separate area i s-steretyped.; hwever, n detailed sequential analysis was carried ut in rder t determine whether there was any specific pattern in preening behaviur. Each preening but was f varying duratin. A similar prcedure is fllwed fr iling the feathers. During sequences f iling, the pigen reaches fr the il gland with the beak, at the base f the upper tail cvers. The feathers are drawn mre rapidly thrugh the beak, and head rubbing seems t be mre frequent during sequences f iling.^ W I N G and LEG S T R E T C H : The bird stretches ne f its wings upward and backward then dwnward and utward, at the same time bringing the leg upward and utward spanning the wing and fllwing it backwards (Plate!C). The tail is als fanned ut and tilted twards the utstretched wing and leg. Pigens tend t stretch the wing n ne side first, and sn afterwards the ther.

44 25 BOTH W I N G S S T R E T C H : The bird mves Its wings slightly utward and upward, s that the bws f the wings are very clse t each ther; the wings are nt fully stretched and the whle sequence des nt last fr lnger than tw t three secnds (Plate IVC). When this behaviur precedes leg and wing stretch the tail is als fanned ut in an arc, and the wings are nt mved utward s much. B 0 D Y S H A K E: The bird fluffs up its feathers, especially the ruff, back and wings, spreads ut its wings slightly and ruffles its whle bdy while shuffling Its wings very rapidlyin an alternating sequence (Plate IVE). This bdy shake is transmitted t the head, resulting In head-shaking, and t the tail which is wagged very rapidly frm side t side almst simultaneusly with the bdy shake. T A I L W A G G I N G als ccurs n its wn especially in between preening buts. F L U F F I N G : In its less transient frm, fluffing is a thermregulatry behaviur (McFarland and Baher, 1968). Fluffing can als be seen during preening and prir t bdyshake, and als during sexual and agnistic pstures. During preening and bdyshake, ruffling f the feathers is mst nticeable arund the breast and back regin; althugh when it is seen in cnjunctin with sexual and agnistic pstures, fluffing is seen mainly arund the head, neck and als the lwer back areas. H E A D S H A K E : A very rapid side t side mvement f the head which als underges sme rtatin and ends abruptly. Headshaking generally ccurs by Itself, althugh it can be seen during bdyshake and preening. It is perfrmed prbably t remve freign matter frm the bill. H E A D-S C R A T C H I N G: The head is lwered and bent twards' the ft, n the side t be scratched. The ft is raised

45 28 t the head, which is scratched with rapid, dwnward strkes f the leg. P E C K I N G : The pigen pecks at the flr (GROUND-PECK), r sides f the cage, smetimes picking up an bject in its beak and then drpping it again. The bird might repeat -the same behaviur with the same bject several times In successin, pecking at the grund rapidly. Apart frm pecking at fd particles prir t (and smetimes during) feeding, withut actually ingesting any, the pigen pecks at grit r ther particles n the flr, especially if it Is placed in a new envirnment. Usually it isdifficult t determine whether the pigen is lking fr fd particles r whether it is investigating the edibility f a nvel bject. I N T E N T I O N GROUND PECK: With relatively slw, dwnward mvement f the head, the bird perfrms a pecking mtin twards the grund r fd particle althugh cntact des nt ccur. This behaviur ccurs thrughut grund-pecking. Smetimes the mtin f the head gives the impressin f ztg-zagging. A T T E N T I ON: While standing In a nrmal, upright psitin the pigen lks arund with jerky head mvements made in a hrizntal plane, but sme are als perfrmed in the vertical plane. The neck feathers are sleeked and the neck is stretched slightly. L O C O M O T I O N : Walking r running by the pigen frm ne place In the cage (r envirnment) t any ther place; le. mvement with n apparent directin. Lcmtin can be slw r fast (as In chasing r f leei ng), P A N T I N G: After an aggressive encunter between tw male birds, r when a pigen has dne a certain amunt f strenuus activity (eg.

46 27 fleeing In a cnfined space), ne r bth birds may shw panting which is visually recgnizable by the pen bill and vibratin f the thrat. The neck feathers are slightly fluffed, F E E D I N G : While pecking at fd particles, sme are picked up in the bill and swallwed, althugh undesirable fd particles are drpped. When eating frm a feeding tray, the pigen may give a few sharp flicks with the beak, scattering grains f fd and/r ther material. This behaviur may be useful during fd selectin. Unlike mst ther birds, during DRINKING pigens suck the vrater up rather than gulp it, D E F E C A T I O N : The bird cruches slightly, lifts the tail and prtrudes the claca. This is fllwed by a lwer abdminal cntractin resulting In the expulsin f the faeces. Defecatin is particularly nticeable when a pigen is subjected t stress situatins, such as being placed in a new envirnment. YAWN I N G: This behaviur was mst cmmn during preening buts r after curtship 'sequences'. The neck is stretched upward, and backward while the beak Is pened wide, and Is clsed again as the head Is brught frward t its nrmal psitin. D O Z I N G : The bird becmes inactive, and assumes a withdrawn r huddled psture with Its feathers slightly ruffled. The nicitating membranes may be drawn ver bth eyes r ver ne eye at a time. Smetimes ne leg is withdrawn s that the bird stands n nly ne leg. 2.5 Behaviur at the nest site M U T U A L P R E E N I N G : While the male shv/s nest demnstratin the female appraches and passes her bill thrugh

47 28 the head feathers f the male very rapidly - a behaviur which lks like preening,(plate IIP). It is very difficult t determine whether this behaviur is in fact preening r whether it Is displacement preening r nibbling by the female, at the nest site (Gdwin, I956, refers t this behaviur as caressing; Miller & Miller, 1958, as heter-preening). NEST D E M O N S T R A T I O N : This term has been used very lsely by several authrs, when describing a 'behaviur' which appeajs nt nly in curtship situatins, but als in. agnistic situatins. This 'behaviur' in fact is cmpsed f several behaviurs namely, ndding, wing vibratin and the 'a' call which (excluding the call), have already been described in the previus sectin. THE AOO CALL: A calls are given by bth males and females but predminantly by the frmer. In the field, male pigens a-call regularly at the beginning f the breeding seasn. Pigens f bth sexes a-call at the nest site, usually in cnjunctin with ndding and wing vibratin; but smetimes the birds a-call while perfrming wing vibratin nly. This call is mst nticeable during the early stages f the preincubatry phase f the breeding cycle; hwever. It Is als given by single male birds and smetimes seems t be directed twards pigens in neighburing cages, whether these are male r female, Male pigens which are pjaced in ttal scial Islatin (s?e Chapter 4) als give this call. Apart frm the alarm call, the a call is very simple in structure (see Fig, 2,l8 t 2,21) and can be rich in harmnics. The call frequency rises frm abut 200 Hz, at the beginning f a call, peaking at abut kso Hz. and then falling ff again t the starting frequency. It is nt uncmmn fr sequences f a calls t last fr ver a minute. The tempral intervals in between the calls are mre r less cnstant, althugh the amplitude increases \

48 0 mmmmwm 41 O s E 0 (b) 0 0 mm (c) P sees. TIME 1.9 Fig, 2.18 P,26. (a) - (c) A calls. Ntice the nn-harmnics in (b),

49 mm a UJ 0 (A) P 31 I O.flS sees. TIME r.7 i ^0. n li P 17 Wsecs. TIME ZO Fig, 2.19 Sequence f A calls, (A) P 31. (B) P 17. it is Interesting t cmpare (A) f this figure with (A) f Fig, Ntice that as the energy and duratin f the call increases, the energy at the higher frequencies decreases.

50 (A) P sees i i (B) P sec* TIME 7.9 Fig Sequence f A calls. (A) P 31. (B) P 30. The tw tnes visible in (A) are iiarmni cal ly unrelated, suggesting that pigens may be capable f using 'tw vlces

51 MM--I n :9i TIME sees. Fig, 2.21 Calls given by female pigens, (a) P 9. Alarm calls, (b) t (d) P 11: (b) and (c) a calls; (d) Bwing calls. Ntice the similarity in structure between sme a calls and the bwing calls.

52 v/lth tine thrughut a sequence f calls. The duratin f each call als Increases. THE A L A R M CALL: The alarm call is prbably the simplest vcalisatin pigens prduce (Fig. 2.21). It is very similar t the alarm nte prduced by ring dves (Miller and Miller, 1S58) but harsher in tne, sunding like a harsh 'hinnnh'. Mrever, the pigen that gives the call, usually a female at the nest site, is in a slightly squat psture with feathers ruffled. Pigens give the alarm call when a stranger r a strange bject (such as the bserver's hand) appraches t clse. N E S T - B O W! NG: When this behaviur is perfrmed at the nest site by the male, the rientatin f his bdy is quite different frm that adpted fr the 'nrmal' bwing behaviur. The bdy is held bliquely, head dwnwards. The bird bw-calls and rtates althugh remaining in the same place. Smetimes the abdmen brushes against the nesting material, and this has the effect f mulding the nest int a ci rcular shape. BODY REST: During the early stages f the pre-i ncubatry phase f the breeding cycle, when the female appraches the male in respnse t his 'nest demnstratin', she will rest her abdminal regin n t the head and nec!< f the male. Cnsequently, the intensity f the male call increases and he may als push his head further underneath the female's bdy (PUSHING by the male at the nest site). P U S H I N G: Unlike Fabricius and Janssn (IS63), I have regularly bserved pushing by males at the nest site. When the female appraches the nest site and shws bdy resting, the male will push himself underneath the female's bdy while perfrming intense wing vibratin and calling at the

53 nest site. Pushing by the female was seen at a later stage in the preincubatin phase, usually when the male is standing at the nest site. 'Nest Demnstratin' by the female is als very intense at this stage, and the pushing pigen, whether male r female, is 'preened' (mutual preening) by the ther mate. 30 NEST M A T E R I A L C O L L E C T I O N : Because f the nature f the nesting material prvidec (v;d, wl r shredded paper), the pigens shwed elements f this behaviur very clearly. The bird picks a single strand f nesting material in its bill and gives several head shakes in rder t lsen it frm the bunch. When the strand is lse, the bird tucks it underneath its abdmen and psitins it by its legs. The pigen may d this with several strands f material, until it picks up ne strand f adequate length (r seemingly s), carries it t the nest site and depsits It in frnt f its mate. NEST B U I L D I N G : The pigen standing at the nest site immediately picks up the strand and tucks it amng the thers smetimes rearranging ther strands in the prcess. If it s happens that the ther pigen is nt at the nest-site, then the bird cllecting the nesting material will arrange the strand in a similar manner t its partner. If the female pigen is at the nest site, the male will pick up a strand f material and carry It t thenest site where the female is shwing 'nest demnstratin'. Althugh it is mre cmmn fr the male t cllect nest material during the early stages f nest building, and fr the female t arrange It at the.nest site, the female will cllect material if the male is at the nest site, thereby reversing nest-building rles. This behaviur Is very similar t the nest building shwn by dves (Streptpelia risria; see Lehrman, 1958a). 2.6 The Curtship encunters The encunter begins by the male pigen appraching, bwing and bw-

54 cing in frnt f the female. This bwing may change t driving if the female mves away frm the male, with an accmpanying change in the call t the driving call. Fllwing driving the male stps and nds, and the female respnds by ndding. Anther behaviur which bth pigens perfrm and which fllws ndding is displacement preening. This is a characteristic behaviur seen during curtship encunters In pigens and is listed by many authrs (eg. Fabricius and Janssn, 1963; Levi, IS^l; Helnrthand Helnrth, 19^9; Gdwin, 1955, 1956). The female will then stp displacement preening and mves away slwly frm the male, t v/hich the male respnds by driving the female very clsely (Fig. 2.22: 2 & 3), at times bumping int her. It is nt as yet very clear what elicits squatting In the female, but she will stp mving suddenly, lwer her head and squat. The male pigen munts, treads and cpulates, the latter actin unbalancing the m.ale, which dismunts (see Fig. 2.22). The female stands up and ften perfrms a frm f driving behaviur, which Is dissimilar t the driving behaviur perfrmed by the male. Bwing behaviur is frequently seen during first encunters between male and female pigens and als during the early stages f the pre-incubatry phase f the breeding cycle (Fabricius and Janssn, I963) pssibly suggesting that the curtship behaviur in pigens, as Indeed in many ther bird species. Is an utcme f a cnflict between sexual mtivatin and agnistic tendencies (eg. see Tinbergen, 1952, 195^). 2,7 The Agnistic encunters The fllwing behaviurs can be seen during agnistic encunters: Aggressive pecking, aggressive billing, bdy pushing, wing flicking, aggressive intentin peck, bwing, bw-cing and smetimes ndding, wing vibratin and the a call. Fleeing and chasing are nt ften seen in the cnfined spaces f the bservatin cage, hwever they can be seen during agnistic, encunters In the free-ranging pigen.

55

56 When a strange male appraches anther male pigen, bth birds perfrm bv;ing, in this situatin this behaviur is prbably the utcme between attack and escape tendencies, if neither f the birds mves away, ne f the pigens wing flicks the ther and appraches clser. Hwever, I cnsider wing flicking t be a threat behaviur (see Tinbergen, 1959), since althugh it is an aggressive behaviur, there is n clse bdily cntact between the tw birds; and at times it may als serve as a deterrent t the strange bird t apprach any clser. This behaviur leads t aggressive billing and bdy pushing which last fr several secnds. When ne f the birds mves away r flees, the ther, dminant bird chases and ften aggressively pecks the fleeing male. After a few secnds the dminant pigen gives up the chase. Aggressive intentin peck and ndding are usually perfrmed by bth dminant and subrdinate males, if these encunter again shrtly after a fight. Ndding may be an appeasement behaviur perfrmed In rder t suppress aggressin. Althugh wing vibratin is seen during encunters between male pigens in the labratry situatin after prlnged encunters, I have never bserved this behaviur between free-ranging male pigens, 2.8 Sme cmments n the functin and causatin f sme f the behaviur alterns!n cntrast t ther mre "straightfrward" behaviur patterns such as feeding, escape behaviur and cpulatin, the functin and causatin f the fllwing behaviur patterns is difficult t understand: Bwing, Driving, Ndding, V/ing vibratin, Displacement preening, Head-rubbing, Ft-stmpi ng, and m.utual preening. In the fllwing sectin I prpse t discuss sme f the general features f these behaviurs and displays which, t my mind, have been misinterpreted. The behaviurs and displays listed are used In agnistic as well as curtship r pair frmatin "ceremnies", v;ith the pssible exceptin f mutual preening.

57 35 Bwlnq and Dri vi n Beach (1951), and Fabricius and Janssn (1962) call the driving behaviur shv/n by a male pigen befre munting, strutting; likewise, there exists sme cnfusin as t which behaviur shuld be termed as "bwing". I have tried t describe this behaviur and driving behaviur visually, In the ethgraph (Fig. 2,3). The cnfusin may have arisen in the first place because several authrs have watched these behaviurs (rather they give the Impressin that they have) in nly ne cntext - that f curtship. I agree with Gdwin (1955) when he suggests that the psture adpted by the driving male is similar t Its behaviur prir t cpulatin. In their discussin, hwever, Fabricius and Janssn d mentin that "driving is even mre similar t the behaviur f a dminant male chasing a submissive male intruder in the territry, and further, actual attacks ccur during driving shwing that the aggressive Instinct Is activated". Cnsequently, I believe it t be unnecessary t call a behaviur, which appears in different cntexts, by different names. Bwing is nrmally seen during first encunters between birds, whether these are bth male r male and female. This behaviur is als seen smetimes at the nest site and, as suggested earlier, ne f Its functins may be t muld the nest Int a suitable shape. In male-female pairs, bwing ccurs during the early stage f the pre-incubatry phase f the breeding cycle; but Its ccurrence decreases during the later stages. During male-male encunters, hv;ever, the ccurrence f bwing alternates with aggressive behaviur. In this cntext, bwing by a dminant male may have an intimidating effect n the subrdinate bird r n ther intruding pigens r near-intruders. S the tendency here is ne f aggressin. Hwever, n unfamiliar grund, a pigen perfrming bwing behaviur may prmte an attack by the ppsing pigen. In this case the tendency is ne f withdrawal r escape. Bth tendencies are evked by the ppnent's agnistic behaviur. It m^y be suggested, therefre, that bwing behaviur is a cnflict behaviur snwing