Chinstrap Penguin

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Chinstrap Penguin portrait Specific Name: Pygoscelis antarctica
Pinguino Barbijo-Antartico Manchot a Jugulaire Zügelpinguin
Adult Height: 71-76cm
Adult Weight: 3.9-4.4kg
Adult Flipper Length: 17-20cm
Estimated Population: 7.5 Million breeding pairs

Distribution / General:

Chinstrap populations are found on the Antarctic Peninsula and nearby islands such as, South Georgia, S. Shetland, S. Orkney, S. Sandwich, Balleny, Bouvetoya and Peter 1 Oy. No subspecies are recognized.

Chinstraps belong to the family of Pygoscelid penguins, along with the closely related Adelie and Gentoo penguins. The species ranges overlap, especially at the antarctic peninsula, and they may breed in close proximity to each other. The Chinstrap has an intermediate range compared to the Adelies which are confined to the antarctic continent, and the Gentoos which have spread as far north as Crozet Island.

The largest populations of Chinstrap Penguins are found on the South Sandwich Islands. There are however significant population centers spread eastwards from S. Sandwich to the Antarctic Peninsula. Many of these populations expanded rapidly during the early second half of the 20th century, but have been in decline in recent years. Census data is patchy, but figures exist for several sites. In the mid-1980s, about 55000 breeding pairs (bp) in 126 colonies were found on the west coast of the Antarctic Peninsula (Poncet and Poncet 1987. BAS Bull. 77, p.109-130). The S. Shetlands were reported to have 800000 bp in 1987 (Shuford and Spear 1988. BAS Bull. 81, p.19-30) and the S. Orkneys over 500000 bp in the early 1980s (Poncet and Poncet 1985. BAS Bull. 68, p.71-82; Croxall et al., 1981. BAS Bull. 54, p.47-56).

At King George Island in the S. Shetlands, populations decreased from about 2500 bp in 1979 to just over 1000 bp in 2004 (Sander et al., 2007. Polar Biol. 30, p.659-661). This population decline is consistent with a number of other reports that point to a gradual decline in numbers in the last decades at numerous breeding sites (Woehler and Croxall 1997. Mar. Ornithol. 25, p.43-66).

Chinstrap Penguin portrait Chinstrap Penguin Distribution Map


Chinstrap Penguins largely forage diurnally near their colonies during the breeding season, although nocturnal foraging is also regularly observed. Foraging may be either pelagic or benthic, depending on local oceanographic and topographic (bathymetric) conditions. Antarctic Krill is the predominant prey. Maximum foraging dive depths of up to 179 meters have been reported. Migration may occur during the winter season with some penguins reaching over 1000 km from their colonies, whilst others remain relatively close to their breeding colonies. The penguins remain in open-water (relatively ice-free) habitats during this period and whenever possible during the breeding season.


Antarctic Krill makes up well over 90% of the summer diet of Chinstrap Penguins in most studies. However, the stomach samples upon which these studies are based primarily reflect food caught in the latter part of feeding trips, whereas food caught earlier and further from the colony will have been largely digested. Hence, the actual proportion of fish consumed may be underestimated. In particular, the nocturnal diet is poorly reflected as the penguins do not land during the night. It is suggested that penguins may feed more on fish during the night, when these are nearer to the surface (Miller and Trivelpiece 2008. Mar. Biol. 154, p.201-208). Winter diet is not known, since the birds do not return to their colonies during this period, thus preventing collection of dietary samples. However, the extended hours of darkness may skew the diet more in the direction of fish during this period.

At Laurie Island (S. Orkneys), diets of breeding adults were studied during the 1997-2002 breeding seasons. Antarctic Krill (Euphausia superba) dominated the diet, making up over 99.5% by weight in all years. Minor quantities of fish (e.g. Myctophid and Notothenid species), amphipods (e.g. T. gaudichaudii) and cephalopods made up the remainder (Rombola et al., 2006. Polar Biol. 29, p.502-509). The mean weight of stomach contents was over 400 grams in 1998, yet as low as 180 g in 2000, with reduced stomach contents correlating to greater levels of digestion, suggesting foraging over a greater range. Maximum stomach contents of over 800 g were reported.

An earlier paper dealing with the same data concentrated on the effect of the late pack-ice break-off in 1998 (Rombola et al., 2003. Polar Biol. 26, p.41-48). It was found that Chinstrap Penguins were returning to the colony less frequently and with a mean of about 170 g of krill prior to the ice break-off, but frequently and with a mean of 450 g thereafter. A similar effect could not be observed in Adelie Penguins which are more adapted to the presence of sea-ice.

At nearby Signy Island, similar results were obtained during the 1997-2001 period with a mean of over 99% Antarctic Krill by weight in all years and mean stomach contents of 560 g over the whole period, with 640 g in 2001 (Lynnes et al., 2004. Polar Biol. 27, p.544-554). Chinstrap Penguins fed on marginally larger krill than Adelie Penguins at the same site, with both species largely focusing on sexually active female krill. The proportion of sub-adult krill decreased during the period between 1997 and 2000, reflecting the fact that no major krill recruitment event occurred during this period. The resulting low levels of krill biomass in the 2000 breeding season reduced breeding success but did not cause a noticeable shift in diet composition. Krill recruitment events are highest when sea ice is extensive and provides good conditions for spawning and juvenile survival. Large cohorts of krill resulting from major recruitment events shape the overall krill population for periods of about 5 years. Krill biomass increases rapidly as juvenile krill from a large cohort grow. Once the cohort reaches maturity, growth stops and the cohort size and biomass is gradually depleted by mortality. During extended periods of low krill recruitment, biomass levels may fall to levels which have a significant impact on penguin populations.

Further Studies at Signy Isl. in 2002 confirmed the almost exclusive reliance on krill in this region (Takahashi et al. 2003. Mar. Ecol. Progr. Ser. 250, p.279-289). This was independent of whether the penguins were feeding benthically or pelagically.

At Livingston Island in the S. Shetlands during the 2002-2007 breeding seasons, Chinstrap penguin diet was correlated to the interannually fluctuating sizes of the krill (Miller and Trivelpiece 2008. Mar. Biol. 154, p.201-208). When the krill were small, the penguins foraged for longer and at greater depth, with more overnight trips. The proportion of fish in the diet increased but remained relatively small.

At Seal Island, NE of the S. Shetlands, krill also dominated the diet, although it was found that Chinstrap Penguins foraging at night were consuming about 20% by weight of fish (Jansen et al., 1998. Mar. Ecol. Progr. Ser. 165, p.161-172). The fish were 95% of Myctophid species such as Electrona antarctica, E. carlsbergi, Gymnoscopelus nicholsi and Krefftichthys anderssoni. This may be site-specific or could have been overlooked in some previous studies where samples were presumably largely taken from birds returning later in the day. However, an older study from the S. Shetlands reported that in 1980/81, the diet of Chinstrap Penguins consisted of 65% fish with only 17% krill and smaller proportions of amphipods and other prey items. Birds returning in the morning were found to have fed almost entirely on fish (Jablonski 1985. Acta Zool. Cracov 29, p.117-186).

Foraging Behaviour

When Chinstrap Penguins spend time at sea, several activities can be distinguished. In particular, porpoising and underwater swimming can be classified as transiting behaviour, whereas dives to depths below 5 meters are generally classified as relating to foraging. Resting and bathing may also be observed.

Studies at the S. Shetlands in 1984 compared the relative at sea activities of Chinstrap and Gentoo Penguins (Trivelpiece et al. 1986. Auk 103, p.777-781). It was found that Chinstraps spent significantly more time in transit (38% v 22% of time at sea), which is not surprising given that the Gentoo is known to be an inshore feeder. Further, the Chinstrap Penguins were diving less long (91 v. 128 sec) and spent relatively more time at the surface. Porpoising was usually only observed when penguins were leaving or approaching the beach and was often followed by a period of bathing on the outward bound journeys. Most of transit time is spent swimming underwater with brief pauses at the surface between each swimming dive. Average transit speeds of about 4.8 km/h were measured, which means that taking the brief pauses into account, swimming speeds were nearly 6km/h. Penguins without attached loggers are likely to be slightly faster. No long pauses are made on return trips as parents return rapidly to provision their chicks.

Several studies have examined Chinstrap Penguin diving behaviour at Seal Island (S. Shetlands). In 1988, during foraging, dive depth and duration averaged 31m and 72 sec, respectively, with maximums of 121 m and 180 sec (Bengtson et al. 1993. Antarctic. Sci. 5(1), p.9-15). Diving activity was most intense around midday (10:00-15:00) and dive depth was greatest at this time (mean 45 m), probably since light levels are most intense in this period making prey more clearly visible at greater depths. A second smaller peak was observed around midnight although this was associated with the lowest mean dive depth of around 20 m. Krill migrate to shallower depths at night and could possibly be detected due to their weak bioluminescence. Birds generally focused trips around the day or nighttime peak, with average trip durations of around 11 hours. Individual birds occasionally switched between day and nighttime foraging, often after above average feeding trips on the previous day.

Foraging at day and night were compared in more detail in a subsequent study based on data obtained in 1993-94 during the brood period (Jansen et al., 1998. Mar. Ecol. Progr. Ser. 165, p.161-172). Here it became apparent that diurnal (daytime) feeding was preferred, since when feeding trips were short (presumably due to high prey availability), both parents were able to feed sufficiently during daylight hours and remained at the nest at night. In 1993, 47% of birds performed a single diurnal trip, whilst 41% performed a trip including the nighttime period. However, in 1994, when conditions were less favourable, only 34% of penguins foraged diurnally and 53% overnight (41% overnight only i.e. not extended to include significant daytime foraging). Generally, foraging trips start during daylight hours between 3 and 6 in the morning or 15 and 21 hrs in the evening (for overnight trips). Most overnight trips were performed by birds that had been relieved late at their nests by their partners and were making their first trip of the day, whilst others (less than 10%) had already performed a short early trip or arrived from a trip spanning the previous night, then waited as their mates made a short daytime trip, after which they departed again in the evening for an overnight trip. Birds rarely depart or arrive on land during darkness, possibly since it is dangerous to swim near the coast at night as obstacles such as rocks may be overlooked. Interestingly, the birds foraging at night returned with only slightly lower mean stomach contents in terms of mass to those foraging diurnally, but had a different dietary constitution. Whilst the diurnal foragers had the usual nearly 100% krill in their stomachs, overnight foragers had 19% largely Myctophid fish by weight, most of which was relatively digested and under a layer of fresher krill. The fish has greater energetic value by mass.

Since Chinstrap Penguins are thought to forage further from their colonies during the night, it was suggested that they may be feeding near the edge of the shelf region where Myctophid fish that vertically migrate to shallower depths during the night feed on krill. The penguins evidently feed on these fish for a while, before gradually starting to move back to their colonies, concentrating again on krill in inshore waters where it is presumably most available as prey at dawn and dusk when light levels are conducive to hunting but the krill has not yet largely descended to deeper waters.

Further studies have documented nocturnal diving activity to significant depths. A long-term study covering the 2002-2007 breeding season at Livingston Island (S. Shetlands) revealed diving to depths of up to 110 m at night, although most dives were shallow or in the 40-50 m range (Miller and Trivelpiece 2008. Mar. Biol. 154, p.201-208). Average nocturnal dive depths were most shallow at the middle of the night and this was suggested to result from upward migration of prey. It is possible that the Chinstraps can detect the weak bioluminescence of the Myctophid fish.

Foraging trips may involve a number of distinct dive bouts, where penguins make a series of consecutive dives to the same prey patch. The organization of such bouts was studied at Seal Island in 1987 (Mori 1997. Ethology 15, p.9-15). The first dive of a bout is generally slightly shorter than all subsequent dives and may primarily serve to locate prey. Bouts generally consisted of about 20 dives (single dive bouts are excluded) and foraging trips included about 5-6 bouts, separated by about 30 min. Intervals between dives within a bout are about 1 min, whilst dive durations averaged about 1.6 min and a depth of 35 m during the study. The number of dives (cycles) during the bout was suggested to depend on the efficiency of the cycles which is basically the ratio between how much prey can be caught and amount of energy spent. Hence, the penguin would stop diving at a certain threshold level. Whilst this may be true, physiological factors may also play a role (e.g. full stomach, lactate build-up), since the mean length of inter-bout rest periods would seem unnecessarily long if the bird was in principle ready to dive again immediately after the end of a bout.

No significant inter-bout intervals were detected in a study on brood-phase Chinstrap Penguins at Ardley Island, Antarctic Peninsula (Wilson and Peters 1999. Mar. Ornithol. 27, p.85-95). In this study, not only dive depth was measured but also swim speed and heading. Birds were largely departing the colony early in the morning or in the evening and were found to travel away from the colony on a relatively straight course before they began to meander and occasionally double back as they started to forage. At the end of the trip, birds headed directly back to the colony. The whole trips had a loop-like track and were largely within 20 km of the colony, with a mean trip length of about 10.6 hours. Maximum diving depth was 100 m, although 80% of dives were to 30 m or less.

Birds appeared to dive almost continuously with only the usual brief rest periods but no extended inter-bout rest phases. Swim speed was high, with 2.6, 2.5 and 2.2 m/sec being measured for descent, bottom and ascent phases of foraging dives, respectively. This is faster than the other Pygoscelid penguins and is indeed only clearly surpassed by the Emperor Penguin. The study further once again revealed the ability of the Chinstrap Penguin to forage effectively compared to other Pygoscelid penguins in low light conditions. Peak feeding activity based on a stomach temperature probe was between 6:00 and 9:00 and 14:00 and 22:00, with the daily minimum around midnight. Nevertheless, low-level feeding activity at relatively shallow depths did continue at this time. The Chinstrap Penguin seems to be the only member of the Pygoscelid family capable of hunting in extremely low light levels around 1 lux and maybe below, albeit at a much reduced efficiency in terms of catch per unit effort.

The study also showed that dives to greater depths were performed at a steeper angle to increase vertical speed. The first dive of a bout was generally unusually steep, possibly so it can be very deep if necessary to locate prey, and V-shaped since it involved no significant bottom time. Subsequent dives within a bout had descent / ascent angles optimized for the planned depth and were generally U-shaped. Dives within a bout were generally of a similar depth, sometimes showing a slightly increasing / decreasing depth over time, possibly reflecting movement of the prey patch. When deep dives were performed, distribution of dives within a bout was occasionally bimodal with some dives going to a similar shallow depth.

Studies on Chinstraps foraging close to land at Signy Island in the 2002 breeding season revealed the characteristic series of square-bottomed dives to similar maximum depths (i.e. IDZ Intra-Depth-Zone dives) which are indicative of benthic feeding (Takahashi et al., 2003. Mar. Ecol. Prog. Ser. 250, p.279-289). This has also been observed in several other penguin species. Nearly 60% of dives by birds performing diurnal trips (average length 7.8 hrs) belonged to IDZ series, with the proportion lower in overnight trips when birds spent more time in deeper water. The birds were feeding almost exclusively on krill and seemed to be able to catch more prey when spending a greater proportion of time foraging benthically. It was concluded that the krill was concentrated near the sea floor. This probably also explains the relative lack of depth wiggles at the bottom of the benthic dives. These wiggles, which represent rapid changes in direction in pursuit of prey, may not be necessary if prey concentrations are high.

Recent technological advances allow beak angle in birds to be measured by attached magnetic sensors wired to a logger on the birds backs. This technology has been successfully applied in combination with a depth logging device to a Chinstrap Penguin breeding at Signy Island (Takahashi et al., 2004. Mar. Ornithol. 32, p.47-54). It was found that beak opening correlated strongly in a linear fashion to depth wiggles (i.e. rapid increases / decreases in depth at the bottom of the dive) and also to dive bottom time, suggesting that any of these factors can be taken as an indicator of feeding activity. Beak opening is brief (mean duration 0.13 sec; max. 1.4 sec; 82% of openings less than 0.1 sec) and occurred from 2-150 times per dive with a mean of 53 (data from 93 successful foraging dives). It is assumed that a single "snap" correlates to a single feeding event, so that given the mass of approx. 1 gram of each krill, the birds were obtaining about 50 g of food per successful foraging dive. Beak-opening hardly occurred in shallow dives of less than 5 m, since these are presumably travelling dives. Interestingly, beak-opening occurred more frequently during ascent periods, suggesting that the penguins may be able to locate prey more easily when viewing it from underneath with backlighting and/or that the krill's field of view is more restricted underneath due to the location of its eyes and thus that it is less able to detect and evade a penguin approaching from beneath.

In contrast, studies on Gentoo Penguins using cameras showed krill largely being approached from above (Takahashi et al., 2008. Pol. Biol. 31, p.1291-1294). However, these studies involved birds feeding at the sea floor and thus often unable to approach the prey from beneath.

During the winter season, Chinstrap Penguins disperse from their colonies and spend several months at sea with only sporadic visits to land, if at all. Whilst the diet of wintering Chinstrap Penguins is unknown, the location of 8 birds from the South Shetlands has been followed by satellite telemetry (Trivelpiece et al. 2007. Polar Biol. 30, p.1231-1237). Birds could be distinguished into two distinct groups which either resided in the region of the S. Shetlands or departed on long migratory trips in the direction of the S. Sandwich Islands, over 1300 km to the east. In 2000, the 4 birds remaining at the S. Shetlands foraged mainly over the shelf to the NW of the Islands with a mean distance from their colonies of about 33 km (max. 142 km), whilst in 2004 the 2 birds showing similar behaviour moved further offshore (mean of 121 km (max. 325 km)), presumably as a result of lower inshore food availability. In each year, one bird performed a long eastward trip, possibly heading as far as the major population center on the S. Sandwich Islands.

Chinstrap Penguins at beach Swimming Chinstrap Penguin

Chinstrap Penguins at Shore

Chinstrap Entering Sea


Nest & Partner Selection

Chinstrap Penguins show high fidelity to their natal colonies. In studies on the S. Shetlands, emigration was less than 1% per year even between monitored colonies less than 3 km apart (Hinke et al. 2007. Oecologia 153, p.845-855). Fidelity to nest sites is also high, especially in experienced breeders. Partner fidelity in the Chinstrap fluctuates strongly between seasons as in other penguins, but appears to lie at around 80%, thus being higher than that of the Adelie and lower than that of the Gentoo. Partner changes are often due to death or late arrival of the previous partner. As explained below, bill size and nest size are two factors playing a role in partner selection. General size and health state are probably also critical.

Most colonies are in elevated areas near to the sea and consist of a number of subcolonies containing from as few to 5 up to as many as thousands of individual nests. These subcolonies are separated by nest-free areas. Colonies are generally on elevated ground up to about 100 m above sea level on rocky headlands and foreshores free of vegetation.

Whilst Chinstrap Penguins may share rookeries with Adelie and Gentoo penguins, the actual nesting sites within the rookeries are still largely segregated by species, in part reflecting different nest area preferences. In mixed colonies, Chinstraps were observed to have a greater tendency to occupy sloping nesting sites near to the sea than the other Pygoscelids. Interestingly, Chinstrap and Adelie Penguins also tend to use larger but fewer stones for nest-building than Gentoos (Volkman and Trivelpiece 1981. Wilson Bull. 93(2), p.243-248).

At Deception Island, it was shown that breeding success is higher in the larger subcolonies (Barbosa et al., 1997. Polar Biol. 18, p.410-414). This was attributed to differences in chick mortality during the guard phase. Mortality (loss of eggs or chicks) was 50% higher in the small subcolonies and was probably caused by increased predation by Skuas. This may however not always be the case, since nests in the smaller subcolonies were found to be larger and may thus confer advantages when weather conditions are poor. The study revealed no significant difference in breeding success between central and peripheral nests within the individual subcolonies. Generally, it is however considered that central nesting positions are favourable. In fact, central nests are generally occupied by more aggressive males with larger beaks which were shown to be preferred by females (Barbosa et al., 1997. J. Morphol. 232(3), p.232). Nests occupied by these penguins also tended to be larger. Nest size may play a role in partner selection although beak size may be a more crucial direct selection criterium, since females were also found to have larger beaks in the center of the colony, in spite of the fact that the male is responsible for nest size until a pair has been established (Minguez et al., 2001. Waterbirds 24(1), p.34-38).

Chinstrap Penguin colony Hannah Point Chinstrap Penguin colony Hannah Point

Hannah Point (Antarctic Peninsula ) Chinstrap Colonies

Chinstrap Colony at Hannah Point

Chinstrap Penguin colony Bailly Head Deception Island Chinstrap Penguin Colony Deception Island

Bailly Head Chinstrap Colonies - Deception Island

Chinstrap Colony on Cliff-Top - Deception Island

Nests are usually spaced about 50 cm apart in Chinstrap penguins, compared to only about 37 cm in Adelies (Trivelpiece and Volkman 1979. Auk 96, p.675-681). Gentoo nests are the most widely spaced amongst the Pygoscelid penguins. The nests are usually constructed from a pile of stones placed over a small scrape in the ground. Nest size is one important determinant of breeding success. Nest size and maintenance thereof by stone-collection has been studied in some detail. It has been suggested by various authors that stone gathering behaviour during incubation and chick-rearing may play a role in pair-bonding or in maintaining nest size above a critical level needed to protect nest contents. During this period, birds may spend several hours gathering stones after they have been relieved at the nest by their partners. Stones are obtained by collection around the nest-site, but largely by theft from nearby nests. Male birds are both more adept at defending their nests and at stealing from their neighbours (Moreno et al., 1995. Polar Biol. 15(8), p.533-540). In small subcolonies, more stones are available both within and around the colony. This accounts for the larger nests and reduced level of stone theft compared to in larger colonies. In large colonies, stones may often only be obtainable by theft and larger stones are focused on (Carrascal et al., 1995. Polar Biol. 15(8), p.541-545). Theft is however only resorted to if necessary, since when stones were artificially made available to birds in the larger colonies these were eagerly collected and levels of theft dropped.

Studies at Deception Island investigated the response of nesting birds to nest manipulation (Fargallo et al., 2001. Behav. Ecol. Sociobiol. 50, p.141-150). Pre-manipulation nest weights ranged from 3-16 kg with an average of about 8 kg. Nests were artificially reduced in size by removing stones, or were reduced in size and surrounded by snow to simulate poor weather conditions. In both cases, stone-gathering behaviour intensified, yet the effect was much more significant for those nests around which snow had been placed. These nests were rapidly built up to above pre-manipulation levels, suggesting that the birds were responding to a perceived risk of flooding by melt-water by increasing the sizes of their nests. Certainly, it was evident that stone-gathering was adapted to nest condition and environmental conditions, rather then being a mere display performed at constant levels during the breeding period to maintain the pair bond. The study also showed that birds that invested most time in stone-gathering had lower haematocrit levels, suggesting poorer condition as energy was consumed in the process and less time was available for foraging.

The importance of nest size to reduce the risk of egg / chick loss has been directly observed in a previous study (Moreno et al., 1995. Polar Biol. 15(8), p.533-540). Here, 14% of eggs/hatchlings were lost due to flooding following a snow-storm, and the smaller nests were much more severely affected. Once chicks are thermoemancipated, flooding appears to present little risk to them and stone-gathering behaviour of parents rapidly declines at this stage from a peak around chick hatching time.

Penguins at the nest always defecate outwards in apparently relatively random directions. This serves to keep the nest clean. Studies on Chinstrap and Adelie Penguins suggest that the faeces in propelled away with pressures of up to about 60 kPa (450mm Hg) with the highest pressure being achieved at the beginning of the process (Meyer-Rochow and Gal 2003. Polar Biol. 27, p.56-58). This is about 5-fold higher than in humans.

Chinstrap Penguin picking up stone Chinstrap Penguin holding twig Chinstrap Penguin building nest

Collecting Rocks for Nest

Moving Old Feather Shaft on Nest

Placing Rock into Nest Bowl

Chinstrap Penguin looking for pebble

Seeking Gift (Stone) For Mate

Chinstrap Penguins have been observed ejecting nesting Adelie Penguins from their nests in mixed colonies. This behaviour has been investigated at Deception Island. In some parts of the colony, over 50% of nests occupied by Adelies were taken over by Chinstrap Penguins (Trivelpiece and Volkman 1979. Auk 96, p.675-681). When the Chinstraps returned to their colonies to breed (about 25 days later than the Adelies), male Adelie penguins were generally on the nest incubating recently laid eggs. The Chinstraps pecked at the heads of the resident Adelies and beat them with their flippers until they left the nest. Several attempts to regain the nest were observed but these were generally unsuccessful. The eggs were usually lost as a result, although one example of an Adelie chick raised by Chinstrap parents was reported.

A subsequent study found that in most cases, the ejected birds were inexperienced Adelie penguins that had nested at sites occupied the previous year by Chinstrap Penguins. These inexperienced Adelies had also lost weight as they had been fasting for several weeks and were thus nearly a kg lighter than the arriving Chinstraps that wanted to reoccupy their nests (Trivelpiece et al., 1984. Auk 101(4), p.882-884). The lower experience and weight probably account for the inability of the Adelies to defend their nests.

Timing of Breeding

Chinstrap penguins only make a single breeding attempt each year, taking advantage of the short antarctic summer. Chinstrap penguins return to their breeding sites in November, with exact dates varying between location and year. Males usually return about 5 days earlier than females in order to (re)claim and maintain a nest. Once the females arrive, a short period of courtship is followed by establishment of a pair bond and shortly afterwards copulation. Eggs start to be laid over an about 2 week period in December with peaks around the 7th on Laurie Island (S. Orkneys) in 1997 or on the 22nd on Deception (S. Shetlands) in 1995 (De Leon et al., 2001. Polar Biol. 24, p.338-342; Belliure et al., 1999. Polar Biol. 21, p.80-83). Generally, it appears that within a given population individual birds lay at a similar date within the range from year to year, i.e. early breeders consistently breed early (Vinuela et al., 1996. J. Zool. 240, p.51-58).

Laying and Incubation

Chinstrap Penguins generally lay two eggs of relatively similar size. These eggs can be genetically identified as belonging to the nesting parents, showing that the penguins are both socially and sexually monogamous (Moreno et al., 2000. J. Avian Biol. 31(4), p.580-583).

Taking studies at Laurie Island as an example, these eggs are generally laid over a period of about 3.3 days (from 2-5). Brood patch temperature is already high, averaging 37'C when the first egg is laid and reaching over 38'C by the middle of the incubation period, although the patch is small at the onset of incubation (De Leon et al., 2001. Polar Biol. 24, p.338-342). Egg temperature is slightly lower. Eggs have an approx. volume of 90 cubic cm and are about 6.7 cm long. In about 95% of cases, the first laid egg hatched first. Laying intervals and the degree of hatching asymmetry could not be correlated, but size asymmetry of the eggs within a clutch could be correlated to hatching asymmetry, suggesting that egg size is a significant determinant of incubation period length, possibly in part due to greater temperature fluctuation in small eggs during incubation. Female condition could not be correlated to laying intervals, although it appeared to correlate to clutch asymmetry.

Incubation periods may be from as short as 31 up to 40 days. The second egg must hatch within 4 days of the first, since thereafter incubation of the remaining egg becomes physically impossible due to the size of the first chick (Fargallo et al., 2006. Behav. Ecol. 17(5), p.772-778).

Evidence for a brood reduction mechanism like in Eudyptid penguins such as the Macaroni Penguin could not be found, although when food is scarce, it was found that it was more likely that the later-hatching starves if the eggs hatch several days apart. This did however not seem to significantly enhance the survival chances of the remaining chick (Moreno et al., 1994. Polar Biol. 14(1), p.21-30).

An extremely detailed study on mortality of chicks depending on hatching order and brood sex compositions was performed at Deception Island (Fargallo et al., 2006. Behav. Ecol. 17(5), p.772-778). Again it was shown that hatching asymmetry could be correlated to size asymmetry of the eggs. Further, it was found that the hatching asymmetry increased when the second egg contained a female embryo. This can be partly accounted for by the fact that the hatching period (time between pipping of the egg by the embryo and emergence of the chick from the egg) averages 1.3 days for males and 1.5 for females. Male chicks are thought to be more muscular due to the effect of yolk testosterone which aids development of the hatching muscle allowing the male embryo to break out of the egg faster. Chicks from larger eggs also hatch faster. The second-hatched chicks were generally subject to higher mortality. Also, male chicks were more likely to survive in mixed sex broods, whilst females were more likely to survive than males when pure female broods were compared to pure male broods. This is probably due to the fact that it is more difficult to provision two male chicks due to their larger size and higher food demands, plus the higher competitive ability of male chicks.

Interestingly, male chicks are generally more frequently found on larger nests (Fargallo et al., 2004. Polar Biol. 27, p.339-343). Large nest size correlates to healthy parents. It is hypothesized that only strong parents can raise healthy male chicks (which require more food than females) able to later effectively compete with other males in a population with a surplus of males due to higher female mortality.

When both chicks survive the first days after hatching, egg size asymmetries could no longer be correlated to respective chick sizes by about 15 days. Interclutch differences were however significant, with those chicks hatching early in the breeding season due to relatively early breeding by the parents growing faster than later-hatching chicks (Belliure et al., 1999. Polar Biol. 21, p.80-83).

Chinstrap Penguin on nest Chinstrap Penguin standing over egg Chinstrap Penguin prone on egg

Incubating Chinstrap Penguin

Standing over Unhatched Egg

Egg Visible under Brood Patch

Incubating chinstrap Penguin preening

Preening on Nest - Note: Egg not under Brood Patch

Incubation Duties / Nest Relief

Chinstrap Penguins alternate in taking care of the clutch with the length of shifts changing at different stages. Behaviour of Chinstrap Penguins at the nest has been observed in detail at Bouvetoya Island (Haftorn 1986. Polar Res. 4 n.s., p.33-45). During incubation, average shifts were 35 hours, with a reduction to about 12 hours during the brood period when chicks require regular meals. As can be seen from the section on foraging, birds may be absent for only a few hours or more than a whole day, depending on food availability. During the incubation period, 92% of time was spent prone on the nest. The rest of the time was taken up standing at the nest or performing various behaviours such as preening. During the early brood, about equal proportions of time were spent prone or standing, with the male spending more time upright than the female. Upon return of the relieving partner, mutual displays were observed and the incubating partner was often relieved within a minute or two. However, on average, nest relief only took place after about 15 min during the early brood. The relieved bird often stayed in attendance of the nest for minutes to hours following relief.

The nest relief ritual, involving the Loud Mutual Display (LMD) and Quiet Mutual Display (QMD) in Chinstrap and Adelie Penguins has been described in detail (Müller-Schwarze and M.-S. 1980. Auk 1997, p.825-831). In the LMD, the birds stand and swing their heads back and forth whilst uttering a cackling noise from their open bills. On the other hand, the QMD also involves similar head swinging but the bills are kept shut and the display is accompanied by a humming sound. Further, the arriving bird may circle the nest nodding its head gently. The resident bird may also leave the nest and circle or circles after relief. Relief was observed on average 3.6 min after arrival, slower than in the other Pygoscelid penguins. The LMD was infrequent (mean 1.38 per nest relief ceremony), whereas the QMD was more frequent (mean 4.88). The LMD was usually the first display and could be instigated by either bird, whilst the QMD was more often instigated by the bird on the nest. The speed of nest relief could however only be correlated to the circling behaviour.

When nest relief is delayed, such as in 1998 at the S. Orkneys when extensive sea-ice restricted access to the sea and inhibited foraging, high levels of nest desertion (52% in the study) during incubation and brood are observed (Rombola et al., 2003. Polar Biol. 26, p.41-48). Nest desertion is the most significant cause of egg / brood mortality in most years since it invariably leads to loss of eggs and chicks due to predation or starvation. In fact, Chinstrap Penguins appear to be poorly adapted to fasting, since they reach the final phase of fasting, when waste products of protein catabolism (e.g. urea) rapidly increase in plasma, more rapidly than other penguins such as the Gentoo (Alonso-Alvarez 2003. Polar Biol. 26, p.14-19). It is thought that a certain level of urea, produced by breakdown of muscular tissue once lipid reserves are exhausted, may be a trigger for abandonment of parental duties.

Chinstraps vigorously defend their nests. Interestingly, once one egg has been removed, the intensity of nest defence is reduced slightly, since the brood has a reduced total reproductive value (Amat et al., 1996. J. Avian Biol. 27(2), p.177-179).

Brood / Guard Phase

Chicks hatch with a protoptyl down which allows efficient heat transfer from parent to the initially poikilothermic chick. This starts to be replaced within days by the mesoptile down which progressively increases in thickness. The increasing thickness, together with metabolic changes, leads to thermoemancipation of the chick by the end of the brood period. Chinstrap chicks have higher metabolic rates than Gentoo chicks, probably due to adaptation to their on average colder environment. By about 10 days the chicks can generate sufficient heat, but only after over 15 days are the completely homeothermic, i.e. the insulating capacity of their down is sufficient to prevent excessive heat dissipation under dry conditions (Taylor 1985. Envir. Physiol. 155(5), p.615-628). The insulation of the chicks down is reduced when wet, although it does remain watertight. After about 15 days, the parents no longer need to brood the chicks but still guard then against predation. This guard phase lasts till chicks reach an age of about 30 days. Chicks are guarded vigorously during the brood / guard phase and nest defence is stronger in comparison to birds defending eggs (Vinuela 1995. Ethol. 99(4), p.323-331), presumably as chicks are considered more valuable.

Chicks have a mass of under 100 g at hatching and, after an initial period of slow absolute growth, rapidly gain weight in a more or less linear fashion, with the rate determined largely by food availability. For example, at Deception Island in 1993/94, chicks reached about 1 kg by 15 days and 3 kg by 32 days (just after the end of the guard phase), after which mass increase stopped. Similar patterns can be observed for flipper and bill growth, the latter however continuing strongly from 32 to 47 days, when the last measurement in the study was taken (Moreno et al., 1998. J. Field Ornithol. 69(2), p.269-275). The study at Deception also addressed the effect of experimental brood reduction on growth of the resulting single chicks compared to two-chick nests. Experimental brood reduction was performed to exclude effects of parental quality, which may be lower in broods that have already lost a chick. Little difference was observed in the size of chicks approaching fledging from reduced broods compared to those from complete broods, although a slight but not statistically significant advantage in terms of mass reached and structural size could be seen. However, near the end of the guard phase (between days 15 and 21), when growth is potentially fastest, single chicks grew significantly faster. Thus at this stage food availability may be limiting.

Parental provisioning behaviour is different when the brood only contains a single chick (Meyer et al., 1997. Polar Biol. 17, p.228-234). At Seal Island (Antarctic Peninsula), parents with 2 chicks were found to spend 15% more time at sea. The duration of foraging trips did not change, but the parents made a larger number of trips and appeared to land with more than 10% higher food loads (reaching 360 g in 1993 and over 600 g in 1994). In the study, chick growth rate in 1 and 2 chick broods was found to be similar in 2 years and higher in 1 chick broods in the other 2 years studied.

Chinstrap Penguin with chicks Chinstrap Penguin brooding chick

Stretching Chinstrap with 2 Chicks

Parent Inspecting Nest While Chick Underneath

Chinstrap Penguin chick pushing head under parent Chinstrap Penguin and chick changing positions on nest

Chick Adopting Preferred "Head-First" Brooding Position

Parent and Chick Changing Position

Chinstrap Penguin with chick Chinstrap Penguin with chick Chinstrap Penguin with chick

Parent and Chick


Chinstrap Penguin with two chicks on nest

2 Chicks Resting by Guarding Parent

Creche Phase

After anything from about 20-40 (usually 30) days, Chinstrap chicks are left unattended as both parents start to forage to meet their own nutritional needs and those of the chicks. The unattended chicks gather in groups (creches) of between a few to several hundred birds. Chicks are usually in the range of 2.5-3 kg when they creche.

The timing of the end of the guard phase is probably determined by the condition of the parents rather than that of the chicks, since chicks that creche late tend to reach larger final sizes (Vinuela et al., 1996. J. Zool. 240(1), p.51-58). It has been shown that high Urea build-up in parental birds can be correlated to a younger creching age for chicks (Penteriani et al., 2003. Polar Biol. 26, p.538-544). Logically, if parental condition is poor (e.g. if food is in short supply), the parents need to both spend more time foraging and have to leave the chicks unguarded earlier to do so. Creching also tends to occur earlier in late-hatching birds, probably because the parents have to reduce the length of the creche period in order to allow themselves sufficient time to forage in preparation for moult (Fledging age is also younger in these birds). However, interestingly, also early-hatching birds were found to creche earlier. These were however found to suffer significant mortality due to aggression from brooding adults. Chicks being raised alone creche significantly older than chicks with a sibling. Raising a single chick has less impact on a parents condition (De Leon 2000. Waterbirds 23(1), p.117-120). The reason that parents leave chicks unattended earlier when their own condition is poor can be explained by the fact that the adult may breed in subsequent seasons and thus has a higher reproductive value than a young chick with an uncertain future. Hence, from a population point of view in a long-lived species like the penguin, it makes more sense for an adult to survive at the expense of a chick than the other way round.

One interesting study suggests that hatching date per se may be the determining factor for creching date rather than parental quality, which has frequently been suggested to correlate to the exact timing of breeding (Moreno et al., 1997. Auk 114(1), p.47-54). One day old chicks were exchanged with 6 day old chicks on other nests and it was still found that the later-hatching chicks creched earlier. Hence, parental quality could not explain differences in creching date according to this study. It should however be noted that parental quality and parental condition are not the same thing, since a parent of essentially good quality will also have a poorer condition as the breeding season progresses and in this study would have to spend additional time raising two sets of chicks from the 1-6 day stage. Further, monitoring immune status, which is one indicator of parental quality, revealed that late breeder and failed breeders had poorer immune status compared to early breeders (Moreno et al., 1998. Oecologia 115, p.312-319). Further, early breeders suffered a decline in health status as the chick-raising period progressed.

The reason for creching remains a subject for debate. Breeding adults regularly attack chicks (apart from their own). In some cases this occurs to avoid interference from unrelated chicks during feeding. However, the majority of aggressive interactions are not related to feeding. It has been suggested that adult aggression towards chicks is a trigger for creching behaviour and may serve to shepherd chicks. A study on about 45 day old chicks at Deception found that aggression did not lead to movement of chicks in any particular direction. Further, passing adults from other subcolonies were involved in aggressive behaviour. These facts were taken to suggest that no shepherding is taking place (De Leon 2002. Polar Biol. 25, p.355-359). However, another study at the same site reached a different conclusion (Penteriani et al., 2003. Polar Biol. 26, p.538-544). Lone chicks were found to move around (about 1.25 m/min), yet chicks in creches were largely static. The movement of the lone chicks was largely induced by adult aggression, which was more frequently directed at lone chicks or those in small groups. Chicks thus aggregated into larger groups when more neighbouring adults were present. Shepherding may thus be an inappropriate term for the adults aggressive behaviour since displacement may not be directional, but aggression may nevertheless ultimately result in creche formation due to increased random movement of chicks until these are in creches.

The aggregation of chicks into larger groups when more adults are present nearby may also be partially explained by a defensive role of the adults (Martin et al., 2006. Behav. Ecol. Sociobiol. 60, p.778-784). In response to a simulated predator attack, a higher density of adults resulted in less rapid and shorter distances of retreat of chicks. Interestingly, younger checks responded less intensely to predator approach, as did healthier chicks. This suggests that younger chicks may not yet be as aware of the risk of predation, and that chicks in poor health condition may sense their greater vulnerability. This higher sensitivity may however simply be due to foregoing increased social harassment by adults or siblings, possibly partly explaining the poor condition.

One of the main reasons generally proposed for creching is the safety-in-numbers hypothesis which suggests that chicks in creches should be less vulnerable to predation. This is based on observations of chicks fleeing into denser aggregations when approached by e.g. Skuas. However, the density of chicks alone did not modify escape responses in the Penteriani et al. study. Since Skuas may examine their potential prey before focusing their attack on a particular chick, the creche may provide little direct protection for a weak chick. However, its chance of being targeted is reduced if it groups together with chicks in even poorer condition. On the other hand, the presence of more adults in the vicinity may be protective. On the S. Shetlands, adult birds have been observed driving giant petrels away from creched chicks (Jansen et al., 2002. Oecologia 131, p.306-318).

Whilst the amount of food provided to chicks gradually increases during the brood phase, chick meals at the end of the guard phase and during the creche phase are relatively constant when krill is abundant. It is considered that at the end of the guard phase parents (of which only one can forage at a time) struggle to meet the chicks needs, and again at the end of the creche phase when both parents can hardly provide enough food for the demanding chicks.

It was long assumed that if both parents can forage during creche, the chicks may be provisioned with twice as much food. This could however not be confirmed in studies on other penguin species. Studies on Chinstraps at Seal Island (South Shetlands) revealed that the adults focused more on more productive diurnal foraging after the end of the guard phase, at the expense of overnight foraging (Jansen et al., 2002. Oecologia 131, p.306-318). The proportion of time at sea increased from guard to post-guard (creche) phase by 17% in parents with one and 21% in parents with 2 chicks. Two-chick parents were generally at sea longer by 7% during guard and 12% during post-guard, this being achieved by increased time at sea overnight and during the day, respectively. Further, parents of two chicks were found to be landing about 10% greater food loads than those of single chicks. The amount of food delivered to single chicks increased linearly, but was higher and constant when two chicks were present. In addition, parents of two chicks performed 11 trips for every 10 of those with a single chick during guard phase, and 12 for every 10 thereafter, as food demands continue to rise.

At Deception Island, during the creche phase, the amount of food brought to land could be correlated to flipper length which was used as a measure of general body size (De Leon et al., 1998. Polar Biol. 19, p.358-360). Mean feed mass of 630 g was determined by stomach lavage of returning adults, with a range of from 300-1000 g. Larger birds tended to land more food, suggesting that where possible adult birds only return to land when their stomachs are full. Interestingly, the smaller females as a whole landed as much food as the males and there was no difference in food landed at a given time between early and late breeders. It should however be noted (see section on feeding) that this mean feed mass is higher than in most other studies, suggesting that Chinstraps are rarely actually limited by stomach size. Feeding is addressed in far more detail in the dedicated section.

Feeding chases can often be observed when parents return to land to feed creche phase chicks. These chases illustrate the relatively high speed with which some penguins can run on land. Several different hypotheses that may account for this form of behaviour have been proposed and assessed (Bustamante et al., 1992. Anim. Behav. 44, p.753-759). These include roles in chick recognition, locomotory training, separation of chicks from unrelated chicks in the creche, separation of siblings to favour feeding of the hungrier or the stronger chick, and avoidance of intense begging which may unsettle the adult or reduce the efficiency of transfer of food. On average, 17 separate feedings were observed per adult visit. When only one chick was present, chases were less frequent and shorter and more chicks were fed within the creche. This is incidentally also observed when one chick is experimentally removed (Moreno et al., 1996. Bird Behav. 11(1), p.31-34). Unrelated chicks are repelled aggressively by parent or own chick and even if the unrelated chicks participated in food chases, they are almost never observed obtaining food. Chasing was observed more frequently after first feedings in about 90% of adults observed. Hence, all these observations make a recognition role seem unlikely. When both chicks were present and participated in a chase, in nearly half of these cases both chicks were still present when feeding began. Hence, separation may also not be the main function.

The data in fact favours a role in the assessment of relative nutritional needs of the chicks. If both chicks are in similar condition, the hungrier chick may be more motivated to chase and thus receives more food. The chick chasing longest was generally observed to obtain more feedings. Further, where one chick is in poor condition, the chase may serve to select against the chick that is unlikely to have a good survival chance, thus increasing the chances of the stronger sibling. This could even be considered as a form of brood reduction mechanism. The separation of chicks observed in many cases may be an additional benefit, since food transfer is more efficient when only one chick is begging and food dropped on the ground as a result of competition is not recovered. Indeed, another study attributed primary importance to the avoidance of harassment of the adult by both chicks during feeding, since it was observed that competition between the chicks slowed the transfer of food. (Moreno et al., 1998. Emu 98(3), p.192-196).

Chinstrap Penguin with chicks Chinstrap Penguin with chick

Chinstrap Parent with 2 Chicks

Parent Taking Chick under its "Wing"

Chinstrap Penguin with chicks Chinstrap Penguin with chicks

Chinstrap Adult with 2 Chicks

Chinstrap Adult with 2 Chicks

Chinstrap Penguin feeding chick Chinstrap Penguin feeding chick Chinstrap Penguin feeding chick

Adult Provisioning Chick

Note: Pinkish Krill Visible in Top of Parents Bill

Adult Provisioning Chick

Chinstrap Penguin feeding chick Fat Chinstrap Penguin chick after feeding Chinstrap Penguin feeding chick

Adult Provisioning Chick

Fat Chinstrap Chick After Feeding

Adult Provisioning Chick

Chinstrap Penguin chick begging Chinstrap Penguin feeding chick

Chick Begging - Fat (Fed) Chick Does Not Compete

Begging Was Successful

Chinstrap Penguin chick Chinstrap Penguin chick funny flipper position Chinstrap Penguin chick

Chinstrap Penguin Chicks in Various Poses

Acoustic Parent-Chick Recognition

During the creche phase, the chicks no longer remain at the nest and tend to gather into groups (creches). Adult-chick recognition now relies at least partially on acoustic signals, especially as the chicks venture further from their nests as the creche phase progresses. Acoustic recognition has been studied in the other two Pygoscelid penguin species, but no detailed studies have been performed on the Chinstrap. It is however likely that the calls are similar to those in the Gentoo or Adelie penguin. Interestingly, in a study performed for an entirely different purpose, one and six day old chicks were exchanged between nests. These chicks were readily fed by the foster parents, suggesting that acoustic recognition is not determined genetically or acquired acoustically through the egg-shell or in the first days after hatching (Moreno et al., 1997. Auk 114(1), p.47-54).

When arriving at the nesting site, Pygoscelid adults call their chicks. The calls are made up of a single series of sound components known as syllables which are relatively evenly spaced in the Gentoo (Jouventin and Aubin 2002. Animal Behav. 64, p.747-757). In this species, recognition is solely based on the harmonic content of the call. The Adelie Penguin call is fundamentally similar. In contrast, Eudyptid penguins (e.g. Macaroni and Rockhopper) have a double vocal signature, where a distinctive pattern of the syllables additionally contributes to recognition. This is in turn less complex than the double vocal signature of the Aptenodytes penguins (i.e. Emperor, King), in which two simultaneous series of harmonically related bands are combined to create distinctive beats due to band interaction. The higher complexity of the call in non-nesting penguin species is accounted for by the fact that the acoustic signal does not only have to distinguish between birds at a particular location (i.e. nest and immediate surroundings) within a colony, but has to be able to discriminate essentially all birds in a colony without a supplementing positional signal.


Once the chicks have developed a waterproof juvenile plumage they are able to enter the sea. The parents continue to feed the chicks for a while before they are left to their own devices. Shortly before Chinstraps fledge, chicks move from the nesting areas towards the sea, often congregating on the beach. Fledging tends to occur in Chinstrap Penguins between about 50 and 65 days of age. This is relatively early compared to other penguins, and is possibly the result of the late start of the Chinstrap breeding season. The chicks are forced to fledge particularly early when conditions are poor or they have hatched late in the season. This is detrimental to their survival. In productive years, chicks tend to fledge weighing 3-4 kg.

Post-fledging mortality is considered to be an important determinant of Pygoscelid population levels. At Deception Island, large numbers of dead chicks are regularly swept onto the beaches shortly after the fledging period (Moreno et al., 1999. J. Evol. Biol. 12(3), p.507-513). These birds were found to have relatively short flippers and were presumably relatively light when they fledged, meaning that their reserves were evidently not sufficient to allow them to survive whilst they started to learn to forage.

Post-Breeding Moult

Little is known in detail about the moult period in Chinstrap Penguins. It is thought that breeding adults spend between 2 and 3 weeks at sea after chicks fledge before returning to moult. The moult occurs in late February / March and is thought to be relatively short (maybe as little as 13 days). It serves to replace the worn plumage with a new one before the penguins head to sea for the long winter foraging season. The moult is energetically highly demanding and severely underweight penguins are unlikely to survive it. At Seal Island (S. Shetlands) in 1990, Chinstraps weighed about 4.1 kg after breeding, 5.1 kg immediately before moult and 2.8 kg post-moult (Croll et al., 2006. J. Zool. 269, p.506-513).

General Behaviour:

As other Penguins, Chinstrap penguins spend significant amounts of time on land preening in order to maintain their plumage and to remove parasites when breeding at more moderate locations.

The preening serves to arrange the feathers and to spread around the oily substance secreted from the uropygial gland at the base of the tail to maintain the water-repellent properties of the down which are necessary for it to exhibit good insulation properties.

Allopreening is not generally observed in Chinstraps or the other Pygoscelid penguins.

Chinstrap Penguin preening Chinstrap Penguin preening Chinstrap Penguin preening




Chinstrap penguins can frequently be observed making donations of stones to their partners even once nest-building is no longer necessary, presumably as a means of maintaining the pair bond. It is possible that this behaviour functionally partially substitutes for the allopreening observed in many other penguins species. Non-breeding Chinstraps can also be observed moving rocks around.

Chinstrap Penguin carrying stone Chinstrap Penguins displaying at nest

Carrying Stone

Mates greeting each other (?)

The most common display observed is the ecstatic display which is performed with the flippers outstretched, in contrast to the same display in the related Gentoo Penguin. The display is accompanied by a loud braying noise. Further, the display is performed more frequently and by both males and females in contrast to in Adelie Penguins.

Chinstrap Penguin ecstatic display Chinstrap Penguin with full lungs during ecstatic display Chinstrap Penguin  ecstatic display

Ecstatic Display

Ecstatic Display - Lungs Filled Pre-Bray

Ecstatic Display

Chinstrap Penguins are considered to be relatively bold compared to the other Pygoscelid penguins. They may charge at an intruder rather than standing their ground like Adelies or fleeing like Gentoos. They have even be observed to attack dogs. Chinstraps have also been reported to jump into open boats at sea and rest there (note: section on Gentoo Penguin shows actual example of Gentoo jumping into boat).

Chinstrap Penguin aggressive interaction Chinstrap Penguins climbing

Aggressive interaction

Rock-climbing Chinstraps


Threats to Chinstrap Penguins include predation, disease and environmental factors that affect e.g. food or nest site availability.

Eggs and young chicks are subject to significant predation by avian predators such as Skuas (Catharacta spp.) or Giant Petrels (Macronectes spp.). Whilst parents attempt to protect them, predators walk or fly around the colony waiting for opportunities to pounce when parents are off-guard. Skuas may also hunt cooperatively. For example, one bird walks around the nest picking at the edge of the nest bowl and making the parent continually swivel around on the nest to keep facing towards it. This persistent harassment may result in nest abandonment or the penguin may become slightly unbalanced during the procedure and expose the egg, at which point the second Skua may pounce on it from behind (Schulz 2004. Notornis 51, p.167). At the beginning of the creche phase, small chicks are particularly vulnerable to avian predation, especially in years where food is scarce and the chicks creche at a lower weight.

Adult Chinstraps, large chicks and juveniles are not usually threatened by avian predators, yet a number of larger predators threaten them at sea such as Orcas and several species of seal. Leopard Seals are major predators of penguins, which may make up a significant proportion of their prey (Ainley et al., 2005. Antarct. Sci. 17, p.335-340). A number of these seals were observed hunting Chinstrap Penguins at Seal Island, S. Shetlands (Hiruki et al., 1999. J. Zool. 249, p.97-109). Predation was highest during the breeding season and peaked between 17:00 and 18:00 hours when high numbers of penguins were returning to their colonies. The seals either lunged at the penguins in the surf or chased them in the open sea. One seal managed to catch a penguin as it walked by on the beach. Leopard Seals may catch as many as 6 penguins per hour, yet their populations are not dense so the overall level of predation is sustainable.

Other seals may also sporadically feed on penguins, and eye-witness accounts exist of Fur Seals (Visser et al., 2008. Aquat. Mam. 34(2), p.193-199) and Crabeater Seals (Todd 1988. Condor 90(1), p.249-250) preying on Chinstrap Penguins. Whilst the hunting of penguins by Fur Seals presently appears sporadic, it appears conceivable that changing environmental conditions could cause a shift in prey preference and result in increasing numbers of penguins falling victim to the huge Fur Seal populations present at some of the more northerly Chinstrap breeding sites.

Large populations of Fur Seals are also likely to negatively affect penguin numbers due to competition for food. For example, at the S. Shetland Islands, penguins, Fur Seals and commercial fisheries all compete for the same limited food source, Antarctic Krill (Croll and Tershy 1998. Pol. Biol. 19, p.365-374). Worsening matters, each is active in similar areas and largely at the same time. The krill fisheries industry is predicted to increase rapidly and needs to be closely monitored. Since compared to the seals and fishing boats the penguins are most restricted in foraging range, it is likely that they will be most affected by krill shortages.

Climate and natural interannual variation are the most significant determinants of overall krill availability. Warmer temperatures correlate to reduced krill availability, since krill are dependent on sea-ice around the antarctic peninsula for successful breeding. Rising temperatures have significantly reduced the average extent of sea-ice in recent decades (Miller and Trivelpiece 2007. Polar Biol. 30, p.1615-1623 and references therein). Interestingly, earlier research had suggested that rising temperatures and reduced winter sea ice cover may have accounted for increasing Chinstrap Penguin populations at many sites between the 1950s and 1990s (Fraser et al., 1992. Polar Biol. 11(8), p.525-531). Also it had been argued that the decline in baleen whale populations had benefited the penguins. However, populations have recently declined at many sites. Whilst breeding performance appears to be relatively steady, it appears that the number of juvenile penguins that have survived till recruitment into the breeding population is declining (Hinke et al. 2007. Oecologia 153, p.845-855). Recruitment levels are highest for populations that fledge a year before mean krill length peaks, yet recently overall krill availability has been lower so an overall downward trend in recruitment is evident, probably due to starvation of birds after fledging. Adult weight and fledging weight could both be correlated to krill abundance at the S. Shetlands in 1990-92 (Croll et al., 2006. J. Zool. 269, p.506-513). Adults did not seem willing or able to compensate for lower krill availability by increased foraging, suggesting that maintaining own condition has priority over enhancing chicks survival chances in poor years. However, other studies show increased foraging effort to compensate for smaller krill (Miller and Trivelpiece 2008. Mar. Biol. 154, p.201-208). Whatever the case, a certain point is reached when krill availability is so poor that even maximal possible foraging activity cannot compensate for shortages.

The Antarctic Peninsula is in fact one of the most rapidly warming regions on Earth with an over 5'C increase in mean winter temperatures over the last 50 years (Ducklow et al., 2007. Phil. Trans. RSL B Biol. Sci. 362, p.67-94). Further, a less rapid yet significant rise in water temperatures has been reported in the coastal waters of the peninsula where sea ice coverage is critical to the whole ecosystem. Hence, the warmer and damper climate of the northern Antarctic Peninsula has been shifting gradually south and replacing the drier continental climate. This results in less sea ice but more snowfall, the latter being a problem at the nesting sites.

The impact of disease and parasites on wild penguin populations has only been subjected to limited study. Since Chinstrap Penguins live in cold regions, the level of ectoparasites is limited, yet even antarctic penguins suffer from parasitic organisms in the gastrointestinal tract such as helminths. Bacterial or viral infections may also sporadically affect colonies.

Pollution is presently negligible in the antarctic, although the risk of oil spills is ever present due to the number of tourist / supply ships passing through the region.

The effect of human disturbance on Chinstrap Penguin populations has not been studied extensively, yet data from other penguin species suggest that whilst penguins may regard humans as potential predators and be unsettled by their presence, this is probably not to the extent that it significantly affects their breeding success. Due to their locations, Chinstrap colonies are essentially only accessible to scientists and supervised tourist groups.

The response of 1-year old Chinstrap Penguins to human approaches has been studied at Deception Island (Martin et al., 2004. Polar Biol. 27, p.775-781). These penguins usually hang around at the edges of the actual nesting areas. It was found that direct and fast approaches by humans were most disturbing and resulted in the penguins fleeing fastest and furthest. However, whilst sometimes fleeing towards the actual nesting areas, they avoided running into the actual colony due to the threat of aggression from nesting adults. Larger penguins could be approached more closely than smaller conspecifics, suggesting that these are more confident in dealing with perceived predatory risks. The stress imposed by human approach should not have a significant direct impact unless the penguins are already weakened by other factors. Nevertheless, it should be reduced where possible by slow and indirect approaches.

Where To See:

Chinstrap Penguins can be easily observed in the wild. Further, a number of Zoo collections include Chinstrap Penguins. The most commonly visited Chinstrap breeding sites are those on or near the Antarctic Peninsula, which has experienced a boom in ship-based tourism in recent years. Chinstrap breeding colonies be seen at a number of landing sites including Hannah Point, Nico Harbour or Bailly Head (Deception Island).

Chinstrap Penguins and ship at Hannah Point Hannah Point Antarctic Peninsula region

Hannah Point, Antarctic Peninsula. Prof. Molchanov in Background

Hannah Point. Home to Chinstrap and Gentoo Penguins

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Chinstrap Penguin Chinstrap Penguin Chinstrap Penguin

Chinstrap Penguin with pair of chicks

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