Penguin Colonies Research Articles

Predicting onset and success of breeding in little penguins Eudyptula minor from ocean temperatures

As is the case for many seabirds, we found that the timing and breeding success of little penguins Eudyptula minor on Phillip Island, southeastern Australia, was associated with sea surface temperature (SST) variation. Using 31 yr of data (1968 to 1998), we examined the correlations be- tween breeding variables and regional SST at different times of the year. The next 9 yr of data (1999 to 2007) were used to test the performance of our statistical predictive models. Egg-laying date, chick mass and the number of chicks fledged per pair were correlated with SST in the first 3 mo of the year prior to breeding, in slightly different ways. SST provided more accurate predictions of mean laying date (53% variance) than of chicks produced per pair (22%) or mean chick mass at fledging (16%). This model predicted an early egg-laying date, higher average chick mass at fledging and a higher number of chicks produced per breeding pair when SSTs in Bass Strait are warmer than average in March. The models presented predict that an increase in SST is likely to lead to a reversal of the trend towards later breeding and suggest improved growth of the colony of little penguins on Phillip Island, at least in the immediate future.

The phylogeography of Adelie penguin faecal flora

The gut of animals changes quickly from a totally sterile environment before birth to a numerous and highly diverse microbial community shortly after birth. However, few studies have examined the source of the bacteria colonizing the gut. We used a genetic based approach to investigate the distribution and acquisition of faecal microbial communities by Adelie penguins, Pygoscelis adeliae, breeding in the Ross Sea region of Antarctica by cloning a portion of the 16S rRNA gene and by automated ribosomal intergenic spacer analysis (ARISA). We hypothesized that bacteria were either acquired from the penguins' neighbours or inherited from their ancestors. Samples were collected from Adelie penguin breeding colonies at the north-western edge of the Ross Sea coast through to the southernmost Adelie penguin colonies on Ross Island. Most of the bacterial sequences we obtained were only distantly homologous with previously published sequences. Bacterial taxa appear to have a restricted distribution as the majority of 16S rRNA clones were isolated from only one or two hosts. Faecal bacterial community similarity was strongly negatively correlated with the genetic distance between hosts suggesting that bacterial communities are inherited. There was little support for a correlation between distance between collection sites and community similarity.

Changes in soil nematode populations indicate an annual life cycle at Cape Hallett, Antarctica

Soil biological studies have suggested that generations of terrestrial nematodes in continental Antarctica may take many years. We sampled soil nematodes at three sites in the Adélie penguin colony at Cape Hallett on four dates in a two month sampling period (16 November 2002–18 January 2003). The size class distribution of over 3500 nematodes, and the occurrence of adults, indicate an annual life cycle of the bacterial-feeding Panagrolaimus davidi and Plectus murrayi , at each site. Nematode abundance ranged from 2 to 1375/g dry soil. Moderate temperatures and the regular presence of free water underlie this biological activity and related contribution to soil processes.

Relating Demographic Performance to Breeding-Site Location in the King Penguin

Abstract. In colonial species, it is often assumed that locations in the center of the colony are of highest quality and provide highest breeding success. We tested this prediction, known as the “central-periphery model,” in a King Penguin colony in the subantarctic Crozet Archipelago. Breeding activity and survival of 150 penguins, ftted with transponder tags, were monitored over an entire breeding season. Among these 150 bird s, 50 bred on t he slope at the upper periphery of the colony, where the rates of predation and parasitism by ticks were high. fifty birds bred in the center of the colony, where rates of predation and tick parasitism were low, and 50 bred at the lower end of the colony, where the rate of tick parasitism was low but predation and fooding were important risks. We predicted that the center of the colony should provide the safest breeding place and consequently be characterized by the highest breeding success and be used by the highest-quality individuals. Yet we found that penguins b...

Greenhouse gas emissions from penguin guanos and ornithogenic soils in coastal Antarctica: Effects of freezing–thawing cycles

In coastal Antarctica, freezing and thawing influence many physical, chemical and biological processes for ice-free tundra ecosystems, including the production of greenhouse gases (GHGs). In this study, penguin guanos and ornithogenic soil cores were collected from four penguin colonies and one seal colony in coastal Antarctica, and experimentally subjected to three freezing–thawing cycles (FTCs) under ambient air and under N 2. We investigated the effects of FTCs on the emissions of three GHGs including nitrous oxide (N 2O), carbon dioxide (CO 2) and methane (CH 4). The GHG emission rates were extremely low in frozen penguin guanos or ornithogenic soils. However, there was a fast increase in the emission rates of three GHGs following thawing. During FTCs, cumulative N 2O emissions from ornithogenic soils were greatly higher than those from penguin guanos under ambient air or under N 2. The highest N 2O cumulative emission of 138.24 μg N 2O–N kg −1 was observed from seal colony soils. Cumulative CO 2 and CH 4 emissions from penguin guanos were one to three orders of magnitude higher than those from ornithogenic soils. The highest cumulative CO 2 (433.0 mgCO 2–C kg −1) and CH 4 (2.9 mgCH 4–C kg −1) emissions occurred in emperor penguin guanos. Penguin guano was a stronger emitter for CH 4 and CO 2 while ornithogenic soil was a stronger emitter for N 2O during FTCs. CO 2 and CH 4 fluxes had a correlation with total organic carbon (TOC) and soil/guano moisture (M c) in penguin guanos and ornithogenic soils. The specific CO 2–C production rate (CO 2–C/TOC) indicated that the bioavailability of TOC was markedly larger in penguin guanos than in ornithogenic soils during FTCs. This study showed that FTC-released organic C and N from sea animal excreta may play a significant role in FTC-related GHG emissions, which may account for a large proportion of annual fluxes from tundra ecosystems in coastal Antarctica.

Population Trend and Breeding Biology of Gentoo Penguin in Martillo Island, Tierra Del Fuego, Argentina

Abstract Data on population size and some aspects of the breeding biology of Gentoo Penguins (Pygocelis papua) have been studied as part of a long-term monitoring program at Martillo Island in the Beagle Channel, Tierra del Fuego. The colony of Gentoo Penguin on Martillo Island is the only one reported in Argentina and has been monitored regularly since 2000. Timing and hatching success were similar to those reported at other colonies in the South Atlantic Ocean/Antarctic Peninsula region. A maximum of twelve nests were recorded during the 2006/2007 season, with an average breeding success of 1.0 chicks/nest. The Gentoo Penguin colony at Martillo Island increased by 19% in the past 13 y, while other colonies in the south Atlantic region and the Antarctic Peninsula have been decreasing or stable.

Penguin occupation in the Vestfold Hills

AbstractDuring CHINARE-22 (December 2005–March 2006), we investigated six penguin colonies in the Vestfold Hills, East Antarctica, and collected several penguin ornithogenic sediment cores, samples of fresh guano and modern penguin bone and feather. We selected seven penguin bones and feathers and six sediments from the longest sediment core and performed AMS14C dating. The results indicate that penguins occupied the Vestfold Hills as early as 8500 calibrated years before present (cal. yrbp), following local deglaciation and the formation of the ice free area. This is the first report on the Holocene history of penguins in the Vestfold Hills. As in other areas of Antarctica, penguins occupied this area as soon as local ice retreated and the ice free area formed, and they are very sensitive to climatic and environmental changes. This work provides the foundation for understanding the history of penguins occupation in Vestfold Hills, East Antarctica.

Stable isotope natural abundance of nitrous oxide emitted from Antarctic tundra soils: effects of sea animal excrement depositions

Nitrous oxide (N2O), a greenhouse gas, is mainly emitted from soils during the nitrification and denitrification processes. N2O stable isotope investigations can help to characterize the N2O sources and N2O production mechanisms. N2O isotope measurements have been conducted for different types of global terrestrial ecosystems. However, no isotopic data of N2O emitted from Antarctic tundra ecosystems have been reported although the coastal ice-free tundra around Antarctic continent is the largest sea animal colony on the global scale. Here, we report for the first time stable isotope composition of N2O emitted from Antarctic sea animal colonies (including penguin, seal and skua colonies) and normal tundra soils using in situ field observations and laboratory incubations, and we have analyzed the effects of sea animal excrement depositions on stable isotope natural abundance of N2O. For all the field sites, the soil-emitted N2O was 15N- and 18O-depleted compared with N2O in local ambient air. The mean delta values of the soil-emitted N2O were delta15N = -13.5 +/- 3.2 per thousand and delta18O = 26.2 +/- 1.4 per thousand for the penguin colony, delta15N = -11.5 +/- 5.1 per thousand and delta18O = 26.4 +/- 3.5 per thousand for the skua colony and delta15N = -18.9 +/- 0.7 per thousand and delta18O = 28.8 +/- 1.3 per thousand for the seal colony. In the soil incubations, the isotopic composition of N2O was measured under N2 and under ambient air conditions. The soils incubated under the ambient air emitted very little N2O (2.93 microg N2O--N kg(-1)). Under N2 conditions, much more N2O was formed (9.74 microg N2O--N kg(-1)), and the mean delta15N and delta18O values of N2O were -19.1 +/- 8.0 per thousand and 21.3 +/- 4.3 per thousand, respectively, from penguin colony soils, and -17.0 +/- 4.2 per thousand and 20.6 +/- 3.5 per thousand, respectively, from seal colony soils. The data from in situ field observations and laboratory experiments point to denitrification as the predominant N2O source from Antarctic sea animal colonies.

Impact of the Treasure oil spill on African penguins Spheniscus demersus at Dassen Island: case study of a rescue operation

The bulk ore carrier MV Treasure sank between Robben and Dassen islands off western South Africa in June 2000. Although releasing less oil than the Apollo Sea spill six years earlier, the number of African penguins Spheniscus demersus oiled (approximately 19 000) in the Treasure spill was almost double the number oiled in the Apollo Sea incident. The majority of oiled penguins was collected from Robben Island. The capture, stabilisation and transport of oiled penguins following the Treasure spill were substantially more successful than during the Apollo Sea rescue operation and resulted in an increase in the percentage of oiled penguins that were released back to the wild. In addition to the 19 000 oiled penguins that were caught, 19 500 un-oiled birds (12 345 from Dassen Island) were evacuated to Cape Recife, 800 km to the east, to prevent them from becoming contaminated. The evacuated birds returned rapidly to Dassen Island and many resumed breeding soon after their return. The restoration success (proportion of birds observed at Dassen Island that were recorded breeding) was substantially greater for evacuated birds than for de-oiled birds. Lightly oiled birds that were released without being cleaned had lower survival rates and were less successfully restored into the breeding population than de-oiled birds, especially if more than 5% of their body was covered in oil. Reproduction exerted a greater cost to de-oiled birds than to evacuated birds. A total of 1 787 orphaned chicks was hand-reared at two separate facilities on the mainland and were released at Robben and Dassen islands. The chicks did not necessarily return to the colony at which they were released. The survival rates and restoration success of chicks reared at the two facilities differed, probably as a result of one group being overfed. Despite the death of about 2 000 African penguins in the Treasure spill, and the substantial disturbance that resulted from the rescue operation, the penguin colonies at Robben and Dassen islands increased by 18% and 26% respectively in the year following the spill. This increase was attributed to a significant increase in the biomass of anchovy Engraulis encrasicolus and sardine Sardinops sagax in 2001. These findings highlight the importance of preventing oil spills in the first place, and in the event of a large oil spill, the conservation value of evacuating un-oiled penguins to minimise their risk of becoming contaminated.

Evidence for gene flow differs from observed dispersal patterns in the Humboldt penguin, Spheniscus humboldti

The Humboldt penguin, once common throughout its range, is today listed as Vulnerable by the IUCN. Mark-recapture and telemetry studies indicate that adult Humboldt penguins are sedentary, suggesting strong genetic differentiation between colonies. We developed genotypes for 336 individuals at 12 microsatellite loci sampled at four different localities spanning the entire range of this species. Results show that long-term gene flow has occurred but appears to be affected by geographic distance as pairwise F ST comparisons involving the colony at Punta San Juan (Peru) and the two colonies at Algarrobo (central Chile) and Puñihuil (southern Chile) are significant. Bayesian estimates of recent migration rates indicate substantial dispersal among all colonies. Despite the dramatic decline in numbers, we did not observe a bottleneck in any population. Furthermore, we did not detect a founder effect in the recently discovered colony at Puñihuil. As our indirect estimates signal strong gene flow between populations, we suggest that Humboldt penguin colonies need to be managed as a metapopulation rather than as discrete management units.

Satellite tracking reveals distinct movement patterns for Type B and Type C killer whales in the southern Ross Sea, Antarctica

During January/February 2006, we satellite-tracked two different ecotypes of killer whales (Orcinus orca) in McMurdo Sound, Ross Sea, Antarctica, using surface-mounted tags attached with sub-dermal darts. A single Type B whale (pinniped prey specialist), tracked for 27 days, traveled an average net distance of 56.8 ± 32.8 km day−1, a maximum of 114 km day−1, and covered an estimated area of 49,351 km2. It spent several days near two large emperor penguin (Aptenodytes forsteri) colonies, a potential prey item for this form. By contrast, four Type C killer whales (fish prey specialists) tracked for 7–65 days, traveled an average net distance of 20 ± 8.3 km day−1, a maximum of 56 net km day−1, and covered an estimated area of only 5,223 km2. These movement patterns are consistent with those of killer whale ecotypes in the eastern North Pacific where mammal-eating ‘transients’ travel widely and are less predictable in their movements, and fish-eating ‘residents’ have a more localized distribution and more predictable occurrence, at least during the summer months.

Population trends of Adélie penguin (Pygoscelis adeliae) breeding colonies: a spatial analysis of the effects of snow accumulation and human activities

Many of the Adelie penguin colonies used for long-term demographic studies are located near research stations, and there is a need to disentangle the effects of human activities and environmental variability on Adelie penguin population trends. This study used Geographic Information Systems and decision trees to examine whether potential changes in snow cover and/or proximity to human activities were able to explain the varying population trends of colonies at two breeding localities near Casey, East Antarctica. At the less visited site, Whitney Pt, wind exposure and snow accumulation correctly predicted the broad trends of colonies in most (84%) instances, whereas at Shirley I their predictive accuracy fell to 58%. At Shirley I, proximity to human activity correctly predicted the broad trends for 84% of colonies. While snow accumulation patterns are a primary driver of variation in population trends among colonies, the effect of snow accumulation is outweighed by proximity to human activities near Casey.

Nitrous oxide emissions from sea animal colonies in the maritime Antarctic

Little is known about nitrous oxide (N2O) emissions from wild animal colonies. N2O fluxes were measured from a penguin colony on Ardley Island, a seal and skua colony on Fildes Peninsula in the maritime Antarctic using a static chamber technique. Mean fluxes from penguin, skua and seal colonies were 856, 132 and 189 μg N2O‐N m−2 h−1, respectively. The deposition of sea animal excreta controls spatial variations of N2O fluxes from the colonies. The highest fluxes (2559, 2836 and 2081 μg N2O‐N m−2 h−1 for penguin puddles, seal wallows and skua puddles, respectively) occurred during the freezing‐thawing period. Laboratory experiments showed that the freezing‐thawing cycle induced a flush of N2O from the soils sampled from the colonies and denitrification was the predominant process for the N2O source. We proposed that sea animal colonies represent the strong point sources of N2O in the maritime Antarctic.

Giant PetrelsMacronectesHunting Northern Rockhopper PenguinsEudyptes moseleyiat Sea

Adult penguins eaten at sea form a large proportion of the diet of giant petrels Macronectes spp. It is widely assumed that they are scavenged after being killed or injured by more agile predators such as fur seals Arctocephalus spp. We observed non-breeding Northern Giant Petrels M. halli hunting and killing Northern Rockhopper Penguins Eudyptes moseleyi offshore from a penguin colony on Nightingale Island, Tristan da Cunha. Penguins were killed at an average rate of 0.4 h-1 spent hunting by petrels. The most successful technique was a stabbing vertical lunge as a penguin surfaced or swam close to the surface near a petrel, but some were caught when a petrel dropped onto a group of penguins from the air, or when penguins fell back into the sea after attempting to land. Petrels also tried to sneak up on penguins resting on the surface by swimming towards them while lying flat on the water, but none of these ‘stealth’ attacks was successful. Penguins killed were grasped by the hind-neck and held underwater...

Population size, breeding success and provenance of a mainland colony of Little Penguins (Eudyptula minor)

Although most Little Penguins (Eudyptula minor) breed on offshore islands, several small colonies occur on the mainlands of New Zealand and Australia, including mainland Tasmania. Unlike island colonies, most mainland colonies have declined over recent decades, several having gone extinct. A mainland colony of Little Penguins in North Harbour, Sydney, Australia, was monitored over three consecutive breeding seasons (2002–03 to 2004–05). The number of known nesting pairs was 49–56 per annum. The mean number of eggs laid per pair (2.45), eggs hatched per pair (1.84), fledglings produced per pair (1.71), hatching success (0.72) and breeding success (0.70) were among the highest reported from Australian colonies. Underlying these figures was a particularly high proportion of pairs that double-brooded (14–31% per annum, mean 24%). Fledging mass as a percentage of mean adult mass (103%) was also high. Together, these results suggest that food at the North Harbour colony was abundant during the period of study. Fledglings first returned to the colony at 1–4 years of age and first bred at 2–4 years of age. The recruitment rate of fledglings produced at the North Harbour colony was up to 15%, much higher than that recorded elsewhere. Banding recoveries (1997–2005) show that the North Harbour colony contains a substantial number of immigrants that have come from as far afield as Phillip Island, 761 km south of Sydney. Individuals banded at North Harbour have been recovered as far away as Sydenham Inlet, Victoria, 485 km to the south. The mixed provenance of the North Harbour population demonstrates that it is not isolated, either demographically or genetically, from other colonies in south-eastern Australia.

Dominance in feeding territories relates to foraging success and offspring growth in brown skuas Catharacta antarctica lonnbergi

Territoriality should lead to strict dominance, as territory holders typically control access to resources and exclude others from their use. In feeding territories, dominance should be reflected in foraging success and ultimately in reproduction differences; however, these successive links have rarely been made explicit. Therefore, we investigated a population of brown skuas Catharacta antarctica lonnbergi, in which only part of the breeding population occupied feeding territories within penguin colonies. We identified the dominance hierarchy and determined the foraging success of the participants in fights for access to penguin carcasses within the territories. Furthermore, we monitored offspring growth from parents with and without feeding territories. Our results indicated a clear dominance hierarchy with territorial birds in their own territory dominating over territorial breeders from other territories, non-territorial breeders and non-breeding birds. However, territory owners could not completely exclude others from access to food. Foraging success was positively related to dominance scores: The dominant territory owners received 63% of a carcass, whereas non-territorial pairs could get less than 10%. The link between foraging success and offspring development was less clear: Although male chicks of non-territorial parents suffered from lower growth rates and, thus, delayed fledging, there were no such differences in female chicks. Territoriality in skuas did not imply a complete occupation of food, but guaranteed optimal growth conditions for offspring. Non-territorial individuals were forced to search for alternative resources, and the restricted access to the preferred food resulted in inferior conditions for offspring development, making this foraging strategy less rewarding.

Многолетние изменения в популяциях птиц в районе Украинской антарктической станции Академик Вернадский

Quantitative distribution of penguins and other mass species of birds and also features of their behavior and reproduction were studied. Obtained data were compared with results of the previous researches that have allowed to observe tendencies of long-term variability of number in colonies of penguins and in populations of other birds. It was found that in comparison with 70s of the last century on islands Petermann, Pléneau and Booth the quantity of nests of the subantarctic gentoo penguin has increased in 3-4 times, and since 1997 to 2005 it has increased approximately in 2 times. Besides, the natural habitat of this species extends southward and the new most southern colony of gentoo was found on small islands near Moot Point, whereas the large penguins that perhaps belong to the northern subspecies of the gentoo were marked on Pléneau Island. Number of nests of the Antarctic penguin Adeli on islands Petermann, Booth and Yalour has decreased approximately in 2 times from 1993 to 2005. Last years the reduction of numbers of the blue-eyed shag and some other species of birds in the region of the Ukrainian station was marked. The reasons of the changes occuring in colonies of penguins are discussed.

Krill (Euphausia superba) abundance and Adélie penguin (Pygoscelis adeliae) breeding performance in the waters off the Béchervaise Island colony, East Antarctica in 2 years with contrasting ecological conditions

Abstract In 2001 and 2003 small-scale acoustic surveys of Antarctic krill (Euphausia superba) distribution and abundance were conducted offshore from an East Antarctic colony of Adelie penguins on Bechervaise Island (67°35′S, 62°49′E) that has been monitored for 15 years. Although the distribution of krill was similar between the two summers, their abundance in 2001 was estimated to be 3 times higher than in 2003. This biomass difference was reflected in the breeding performance of the penguins at the monitored colony. Significant differences were observed between the two seasons in foraging trip duration during chick rearing, breeding success, meal mass and dietary composition. Penguins travelled further to forage in 2003 than 2001, stayed away longer and brought back smaller meals. Fish (mostly Pleuragramma antarcticum) contributed significantly to the diet in 2003 but were only a minor component in 2001. Differences between years were particularly apparent during the late guard to early creche stages of chick rearing, coinciding with the timing of the krill survey. Chick mortality peaked during this period also. Krill demographics showed little difference between the 2 years. Oceanographically, the two summers differed; in 2003 the mixed layer was fresher and shallower, indicating a delayed melting of sea-ice in the study area when compared to 2001. Satellite observations indicated that the pack-ice directly offshore from the Mawson coast broke out earlier in 2001 and the perennial fast-ice along the coast persisted later in 2003.

The initial journey of juvenile emperor penguins

1. The first major journey of emperor penguins, among several in their lifetime, is the juveniles' dispersal from their natal colony on a trip that takes them beyond Antarctic waters. The route taken by fledglings from Cape Washington (74.5° S; 165.4° E) was studied by applying satellite transmitters to ten individuals during December 1994–1996. In January 2001 transmitters with longer transmission capacity were also applied to six hand-fed fledglings, which had been held captive for one month while attaining a body mass exceeding that of wild birds. These post-captive birds were released at the ice edge of McMurdo Sound (77.5° S; 165.0° E), which is in the vicinity of other emperor penguin colonies, and 320 km south of their natal colony of Cape Washington. 2. Independent of their parents, the wild birds travelled north-east for the next two months, reaching locations as low as 57° S. The post-captive birds travelled north also, but their trek reached only to about 63° S before they turned south, or remained near their most northerly position from March through May. 3. It was concluded that among colonies in the southern Ross Sea: (a) most healthy fledglings survive at least the first two months at sea, feeding themselves as they go; (b) the Cape Washington fledglings travelled as far north as 57° S, and much of this journey was in ice free waters; (c) by April, the post-captive birds reached at least as far as the large-scale pack ice edge and possibly beyond the edge at 63° S; (d) by early March the trend north ends, and by about late March the birds travel to, or remain near the northern ice edge. 4. The reason the birds travel so far north remains a mystery. Copyright © 2008 John Wiley & Sons, Ltd.

Avian predation at a Southern Rockhopper Penguin colony on Staten Island, Argentina

We studied predation risk in relation to nest location and subcolony size in Southern Rockhopper Penguins (Eudyptes chrysocome chrysocome) during the chick-rearing period. Striated Caracaras (Phalcoboenus australis), the main predator, preferentially attacked from tussock grasses which are found in the periphery of all subcolonies (peripheral tussocks) and often scattered within them (central tussocks). The greatest numbers of predation and attempted predation events were observed on nests in the periphery of the subcolony next to peripheral tussocks, and on those nests next to central tussocks. Central tussocks offer Striated Caracaras an additional “edge” area from which to prey, much in the same way as do the peripheral tussocks. Predation rate per individual was not correlated with subcolony size possibly due to the presence of central tussocks which, by creating an extra edge area, change the subcolony shape. There is a suggestion (P = 0.06) of increased probability of nest success with subcolony size.