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Modelling marine predator foraging habitats is a widespread research approach for projecting species responses to a rapidly changing Southern Ocean. Yet a key remaining challenge is to understand how changing prey biomass within foraging habitats could affect predator foraging success. Quantifying this using observed prey information is challenging given a paucity of synoptic data. Here, we investigated whether prey biomass from a mechanistic model, could provide useful predictions of pre-breeding arrival body mass of macaroni penguins (Eudyptes chrysolophus) from Marion Island, a standard metric of predator foraging success, measured over a 20-year period. In testing this, we used a spatially iterative correlation approach between predicted prey biomass and observed penguin arrival body mass, allowing likely foraging areas to emerge in regions most frequently associated with significant correlations. We then considered whether the distribution of these emergent foraging areas is consistent with tracking-derived foraging distributions for this species and island. Our results indicated emergent foraging areas where prey biomass was most often correlated with arrival body mass were located within expected and observed foraging ranges. Further, variability in prey biomass, within these emergent foraging areas provided reasonable predictions of annual penguin arrival body mass and outperformed metrics of primary production within these foraging areas. Our findings demonstrate that mechanistic models can provide biologically meaningful representations of difficult-to-observe prey, and can predict predator foraging success. This work could improve understanding of predator responses in a changing habitat.

Dietary studies of marine predators offer an immediate signal of foodweb changes occurring at lower trophic levels, and therefore are often used to assess the ecosystem status of marine systems. Conventionally, these studies are based on morphological analysis of prey remains in stomach contents, involving invasive and destructive techniques to collect samples. More recently, the number of dietary studies based on less invasive biochemical and molecular approaches has dramatically increased. However, all three methods, morphological, biochemical and molecular, have well-documented limitations for resolving taxonomy, temporal variation or biomass composition. In this study, we minimise these limitations by considering multiple techniques in combination. As a case study, we report the target prey species and diet composition of a marine predator that has been used to assess annual change in managed fishing areas for several decades, the macaroni penguin Eudyptes chrysolophus . We use biochemical (stable isotope) and molecular (DNA) analysis of faecal samples collected across the different phases of a single breeding season, and compare the resolved diet to a 26-year dataset of stomach contents collected from a closely located colony (0.25 km apart) that exploits identical foraging grounds. Molecular analysis increased the known target prey species for this highly monitored population by 31%, including a fish species of commercial importance. Biochemical analysis detected subtle changes in the proportion of fish and krill in the diet, demonstrating promising opportunities for using a combined molecular and biochemical method to assess inter-annual foodweb changes at lower trophic levels. The combined approach offers a less invasive sampling methodology, compared to morphological analysis, and provides more information regarding prey species diversity and the overall trophic signature of the diet. Further studies are required to examine the feasibility of using this approach for long-term dietary studies of different marine predator species. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms that link prey availability to predator behaviour and population change is central to projecting how a species may respond to future environmental pressures. We documented the behavioural responses and breeding investment of macaroni penguins Eudyptes chrysolophus across five breeding seasons where local prey density changed by five-fold; from very low to highly abundant. When prey availability was low, foraging trips were significantly longer and extended overnight. Birds also foraged farther from the colony, potentially in order to reach more distant foraging grounds and allow for increased search times. These extended foraging trips were also linked to a marked decrease in fledgling weights, most likely associated with reduced rates of provisioning. Furthermore, by comparing our results with previous work on this population, it appears that lowered first-year survival rates associated, at least partially, with fledging masses were also evident for this cohort. This study integrates a unique set of prey density, predator behaviour and predator breeding investment data to highlight a possible behavioural mechanism linking perturbations in prey availability to population demography. [ABSTRACT FROM AUTHOR]

• Modelled mid-trophic prey biomass may be useful to predict predator foraging success. • Tested if prey biomass and predator foraging success was correlated in foraging areas. • Identified foraging areas by correlating prey biomass and predator foraging success. • Emergent foraging areas did occur within observed foraging distributions. • We highlight the applicability of prey models in marine predator foraging ecology. Modelling marine predator foraging habitats is a widespread research approach for projecting species responses to a rapidly changing Southern Ocean. Yet a key remaining challenge is to understand how changing prey biomass within foraging habitats could affect predator foraging success. Quantifying this using observed prey information is challenging given a paucity of synoptic data. Here, we investigated whether prey biomass from a mechanistic model, could provide useful predictions of pre-breeding arrival body mass of macaroni penguins (Eudyptes chrysolophus) from Marion Island, a standard metric of predator foraging success, measured over a 20-year period. In testing this, we used a spatially iterative correlation approach between predicted prey biomass and observed penguin arrival body mass, allowing likely foraging areas to emerge in regions most frequently associated with significant correlations. We then considered whether the distribution of these emergent foraging areas is consistent with tracking-derived foraging distributions for this species and island. Our results indicated emergent foraging areas where prey biomass was most often correlated with arrival body mass were located within expected and observed foraging ranges. Further, variability in prey biomass, within these emergent foraging areas provided reasonable predictions of annual penguin arrival body mass and outperformed metrics of primary production within these foraging areas. Our findings demonstrate that mechanistic models can provide biologically meaningful representations of difficult-to-observe prey, and can predict predator foraging success. This work could improve understanding of predator responses in a changing habitat. [ABSTRACT FROM AUTHOR]

Knowledge regarding interactions between predators and their prey is fundamental for understanding underlying links between climate change and ecosystem responses, including predator demographics, in the Southern Ocean. This study reports data on reproductive performance, total population size and diet composition for macaroni and chinstrap penguins breeding at Nyrøysa on Bouvetøya during the summers of 1996–97, 1998–99, 2000–01 and 2007–08. The breeding populations of these two species at Nyrøysa decreased significantly over the study period, with an 80% decline for chinstraps and a 50% decline for macaroni penguins, despite relatively high levels of chick production. During this period macaroni penguins at this site ate a diverse diet, dominated by myctophid fish and two krill species, whereas chinstrap penguins were Antarctic krill specialists. The population changes are probably primarily due to the expanding Antarctic fur seal population, and also to landslides that are the result of increased melting on the island which have destroyed penguin breeding sites. Additional impacts from global warming of the ocean might also be playing a role and could exacerbate the decline in these penguin populations if krill and other prey are negatively impacted in the future in this region. The local chinstrap penguin population would probably be most heavily affected given its narrow feeding niche and small current population size. [ABSTRACT FROM PUBLISHER]

Aim To infer the potential for competition between an important Antarctic predator, the macaroni penguin, and the krill fishery by examining the spatial overlap in prey consumption and catches. Location Scotia Sea and adjacent waters. Methods The study focused on the winter period as this is the only time of the year when spatio-temporal overlaps between macaroni penguin foraging and the krill fishery can occur. We tracked adult macaroni penguins from a colony in South Georgia using global location sensors to determine winter distribution, and bioenergetics models to calculate the biomass of food consumed during the winter period. We combined these to produce a surface of the tonnes of krill consumed, which could be compared directly with the spatial distribution of the tonnes of krill caught by the fishery. Results Adult macaroni penguins from South Georgia consumed 135,826 tonnes of krill (95% CIs: 83,446-188,140) during the winter, which is similar to the 98,431 tonnes caught by fisheries over the same period. However, macaroni penguins had a very wide pelagic distribution across the Scotia Sea, whereas the fishery was restricted to three small areas on shelf edges, such that their spatial overlap was negligible. The proportion of the estimated krill stock taken by macaroni penguins and the krill fishery was small at both the scale of the Scotia Sea and the local areas within which the fisheries operate. Main conclusions Competition between macaroni penguins and the krill fishery is low under current management and far less than that among the various species of krill predators that occur in the Scotia Sea. Our method will allow quantification of changes in competition between macaroni penguins and krill fisheries should the latter expand in the future, and provides a framework for assessing predator-fishery competition in other systems. [ABSTRACT FROM AUTHOR]

Due to their restricted foraging range, flightless seabirds are ideal models to study the short-term variability in foraging success in response to environmentally driven food availability. Wind can be a driver of upwelling and food abundance in marine ecosystems such as the Southern Ocean, where wind regime changes due to global warming may have important ecological consequences. Southern rockhopper penguins (Eudyptes chrysocome) have undergone a dramatic population decline in the past decades, potentially due to changing environmental conditions. We used a weighbridge system to record daily foraging mass gain (the difference in mean mass of adults leaving the colony in the morning and returning to the colony in the evening) of adult penguins during the chick rearing in two breeding seasons. We related the day-to-day variability in foraging mass gain to ocean wind conditions (wind direction and wind speed) and tested for a relationship between wind speed and sea surface temperature anomaly (SSTA). Foraging mass gain was highly variable among days, but did not differ between breeding seasons, chick rearing stages (guard and crèche) and sexes. It was strongly correlated between males and females, indicating synchronous changes among days. There was a significant interaction of wind direction and wind speed on daily foraging mass gain. Foraging mass gain was highest under moderate to strong winds from westerly directions and under weak winds from easterly directions, while decreasing under stronger easterly winds and storm conditions. Ocean wind speed showed a negative correlation with daily SSTA, suggesting that winds particularly from westerly directions might enhance upwelling and consequently the prey availability in the penguins' foraging areas. Our data emphasize the importance of small-scale, wind-induced patterns in prey availability on foraging success, a widely neglected aspect in seabird foraging studies, which might become more important with increasing changes in climatic variability. [ABSTRACT FROM AUTHOR]

Macaroni penguins Eudyptes chrysolophus are thought to be one of the most important mesopredators in the Southern Ocean having a greater impact on prey availability and abundance than any other seabird species. Their population centre has long been held to be South Georgia where populations were thought to comprise many million animals. Here we report the results of a recent census of the macaroni population at South Georgia undertaken using aerial survey methods. We report dramatic declines in numbers (∼1.0 million breeding pairs) compared to numbers observed in the late 1970s (∼5.4 million pairs), but show that these reductions have occurred principally at sites where numbers had previously been very large. During the breeding season, the main foraging grounds of birds from these sites overlap with the foraging grounds of Antarctic fur seals Arctocephalus gazella, a major competitor for their principal prey, Antarctic krill Euphausia superba. We suggest that the redistribution of the macaroni penguin population at South Georgia reflects the recent recovery of fur seal populations and thus the ongoing consequences of human intervention at South Georgia, a process which started more than 2 centuries previously. The implied resource competition and the observed population changes may also be exacerbated by recent reductions in Antarctic krill abundance which have been linked with reductions in seasonal sea ice following recent, rapid, regional warming in the Antarctic; however, the recovery of fur seal populations, and the ongoing recovery of krill-eating whale populations argues that tropho-dynamic interactions may be sufficient to explain the observed changes. [ABSTRACT FROM AUTHOR]

The article discusses sighting of an apparent immature Royal Penguin Eudyptes Schlegeli on New Island, Falkland Islands. The white-faced bird sighted on New Island had comparatively short crest feathers, suggesting it was not yet a fully grown adult. Based on its overall size and its long and high build, it is suggested that the bird was a male. The observed sizes differences and stronger likelihood that a pale-faced individual is a Royal Penguin argue against the possibility that it was an aberrant Macaroni Penguin.

Hatching asynchrony in avian species generally leads to a size hierarchy among siblings, favouring the first-hatched chicks. Maternally deposited hormones affect the embryo and chick's physiology and behaviour. It has been observed that progesterone, a hormone present at higher levels than other steroid hormones in egg yolks, is negatively related to body mass in embryos, chicks and adults. A differential within-clutch progesterone deposition could therefore be linked to the size hierarchy between siblings and to the resulting brood reduction. We tested whether yolk progesterone levels differed between eggs according to future parental ability to feed the entire clutch in wild rockhopper penguins Eudyptes chrysocome. This species presents a unique reversed egg-size dimorphism and hatching asynchrony, with the larger secondlaid egg (B-egg) hatching before the smaller first-laid egg (A-egg). Yolk progesterone levels increased only slightly with female body mass at laying. However, intra-clutch ratios were not related to female body mass. On the other hand, yolk progesterone levels increased significantly with the date of laying onset for A-eggs while they decreased for B-eggs. Early clutches therefore had proportionally more progesterone in the B-egg compared to the A-egg while late clutches had proportionally less progesterone in the B-egg. We propose that females could strategically regulate yolk progesterone deposition within clutches according to the expected food availability during chick growth, an adaptive strategy to adjust brood reduction to conditions. We also discuss these results, relating to yolk progesterone, in the broader context of other yolk steroids. [ABSTRACT FROM AUTHOR]

The article discusses a research study on macaroni penguins, their distribution at sea during winter and trophic ecology variation in several colonies compared to neighbouring localities. Observed were 30 penguins from Kerguelen and Crozet Islands in the Indian Ocean from 2006-2007 through the stable isotope analyses for trophic ecology and their habitat use with miniatrurised light-based geolocators. Results indicated large distribution patterns of macaroni penguins in Polar Frontal Zone deep oceanic waters with temperatures ranging from 3.0 to 3.5 degrees Centigrade. Additional findings include the distribution of those from Crozet in distinct areas far from the Kerguelen birds while their trophic ecology remain similar.

Where life-history stages overlap, there is the potential for physiological conflicts that might be important in mediating carryover effects. However, our knowledge of the specific physiological mechanisms underlying carryover effects remains rudimentary, and specific examples remain rare. Here we show that female macaroni penguins (Eudyptes clirysolophus) initiate vitellogenesis and yolk formation while at sea during return migrations to breeding colonies; yolk formation takes approximately 16 days, but females lay only 714 days after their return. Once on land, Eudyptes penguins show a unique reproductive pattern of extreme egg size dimorphism in which the smaller, first-laid A-egg is 55%-75% of the size of the larger B-egg. We show that the degree of egg size dimorphism is inversely correlated with time between arrival and laying; that is, females that begin reproductive development well in advance of their return produce more dimorphic eggs. Furthermore, late-arriving females that produce the most dimorphic eggs have lower plasma levels of the yolk precursor vitellogenin on arrival; that is, they show lower reproductive "readiness." These data support the hypothesis that extreme egg size dimorphism in Eudyptes penguins is due to a physiological constraint imposed by a migratory carryover effect and argue against small A-eggs having a specific, adaptive function. [ABSTRACT FROM AUTHOR]

The article reports on avian disease outbreaks at sub-Antarctic Marion Island, one of South Africa's Prince Edward Islands in the south-west Indian Ocean, and considers what procedures should be adopted to reduce the risks of further outbreaks at the island group. Several species of King Penguins Aptenodytes patagonicus and an estimated 5-10 thousand Macaroni Penguins Eudyptes chrysolophus were reportedly killed by unknown diseases in the island during 1992 and 1993. An outbreak of avian cholera Pasteurella multocida was also reported in the same island during November 2004. Procedures for preventing these outbreaks have been developed in the islands and in Antarctica.

We measured daily energy expenditure (DEE) continuously for a whole year in a free ranging bird, the macaroni penguin Eudyptes chrysolophus. We combined these measurements with concurrently recorded foraging behaviour, and literature information on body mass and dietary factors to estimate prey consumption rates and foraging success. DEE was at a maximum during late chick-rearing but was equally high during all other active phases of the breeding season. DEE was approximately 4×resting metabolic rate, which accords with established theory and suggests a common ‘energetic ceiling’ throughout the summer period. However, whether this represents a maximum in physiological capacity, or a rate which optimises fitness is still unclear. Rates of prey consumption and foraging success followed different patterns from daily energy expenditure. Daily prey consumption was high as the penguins prepared for long fasts associated with moulting and incubation but relatively low during chick-rearing, when foraging areas were restricted and foraging success lower. It appears that the energy intake of macaroni penguins is subject to extrinisic or environmental constraints rather than to intrinsic physiological limits. [ABSTRACT FROM AUTHOR]

The article discusses research on the at-sea movements of the macaroni penguin Eudyptes chrysolophus during its inter-breeding period at Kerguelen Islands. The study utilized global location sensors (GLS) attached to the penguins in order to monitor their foraging movements and feeding habits during winter. It has observed varying monthly traveling speed in the penguins during the season. Other findings include similar migratory behaviour in all the penguins and unexpected dispersal over winter.

We surveyed the coast of Chile between Isla Terhalten (54° 20' S) and Islote Leonard (55° 44' S) by boat during November-December 2005 to document breeding locations of Rockhopper (Eudyptes chrysocome chrysocome) and Macaroni (E. chrysolophus) penguins, and to count the number of nests during the early incubation period. A yacht-based observation recorded 1,000 Rockhopper Penguin nests at Isla Terhalten. Ground-based counts at Isla Noir estimated a total of 158,200 Rockhopper and 3,470 Macaroni penguin nests in 17 mixed colonies and one Macaroni Penguin breeding colony. The Rockhopper population on Isla Noir increased significantly from the previous estimate of 70,000 pairs, making this island the most important breeding site for the southern subspecies of Rockhopper Penguin. The new estimate for Rockhopper Penguins suggests a population increase over the last 20 years, consistent with recent data for the main colony in Argentina. Conservation status of the species and the factors potentially responsible for population declines elsewhere may need to be re-evaluated. [ABSTRACT FROM AUTHOR]

Macaroni (Eudyptes chrysolophus) and Southern Rockhopper penguins (E. c. chrysocome) have been classified as Vulnerable due to decreasing populations in recent decades. We report on a survey of Isla Recalada, Chile, a site described historically as containing an estimated population of 10,013 (±-570) Rockhopper and 559 Macaroni penguins. Our survey was conducted on 14 and 15 November 2005 to coincide with peak colony attendance. No Rockhopper or Macaroni penguins were observed on Isla Recalada during this period. This survey suggests the population of these penguins has dispersed due to possible anthropogenic pressures or climate variation, and that both species of penguins have been extirpated from Isla Recalada. [ABSTRACT FROM AUTHOR]

How animals manage their oxygen stores during diving and other breath-hold activities has been a topic of debate among physiologists for decades. Specifically, while the behavior of free-ranging diving animals suggests that metabolism during submersion must be primarily aerobic in nature, no studies have been able to determine their rate of oxygen consumption during submersion (VO2D) and hence prove that this is the case. In the present study, we combine two previously used techniques and develop a new mode! to estimate VO2D accurately and plausibly in a free-ranging animal and apply it to data for macaroni penguins (Eudyptes chrysolophus) as an example. For macaroni penguins at least, VO2D can be predicted by measuring heart rate during the dive cycle and the subsequent surface interval duration. Including maximum depth of the dive improves the accuracy of these predictions. This suggests that energetically demanding locomotion events within the dive combine with the differing buoyancy and locomotion costs associated with traveling to depth to influence its cost in terms of oxygen use. This will in turn effect the duration of the dive and the duration of the subsequent recovery period. In the present study, VO2D ranged from 4 to 28 ml·min-1·kg-1, indicating that, at least as far as aerobic metabolism was concerned, macaroni penguins were often hypometabolic, with rates of oxygen consumption usually below that for this species resting in water (25.6 ml·min-1·kg-1) and occasionally lower than that while resting in air (10.3 ml·min-1·kg-1). [ABSTRACT FROM AUTHOR]

Macaroni penguins were implanted with data loggers to record heart rate (fH), abdominal temperature (Tab) and diving depth during their pre-moult trip (summer) and winter migration. The penguins showed substantial differences in diving behaviour between the seasons. During winter, mean and maximum dive duration and dive depth were significantly greater than during summer, but the proportion of dives within the calculated aerobic dive limit (cADL) did not change. Rates of oxygen consumption were estimated from fH. As winter progressed, the rate of oxygen consumption during dive cycles (sVO2DC) declined significantly and mirrored the pattern of increase in maximum duration and depth. The decline in sVO2DC was matched by a decline in minimum rate of oxygen consumption (sVO2min). When sVO2min was subtracted from sVO2DC, the net cost of diving was unchanged between summer and winter. We suggest that the increased diving capacity demonstrated during the winter was facilitated by the decrease in sVO2min. Abdominal temperature declined during winter but this was not sufficient to explain the decline in sVO2min. A simple model of the interactions between sVO2min, thermal conductance and water temperature shows how a change in the distribution of fat stores and therefore a change in insulation and/or a difference in foraging location during winter could account for the observed reduction in sVO2min and hence sVO2DC. [ABSTRACT FROM AUTHOR]

It is generally assumed that air-breathing aquatic animals always choose the shortest route to minimize duration for transit between the surface and foraging depth in order to maximize the proportion of time spent foraging. However, empirical data indicate that the body angles of some diving animals are rarely vertical during descent and ascent. Why do they choose shallower body angles that result in longer descent and ascent durations? To investigate this question, we attached acceleration data loggers to eight female macaroni penguins, breeding on the Kerguelen Islands (48°45'-50°00' S, 68° 45'-70°58' E; South Indian Ocean), to record depth, two-dimensional acceleration (stroke cycle frequency and body angle) and temperature. We investigated how they controlled body angle and allocated their submerged time. The instrumented females performed multiple dives (N=6952) with a mean dive depth for each bird ranging from 24.5±28.5 m to 56.4±75.1 m. Mean body angles during descent and ascent were not vertical. There was large variation in mean descent and ascent angles for a given dive depth, which, in turn, caused large variation in descent and ascent duration. Body angles were significantly correlated with time spent at the bottom- phase of the dive. Birds that spent long periods at the bottom exhibited steep body angles during ascent and subsequent descent. By contrast, they adopted shallow body angles after they had short or no bottom phases. Our results suggest that macaroni penguins stay at the bottom longer after encountering a good prey patch and then travel to the surface at steep body angles. If they do not encounter prey, they discontinue the dive, without staying at the bottom, ascend at shallow body angles and descend at shallow body angles in a subsequent dive. A shallow body angle can increase the horizontal distance covered during a dive, contributing to the move into a more profitable area in the following dive. During the ascent, in particular, macaroni penguins stopped beating their flippers. The buoyantly gliding penguins can move horizontally with minimum stroking effort before reaching the surface. [ABSTRACT FROM AUTHOR]

We tested the hypothesis that implanted data loggers have no effect on the survival, breeding success and behaviour of macaroni penguins Eudyptes chrysolophus. Seventy penguins were implanted with heart rate data loggers (DLs) for periods of up to 15 months. When compared to control groups, implanted penguins showed no significant difference in over-wintering survival rates, arrival date and mass at the beginning of the breeding season. Later in the breeding season, implanted penguins showed no significant difference in the duration of their incubation foraging trip, breeding success, fledging mass of their chicks, date of arrival to moult and mass at the beginning of the moult fast. We conclude that implanted devices had no effects on the behaviour, breeding success and survival of this species. We contrast these results to those from studies using externally attached devices, which commonly affect the behaviour of penguins. We suggest that implanted devices should be considered as an alternative to externally attached devices in order to obtain the most accurate representation of the free-ranging behaviour, ecology and physiology of penguins. [ABSTRACT FROM AUTHOR]

The metabolic rate of moulting macaroni penguins Eudyptes chrysolophus was investigated using three techniques in order to test two hypotheses concerning the energetic cost of the moult fast in penguins. First, that energy expenditure during the moult is greater than that while penguins are onshore during the breeding season. Second, techniques that do not measure energy expenditure throughout the moult fast do not accurately determine the true cost of the moult. Mass loss calculations, measurement of the rate of oxygen consumption and estimation of the rate of oxygen consumption from heart rate in the field were used with captive and free-ranging penguins. Comparison of the results from these techniques suggest that metabolic rate is higher in the field than in a respirometer due to an increase in thermoregulatory costs. Furthermore the average metabolic rate of female penguins during the moult at 5.04±0.85 W kg−1 was not significantly different from that of female penguins on-shore during the breeding season at 6.27±0.38 W kg−1. Metabolic rate in the field changed during the moult fast as feather loss and increased vascularisation of the skin caused increased heat production, illustrating the importance of determining energy expenditure from animals in the field throughout the whole of the moult fast. [ABSTRACT FROM AUTHOR]

The foraging patterns of ten male rockhopper penguins Eudyptes chrysocome from the Falkland Islands were recorded during the incubation period by using satellite telemetry. Irrespective of study site and year, two different foraging areas could be identified. Three foraging trips were directed towards the slope of the Patagonian Shelf c. 140 km to the northeast of the breeding colony and these trips had a duration of 11–15 days. The seven other rockhopper penguins travelled c. 400 km towards the edge of the Falkland Islands’ waters; all these foraging trips followed an anti-clockwise direction and lasted 16–27 days. The calculated mean daily travelling speed, based on the time spent underwater and the distance covered between two positions, was significantly higher in birds travelling to the edge of the Falkland Islands’ waters compared with those foraging at the shelf slope (4.4±1.6 km/h vs. 3.4±2.0 km/h, respectively). The consistent foraging patterns exhibited during the long trips may be linked to the Falklands current, allowing the penguins to reach remote areas while reducing their energy expenditure. Potential interactions between commercial fisheries and hydrocarbon exploration are discussed. [ABSTRACT FROM AUTHOR]

Summary 1. Breeding female Macaroni Penguins (Eudyptes chrysolophus ) were implanted with heart rate, temperature and depth data loggers in order to estimate their rate of energy expenditure from heart rate. 2. The estimated average daily metabolic rates (ADMR) of birds during the brood and crèche phases of the breeding season were 8·17 ± 0·44 W kg-1 and 8·24 ± 0·41 W kg-1 , respectively. There was no significant difference between these estimates and the pooled ADMR for all birds was 8·22 ± 0·38 W kg-1 . 3. Metabolic rate while the penguins were at-sea was 9·03 ± 0·39 W kg-1 and this was significantly greater than the metabolic rate of 6·27 ± 0·38 W kg-1 while they were on-shore. 4. Females undertook shorter foraging trips during the crèche phase than during the brood phase. 5. When considered as a breeding pair, Macaroni Penguins expend more energy in raising their chick during the crèche phase of the breeding season as the male assists in provisioning the chick only at this time. [ABSTRACT FROM AUTHOR]

Summary 1.Estimating food consumption is central to defining the ecological role of marine predators. This study developed an algorithm for synthesizing information about physiology, metabolism, growth, diet, life history and the activity budgets of marine predators to estimate population energy requirements and food consumption. 2.Two species of marine predators (Antarctic fur seal Arctocephalus gazella and macaroni penguin Eudyptes chrsolophus ) that feed on krill in the Southern Ocean were used as examples to test the algorithm. A sensitivity analysis showed that estimates of prey consumed were most sensitive to uncertainty in some demographic variables, particularly the annual survival rate and total offspring production. Uncertainty in the measurement of metabolic rate led to a positive bias in the mean amount of food consumed. Uncertainty in most other variables had little influence on the estimated food consumed. 3.Assuming a diet mainly of krill Euphausia superba , annual food consumption by Antarctic fur seals and macaroni penguins at the island of South Georgia was 3·84 [coefficient of variation (CV) = 0·11] and 8·08 (CV = 0·23) million tonnes, respectively. This was equivalent to a total annual carbon consumption of 0·35 (CV = 0·11) and 0·72 (CV = 0·23) G tonnes year-1 . Carbon expired as CO2 was 0·26 (CV = 0·06) and 0·65 (CV = 0·19) G tonnes year-1 for fur seals and macaroni penguins, respectively. The per capita food consumption varied depending upon sex and age but, overall, this was 1·7 (CV = 0·22) tonnes year-1 for Antarctic fur seals and 0·45 (CV = 0·22) tonnes year-1 for macaroni penguins. 4.The algorithm showed that the seasonal demand for food peaked in both species in the second half of the breeding season and, for macaroni penguins, there was a second peak immediately after moult. Minimum food demand... [ABSTRACT FROM AUTHOR]

Explores the heart rate and rate of oxygen consumption of exercising macaroni penguins. Absence of significant difference in heart rate and oxygen consumption between moulting and breeding penguins; Difference of heart rate and oxygen consumption between all females and breeding males; Physiological stress experienced by moulting penguins.

Examines the isolation and characterization of Campylobacter jejuni subsp. jejuni from marconi penguins in Bird Island, Antarctica. Phenotypic profile of the C. jejuni isolates; Sequence analysis of the flaA gene as a tool for molecular typing of C. jejuni; Genetic diversity of the Campylobacter strains.

The article presents information on a study which tested whether females rockhopper penguins, Eudyptes chrysocome chrysocome, depositing high androgen concentrations experienced higher mass losses than females depositing low androgen concentrations. A review of the related literature is given. It observes that energetic cost to androgen deposition is absent during egg formation. Highlights of the research findings are explained.

The article discusses a study on Brown Skuas Stercorarius (S.) antarcticus that were found incubating Macaroni Penguin Eudyptes (E.) chrysolophus at Marion Island. The general appearance of the white egg was not the same as the egg of a giant petrel but similar to that of a penguin's. The penguin egg in the skua nest lasted for approximately 47 days, which was longer than the incubation period of Brown Skua. The presence of foreign eggs in bird nests is unexplainable but researchers associated it with nest-parasitism.

This data set represents the accumulation of 19 years of seabird population abundance data collected by the Antarctic Site Inventory, an opportunistic vessel-based monitoring program surveying the Antarctic Peninsula and associated sub-Antarctic Islands. This Data Paper, which includes 1124 records from 113 locations for seven species of seabirds (Adélie Penguin [Pygoscelis adeliae], Gentoo Penguin [P. papua], Chinstrap Penguin [P. antarctica], Macaroni Penguin [Eudyptes chrysolophus], Blue-eyed Shag [Phalacrocorax atriceps], Kelp Gull [Larus dominicanus], and Southern Giant Petrel [Macronectes giganteus]), includes data already published by the Antarctic Site Inventory as well as seven years of recent data not previously published. Census data represent a mix of nest and chick counts; each census record includes the location, date, and precision of the census count, along with any auxiliary notes. Included with the database are maps to clarify the location of specific breeding populations that may be new (and thus not previously reported) or ambiguous. This compilation represents the best single source of raw data on the spatiotemporal dynamics of the Pygoscelis penguins in the Antarctic Peninsula region and provides population data on several flying bird species less frequently studied. [ABSTRACT FROM AUTHOR]

Presents an abstract of the article "Effects of Long-Term Implanted Data Loggers on Macaroni Penguins Eudyptes chrysolophus," by J. A. Green et al that was published in a 2004 issue of the "Journal of Avian Biology."

Reports on research conducted by Katsufumi Sato and colleagues to determine why foraging macaroni penguins ascend gently after diving for food. Birds' use of different diving strategies depending on how long they remained at depth; Wing beat pattern of the birds as they swam.