BEHAVIOR of the ADELIE PENGUIN CHICK 273 Age Age Was 19.2 Days at One Colony and 21.6 Days at Another

BEHAVIOR OF THE ADkLIE PENGUIN CHICK

E. B. SPURRl Zoology Department University of Canterbury Christchurch, New Zealand

Previous studies have shown that chicks of the In the first summer ( 1967-68), observations were Ad&lie Penguin (Pygoscelisadeliue) are semi- made until the chicks departed for sea, but in subsequent summers observations were terminated just altricial when they hatch (Nice 1962, Reid before chick departure. In the summer of 1968-69, 1965, Reid and Bailey 1966). At first they are individual chicks were observed for periods of 10 min unable to leave the nest and require a great at intervals of approximately 5 days. In 1969-70 and deal of parental care. The chicks are covered 1970-71, nests were checked daily but with no set in down at hatching, but their body tempera- observation period. ture is not regulated completely until about BACKGROUND AND DEFINITIONS 15 days of age ( Sapin-Jaloustre and Bourliere’ Most parents hatch two chicks about 1.4 days 1951, Goldsmith and Sladen 1961). Their apart (Taylor 1962, Spurr 1972). The period growth rate approximates a truncated normal during which parents care for their chicks can curve ( Sapin-Jaloustre and Bourliere’ 1951, be divided into a guard stage and a creche Sapin-Jaloustre 1955, Sladen 1958, Taylor and or post-guard stage. The term creche is meant Roberts 1962). For the first few days little to imply simply a collection of young. There or no weight may be gained; in fact, some are no “guardians” of the creche (Sladen chicks are not fed until 3 days old. With reg- 1958). ular feeding, however, chicks show a rapid, In the guard stage one of the parents guards steady increase in weight from about 90 to and feeds the chicks while the other goes to nearly 4000 g in about 6 weeks. In the week sea to collect more food. At Cape Bird, the prior to departure for sea, the average weight parents usually change duty every day or of chicks decreases slightly, though weight twice every 3 days (Spurr 1972). For about may fluctuate markedly due to infrequent the first 5 days, chicks spend most of their large feeds. Ainley and Schlatter (1972) time completely under the cover of the par- showed that the weight of fledglings was cor- ents’ brood patch. The parent lies over the related to the parents ’ ages. chicks in a manner similar to the egg incuba- Other studies have described changes in tion posture (Spurr 1974). As the chicks plumage of chicks (Taylor 1962) and aspects grow, they become more exposed and can be of parent-chick recognition (Sladen 1953, brooded by their parents only partly. Until 1958, Penney 1968, Thompson and Emlen they are at least 10 days old, chicks usually 1968 ) . have their heads under the brood patch with The present paper describes the develop- only the posterior part of the body sticking ment of the behavior of the Adelie’ Penguin out. Between 11 and 15 days, the chicks sim- chick. Some aspects of chick behavior have ply may huddle against the parent (which been described previously (e.g., Sapin-Ja- may lean against the chicks). After about 15 loustre and Bouliere 1951, 1952, Sladen 1953, days, by which time the chicks are completely 1958, Taylor 1962, Penney 1968), but here homeothermic, most parents stand to one side an attempt is made to provide a more com- of the nest, leaving the chicks lying or stand- plete account. Following the descriptions of ing in it. behavior, the stages in development are com- In the creche or post-guard stage, the chicks pared with those determined for several spe- are left unguarded by their parents for many cies of birds by Nice ( 1962). hours of the day. Parents continue feeding their own chicks, but neither parent remains METHODS AND PROCEDURE with the chicks very long after feeding. In Observations were carried out over four summers as the absence of their parents, the chicks may part of another study ( Spurr 1972), at the University remain at the parental nest site or cluster with of Canterbury field station, Cape Bird, Ross Island, other unguarded chicks to form creches. Antarctica (77”1310”’ S, 166”2830”’ E ). Chicks were observed at marked nests from the time of hatching. The age at which chicks are first left unguarded varies slightly from colony to colony lPresent address: N.Z. Forest Service, P.O. Box 106, Ran- giora, New Zealand. and from year to year. In 1969-70, the aver- 12721 The Condor 77:272-280, 1975 BEHAVIOR OF THE ADELIE PENGUIN CHICK 273 age age was 19.2 days at one colony and 21.6 days at another. In 1970-71, the respective ages were 20.6 and 20.1 days. The youngest chick left unguarded was 14 days, and the oldest chick still being guarded was 30 days. At Cape Royds, Taylor (1962) recorded an average of 22.4 (R = 17-32) days. Sladen (1958) recorded an average of 30 (R = 28- 32) days for six chicks at Hope Bay, and 19 (R = 17-28) days for ten chicks at Signy Is- land. However, he considered the Signy Is- land dates atypical and suggested that the average age of creching was “about one FIGURE 1. Chick begging for food from parent. month.” Taylor ( 1962) established that chicks usually is accompanied by a single syllable hatched early in the season tend to be guarded call (“peep” of Sladen 1958). The white longer than those hatched later. Also, parents sclerae of the eyes may show shghtly, appar- at the periphery of a colony tend to guard ently as a consequence of raising the head. their chicks longer than parents in the center The flippers may be held out for balance. of a colony. These same relationships were Chicks beg from parents at any time but observed at Cape Bird. In addition, parents do so especially when a parent just returns that hatched only one chick tended to guard from sea. Older chicks may beg immediately their chicks longest. These parents need not following the Loud Mutual Display move- supply as much food as parents with two ments and vocalizations (see below), but beg- chicks. Consequently, a returning parent may ging and Mutual Display are separate move- not feed its chick immediately upon arrival ments (Sladen 1953, 1958). at the nest site, and the relieved parent may Comfort activities. Comfort activities are not leave for sea immediately. among the first types of behavior recorded Chicks are fed throughout the creche stage, (table 1). Yawning, shaking (the whole body, and probably do not go long without food be- head, or flippers), stretching (including fore they depart for sea. However, for about stretching the flippers upwards), swallowing, two weeks before departure, they are fed scratching (with foot over fhpper ) , and preen- progressively less by their parents, and their ing are all similar to adult activities. All oc- weight decreases slightly (Taylor and Roberts cur in chicks less than 10 days old. Panting 1962). occurs from 7 or 8 days of age, although chicks are not completely homeothermic until about RESULTS AND DISCUSSION 15 days. Chicks commonly sleep lying flat BEHAVIOR OF CHICKS on the ground, but as they grow older, they The behavior of chicks is described in its may also sleep while standing. After about approximate order of appearance (table 1). 15 days, chicks may sleep with the bill tucked References are made to adult behavior de- under the flipper, as do adults. scribed elsewhere (Sladen 1958, Sapin-Jalous- Chicks sometimes preen the breast feathers tre 1960, Penney 1968, Spurr 1974). of their parents or the breasts of siblings. Food begging. Food begging occurs on the Such allo-preening does not occur in adult day of hatching but at first is not essential Ad&lie Penguins. to initiate feeding. A parent will bend over Gripping at nest stows. Chicks less than 5 and place its bill beneath that of a newly days old may grip at nest stones with the hatched chick without any prior begging. bill. Between 6 and 10 days, chicks start Subsequent begging by the chick then stim- reaching out and dragging in nest stones from ulates the parent to regurgitate food into the the periphery of the nest (similar to the stone chicks now open bill. As the chicks grow rearranging of adults during nest building). older, they initiate more feedings by begging Small stones are sometimes swallowed. from passive parents. Locomotion. Newly hatched Ad&lie Pen- When begging for food, the chick reaches guin chicks are unable to move out of the nest. up with wobbly head movements and vibrates However, in 6 to 10 days they may stand at its bill at the base or tip of the parents’ bill the edge of the nest. Between 11 and 15 days, (fig. 1). The mandibles of the bill may be chicks start moving freely around the nesting rubbed slightly against one another. Begging territory. However, they seldom venture far 274 E. B. SPURR

TABLE 1. Age of chick at which behavior patterns were first recorded.

Age ( days ) Behavior recorded

o-5 Completely brooded by parent I & II Beg with peeping call Some comfort movements (e.g., yawn) Grip at nest stones B-10 Head under brood patch III of stooping parent May stand at edge of nest Crouch in nest when disturbed or exposed FIGURE 2. Chick Loud Mutual Display with parent. Comfort movements common (e.g., yawn, shake, stretch, scratch, preen) Pant on warm days of the adult Loud Mutual Display. This dis- Reach out and pull in stones; playing occurs at reunion with parents, usually swallow small stones at the nest site (fig. 2). It is distinguished 11-15 Head under brood patch, or lie IV clearly from begging. The raised head is in front of parent (who leans against chick) waved from side to side in a much more exag- Move around nest freely when gerated manner than for begging; the bill is parent absent, as at nest change opened wide, and the accompanying call con- Loud Mutual Display with parents, sists of several syllables (“tremulous” call of especially at nest relief Avoidance reactions to disturbance Sladen 1958). At first, the eyes may not be by intruding adults, skuas, etc. actively rolled downwards, but after about Gape at one another, and 16 days of age, the eyes usually are rolled peck at bills strongly, exposing much white of the sclerae. 16-20 Lie in nest while parents IV Because of the covering of down, it often is stand beside difficult to determine if feathers are erected. Some left unguarded by parents Completely homeothermic However, when they do become visible, the Free movement around territory crest feathers certainly are erect. Loud Mu- Quiet Mutual Display with tual Display, begging, and feeding may follow parents when disturbed in quick succession, but the three stages are Peck and grip feathers on back of sibling and beat with flippers separate. 21-25 Most left unguarded by parents V Quiet Mutual Display. Chicks perform the May venture alone outside colony Quiet Mutual Display with parents after both React aggressively to adults or have been disturbed, for example, by an in- other chicks passing too close truder. The head is raised and waved from Feeding chases before and after feeding side to side, but neither chick nor parent calls. Start shedding down and Escape behavior. Chicks show obvious es- acquiring juvenile plumage cape reactions from about the time they can ~1Stages in development corresponding to those determined first stand at the nest. Stimuli that elicit es- for several species of birds by Nice (1962); see text for explanation. cape reactions include intruding adults, pred- atory skuas ( Catharacta maccormicki) , and from the nest until about 21 days. After this, humans. When disturbed at the nest, a young chicks left unguarded by parents may move guard-stage chick crouches low to the ground away from the nest to join with others in a and huddles against its parent or sibling. creche. When a parent has been drawn into a fight The ability to walk develops gradually. The and the chicks are exposed at the nest site, first attempts around the nesting territory are young chicks usually remain crouched in the very slow and are accompanied by frequent nest, keeping very still. Older chicks, how- head-long falls. Even after chicks start mov- ever, often run away from these disturbances ing farther away from the nest, they are prone (see section on adult aggression toward to trip and fall. When trying to run, a chick chicks ) . may fall forwards and scramble along at times Unguarded chicks huddle together into with its breast on the ground. creches when disturbed. Chicks in these hud- Loud Mutual Display. At about 11 days, dles characteristically face toward the source chicks start performing an immature version of disturbance. This is in contrast to undis- BEHAVIOR OF THE ADSLIE PENGUIN CHICK 275 turbed huddles in which they face inward, erected. However, the eyes are rolled to ex- which may be either a response to tempera- pose the white sclerae during threatening. ture conditions or simply a propensity for Feeding chase. Feeding chases become fre- company (Richdale 1951). In several species quent when chicks are older than about 21 of penguin, the formation of creches has been days and have joined a creche. A parent who interpreted variously as a response to distur- gives the Loud Mutual Display call on ap- bance by predators and adverse weather (e.g., proaching the vicinity of its territory usually Roberts 1940, Stonehouse 1953, 1960, Pettin- attracts only its own chick(s), although other gill 1960, Warham 1963, 1974). In the Ad&lie chicks sometimes come out of the creche. The Penguin, however, probably most creches are parent then runs away from the area, often formed in response to aerial predators (Sladen right out of the colony, and is pursued by the 1958). Although chicks in the colonies have chicks. The chicks run along with flippers learned to respond to aerial predators, in the held up over the back, and open and close water there is at first an apparent lack of re- the bill to utter the peep call. Strange chicks sponse to aquatic predators (see section on ususally give up the chase very quickly. When chick recognition of predators). there are two sibling chicks, one also even- Aggressive behavior. Ad&lie Penguin chicks tually gives up the chase and walks back to actively seek contact with other chicks. Sib- the colony (usually to the vicinity of the pa- ling chicks frequently huddle together, side rental territory). The other chick may be fed by side or one half on top of the other. As several times before it also loses contact with they get older, chicks from adjacent nests the parent. Contact is re-established when often huddle together into creches without both parent and chicks return to the parental any signs of aggression. territory. The first indications of aggressive behavior Sibling chicks do not fight one another for occur ofter about 11 days, when sibling chicks food. However, when two chicks are together, occasionally gape and bill-grip with one an- they both constantly reach up for food; this other. From about 16 days of age, a chick interferes with feeding and spills food. The may grip its sibling by the feathers of the feeding chase separates siblings, so that inter- back, and beat it with the flippers. Creche ference is reduced. It also may act as a se- chicks also gape and peck with the bill and lective mechanism if food is in short supply. beat one another with the flippers. However, However, by periodically returning to the these “aggressive” reactions probably are best nesting area, parents normally ensure that termed play behavior because they lack any both chicks are fed. quality of “seriousness” (see Marler and Ham- Aark call. An immature aurk call (Sladen ilton 1966). In these situations, the chicks do 1958) is first heard among creche chicks. It not compete with a rival for a possession (e.g., occurs when chicks are alarmed, for example, food, mate, or territory). by the presence of skuas or humans. The Serious aggressive behavior by chicks is ob- calling becomes more frequent when the served only after about 21 days of age. This creches start to disperse and the chicks move behavior is directed toward strange adult pen- about outside the colonies, and is strongest quins or other chicks passing by the parental when the chicks enter the water on departure territory or coming too close to a creche. for sea. Thus, in chicks it appears to be a Older creche chicks also react aggressively to response to a novel situation, whereas in skuas. The change in response to skuas seems adults it functions as a contact call. Ainley to occur when the chicks are large enough to (1972) considered that the calling had little defend themselves. social significance for chicks because “they All aggressive reactions of chicks are sim- make no effort to catch up to or wait for each ilar to those of adults. Physical attack (with other” in the water. However, part of the ex- bill or flippers) is the most common form of planation for this may be the small size of aggression. However, charging forward, gap- departing groups at Cape Crozier compared ing, pointing the bill, waving the head from to Cape Bird (see section on chick departure). side to side, holding the head to one side, and Cape Bird chicks which left in definite groups rolling the head at the side of the body also remained in groups although they were more occur. These correspond to the adult displays dispersed than adult groups. of Charge, Gape, Point, Alternate Stare, Side- Play. Besides play-aggression, older creche ways Stare, and Bill-to-Axilla (Spurr 1974). chicks perform play movements in which they Until the down feathers start to molt, it is run about, sometimes in semi-circles, waving difficult to determine if the feathers are their flippers in an irregular manner. Such 276 E. B. SPURR running about occasionally leads to immature nests, occasionally calling loudly. Suddenly, (play) flipper attacks when chicks collide. the parent heard the calling, became restless, This running about does not appear to cor- and started looking around. The parent then respond to play-fleeing described by Nice gave a Loud Mutual Display call. The chick (1962) for several bird species, and it occurs seemed to recognize this call and ran a little at a time when chicks already are showing closer, before pausing and calling again. The escape reactions in response to skuas. Fur- parent again replied with a Loud Mutual Dis- thermore, adults have no natural terrestrial play call. The chick soon found its way to predators. Possibly it is important as “exer- the nest where it joined in a Loud Mutual cise” or “practice,” aiding maturation of legs Display with the parent. From cross-fostering and especially flippers prior to departure for experiments, Thompson and Emlen (1968) sea (see also Warham 1963). The behavior reported that parents begin to identify their probably is best termed play-swimming own young between 8 and 17 days. This is (equivalent to flying in other species). also the period in which chicks start perform- Ecstatic Display. An immature version of ing immature versions of the Loud Mutual the adult Ecstatic (advertising) Display oc- Display. curs in creche chicks older than about 35 days. Adults and chicks probably recognize one The head is raised vertically, the eyes rolled, another visually also, using various features of and the flippers beat up and down. The bill appearance and behavior. However, rapid is opened, and a shrill multiple-syllable call growth in size and changes in appearance of is uttered. The call resembles that of the chicks require constant learning of visual cues. Loud Mutual Display. Such an Ecstatic Dis- Vocalizations also change slightly as the chicks play was given by a chick after losing its par- grow, but not so markedly as external appear- ent in a feeding chase. Another display was ance. The importance of auditory recognition performed by a creche chick standing at the is illustrated by its early appearance in the colony periphery. The stimulus for these Ec- behavioral development of chicks. By the static Displays of chicks may be separation time chicks are first left unguarded, parents from parents, while in adults the display seems are able to recognize their own chicks, and to be stimulated by being alone and sexually chicks are able to recognize their own parents. receptive. This has also been reported for Little Blue Penguins (Eudyptula minor), Yellow-eyed PARENT-CHICK RECOGNITION Penguins ( Megadyptes antipodes) (Richdale Sladen (1953,1958) was the first to show that 1951)) Rockhopper Penguins (Eudyptes chrys- Ad&lie Penguins feed only their own creche ocome) ( Pettingill 1960, Warham 1963)) chicks. This behavior implies that parents Royal Penguins (E. chrysolophus schlegeli) and chicks are able to recognize one another. ( Warham 1971)) Chinstrap Penguins ( Pygos- Some aspects of this recognition can be deter- celis antarctica) ( Sladen 1955), King Pen- mined from observations in both natural and guins ( Aptenodytes patagonica) (Stonehouse experimental situations. 1960), and Emperor Penguins (A. forsteri) Creche chicks clearly recognize their own (Prevost 1955). parents. Many adults return with food to the vicinity of the creche, but individual chicks ADULT AGGRESSION TOWARD CHICKS usually respond only to the Loud Mutual Dis- Chicks of any age wandering away from their play call of their own parents. Occasionally, natal territory are attacked by other terri- strange chicks initially will respond to an torial penguins as strongly as are intruding adults’ call, but the response does not persist. adults. This is especially evident before the Most creche chicks ignore the calls of adults breakdown of the territorial structure of col- other than their parents. Penney (1968) pro- onies and the formation of creches. Chicks vided experimental evidence of the importance of 16 to 20 days, with some degree of mobility of a parents’ vocalizations in bringing parent but not yet creched, may be pecked by neigh- and chick(s) together. bors if they take a few steps from the edge of Parents also recognize their own chicks. the nest. Sometimes, instead of turning back This was demonstrated when, during a dis- to the parental nest, the chicks may run far- turbance in the colony, a 14-day-old chick was ther away, drawing threats and pecks from displaced several meters from the nest. The all territorial penguins in their path, and creat- parent apparently was unaware of its disap- ing chaos in the colony. These wandering pearance and remained guarding the sibling. chicks usually run with the body almost hori- The chick scrambled around between nearby zontal and the head low to the ground. BEHAVIOR OF THE ADfiLIE PENGUIN CHICK 277

Younger chicks with little locomotor ability can be seriously injured and even killed by 1500 l -+_ adults whose vicious pecks are usually directed at the head. The chicks ’ avoidance behavior clearly has survival value in that the chick is lOOO- withdrawn as far as possible from adult at- 3 tacks. However, it appears to have little ap- z peasement value, as adults continue to attack 500 - wandering chicks so long as they remain within range. Wandering chicks often attempt to bury their heads into the brood patches of 15 20 25 30 4 9 1 territorial adults. If they are successful, peck- JANUARY FEBRUARY ing may stop, at least briefly, especially when FIGURE 3. Number of chicks remaining in a sample the adult has one or two chicks of its own. of colonies at Cape Bird, Jan.-Feb. 1968. Adult aggression to wandering chicks has marked survival value for their own chicks. Parents normally cannot rear more than two during a feeding chase also may return to chicks. A few instances in which adults the natal territory, which may be up to 50 m adopted a strange third chick all resulted in away. Playbacks of parent Loud Mutual Dis- death by starvation of the smallest chick. play vocalizations from outside the colony by This was usually the parents ’ own smallest Penney (1968) also caused chicks to return chick because the adopted chick, already old to their natal territory. enough to move about freely, was larger than The ability of chicks to return to their natal the parents ’ own chicks. territory is very important for establishing Creched chicks are sometimes molested by contact with parents in a crowded colony. adult strangers. These adults are usually un- Nelson (1966) suggested that this ability may successful (probably young) breeders and lead to philopatry, “the tendency for young nonbreeders (Sladen 1958). They may ap- adults to acquire nesting sites in the precise proach a creche chick and attempt to mount area of their birth.” From a study of known- it. When the chick tries to escape, it may be age birds, LeResche and Sladen (1970) dem- chased, severely pecked, and beaten with the onstrated that philopatry exists in the Ad&lie flippers. Penguin. Parents show mild aggression toward their own chicks older than about 16 days when CHICK RECOGNITION OF PREDATORS they persistently beg for food. Such aggres- Young guard-stage chicks at first appear not sion usually consists of mild snapping and jab- to recognize predators but must learn quickly bing the bill at the chicks’ bill, sometimes from the crouching reactions of parents when while backing away. This frequently occurs predators approach. From the time when when the chicks approach a parent prior to, chicks are able to stand at the nest, they watch and during, feeding chases. skuas flying high overhead and turn their heads to follow them as they fly farther away. CHICK RECOGNITION OF NATAL TERRITORY When skuas approach, chicks dive head-first Even during the guard stage, chicks that are under a parents’ brood patch. Unguarded displaced or wander from the nest usually chicks disturbed by skuas quickly form creches find their way back. However, they may be and utter the aurk call. vigorously pecked by adults and wander aim- The responses to predators are learned in- lessly for some time before returning. As dividually for different types of predator. noted earlier, return to the nest may be aided Chicks departing for sea have not previously by parental vocalizations. encountered the Leopard Seal (Hydrurga Chicks that have entered creches, however, leptonyr) and appear not to recognize it as a are easily able to find their natal territory predator. Thus, chicks may enter the water again. Before the return of the parent with and even swim toward seals that are attack- food, chicks may leave the creche (up to IO ing other chicks already in the water (see also m) and return on their own to the vacant Ainley 1972). natal territory. (The timing of this response possibly is based on the regularity of feeding CHICK DEPARTURE FOR SEA and the amount of food in the chicks’ stom- In the summer of 1967-68, chicks started to ach.) Chicks that lose contact with a parent wander away from the confines of their col- 278 E. B. SPURR

When the surf is heavy, chicks have diffi- culty getting to open water. Of a group that rushes toward the breakers, only a few get through. The rest are swept back up the beach. After regrouping, the sequence is re- peated. Once in the water, past the narrow line of breakers, the chicks splash around on the surface, with much loud calling (see aark call). They can swim under the water, but none was

_ --- observed to “porpoise” as the adults do. After ‘B’29’J)‘31rl ‘2 ‘3 ‘4’5’6’7’8 ‘9’10’11 12 13 14 JANUARY FEBRUARY swimming several meters under water, the chicks stop and come to the surface. After FIGURE 4. Number of chicks gathered on a section of shore at Cape Bird, Jan.-Feb. 1968. splashing around on the surface for several seconds (sometimes minutes), they again dive under the water. By this slow alternation of onies from about 20 January. They began of swimming and surfacing, the chicks gradu- gathering on the beaches at the waters’ edge ally head away from the shore in a northerly on 28 January. Most chicks had left their direction. colonies by the end of the second week in February (fig. 3). Once they reached the STAGES OF DEVELOPMENT OF BEHAVIOR: beach, chicks usually did not remain ashore A DISCUSSION for long. The numbers gathered on the shore Nice (1962) recognized five stages in the de- each day probably reflect the rate of departure velopment of avian behavior (table 1) and quite closely (fig. 4). This pattern of de- compared these in a number of species. The parture is very similar to that recorded at stages she recognized are: Cape Royds by Taylor (1962) and Yeates (1968). I Post-embryonic: co-ordinations concerned Chicks were first observed swimming out mainly with nutrition. to sea, alone or in pairs, on 28 January, the same day they began gathering on the shore. II Preliminary: beginnings of comfort move- Unfortunately, no chicks were marked the ments. first summer, and it was not possible to make III Transition: maturation of comfort move- observations in subsequent summers. How- ments; escape reactions. ever, the maximum possible age of the chicks seen leaving in 1967-68 was 54 days. This is IV Locomotory: leaving nest; start of self- within the range of 4156 days (X = 50.6) re- feeding. corded by Taylor (1962) for departing chicks V Socialization: aggression; perfection of lo- at Cape Royds. Chicks that hatch later in the comotion. season tend to leave at a younger age than those that hatch earlier. The present study shows that Adelie’ Pen- The chicks usually depart for sea in groups guin chicks follow much the same pattern of whose average size is 13 (R = l-100). At development as the young of other birds. The Cape Royds, the departing groups never con- first three stages of Nice (1962) are passed tain more than 12 chicks (Taylor 1962). How- in about 10 days (table 1). During this pe- ever, the long sandy beaches at Cape Bird riod, activities are concerned mostly with feed- provide much wider access to the sea than ing and comfort behavior. In the final two the small rocky beach at Cape Royds. At stages locomotory and social behavior are Cape Crozier, where chicks must dive into developed. Thus, after about 10 days, mutual the water, departing groups consist of only recognition develops between chicks and par- one or a few chicks ( Ainley 1972). ents. Locomotion becomes more evident along Chicks often leave for sea when no adults with escape reactions (from strange adults are present. Nevertheless, departure of adults and predators). After about 21 days, serious (usually not their parents) encourages chicks aggressive behavior occurs. Isolated occur- into the water. Once in the water, however, rences of the Ecstatic Display in older chicks the adults soon leave the chicks behind. may represent a precursor of adult sexual be- Chicks sometimes return to the shore after havior. However, sexual behavior does not entering the water (Taylor 1962, Yeates 1968) develop fully until the young penguins are or climb onto ice floes in the water. more than two years old. First breeding does BEHAVIOR OF THE ADBLIE PENGUIN CHICK 279 not occur until at least three years in females adults, The integration of behavior is a con- and four years in males ( LeResche and Sladen tinuing process, still occurring in juveniles and 1970). young birds who return to the colonies as The first three stages in development of “wanderers” (Sladen 1958, LeResche and chick behavior represent a period of immo- Sladen 1970). bility; the fourth stage is a period of moderate In the limited breeding season of the Ant- mobility and the fifth stage is a period of full arctic summer, chicks hatched early in the activity (Nice 1962). The period of immo- season receive more care before being left bility is characteristic of all altricial (and unguarded and before departing to sea than semi-altricial) species. The duration of each chicks hatched late in the season. This sug- period, however, varies from species to spe- gests that they will be in better condition to cies, Thus, the period of immobility lasts face the northward migration to the winter- about 10 days in the altricial Song Sparrow ing areas and will be better able to acquire (Melospiza melodia) (Nice 1962) compared the skills of swimming and feeding before the to about 22 days in the altricial Shag (Phala- onset of adverse weather. crocorax aristotelis) (Snow 1963). Even within one family, for example, the Sphenisci- SUMMARY dae, different species may have a chick period Observations from time of hatching to time of different length. In the King Penguin, of fledging were made over four summers on chicks are fed by their parents for about 10 Ad&e Penguin chicks at marked nests. The months ( Stonehouse 1960), and chick devel- chicks are semi-altricial at hatching, and re- opment is correspondingly drawn out com- quire a great deal of parental care. Observa- pared to the Ad&lie Penguin. tions of known individuals show that feeding The stage of development at which a par- and comfort behavior develop first, followed ticular behavior first appears is relatively con- by recognition of parents, locomotion, escape stant in several different species (Nice 1962). reactions, aggression, and finally sexual be- Thus, of the 17 motor co-ordinations described havior. This follows closely the order deter- by Nice (1962), most occur at a similar stage mined by Nice (1962) for several species of of development in all the species she analyzed, birds. and also at a similar stage of development in Chicks become independent of parental Ad&lie Penguin chicks. However, exploratory protection from climate and aerial predators pecking (at nest material) occurred very by about three weeks when they may be left early, while bathing, swimming (the equiv- unguarded for many hours of the day. Com- alent of flying), and feeding did not occur plete independence from the parents does not until chicks departed for sea at about 50 days. occur until the chicks depart for sea, at about It is only when the chicks depart for sea that seven weeks. they become completely independent of parents. Swimming movements at first are not as ACKNOWLEDGMENTS efficient as those of adults and probably take This work was done while I was a member of the time to perfect. “Play exercises” mentioned University of Canterbury Antarctic research unit. earlier possibly assist in this development. Field support was provided by Antarctic Division, Observations are lacking on the development D.S.I.R. (Christchurch, New Zealand) and Scott Base. Logistic support was provided by the U.S. of self-feeding, but this must also improve Navv VXE-6 Sauadron. Penguin flinner-bands were with practice (see also Ainley and Schlatter supplied by WY J. L. Sladen of the USARP Bird 1972). As concluded by Kruijt (1964) for Banding Program. During one summer, financial the Burmese Red Junglefowl (Gallus gallus support was received from the Canterbury Branch of the New Zealand Antarctic Society. spadiceus) , various activities first develop in I am grateful to Professor E. C. Young for en- relative isolation of each other and only couragement throughout the study. Helpful criticism gradually become integrated into co-ordinated of the manuscript was offered by V. Benzie and my behavior patterns. Some examples in the wife, Barbara. behavior of Ad&lie Penguin chicks include LITERATURE CITED exploratory handling of nest material, early escape reactions, play aggression, play swim- AINLEY, D. G. 1972. Flocking in Adelie Penguins. Ibis 114:388-390. ming, and the immature Ecstatic Display. AII\LEY, D. G., AND R. P. SCHLATTER. 1972. Chick Thus, escape behavior first develops in re- raising ability in Ad&lie Penguins. Auk 89 :559- sponse to external disturbances (such as in- 566. GOLDSMITH, R., AND W. J. L. SLADEN. 1961. Tem- trusion of predators) and only later in re- perature regulation of some antarctic penguins. sponse to aggression by other chicks and J. Physiol., Lond. 157:251-262. 280 E. B. SPURR

KRUIJT, J. P. 1964. Ontogeny of social behaviour SLAUEN, W. J. L. 1953. The Ad&lie Penguin. Na- in Burmese Red Junglefowl (Gullus gallus spadi- ture 171:952-955. ceus ) Bonnaterre. Behaviour Suppl. 12 : l-201. SLADEN, W. J. L. 1955. Some aspects of the be- LERESCHE, R. E., AND W. J. L. SLADEN. 1970. Es- haviour of Ad&lie and Chinstrap Penguins. Acta tablishment of pair and breeding site bonds by XI Congr. Int. Ornithol.:241-247. young known-age Adelie Penguins (Pygoscelis SLADEN, W. J. L. 1958. The Pygoscelid penguins. adeke). Anim. Behav. 18:517-526. I. Methods of study. II. The Ad&lie Penguin MARLER, P., AND W. J. HAMILTON. 1966. Mecha- Pygoscelis adeliae ( Hombron & Jacquinot ). Falk- nisms of animal behavior. John Wiley & Sons, land 1~1. Depend. Sur. Sci. Rep. 17:1-97. New York. SNOW, B. K. 1963. The behaviour of the shag. NELSON, J. B. 1966. The behaviour of the young Brit. Birds 56:77-103, 164-186. gannet. Brit. Birds 59:343-419. SPURR, E. B. 1972. Social organisation of the NICE, M. M. 1962. Development of behavior in Ad&lie Penguin, Pygoscelis adeliae. Ph.D. Thesis, precocial birds. Trans. Linnaean Sot. New York Univ. Canterbury, Christchurch, New Zealand. 8:1-211. SPURR, E. B. 1974. Communication in the Ad&lie PENNEY, R. L. 1968. Territorial and social behavior Penguin, p. 449501. In B. Stonehouse [ed.], The in the Ad&lie Penguin. Antarctic Res. Ser. 12: biology of penguins. Macmillan, London. 83-131. STONEHOUSE, B. 1953. The Emperor Penguin Ap- PETTINGILL, 0. S. 1960. Creche behavior and in- tenodytes forsteri Gray. I. Breeding behaviour dividual recognition in a colony of Rockhopper and development. Falkland 1~1.Depend. Sm. Sci. Penguins. Wilson Bull. 72:213-221. Rep. 6: l-33. PROVOST, J. 1955. Observations kcologiques sur le STONEHOUSE, B. 1960. The King Penguin Apteno- Manchot Empereur ( Aptenodytes forsteri). Acta dytes patugonica of South Georgia. I. Breeding XI Congr. Int. Ornithol.:248-251. behaviour and development. Falkland 1~1. De- REID, B. E. 1965. The Ad&lie Penguin (Pygoscelis pend. Sur. Sci. Rep. 23:1-81. adeliae) egg. N.Z. T. Sci. 8:503-514. REIU, B. E.,AND”C.‘ BAILEY. 1966. The value of the TAYLOR, R. H. 1962. The Ad&lie Penguin Pygos- celis adeliae at Cape Royds. Ibis 104:176-204. yolk reserve in Adklie Penguin chicks. Rec. Dom. Mus. 5:185-193. TAYLOR, R. H., AND H. S. ROBERTS. 1962. Growth RICHDALE, L. E. 1951. Sexual behavior in pen- of Adelie Penguin (Pygoscelis adeliae Hombron guins. Univ. Kansas Press, Lawrence. & Jacquinot) chicks. N. Z. J. Sci. 5:191-197. RODERTS, B. 1940. The breeding behaviour of pen- THOMPSON, D. H., AND J. T. E~~LEN. 1968. Parent- guins with special reference to Pygoscelis papua chick individual recognition in the Adelie Pen- (Forster ). Brit. Graham Land Exped. 193437 guin. Antarctic J. U.S. 3:132. Sci. Rep. 1: 195-254. WARHAM, J. 1963. The Rockhopper Penguin, Eu- SAPIN-JALOUSTHE, J. 1955. Quelques aspects de la dyptes chrysocome, at Macquarie Island. Auk vie du Manchot Ad&lie en Terre Adirlie. Acta 80:229-256. XI Congr. Int. Ornithol.:231-240. WARHAM, J. 1971. Aspects of breeding behaviour SAPIN-JALOUSTRE, J. 1960. Bcologie du Manchot in the Roval Penguin E,uduwtes chrusolowhus Ad&lie. Hermann, Paris. schlegeli. Notornis i8:91-115: ’ ” ’ SAPIN-JALOUSTRE, J., AND F. BOURLI~RE. 1951. In- WARHAM, J. 1974. The Fiordland Crested Penguin cubation et developpement du poussin chez le Eudyptes pachyrhynchus. Ibis 116: l-27. Manchot Ad&lie, Pygoscelis adeliae. Alauda 19: YEATES, G. W. 1968. Studies on the Adklie Penguin 65-83. at Cape Royds 1964-65 and 1965-66. N. Z. J. SAPIN-JALOUSTRE, J., AND F. BOURLI~RE. 1952. Pa- Mar. Freshwater Res. 2:472-496. rades et attitudes caracteristique de Pygoscelis adeliae. Alauda 20:39-53. Accepted for publication 6 August 1974.