Dominance Relationships and Agonistic Behavior of Canada Geese in Winter.pdf

7/30/2019 Dominance Relationships and Agonistic Behavior of Canada Geese in Winter.pdf

1/34

Dominance Relationships and Agonistic Behavior of Canada Geese in Winter

Author(s): Dennis G. RavelingReviewed work(s):Source: Behaviour, Vol. 37, No. 3/4 (1970), pp. 291-319Published by: BRILLStable URL: http://www.jstor.org/stable/4533358 .

Accessed: 26/01/2013 16:44

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp

.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of

content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms

of scholarship. For more information about JSTOR, please contact [email protected].

.

BRILL is collaborating with JSTOR to digitize, preserve and extend access to Behaviour.

http://www.jstor.org

This content downloaded on Sat, 26 Jan 2013 16:44:06 PMAll use subject to JSTOR Terms and Conditions
http://www.jstor.org/action/showPublisher?publisherCode=baphttp://www.jstor.org/stable/4533358?origin=JSTOR-pdfhttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/stable/4533358?origin=JSTOR-pdfhttp://www.jstor.org/action/showPublisher?publisherCode=bap


2/34

DOMINANCE RELATIONSHIPS AND AGONISTICBEHAVIOR OF CANADA GEESE IN WINTER

byDENNIS G. RAVELING 1)2)

(CooperativeWildlife ResearchLaboratory, outhern llinoisUniversity,Carbondale,Illinois,U.S.A.)(With 9 Figures)

(Rec. 15-VII-197o)

INTRODUCTIONThe fact that many animals exist in close, intraspecific, competitivesituations with regard to many essentials of life has stimulated a varietyof studies and explanations of the functions and evolution of aggressionand dominance orders. Studies of dominance in various species of geesehave been reported by JENKINS(I944), COLLIAS(I950a), HANSON (I953),BOYD (I953); LORENZ (I959, I966) and FISCHER (1965) mentionedcertain dominance aspects or implications regarding geese. Past studies werebased on observation of captive or semi-captive birds, or on partially color-marked families or unmarked wild birds. This study is based on repeatedobservations of the same color-marked individuals and families of Canada

geese (Branta canadensis) in the wild, free-living state during winter. Radio-telemetry techniques enabled locations, movements, and behavior of specificindividuals to be recorded. This paper reports results of victories and lossesin aggressive conflict situations and describes the postures associated withthose results. An attemptis made to integrate an understandingof the functionand evolution of agonistic postures in relation to the stable, functionaldominance hierarchy exhibited by Canada geese.

I) Thisstudywas financedmainlyby the NationalScienceFoundationGB-623)withadditionalsupportfrom the CooperativeWildlife ResearchLaboratory,SouthernIllinoisUniversity, Dr W. D. KLIMSTRA,irector. Many personsand agenciescooperated n thiswork. I wish to thank again Messrs W. E. CREWS,W. W. COCHRAN,. A. MEHRHOFF,R. G. PERSONIUS,nd Drs W. D. KLIMSTRA,. C. HANSON,and D. W. WARNER.H. BOYDoffered helpful criticism of the manuscript.Results formed a portionof a Ph.D. disser-tation presented to the Department of Zoology, Southern Illinois University.

2) Present address: Canadian Wildlife Service, I4-A Garry Street. Winnipeg I,Manitoba,Canada.

This content downloaded on Sat, 26 Jan 2013 16:44:06 PMAll use subject toJSTOR Terms and Conditions
http://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsp


3/34

292 DENNIS G. RAVELING

METHODSThis study was conducted at Crab Orchard National Wildlife Refuge,

Williamson County, Illinois where approximately 40,000 Canada geese (B. c.interior; cf. HANSON & SMITH, 1950: 77) spend a large part of the winter.The inviolate portion of the refuge encompasses 22,000 acres including2,600 acres of Crab Orchard Lake where the geese roost and 5,000 acres ofcropland (corn and soybeans) and 2,800 acres of pasturewhere the geese feed.

During the winters of 1963-64 and I964-65, 77 geese were radio- andcolor-marked. These included all or parts of IO families, 2 pairs, and35 yearlings. Color marking involved dyeing the white portions of theabdomen and cheek patches various colors (cf. BOYD, 1952; KOZLIK et al,1959) and attachment of colored /4-inch nasal disks (LINDMEIER &JOHNSON, 1958; BARTONEK & DANE, 1964). Observations of the activitiesof the flock and of radio- and color-marked geese were recorded daily fromlate September to mid-March during the two winters of this study. Furtherdescription of CrabOrchard, details of the recognition and captureof familiesand other social classes of geese, their permanency, local roost and movementpatterns and behavior, and discussion of the techniques of color-markingandradio-trackingare provided in RAVELING(I969a, b, c).Terms.

Immature - from hatching (June) until the return to nesting areas (Hud-son-James Bay lowland muskeg, HANSON & SMITH, 1950: 79) thefollowing April.

Yearling - from the time of return to nesting areas for their secondsummer of life until their return to nesting areas the following spring.Adult - from the beginning of the third summer of life and older.Family - any association of two or more geese resulting from a pairbond or parentage-progeny-sibling relationships. Families of three ormore represent an adult pair with their offspring or surviving membersof such an association.Behavior was not affected by color-marking procedures (RAVELING,I969a). The transmitter was usually concealed in the breast feathers and

held in place by a neck and a body loop. The radio caused more than normalpreening on the breast area but did not affect movements, flight ability orparticipation in any of the activities observed to occur with unmarked geese(RAVELING, i969a).Since the history of the marked geese of this study before trapping wasunknown, it is not possible to be certain that the young of these families



4/34

AGONISTIC BEHAVIOR OF CANADA GEESE IN WINTER 293

were in fact hatched and raised by the adults they were in company withwhen trapped. However, the result was the same in that the study animalsbehaved as a unit in all their daily winter activities (see RAVELING, I968a,I969a-c).PART I - DOMINANCE RELATIONSHIPS

For the present discussion distinction is made only between fights andthreat-chase behaviors. Fights refer to an occurrence when two geese rushedat each other, grabbedeach other's feathers at the base of the neck, rose erect,and beat each other with their open, bent wings. Besides superiority in afight the other category of victories referred to here includes all forms ofthreat and chasing when these movements were linked with avoidance oractive escape on the part of a submitting goose.

RESULTSGeneral ecological situation of aggressive behavior.

In general the geese at Crab Orchard roosted on the main lake during thenight and the mid-day. They flew to nearby fields to feed in early morningand late afternoon. Lengths of feeding periods were extended when overcastsky conditions prevailed.Canada geese were gregarious in all their daily activities during winterbut frequency and intensity of aggression fluctuated widely. Conflicts weremost frequent at the roost lake in two situations: (a) just after geese arrivedfrom their morning feeding period and were moving to and establishingtheir loafing areas, and (b) when geese became more active in the hour ortwo before flying out to feed in the afternoon. Conflicts were most numerousand intense during feeding activity in fields.

TABLE INumbers of aggressive encounters between Canada geese observed in

different situations (October 3-1I, 1964)Number of Estimated15 minute numbers of Numbers ofobservation geese threats and Numbers of

Situation periods observed chases fightsLake shoreline 9 I25* 23 0.4(midday, p.m.) (go - I6o)** (12 - 36) (o - 2)VWheat 2 i30 50 3(a.m. feeding period) (IIo & I50) (44 & 55) (2 & 4)Millet 5 I 5 I17 4(a.m. feeding period) (Ioo - I30) (74 - I56) (2 - 5)* Average, ** Range.



5/34


To compare the magnitude of conflicts in different situations, approximate-ly I00-I50 geese were isolated in the field of view of a spotting scope andall attack-fleeing incidents observed in 15 minute periods were noted. Thesedata demonstrate that more conflicts occurred when geese were in an areawhere food was concentrated (millet) than when it was evenly dispersed(wheat), or absent (lake shoreline) (Table I). Even greater frequency andintensity of encounters among the geese were observed when they werefeeding in corn fields but it proved virtually impossible to keep track of arelatively constant number of geese and record all conflicts. While notquantitatively documented, the above relationship of frequency of conflictsprevailed all winter.Relationship of social status to aggression andrank order.

The opportunity to observe different families and single geese of knownage and sex made it possible to comparesuccess of these animals in aggressivesituations. Data presented in Table 2 are pooled results from all radio-marked

TABLE 2Results of observations of 516 aggressive encounters involving radio- andcolor-marked Canada geese

Total number NumberSocial status N of conflicts of victoriesSingle immatures 3 20 o (o%)Single yearling females 9 29 5 (17%)Single yearling males Io 64 i6 (25%)Single adult female I 9 I *Single adult males 3 I3 7 *Total all singles 26 135 29 (2I%)Pairs 6 39 I2 (3I%)Families of 3 7 57 32 (56%)Families of 4 7 92 69 (75%)Families of 5 4 I8i I49 (82%)Family of 6 I 12 9 ** Percent not calculatedwhen total conflicts


6/34


TABLE 3.Rank order of five, single, captive Canadageese as determined by threat

and peck victories during six hours of observationLossesBird no. A B C D EA3-year old or X 8 II 16 7older male

B*2-year old X 6 38 4male

C*2-year old X 10 9> male

D*2-year old X 35female

E*2-year old Xfemale

* Age known becausegeese were trapped previousyear as yearlings.that were combined to make up totals in Table 2 (X2 - 4.94, 3 d.f., p>o.Io;x2 -= 0.32, 6 d.f., p>o.IO, respectively for families of five and four).Numbers of different individuals or groups contributing to totals inTable 2 vary from the actual number of individuals or families that wereradio-marked. The same individuals may be represented in observations ofdifferent sized groups because of temporary separation of family membersor deaths. Using observations of an adult pair and one immature as a familyof three even though there were two other offspring that were separated atthe time of a particular observation is believed to be valid as dominanceposition is directly and immediately related to numbers of individuals in afamily at any one time (JENKINS, I944; COLLIAS, I950a; BOYD, I953: IIO,FISCHER, 1965: 270; see below).Results of aggressive encounters and defeats (Table 2) reveal that successwas related directly to family size. Data for single geese indicate considerabledifferences of success in conflicts depending upon age and sex. Single imma-tures were the most submissive geese and rarely initiated an encounter, butwere often continuously "busy" avoiding other geese. Among geese held



7/34


captive during this study single adults dominated single yearlings and in-dividuals in both these age classes dominated single immatures. Within anyage class, single males were dominant over single females. Dominance orderwas quantified as to victories and losses for five unrelated, single geese thathad been held in captivity for a year (Table 3).Intrafamily participation in aggressive encounters.

Identification of unmarked families depends upon unity of family actionin Triumph Ceremonies (exaggerated head and neck motions often withraucous honking - see FISCHER, I965; LORENZ, I966; RAVELING, I967),attack-escape situations, and "purposeful" movements. While this procedureoften yields correct interpretations, chances for error are considerable. Itwas relatively rare that an entire family entered into aggressive postures orall members came together in a Triumph Ceremony. Of 325 encounters in-volving marked pairs and families in which the activities of all members of

TABLE 4Interrelationships of members of pairs and families of radio- andcolor-marked Canada geese with respect to initiation and participationin victorious conflicts

Number ofNumber of victoriesGroup and victorious in whichnumberof Individual conflicts all membersvictories* of group initiated participatedPairs Adult male 6 (6o%) 3 (30o%)Io Adult female 4 (40%)Families of 3 Adult male I9 (76%)

25 One of the I (4%)others 6 (25%)Families of 4 Adult male 45 (71%)63 One of the 5 (8%)others I8 (29%)Families of 5 Adult male 112 (75%)

I49 One of the 12 (8%)others 37 (25%)Totals Adult male I82 (74%)247 One of the 21 (8.5%)others 65 (26%)* Numbers of conflicts may vary from totals presented elsewhere; data in this tablerepresentconflicts in which activity of all membersof group were recorded.



8/34


the family were recorded,only 33 (ca IOpercent) involved unified action of allmembers of the family (Tables 4 and 5). The greater the intensity of anencounter the greater was the unity of family participation. Often a goose(or geese) submitting to one or more threatening members of a familyappeared as a single or small family but actually was a portion of a largerfamily. For example, in 32 percent of the losses of marked pairs andfamilies only the adult male received or noticeably reacted to a threat or chase(Table 5). Unified action of all members of a family occurred twice as oftenin defeat as in victory (Tables 4 and 5).

TABLE 5Interrelationships of members of pairs and families of radio- andcolor-marked Canada geese in losses to more dominant geese

Group and Individualof group reacting Number ofnumberof losses* as loser in conflicts lossesPairs Only adult male 2 (I8%)

II Adult female 5 (45%)Both 4 (37%)Families of 3 Only adult male 5 (33%)I5 One or both of the others 8 (53%)All 3 2 (13%)Families of 4 Only adult male 6 (30%)20 One or more of the others II (55%)All 4 3 (i5%)Families of 5 Only adultmale 12 (38%)32 One or more of the others 17 (53%)

All 5 3 (9%)Totals Only adult male 25 (32%)78 One or more of the others 41 (53%)All members of a group 12 (I5%)* Numbers of conflicts may vary from totals presentedelsewhere; data in this tablerepresentconflicts in which activity of all membersof group were recorded.

I sometimes observed an immature of a family avoid another threateninggoose (or group) while the rest of its family made no move to attack or avoidthe aggressor. Sometimes the gander of a family would chase a goose (orgroup) that had threatened one of his family. Immatures of a family couldbe as successful as their gander at chasing away other geese, even adultsand families, if the immature was near its gander.Some defeats indicated for families in Tables 2 and 5 were a result of anBehaviourXXXVII I9



9/34


immature being threatened while the gander did not respond so that thepercentage of victories in Table 2 under-emphasizes the high success offamily ganders in dominating other geese. Ganders were involved in 82.5percent of victorious aggressive encounters (Table 4, initiation plus parti-cipation) but reacted directly in only 47 percent of defeats (Table 5, reactionsof adult male only plus reaction by all of a family). The numbers of youngin a family were directly related to dominance position, but rank order wasmost clearly defined by the action of the gander in dominating or submitting.All groups had a higher success ratio in encounters in which the gander wasinvolved (Table 6) as compared to all conflicts combined regardless ofwhich family member was involved (Table 2).

TABLE 6Percent success of aggressive encounters involving the adult male of radio-and color-markedpairs and families of Canada geeseGroup ndnumber fconflicts n whichadult Numberofmalewas involved victoriesPairs 9 (6o%)

I5Familiesof 3 i9 (70%)27Families of 4 50 (85%)59Families of 5 124 (89%)I39

Dominance relation as determined from observationsof fighting between ganders of unmarked families.Participation of all members of a family in an aggressive encounter was

directly related to the intensity of display and failure of threatening posturesto cause avoidance by another individual or family. In 516 encounters (Table2) of marked geese, fighting occurred only I4 times (2.7 percent). Nine ofthese 14 fights involved the gander of a family of five, two fights eachinvolved ganders of families of four and three, and one the gander of a pair.Of 33 occasions in which all members of a marked family were distinctlyunited in attack and/or escape, 14 of these observations occurred duringthe fights described above. Intense Triumph Ceremonies involving all mem-bers of the victorious family followed the most vigorous chases and fights.

Thus, the most reliable way to identify numbers of geese in unmarkedfamilies is to observe two groups displaying prior to, and the victors after,



10/34


the most vigorous aggressive encounters. The outcome of 26 such fightsobserved in I964-65 between ganders of unmarked families is presented inTable 7. These results reveal only one deviation from the expected occurrenceof the largest family always winning.TABLE 7

Relationship between size of family and victories in 26 fights betweenganders of unmarked families lof Canada geese

LossesFamilysize*8 7 6 5 4 3 28 X I

7 X I6 X 3 35 2 5 24 I 2 2 I

3 I I2 I

* Size of families dentifiedbecause f highintensityof displaysbefore he fights.Effects of separation of family members ondominance position.

When one of the marked immature males of a family of six was separatedon one occasion he became a very submissive, avoiding goose. He was threat-ened and pecked I times and he never threatened other geese. Prior to beingseparated and after being reunited this individual was one of the most activeand aggressive immatures seen in this study, but only in the presence ofhis family.A family of four had been observed in 43 wins and 15 losses in aggressiveencounters. When an immature was separated the remaining three wereobserved in four victories and five losses. Too few encounters of otherfamilies affected by separation were observed to allow statistical comparisons.However, the changes in general disposition were striking and conclusive indemonstrating the effects of separation and reunification on dominance. Thechange was best observed in a highly aggressive family of five at a timewhen the adult pair and one immature were separated from the other twoyoung. The gander then avoided geese and was less alert. At a point when



11/34


a fight seemed inevitable this gander turned away and the family of threewas put to rout by a gander of a family of four. No family of four was everobserved to defeat this family when they were intact. The next day one ofthe separated immatures rejoined the family and the increase in activity andaggressiveness was notable; the gander was observed making nine successfulattacks and in the most intense encounter he thrashed a gander of a familyof four. Finally, the third immature was reunited and the family resumedits previous high position in the rank order.Aggressive conflicts per unit time.

Data provided by radio- and color-marked geese clearly demonstrate thatfamilies of four and five were involved in the most conflicts (Table 8).There are no significant differences in the rates of conflict of all categoriesof singles or among singles, pairs, and families of three (X2 = .93; 4 d.f.,p > 0.70; X2 = 0.28, 2 d.f., p > 0.80, respectively). Families of four wereinvolved in more conflicts per unit time than families of three (X2 = 5.22,i d.f., p 0.80).

Families of four and five were involved in approximately twice as manyencounters as smaller groups and singles. Since most conflict observationswere obtained when geese were at the roost lake the ratios are probablybiased as actual conflicts per day would probably show much more than atwofold increase for large families if more feeding period conflict recordswere available (cf. Table I).TABLE 8

Aggressive encounters per unit time observed to occur with different socialstatus radio- and color-markedCanadageese.Number Lengthof timeofof observations ConflictsperGroup conflicts (hours) hour

Single immatures 20 i8.6 I.ISingle yearling females 29 I7.4 1.6Single yearling males 64 48.2 1.3Single adult female 9 10.2 0.9Single adult males 13 12.0 I.ITotal all singles 135 o06.4 1.3Pairs 39 33.8 1.2Families of 3 57 49.9 I.IFamilies of 4 92 43.6 2.1Families of 5 i82 72.0 2.5Family of 6 12 34 3.6



12/34


Exceptions to the usual dominance hierarchy.No pair formation was known to have occurred among any of the marked

geese. However, behavior was observed that I interpreted as preliminary topairing ("courtship") and as proof of the culmination of pair bond formationamong some unmarked geese. Such occurrences were rare and took placein February or March just before spring migration. Descriptions of posturesinvolved are provided elsewhere (RAVELING, 1967: 57-6I). While it differsin some aspects of form and time relations as compared to greylag geese(Anser anser) I believe the essential functions and results with regard toenabling association and effects in social relations and dominance are asdescribed for greylags by HEINROTH (I9II: 622); LORENZ (I959, I966),and especially FISCHER I965).

Many ganders of large families seemed to avoid fighting with ganders ofnewly formed pairs. Often a family gander was observed to start Head-pumping and Rolling (Agonistic associated display - see Part II) but thenewly mated male did not usually stop and display, or when he did it wasvery brief. Instead he went into attack almost immediately and the familygander turned away from this onslaught.Other exceptions to the usual dominance order occurred in "artificial"situations. The normal pattern of family members remaining close to eachother while feeding with the gander performing many threats and chaseswas altered at baited trap sites or when corn was spread to supplement foodavailability for the geese. In those situations food was concentrated andlarge numbers of geese attempted to feed in a relatively small area. Initiallythe ganders of families engaged in enormous amounts of hostile behaviorbut often geese continued to move toward the food and "family-defense"became physically impossible. When this happened, geese crowded body tobody and aggressive behaviorwas reducedmost commonlyto vigorous peckingalternating with attempts to eat. Family unity was almost always disrupted.Intrafamily aggression.

Downy siblings may fight among themselves (COLLAS& JAHN,1959) butwhen the Triumph Ceremony display becomes fully coordinated,attack amongsiblings is inhibited (FISCHER, 1965: 264). LORENZ (1935) commented onthe compatabilityof young geese within a family without there being a rankorder.

The following data were derived from 169 hours of observation of markedfamilies during which the activity of each family memberwas recorded. Adultmales were seen pecking one of their young on four occasions, and adult



13/34


females pecked one of theirs on three occasions. Pecks between siblings wereobserved six times. Pecks within a family were less forceful and not followedby escape or attack behavior which occurred when non-family birds werepecked. Intrafamily pecks occurred when one individual moved its head rightnext to the other when feeding, althoughthis often happenedwithout resultingin pecking. These pecks were of very low intensity and, except on oneoccasion, the pecked goose either swung its head away slightly or nevermoved. The behavior of the pecking goose was ambivalent, as exhibitedby intention movements of pecking and withdrawing, or very rapid with-drawal and hesitation after a peck had been delivered. It was clear thataggression within the family was effectively inhibited.

DISCUSSIONComparison to other investigations.

DELACOUR & MAYR (1945: 8-io) noted that geese are mostly grazers andthat manifestations of social rank seem to be absent in the wild but developin confinement where food is localized. However, conflicts associated withrank position were noted during all aspects of daily activities of the geeseduring this study, i.e., while grazing or even "loafing" during periods ofrelative inactivity.Since victories in aggressive encounters were related directly to family size,this order should correspond to the dominancehierarchy of Canadageese, i.e.,large family > smaller family > pair > single. JENKINS(I944) reportedthat families dominated pairs and that single geese were lowest in a rankorder observed in a partially captive flock of blue and snow geese (Ansercaerulescens) and Canada geese. For B. c. interior, HANSON (I953) con-cluded that the rank order was family > pair > unmated adults and year-lings; BOYD (I953: Ioo) noted the same in white-fronted geese (Anseralbifrons) as well as an increase in success of the largest families.Data presented here suggest a rigid rank order in which a family's positionis directly influenced by the total numbers in the family and that a differenceof even one in family size is highly influential in their rank relations. BOYD(1953: 93, IOO) found similar relations in white-fronted geese, but his dataon victories and losses of various social status families reveal many instancesin which supposedly larger families were dominated by smaller groups oreven singles.The discrepancy between the rigidity of the rank order observed in thisstudy and the greater frequency of smaller families dominating larger familiesin BOYD'S(I953) study is probably explained by a bias introduced in my



14/34

AGONISTIC BEHAVIOR OF CANADA GEESE IN WINTER 303method of capturing the animals. Cannot-net traps (DILL & THORNESBERRY,I950) were used to catch the geese but in locations where only a few geeseroosted. Conflicts over a small amount of bait in front of the net eventuallyleft only one family in position to be trapped by virtue of the intensity andsuccess of a family's gander in keeping all other geese away. The suggestionis that only highly aggressive ganders and their families were caught andmarked.

Subsequent research on large samples of color, neck-banded geese takenfrom trapping efforts during the molt or large cannon-net catches has revealeda large range of variation in aggressive inclinations by individual gandersregardless of family size (RAVELING, npublished data). While the generaltheme of family size as the most importantcorrelate and probabledeterminantof success in hostile encounters is still true, and still especially noticeable inganders that do much chasing and fighting, there are some family ganderswho rarely engage in this activity. A further correlate of a lack of aggres-siveness by some ganders is a more loose family association where familymembers repeatedly separate and rejoin (RAVELING, npublished data). Incontrast, the families in this study were together on 96 percent of all observa-tions (RAVELING, I969a).Other factors which could partially explain the difference between BOYD'S(1953) study and this one in numbers of smaller families dominating largerfamilies is the lack of marked birds in BOYD'S 1953) study. Because of thisit would be difficult to record all subtle or low intensity actions observed asrelated to family size because united action of an entire family is relativelyrare (Tables 4 and 5).

Conditioning is often very important in influencing aggressive behavior(cf. SCOTT, 958: IO-I7), but in geese both the rank of the remaining groupand separated individual(s) of families are most dependent upon physicalproximity of related birds (JENKINS, 1944; FISCHER, I965: 270; BOYD,1953: IIO; COLLIAS, 95oa). The same result occurred in Canada goosefamilies during this study when separation and reunification were observed.Establishment and function of rank order in a largeflock.

Since the ability of geese to be victorious in aggressive encounters isrelated directly to the numbers of individuals cofa family and this dominanceability can change immediately upon separation and reunification of relatedgeese, important questions arise about the mechanisms causing geese to bemore or less successful? How do other geese recognize individuals andgroups that are superior or inferior to them in fighting ability?



15/34


In addition to causing dispersion of individuals, a major function ofaggressive behavior and rank orders is to promote stability in a group.Fighting and hostile behavior leads to less fighting because an individuallearns to recognize individuals which have defeated or can defeat him andthose which he can defeat. Once this is learned, these geese can coexistwithout fighting because then intention movements of attack (threats) sufficeto maintain the benefits of being superior (e.g., access to food, space) andconstantly reinforce individuals' positions with respect to each other.Because of the size of many wild goose flocks and what superficially appearto be shifting movements or mixing, some workers have denied that individualrecognition and rank order are important in limiting aggression. BOYD(I953: III) concluded this for white-fronts and WYNNE-EDWARDS (I962:136-138) pointed out the impossibility or impracticability of rigid rankorders in huge flocks of birds because of a finite ability to recognize "faces".Such conclusions apply only partially to Canada geese. Geese were not dis-tributed in roosting and feeding areas in a random fashion (RAVELING,I969b). Habit was importantin influencing the locations of geese, particularlyfamilies. The flock at Crab Orchard consisted of many subflocks within whichthe activity and use area of a particular family was limited. Families regularlyused shoreline areas at the lake that contained only a few hundred geese andmany of these must have been the same individuals. Since singles and pairswere so submissive and avoiding, a stable rank order could exist, for example,if the Ioo or 150 family ganders of a group of Iooo geese regularly using aparticular roost site had learned to recognize each other. Geese can probablyrecognize dozens and possibly hundreds of other individuals. FISCHER(I965: 267) noted that even goslings could recognize large numbers of geeseand even where these geese were in relation to their family in the rank order.While I believe that stable rank orders can exist based largely on individualrecognition, behavior differences between individuals and families in largeflocks are probably most important in allowing initial recognition of supe-riority. At Crab Orchard thousands of geese representing several subflocksoften fed in the same field. A rank order depending completely uponindividual recognition in these situations is not plausible. Great increasesin intensity and frequency of aggressive behavior occurred while feeding(Table I). As compared to non-feeding periods, fighting increased approxi-mately tenfold whereas threatening and chasing increased only two to fivetimes. While these data are limited, it is believed that the disproportionateincrease in fighting partially reflects the fact that many families unfamiliarwith each other were brought together.I suggest that fighting in winter usually occurs only between ganders



16/34


which are unfamiliar with each other and have not established a dominancerelationship. However, when thousands of geese were feeding in one area,the increase in fighting observed could not possibly have equalled the increasein the numbers of family ganders unfamiliar with each other. This fact alsosuggests that recognition of rank superiority was accomplished by somemeans other than individual recognition. Nineteen of the 26 fights reportedin Table 7 occurred between ganders with families of equal size or a disparityof one. These data further substantiate that many geese must recognizesuperior families since fighting usually occurred among ganders which wereessentially equally aggressive. In other words single ganders did not fightfamily ganders, ganders of pairs seldom fought ganders of families of fouror larger, ganders of families of four seldom fought ganders of families ofsix and so on.

WYNNE-EDWARDS(I962: I40) noted for many species the lack of correla-tion of dominance with size and apparent strength. This is true in Canadageese as some older, larger males have no young and are submissive toyounger, smaller males with broods. For example, one marked adult maleof IO lbs, 3 oz (larger than average; cf. RAVELING,968b) with greatlyenlarged extensor portions of the carpometacarpus, (indicative of an olderadult male; HANSON, 962) was a gander of a family of three. The behaviorof this bird was typical for that size group and he was not highly aggressive,nor more often victorious than other ganders in families of three. Anothergander in this study weighed 8 lbs, 14 oz (less than average) and had onlymodestly enlarged and still feathered knobs of the carpometacarpus.He wasprobably 212 or 312 years old, but he was a gander of a family of five andwas as successful as ganders of other families of five in winning encounters.

I suggest that the mechanisms which allow recognition and avoidance offighting with ganders of large families by ganders of smaller families andwhich allow the gander of the larger family to win a fight when one occursare associated with the role of increased numbers of young in directlystimulating increased intensity of threat display and fighting ability. Thevigor of display of a gander and the intensity and amount of participationof his family are related to situations in which mild threats do not causeavoidance but instead lead to pre-attack behavior by other geese so that afight becomes imminent. The actions of the ganders involved change frommild threat to ritualized threat serving postures (Erect, Head-pumping, andRolling - see Part II) which usually suffice to prevent a fight because onefamily moves away, especially if the gander of the other family starts to attack.FISCHER(I965: 302) concluded that Rolling served to maintain rank orderwithout severe fighting because intense display and actual performance of



17/34


the activity connected to a display are often largely mutually exclusive. Whilethis appears true it does not explain why the Rolling gander of a smallerfamily avoids or loses to the Rolling gander of a larger family.Stereotyped displays of ducklings and castrated ducks can be caused bytestosterone treatment (PHILLIPS & MCKINNEY, I962). Much research hasdemonstrated the correlation of aggressive behavior and social rank withandrogen production (e.g., see reviews by GOLLIAS,I95ob and DAVIS, I964).HANSON (1953) suggested that pairs of Canada geese with broods mighthave higher "hormone" levels through the winter than unmated geese orpairs without young. Since dominance and aggressive success fluctuate imme-diately upon separation and reunification of family members it appears thatnumbers of a brood serve to stimulate in a rather quantum fashion aggressivebehavior related to androgen level which is permissive to success in "bluffs"and fights. Apparently geese with high motivation (more young) and, thus,fighting ability, display more intensely and this is recognized by lowerranking geese.The fact that ganders of newly formed pairs were dominant over familyganders supports rather than contradictsthe above explanation. The formationof a pair bond, the rather continuous Triumph Ceremony activity of a newpair, and the female's unusual aggressive and inciting behavior (RAVELING,I967: 58) were apparently powerful stimuli causing the male to be in oneof the most aggressive states possible and, therefore, able to attack any goose.The normally much more aggressive family ganders would begin displayingbut were then dominated by the male of a newly formed pair which usuallywent immediately into attack. These observations support the suggestion thatquantitative differences in the vigor of threat display and attack intensityexist between ganders and that these differences account for most of thesubmission of lower ranking geese.Since dominance implies benefits, families of geese are served best byaggressive behavior and in increasing magnitude with increased size offamily. In long-lived species in which the young are dependent on or at leastclosely associated with their parents for a relatively long period of timeconsiderable survival values are attached to behaviors that maintain success-:ful pairs and their offspring. Immature geese in families are assured food,space, and relative freedom from constant attack or defeat as opposed toimmatures without parents and adults without young. With limited foodin a captive flock, JENKINS (I944) observed that the dominant fed first.JENKINS 1944) and HANSON 1953) noted how dominance of pairs withyoung could be important in times of food shortages for insuring the mainte-nance of successfully producing individuals and their offspring.



18/34

BEHAVIOUR XXXVII, (I970): 306 PLATEVIII

Figure I. Common attitude of a Canada goose fleeing from attack.

. :,j,..... .. .

Figure 2. Submissiveattitude of a Canadagoose.

http://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsphttp://www.jstor.org/page/info/about/policies/terms.jsp


19/34

BEHAVIOUR XXXVII, (I970): 306

Figure 3. Erect postures of Canadageese. Extreme position is illustratedby the goosebeing attacked. The goose immediately o the right of the attacker illustrates morecloselythe usual attitude before attacking or fleeing (or resuming other activity).

Figure 5. Triumph Ceremonybetween a pair of Canadageese. The male (left) is in theCackling posture.

PLATE X



20/34

BEHAVIOUR XXXVII, (I970): 306

Figure 7. Bent-neck posture of a Canada goose.

Figure 8. Forward posture of a Canada goose.

PLATE X



21/34

BEHAVIOUR XXXVII, (1970): 307

Figure 9. Attack by a family of 6 Canadageese. The gander (I) is transformingfromRolling movements to attack a gander (A) of another family (remainderof family isout of the photobut were identified in displaybefore the attack). Other membersof theattacking family (2, 3, 4, 5, plus a sixth out of the frame to the right) exhibit varyingBent-neck and Forward postures with the head high or low. Note the sleeked neckfeathers of attacking geese with extended head and neck in contrast to erected neckfeathers of the escaping goose (A). Note also the Erect posture of B in contrast togeneral unalertness of other geese in the vicinity.

PLATEXI



22/34

AGONISTIC BEHAVIOR. OF CANADA GEESE IN WINTER 307

PART II. - AGONISTIC BEHAVIORSIt was established in Part I that benefits of dominance among geese were

usually obtained not by fighting but by recognition of actions which servethe functions of threat and submission. Stereotyped postures with threatfunctions (and other displays serving as social signals) often represent theresultant of the simultaneous activation of two or more incompatible ten-dencies to behave in relatively mutually exclusive manners, e.g. attack orflee (cf. TINBERGEN, I952a, I954, I959, I964; HINDE, I953; BASTOCK t al.,I954; ANDREW, I956; VAN IERSEL & BOL, 1958).This "conflict hypothesis" of motivation analysis has been clearly de-monstrated in Canada geese. BLURTONJONES (I960) experimentally pro-duced stimuli eliciting uninhibited attack, uninhibited escape, and both situ-ations simultaneously with captive, tame geese. His results demonstratedthat certain postures exhibited by Canadageese in aggressive situations wererelated to varying amounts of conflicting tendencies to attack and escape atthe same time. BLURTONJONES (1960) used the terms Erect, Head-pumping,Bent-neck, and Forward to describe four agonistic postures. Other descrip-tions of some threat and attack behavior of Canada geese are provided byBALHAM (I94: 128-137, I58-I59), COLLIAS & JAHN (I959), and KLOPMAN(I96I, I968). I choose to follow the terminology of BLURTONJONES (I960)and FISCHER(I965) rather than KLOPMAN(I968).

RESULTSDescriptions and Interrelationships.

Fleeing.This is the obvious escape of one goose from another (Figure I). Usuallythe neck is erect and the head held high with neck feathers erected.Submissive Posture.The neck is curled and the bill points down and away from other geeseand almost touches the breast, and neck feathers are somewhat erected

(Figure 2). This attitude is especially prevalent among single geese as theymove among other geese or are being approachedby other geese. This postureis frequently assumed by a goose after it has fled from another individual.A goose in this posture is often pecked or threatened by other geese, but notattacked vigorously.Erect Posture.This position is almost identical to the alert position geese assume whendisturbed, except that the body is usually more erect in the agonistic situation



23/34


(Figure 3). The angle of the neck may be vertical or tilted away from ortowards other nearby geese. The Erect posture is similar to fleeing and oftenneck feathers are raised. Sometimes, however, the neck feathers are sleekedand the body feathers erected.The Erect posture is a response to activities of another goose (or groups)in the near vicinity upon which the Erect goose fixates. This posture oftengives way to fleeing, especially when neck feathers are raised and the necktilted away from nearby geese which are exhibiting more elaborate displays.Many times nothing further develops and the goose resumes a normal carriageand continues the activity in which it was engaged previously. The Erectposture may transform to more obvious displays (see below) or attack,especially if the Erect goose has sleeked neck feathers and erected bodyfeathers.

Head-pumping.Repeatedly lowering and raising the head causes a bobbing motion

(Figure 4). The neck is often vertical but it may be tilted towards anothergoose while the pumping continues. This display is initiated when ap-proaching other geese or as a response to other geese which are approachingor exhibiting hostile displays. Nothing further may develop, or Head-pumpingmay transform directly or by transition into Bent-neck, Forward, or Rollingpostures or even attack. Head-pumping may also transform to the Erectposture or escape.

Figure 4. Head-pumping postures of a Canada goose. The head is repeatedly loweredand raised (adapted from BLURTONONES,I960).Rolling.This is the most complex display of Canada geese. At low intensitythe head may be shaken in a manner almost indistinguishable from preflight

Head-tossing (RAVELING, I969C). This involves a vertical lifting of the billwhile the neck is erect. At higher intensity the neck and head are wavedforward and back and from side to side in an arc-like movement with thebill pointing up and the head being vigorously shaken from side to side. The



24/34

AGONISTIC BEHAVIOR OF CANADA GEESE IN WINTER 309white cheek patches are thereby displayed prominently. Strident honkingis characteristic of the display. Wing-flicks or Wing-shaking (MCKINNEY,1965) may accompany the highest intensity performances. Rolling mayalter with Cackling between Triumph Ceremony partners (Figures 5 and 6)and Bent-neck and Forward postures "aimed" at other geese. Thus the headmay swing from rotary Rolling movements to horizontal Cackling to Forwardthreatening and back to Rolling. Rolling and Cackling are two componentsof the Triumph Ceremony of geese and terminology follows FISCHERI965).This behavior is associated with a variety of situations and functions. The

Figure 6. Triumph Ceremony between a pair of Canada geese illustrating Rollingpostures with the male on the left. (Adapted from FISCHER,965: 279).discussion here refers only to the hostile or threat function. Further des-cription of the Triumph Ceremony of Canada geese is provided elsewhere(RAVELING, I967: I8-33).

Rolling is initiated when approaching other geese or as a response toapproach or nearness of another Erect, Head-pumping, Rolling or chasinggoose. It is often a performance between two ganders of different familiesjust prior to attack or fighting. Sometimes nothing further develops butwhen attacks occur they are of the highest intensity. Rolling may developfrom Erect or Head-pumping postures and it may transform to the Erectposture.

Bent-neck Posture.The head is pointed at another goose with the bill often angling slightlydown, and the neck is coiled back to varying degrees (Figure 7). The Bent-neck posture is frequently directed at nearby geese in the Submissive orErect attitude, or already fleeing. Bent-neck positions often develop fromErect or Head-pumping postures or as the goose lowers its head to drinkor eat, but then turns slightly towards another goose. Bent-neck occasionallytransforms to Head-pumping, Erect, or Forward postures, or direct attack.



25/34

3IO DENNIS G. RAVELING

Forward Posture.The head and neck are extended horizontally with the neck more or less

straight and directly oriented at another goose (Figure 8). This posture isgiven in essentially the same situations as the Bent-neck and usually developsfrom the Bent-neck and may revert to it.Attack.Except for fleeing and often the Submissive position, the above

descriptions of agonistic postures refer to geese that are essentially stationary,although hesitant movements toward or away from other geese occur withall the postures. A goose which moves rapidly toward another goose is con-sidered as attacking. Actually it is more common to observe the Forwardposture while an individual is pursuing a fleeing goose than when stationary.Attacks occur in a gradation of intensities and intermediates between thedescribed postures are common, especially the degree of neck coiling of theattacker. However, attacks can be considered in three categories: (a) lowintensity - walking towards another goose while in a Bent-neck, Forward,or intermediate posture; intermediate intensity - running towards anothergoose, often in a Bent-neck posture but usually more in a Forward position;high intensity - running at a goose with head high or low, the neck invarying coiled positions, and, often, with the wings spread slightly (Fi-gure 9).As with Bent-neck and Forward postures given while stationary, low andmedium intensity attacks are usually directed at geese that are already fleeingor in the Submissive attitude. High intensity attacks are often those situationswhere two ganders rush at each other, usually subsequent to Rolling. Highintensity attacks by the victor may continue after the defeated goose hasturned and is fleeing. These types of attack and fighting almost alwaysinvolve ganders of families. After more vigorous attacks and always aftera fight, the victorious gander turns and enters a Triumph Ceremony with oneor more members of his family.

DISCUSSIONOrigin, evolution, motivation, and function ofagonistic behaviors.

Since displays serving threat functions are often considered resultants ofthe conflict to attack and escape at the same time, comparison of threatpostures to actual attack and fleeing is a method of analysis for discoveringthe balance or predominance of underlying motivations and origin of a



26/34


behavior (cf. TINBERGEN, I952a, I959, I964). Some hostile actions may beobscure if they have been ritualized from the original movement or aredisplacement activities which appear irrelevant but have been formalized ina new context having signal value.

Submissive Attitude.Comparison of this "Appeasement" posture to other positions shows thatit is antithetical to attack. The tendency to escape is involved as indicated bythe raised neck feathers and avoiding behavior of the goose. The Submissive

posture is characteristic of single geese and their predisposition to aggressivebehavior is extremely low. The Submissive attitude is, however, differentfrom the usual fleeing behavior and since attack tendencies do not seem tobe involved, the probable motivations resulting in this behavior are complex.

Regardless of how avoiding a goose is, the power of attraction to othergeese and entrance into the activities of a flock prevent single geese fromisolating themselves. I suggest that the Submissive attitude results mainlyfrom the conflicting tendency to approach (but not attack) and be withother geese and flee from them at the same time. Support for this suggestion isderived from three sources: (a) The behavior usually results from thetendency of a single to join and stay with conspecifics even though it maybe rather constantly threatened or chased. (b) This attitude is similar to themanner in which approach and pair formation is initiated in other goosespecies (cf. FI;SCHER, I965: 275) and probably in Canada geese (RAVELING,1967: 57). (C) The Submissive posture and "listless" avoiding attitude whileat the same time approaching many geese is the most characteristic behaviorof individuals separated from and "searching" for their Triumph Cere-mony partner(s).FISCHER (I965: 257) described the unceasing searching behavior of geeseseparated from their mates and families and LORENZ (I959: 216, 1966: 207)gave particularly graphic descriptions of the state of these animals. Suchbehavior was clearly demonstrated on the occasion that an immature maleof a marked family of six was split from the rest of his family. He wasobserved six times for approximately 7 hours while separated and a greatdeal of this time was spent in continually walking among large numbers ofloafing and sleeping geese. He was often threatened, but not vigorouslychased. He was almost continually in the Submissive posture and for 8 dayshe did not fly out to feed. Upon reunification with his family, he abruptlybecameagain one of the most active and aggressive immaturesobserved duringthis study.The Submissive posture seems to have originated from the intention



27/34


movement of withdrawing the head from contact with other geese. Themovement has apparently been ritualized and serves the functions of iden-tifying single geese, allowing approach, habituation, and ultimately pair for-mation. This behavior also serves to prevent violent attacks against theseindividuals, probably because the attitude contains little or no aggressivecomponents. The continuing approach of these lowest ranking individualsclose to other geese, however, causes them to be threatened a great manytimes since any paired or family geese are dominant over them.

Erect Posture.This position with neck feathers raised often gives way to fleeing and theposture is similar to escape and can be considered as the intention movementof escape, but in conflict with a lesser tendency to remain and/or attack.

BLURTON JONES (1960) found that the Erect posture could be elicited onlywhen a tendency to attack coexisted with a strong tendency to flee, but notwhen attack was prevented when no escape causing stimuli were present.When sleeked neck feathers and raised body feathers are characteristic ofthe Erect posture they represent intention elements of attack. BALHAM(1954: I37) and COLLIAS & JAHN (I959) also noted that erected neckfeathers were related to alarm and escape while oppressed neck feathers anderected body feathers were associated with aggressive behaviors. When attacktendencies predominate this posture often transforms into other actionsrepresenting higher levels of attack or conflict motivations (Head-pumping,Rolling) or into attack itself.I interpret the Erect posture as one which represents a balance betweenattack and escape tendencies. Either motivation can predominate dependingupon the behavior of other nearby geese. The position has originated fromintention movements of fighting and escaping but since it often is notfollowed by either such activity it represents a relatively "weak" conflict(cf. TINBERGEN, I952b).The Erect posture is exaggerated in the sense that the angle of the bodycan be extreme and the posture can be held for relatively long periods of time.The behavior appears to have signal fuction as other geese avoid, or reactwith similar postures, an individual in this position. Thus, this posture servesthreat, rank order establishment and maintenance functions.

Head-Pumping.This display appears to represent an almost perfect balance between asimultaneous tendency to escape and attack. When the head is lowered the

posture is almost identical to the Bent-neck and incipient attack. I consider



28/34


this lowering and "aiming"of the head to be an intention movement of attack.When the neck is then straightened and the head held high the posture issimilar to escape and is interpreted as an intention movement of escape. Thebehavior of a Head-pumping goose is ambivalent and either attacking andfleeing can occur. Whether or not a goose will transform to more intensedisplay, attack, or flee can usually be predicted from the rapidity and extentof the Head-pumping in relation to the angle of the neck. If pumping isintense the chances for attacking or fleeing increase and the neck slantstoward or away from another goose and Head-pumping transforms intomore prevailing attack or escape tendencies, respectively. Although I interpretHead-pumping as originating from intention movements of attack and escape,I suggest that this posture is ritualized and that pumping itself is com-municative of attack rather than just the lowered head component. BLURTONJONES (I960) observed Head-pumping only in situations containing simul-taneous attack and flee stimuli. Other geese respond with avoidance ordisplay and thus Head-pumping also serves threat and rank order functions.

Rolling.Rolling contains motor patterns and vocalizations indicating that thisbehavior is the result of a variety of conflicting motivations (FISCHER, I965).

Especially important appears to be the spatial relationship of a gander to hismate and family. Intrusion of another high ranking gander or family on theseboundaries may result in violent attack. Rolling often serves as the highestintensity threat of geese and is responded to by other geese with avoidanceor comparable Rolling.The motivation and the origin of all the components of Rolling are notclearly understood. However, it does seem clear that the exaggerated headand neck movements are derived from preflight Head-tossing which repre-sents a displacement resulting from the conflict of leaving and remaining withTriumph Ceremony partner(s) (RAVELING, 969c). The behavior is highlyconspicuous.In Part I, I suggested that geese recognize superiority on the basis of typeand intensity of threat. The occurrence of Head-pumping and Rolling priorto attack or escape by the markedgeese demonstratedthe much greater amountof posturing engaged in by ganders of families as compared to pairs andsingle geese (Table 9). There was a non-significant difference in amount ofHead-pumping by ganders of different size families but Rolling was observedmore often in families of 5 than in families of 4 (x2 = 2.81, p smaller family>pair> single.4. Unified action by all members of a family occurredin 8.5 percent of victories and15 percentof defeats.5. All members of a family shared equal dominancestatus but the success of a familyin the rank order was most dependentupon the gander.6. Only once in 26 fights between unmarkedfamily ganders did the gander of thelargest family lose.7. Dominance position of family individuals decreased immediately upon separation,and increasedupon reunificationof family members.8. Large families were engaged in significantly more conflicts per unit time than weresingles, pairs, and small families.9. Exceptions to the usual dominance hierarchy occurred after pairs were newlyformed. The gander of a newly formed pair could dominatefamily ganders.o1. Intrafamilyaggression was rare and of low intensity.T . Fights rarely occurred; threats and chases were common.

I2. In some instances,rank orders based upon individualrecognitioncould exist. How-ever, stable rank orders in most large flocks appearto be based on recognitionofdifferent posturesand levels of intensity of threat.13. 'The dominance order of geese yields benefit in terms of food and space acquisitionand freedom from defeat in aggressive encounters for the pairs and their young indirect relation to those most successful at raising a brood.Part TI1. Postures associated with attack or fleeing or simultaneous endencies to do both aredescribed.These include actual fleeing or attack, Submissiveattitude,Erect, Head-pumping,Rolling, Bent-neck, and Forward postures.2. The Submissiveattitudeis exhibitedmostly by single geese and probablyresults fromthe conflicting tendency to approach(but not attack) and flee from other geese atthe same time. This posture functions to identify single geese, allow approach,habi-tuation,and ultimatelypair formation,and inhibitsviolent attack.



31/34


3. The Erect posture may take either the form of intention movements of escape orattack and representsan ambivalentmotivationbetweenthese two tendencies.4. Head-pumpingcontainsalternatingintentionmovements of attackingand fleeing andrepresents almost a perfect balance between these two tendencies but is of higherintensity and ritualization than the Erect position.5. Rolling is a complex portionof the TriumphCeremonybut also serves as the mostintense threat of Canadageese and is highly ritualized. The spatial relationshipsof aganderto his mate and family appearmost important n motivatingRolling. Intrusionof another high ranking gander or family on those boundariesmay result in violentattack.6. Erect, Head-pumping,and Rolling serve as three different intensity threats whichare recognized by other geese and serve to maintainand establishthe rank order ofgeese without undue fighting.7. Bent-neck and Forward postures may occasionally represent conflicting attack andflee tendenciesbut often appearto representa conflict of attack and remaindoinganother activity such as feeding or preening.These postures serve to maintainandreinforce a rank order but are probablynot very importantin initial establishmentof rank.

REFERENCESANDREW,R. J. (I956). Some remarks on behaviourin conflict situations,with specialreference to Emberizaspp. - Brit J. Anim. Behav. 4, p. 41-45.BALHAM, R. W. (I954). The behavior of the Canada goose (Branta canadensis) inManitoba.- Ph.D. dissertation.Univ. Missouri, Columbia.229 pp.BARTONEK, J. C. & DANE, C. W. (I964). Numberednasal discs for waterfowl. J.Wildl. Mgmt. 28, p. 688-692.BASTOCK, M. D., MORRIS, D. & MOYNIHAN, M. (I954). Some comments on conflict andthwarting in animals.- Behaviour6, p. 66-84.BLURTON JONES,N. G. (196o). Experiments on the causation of the threat posturesofCanada geese. - Wildfowl Trust Ann. Rept. II, p. 46-52.BOYD,H. (1952). Notes on colour marking of geese. - Wildfowl Trust Ann. Rept. 4,p. 14-16.- (I953). On encounters between wild white-fronted geese in winter flocks. -

Behaviour5, p. 85-129.CoLLIAS, N. E. (I95oa). Some variations in grouping and dominancepatterns amongbirds and mammals. - Zoologica 35, p. 97-II9.- (I95ob). Hormonesand behaviorwith special reference to birdsand the mechanismsof hormone action. - In: A Symposiumon Steroid Hormones.E. S. GORDONed.).University of Wisconsin Press. Madison, p. 277-329.& JAHN,L. R. (I959). Social behavior andbreedingsuccess in Canadageese (Brantacanddensis)confined underseminaturalconditions.- Auk 76, p. 478-509.DAVIs, D. E. (1964). The physiologicalanalysis of aggressive behavior.- In: Socialbehavior and organization among vertebrates. W. ETKIN ed.). Univ. of ChicagoPress. Chicago, p. 53-74.DELACOUR,J. & MAYR, E. (I945). The family Anatidae. - Wilson Bull. 57, p. 3-55.FISCHER, HELGA (I965). Das Triumphgeschrei der Graugans (Anser anser). - Z. f.Tierpsychol. 22, p. 247-304.HANSON, H. C. (I953). Inter-family dominance in Canada geese. - Auk 70, p. II-I6.-- (I962). Characters of age, sex, and sexual maturity in Canada geese. - IllinoisNat. Hist. Surv. Biol. Notes 49. 15 pp.- & SMITH,R. H. (I950). Canada geese of the Mississippi Flyway: with specialreference to an Illinois flock. - Illinois Nat. Hist. Surv. Bull. 25, p. 67-210.



32/34


HEINROTH, . (I9II). Beitrage zur Biologie, namentlichEthologie und Psychologie derAnatiden. - Verhand. Tnter.Ornithol. Kongr. 5, p. 589-702.HINDE,R. A. (I953). The conflict between drives in the courtshipand copulationof theChaffinch.- Behaviour5, p. I-3I.IERSEL, J. J. A. VAN & BOL,A. C. A. (1958). Preening of two tern species. A study ofdisplacementactivities. - Behaviour 13, p. 1-88.

JENKINS, D. W. (I944). Territory as a result of despotism and social organization ingeese. - Auk 6I, 30-47.KLOPMAN,R. B. (I96I). The greeting ceremonyof Canadageese. - Mag. of Ducks andGeese 12, p. 6-9.- (1968). The agonistic behavior of the Canada goose. - Behaviour 30, p. 287-319.KOZLIK,F. M., MILLER, A. W. & RIENECKER,W. C. (I959). Color-markingwhite geesefor determiningmigration routes. - Calif. Fish and Game 45, p. 69-82.

LINDMEIER,J. P. & JOHNSON, L. L. (I958). Marking ducks for research. - Flicker 30,p. 98-99.LORENZ,K. (I935). Der Kumpanin der Umwelt des Vogels. - J. f. Orithol. 83, p. 137-214; p. 289-413.- (I959). The role of aggression in group formation. - In: Group processes: Trans-actions of the fourth conference.B. SCHAFFNERed.). Josiah Macy. Jr. Foundation.N.Y., p. 181-252.- (1966). On aggression.- Harcourt, Brace & World, Inc. N.Y. 306 pp.

McKINNEY, F. (I965). The comfort movements of Anatidae. - Behaviour 25, p. 120-220.PHILLIPS, R. E. & McKINNEY,F. (1962). The role of testosterone n the displays of someducks. - Anim. Behav. 10, p. 244-246.RAVELING, D. G. (I967). Sociobiology and ecology of Canada geese in winter. Ph.D.dissertation.Southern Illinois Univ. Carbondale.213 pp.(I968a). Can counts of group sizes of Canadageese reveal populationstructure?-In: Canadagoose management.(R. L. HINE & C. SCHOENFELD,ds.). Dembar Educ.Res. Serv. Inc., Madison,Wisc. p. 87-91.(I968b). Weights of Branta canadensis nterior during winter. - J. Wildl. Mgmt.

32, p. 412-414.- (I969a). Social classes of Canadageese in winter.- J. Wildl. Mgmt. 33, p. 304-318.(I969b). Roost sites and flight patterns of Canadageese in winter. - J. Wildl.Mgmt. 33, P. 319-330.- (I969c). Preflight and flight behaviorof Canadageese. - Auk 86. p. 671-681.SCOTT,. P. (I958). Aggression. - Univ. of Chicago Press. Chicago. 149 pp.

SIEGEL, S. (I956). Nonparametricstatistics for the behavioral sciences. - McGraw-HillBook Co., Inc. N.Y. 312 pp.TINBERGEN, N. (I952a). "Derived" activities; their causation, biological significance,origin and emancipation during evolution. - Quart. Rev. Biol. 27, p. 1-32.- (I952b). A note on the orgin and evolution of threat display. - Ibis 94, p. 160-162.

- (1954). The origin and evolution of courtship and threat display. - In: Evolutionas a process.A. C. HARDY,J. S. HUXLEY,nd E. B. FORD(eds.). Allen and Unwin,Ltd. London. pp. 233-250.- (959). Comparative tudiesof the behaviourof gulls (Laridae): A progressreport.- Behaviour 15, p. 1-70.- (I964). The evolutionof signaling devices. - In: Social behaviorand organizationamong vertebrates.W. ETKIN (ed.). Univ. Chicago Press. Chicago.pp. 206-230.

WYNNE-EDWARDS, V. C. (I962). Animal dispersion in relation to social behavior. -Hafner Co. N.Y. 653 pp.



33/34

3I8 DENNIS G. RAVELING

RfSUMPLa predominancedes parenteset I'associationdes po,stureshostiles des Oies du Canada,ont ete'etudiees durant les hivers de I963 a I964 et de I964 a 1965, par l'observationdu

comportementdes families, marquees par la ,,radio" ou par la couleur et d',individusappartenanta un grand troupeausauvage du sud de l'Illinois.1ere PartieT. Le comportementn'etait pas significativementaltere en marquant es sujets par lacouleur et en leur attachantdes radio-emetteurs.2. Des rencontres hostiles se sont produitespresque toujoursdurant toutes les activites,variant largement dans Ia frequence et l'intensite. Elles etaient surtout associees al'alimentation.3. Le succes des rencontreshostiles etait directementlie a la taille de la famille, parexemple: une grande famille> une plus petite famille> un couple> ou unique.4. L'action unifee de tous les membres de la famille s'operedans 8.5% des victoires etde 15% des echecs.5. Tous les membres de la famille partagentegalement la position autoritaire; mais lesucces d'une fanille quant a l'ordre de son rang depend surtout du jars.6. Dans 26 combats entre families de jars non marques, seulement une fois les jarsde la plus grande famille ont echoue.7. La position predominantedes individus diminue immediatementapres la separationd'avec la famille et augmente par la reunification des membresavec la famille.8. Les grandes familles etaient significativement engagees dans de plus grand conflits

que les individusisoles, les couples et les petites familles.9. Exceptions a la predominancehierarchiquehabituelle, se sont produites apres laformation de nouveaux couples. Le jars d'une famille recemmnentormee, peutdominer une famille de jars.To. L'agression intrafanille etait rare, et sont intensite tres faible.IT. Les combats se sont rarement produits,mais les menaces et les poursuitesetaientfrequentes.12. Dans quelquescas, l'ordre des rangs, fonde stur a reconnaissancedes individuspeutexister, bien que l'ordre le plus stable dans les grandes bandes soit fonde sur lareconnaissancede differentes posturessur les degres de l'intensite de la menace.13. L'ordre de dominancedes Oies donne un benefice en nourriture,en espace, et enliberte a la suite des rencontresagressives des couples et de leurs petits et se tienten relation directe avec l'aptitudea elever une nichee.2eme Partiei. Les postures associees a l'attaque,ou a 1'envol ou aux deux sont decrites. Celles-cicomprennent 'envol ou I'attaque.Attitude soumrise, rigee, gonflant la tete, roulant,cou penche et tete portee en avant.2. L'attitude somllise est surtout prise par les Oies isoles et resulte souvent d'unetendance a s'approcherdes autres Oies, non pour attaquermais pour les eloigner.Cette positiona pour but d'identifier les Oises isolees, permettrel'approche,a fami-liarisationet finalementla formationdu coupleet empecherune attaqueviolente.3. L'attitudeerigee prend soit la forme des mouvementsavec l'intentionde s'echapperou d'attaquer,et represente une motivation ambivalente entre ces deux tendances.4. Le comportementdit ,,pompagede la tete" consiste alternativementen des mouve-ments avec l'intention d'attaquerou de s'enfuir et repre'sentepresque un parfaitequilibreentre ces deux tendances; mais il est d'une intensite et d'une ritualisationplus haute que ,,la posture herissee".



34/34


5. L'attitudedite de ,,roulement"est un segment complexede la ceremonie du triomphe;elle figure la menace la plus intense qu'expriment es OiescduCanada.Les relationsspatiales d'un jars avec sa femelle et sa famille semblent tres importantesdans lamotivation de l'attitude,,roulement".L'intrusion d'un jars d'un rang social eleve oud'une famille sur ces frontieres peut provoquerune attaqueviolente.6. L'attitude ,,tete gonflee" et ,,roulement herissee' servent de menaces differentesqui sont reconnuespour telles par les autres Oies, etablissentet maintiennent 'ordrehierarchiquedes Oies sans bataille excessive.7. ,,Cou penche" et ,,tete en avant" representent eventuellement une attaque ou unetendance a s'enfuir, mais souvent semblent representer une attitude d'attaque, secombinanta d'autres activites telles que la prise de nourriture ou le lissage desplumes. Ces poses aident a maintenir et a renforcer l'ordre hierardhique,maislelles sont moins importantesque d'autres dans l'etablissement nitial du rang.

Documents

Dominance Relationships and Agonistic Behavior of Canada Geese in Winter.pdf