The emperor penguin dives deeper and longer, fasts longer, and endures the harshest weather conditions of all diving birds. It spends about four and half months per annum deep in Antarctic pack ice away from shore and stations, and thus is largely unavailable for study. This time includes preparation for the molt, and travel to the colony to breed, a time period in which great swings in body weight occur. This study will fill an important gap in what we know about the biology of the annual cycle of the emperor by examining the molt-post molt period. The P.I. proposes to traverse the Amundsen and Bellingshausen seas on the Oden, to locate and tag emperor penguins during the molt season. The objectives are to (1) Place satellite tags on 20 adult post molt birds to determine their route, rate of travel, and diving behavior as they return back to their breeding colonies, (2) Obtain an index of body condition, (3) Collect guano to determine the type of food consumed by emperor penguins in the region, (4) Conduct shipboard surveys to sight and plot the location and abundance of adult and juvenile birds on the ship's track. The PI hypothesizes that bird dives will be shallow during the initial post-molt phase, and that food will consist primarily of krill; that there will be differential dispersal of birds from the Ross Sea vs. Marie Byrd Land, with Ross Sea birds traveling farther; and that the greatest adult mortality occurs during the molt and early post molt period. Broader impacts include training of a post doc, a graduate student, and an aquarium volunteer. The P.I. also will present findings through a website, through public lectures, and in collaboration with the Birch aquarium.

Like many polar animals, emperor penguin populations are challenging to monitor because of the species’ life history and remoteness. Consequently, it has been difficult to establish its global status, a subject important to resolve as polar environments change. To advance our understanding of emperor penguins, we combined remote sensing, validation surveys, and using Bayesian modeling we estimated a comprehensive population trajectory over a recent 10-year period, encompassing the entirety of the species’ range. Reported as indices of abundance, our study indicates with 81% probability that the global population of adult emperor penguins declined between 2009 and 2018, with a posterior median decrease of 9.6% (95% credible interval (CI) -26.4% to +9.4%). The global population trend was -1.3% per year over this period (95% CI = -3.3% to +1.0%) and declines likely occurred in four of eight fast ice regions, irrespective of habitat conditions. Thus far, explanations have yet to be identifi..., During the 2018 Antarctic field season, under permit #2019-006 granted by the National Science Foundation, our US-based team conducted aerial photography at emperor penguin colonies in the Ross Sea to add to robust validation of imagery. Our efforts included one flight via fixed wing aircraft over colonies distant from McMurdo Station and five flights via helicopter to a single colony (Cape Crozier) near the station. The five flights to Cape Crozier, 24 October to 15 November, were used to better understand population fluctuation through a single season. Our fixed wing survey took place on 31 October 2018, flying in the vicinity of Beaufort Island (ASPA 105), Franklin Island, Cape Washington (ASPA 173), Coulman Island, and Cape Roget. At each location (both by fixed wing and helicopter), we circled the colony 1-4 times, maintaining a minimum of 500 m horizontal distance from the periphery of the colony and a minimum altitude of 500 m. No behavioral disturbance to birds (e.g., rapid move..., , # LaRue et al. (2024): Advances in remote sensing of emperor penguins: first multi-year time series documenting global population change

10.5061/dryad.m63xsj48v

Overview

This repository contains data, code, and model output associated with the global-scale analysis of Emperor penguin population dynamics described in LaRue et al. (2024), based on integrating raw data from aerial surveys with time series of circumpolar satellite surveys of known emperor penguin colonies.

The model is used to estimate an annual index of abundance at every known Emperor penguin colony in Antarctica (as of 2018), for every year between 2008 and 2018. Regional and global population indices are then calculated by summing colony-level estimates, according to regional colony membership.

Simulations are also performed to evaluate the ability of the model to accurately detect population trends, if they exist.

File structure and code description

• analysis/
  • **ou...

The Antarctic Penguin Biogeography Project is an effort to collate all known information about the distribution and abundance of Antarctic penguins through time and to make such data available to the scientific and management community. The core data product involves a series of structured tables with information on known breeding sites and surveys conducted at those sites from the earliest days of Antarctic exploration through to the present. This database, which is continuously updated as new information becomes available, provides a unified and comprehensive repository of information on Antarctic penguin biogeography that contributes to a growing suite of applications of value to the Antarctic community. One such application is the Mapping Application for Antarctic Penguins and Projected Dynamics (MAPPPD; www.penguinmap.com) - a browser-based search and visualization tool designed primarily for policymakers and other non-specialists (Humphries et al., 2017), and ‘mapppdr’, an R package developed to assist the Antarctic science community. The Antarctic Penguin Biogeography Project has been funded by the National Aeronautics and Space Administration (NASA), the Pew Fellowship for Marine Conservation, and the Institute for Advanced Computational Sciences at Stony Brook University.

Antarctic Penguin Biogeography Project: Database of abundance and distribution for the Adélie, chinstrap, gentoo, emperor, macaroni, and king penguin south of 60 S is an occurrence and sampling event type dataset published by SCAR-AntBIOS.

This dataset contains records of Pygoscelis adeliae, Pygoscelis antarctica, Pygoscelis papua, Eudyptes chrysolophus, Aptenodytes patagonicus, and Aptenodytes forsteri annual nest, adult, and/or chick counts conducted during field expeditions or collected using remote sensing imagery, that were subsequently gathered by the Antarctic Penguin Biogeography Project from published and unpublished sources, at all known Antarctic penguin breeding colonies south of 60 S from 1892-11-01 to 2022-02-12.

The data is published as a standardized Darwin Core Archive and includes an event core and occurrence and eMoF extensions. This dataset is published by SCAR-AntOBIS under the license CC-BY 4.0. Please follow the guidelines from the SCAR Data Policy (SCAR, 2023) when using the data. If you have any questions regarding this dataset, please contact us via the contact information provided in the metadata or via data-biodiversity-aq@naturalsciences.be. Issues with dataset can be reported at https://github.com/biodiversity-aq/data-publication/

This dataset is part of the Antarctic Penguin Biogeography Project project funded by National Aeronautics and Space Administration (NASA), the Pew Fellowship for Marine Conservation, and the Institute for Advanced Computational Sciences at Stony Brook University.

Creching emperor penguin (Aptenodytes forsteri) chickswere exposed to two overflights by an S-76 twin engine helicopter at 1000 m: a current operational guideline for helicopter activity in Antarctica. The flights were conducted on the same day but under different wind conditions: a morning flight with a 10 kt (18 km.hr-1) katabatic blowing perpendicular to the direction of helicopter travel and an afternoon flight with virtually no wind. Background noise levels recorded in the morning, before the helicopter flight, were significantly higher than in the afternoon, but these differences were not detectable when the helicopter was overhead. There were also no significant differences in the way chicks responded to helicopters between the morning and afternoon flight. All chicks became more vigilant when the helicopter approached and 69% either walked or ran, generally moving less than 10 m toward other chicks (i.e. not scattering). Most chicks (83%) displayed flipper-flapping, probably indicating nervous apprehension. This behaviour was seldom displayed in the absence of disturbance. Although all effects were relatively transitory, results support the introduction of more conservative guidelines for helicopter operations around breeding localities of this species.

The fields in this dataset are:

Time Action Date Lying Standing Walking Preening Flapping

The exact location of an Emperor Penguin Colony on Peterson Bank continually changes due to the changing ice conditions of where the colony is situated.

The location confirmed on the 3rd of November 1994 on fast ice at Peterson Bank was 65.9333 S, 110.2 E, 41km NNW of Australia's Casey Station. The location was recorded by Ward Bremmers during a helicopter flight involved in the resupply operations from an ice-bound ship to Casey Station.

The presence of chicks was confirmed on landing and an approximate count estimated chick numbers at 2000 with at least 1000 adults present. Many foraging animals were also observed in transit in the surrounding area. Approximately 100 dead chicks, ranging in age from a few weeks to 3 months old, were observed during a casual check in the immediate vicinity.

The colony lies on fast ice amid grounded bergs in Peterson Bank. The surrounding icebergs are widely spaced (1-2km), so the colony site is relatively unsheltered from the prevailing easterly gales. The sea-ice thickness at the colony sites was 7-8m, suggesting the ice had been stable for the previous three or our seasons. However, during a second visit to the site on 24 December 1994, the ice at the colony site was breaking up, and 200 chicks in the process of moulting were observed drifting on a large ice floe.

On the 24 of April in 1995, a large group of Adults on new ice amid grounded bergs in the Peterson Bank was sighted, suggesting that the colony was reforming.

The fields in this dataset are:

Date Latitude Longitude Number of Adults Number of Chicks Dead Chicks Comments

This project on emperor penguin populations will quantify penguin presence/absence, and colony size and trajectory, across the entire Antarctic continent using high-resolution satellite imagery. For a subset of the colonies, population estimates derived from high-resolution satellite images will be compared with those determined by aerial surveys - these results have been uploaded to MAPPPD (penguinmap.com) and are freely available for use. This validated information will be used to determine population estimates for all emperor penguin colonies through iterations of supervised classification and maximum likelihood calculations on the high-resolution imagery. The effect of spatial, geophysical, and environmental variables on population size and decadal-scale trends will be assessed using generalized linear models. This research will result in a first ever empirical result for emperor penguin population trends and habitat suitability, and will leverage currently-funded NSF infrastructure and hosting sites to publish results in near-real time to the public.

The emperor penguin, an iconic species threatened by projected sea-ice loss in Antarctica, has long been considered to forage at the fast ice edge, presumably relying on large/yearly-persistent polynyas as their main foraging habitat during the breeding season. Using newly developed fine-scale sea-icescape data and historical penguin tracking data, this study for the first time suggests the importance of less-recognized small openings, including cracks, flaw leads and ephemeral short-term polynyas, as foraging habitats for emperor penguins. The tracking data retrieved from 47 emperor penguins in two different colonies in East Antarctica suggest that those penguins spent 23% of their time in ephemeral polynyas and did not use the large/yearly-persistent, well-studied polynyas, even they occur much more regularly with predictable locations. These findings challenge our previous understanding of emperor penguin breeding habitats, highlighting the need for incorporating fine-scale seascape features when assessing the population persistence in a rapidly changing polar environment.

Metadata record for data from ASAC Project 1252 See the link below for public details on this project.

Currently three datasets are attached to this metadata record. Dive data collected in 1988, track data from adult birds collected in 1994 and track data from fledglings collected in 1995.

Dive data are available in Microsoft Word format, while the track data are available in Microsoft Excel format.

A readme file (txt) is included in each download file to explain column headings, etc.

---- Public Summary from Project ---- To breed successfully the winter-breeding emperor penguins must fatten on two occasions: once before the onset of moult in January, and again prior to the commencement of the new breeding season in March. Interference with the capacity of the penguins to fatten in summer might be detrimental to the their breeding performance and survival later on in winter. This study seeks to determine the likely impact of commercial fishing operations on emperor penguin colonies at the Mawson Coast. More specifically, the data pertains to the locations of emperor penguins when fattening prior to the moult, and prior to the new breeding season.

Project objectives: 1. To determine the extent and location of foraging areas of post-breeding adult Emperor penguins in summer. 3. To determine the extent and locations of foraging areas of fledgling Emperor penguins on their first trip to sea. 4. To identify interseasonal and interannual variations in foraging areas in conjunction with changes in seaice conditions and compare these with results from different colonies. 5. To survey the coastline of the AAT to verify the existence (or non-existence) of Emperor penguin colonies.

Emperor penguins are icons of Antarctic wildlife and their conservation is of paramount interest to the wider community. They are also key consumers of marine resources in several areas and consequently there is great potential for interactions between feeding penguins and harvesting of fish and krill. Emperor penguins are one of the few species to breed on the fast ice (although there are three known land-based colonies, one of which has all but ceased to exist in recent years). Thus, the breeding habitat of Emperor penguins is subject to direct alteration as a result of climate change. Colonies of Emperors are found across a wide latitudinal range, from deep in the Ross Sea to the tip of the Antarctic Peninsula. This range includes breeding areas where significant changes in seaice are not (yet?) thought to be occurring to areas where seaice is changing rapidly. Accordingly, studies at multiple locations will provide valuable clues on how this species will be affected by a warming Antarctic. Additionally, Emperor penguins are large animals that live in a relatively small number of discrete locations. It is therefore more than feasible, using an international effort, to study an entire species and to make some predictions about their response to a warming world and to current and future fishing practices. This project aims to make the first steps towards an overall conservation assessment of Emperor penguins through studies in several locations around the Antarctic continent. Should these attempts be successful, then a more ambitious international project will be launched to take a species-wide perspective.

As seabirds emperor penguins spent a large proportion of their lives at sea. For food they depend entirely on marine resources. Young penguins rarely return to their natal colonies after their first year. Satellite tracking will give us insights into where foraging areas may be that are important for these birds. This tracking work is part of a multi-species study funded by the Integrated Marine Observation System (IMOS).

These data are from penguins from the Amanda Bay area, and for the 2012-13 season.

Metadata record for data from ASAC Project 2954. See the link below for public details on this project.

Public The primary goal of this project is to determine the status and origin of diseases in Emperor Penguins at Auster Rookery near Mawson Station, Antarctica. We will investigate the origins of such disease and the role humans may have played. We will sample adults and chicks in order to isolate and describe the pathogens. A high percentage of Emperor Penguin chicks have antibodies to infectious bursal disease (IBDV). This study will investigate the role the adults play in transmitting IBDV to their chicks. The high prevalence of IBDV antibodies should help us to isolate the virus and discover its origin.

Project objectives: Status of Disease in the Emperor Penguins of Auster Rookery

1) To determine the prevalence of disease in adult Emperor Penguins (Aptenodytes forsteri) at Auster Rookery. Over 65% of Emperor Penguin chicks at Auster Rookery had serum antibodies to Infectious Bursal Disease Virus (IBDV) in December 1995 (Gardner et al. 1997). We have no information on the presence of the same antibodies on adult Emperor Penguins. We will focus on IBDV, but will also test for other common avian diseases.

2) To repeat the sampling of Emperor Penguin Chicks by Gardner et al. (1997) in order to compare the prevalence of IBDV in Emperor Penguin chicks in 2008 with 1995.

3) To determine the seasonal progression of IBDV antibody prevalence in both adults and chicks.

4) To determine the possible source(s) of viral infection in Emperor Penguin chicks. Because Gardner et al. (1997) had no information on adult Emperor Penguins we do not know how the chicks are exposed to IBDV. Gardner et al. (1997) suggested that poultry waste from the nearby Mawson Station may be a source of virus for the Emperor Penguin chicks. Penguins do not scavenge food, however, so the source of infection must be either from the environment, local predators/scavenger, or from parents feeding their young. By sampling both adults and chicks in different parts of the season, we will determine when antibodies first appear in the chicks. If they have antibodies in the early season, then scavengers/predators can not account for their exposure to IBDV.

5) To determine the source of the IBDV. We will attempt to isolate virus from Emperor Penguins in order to identify the strains responsible for the antibody reactions in Emperor Penguins. Using reverse transcription polymerase chain reaction (RT-PCR), we will sequence genes from the virus which can be compared with known gene sequences from serotypes available from GenBank.

6) To monitor the chick mortality and conduct field necropsies of the Emperor Penguins at the Auster colony to determine whether IBDV or other diseases are a factor in reproductive success.

7) To contribute to a conservation strategy for Antarctic wildlife. By developing information on the importance and origins of disease in Emperor Penguins we can clarify the role of human visitors in the transmission of disease in Antarctic wildlife.

Progress against objectives: Excellent progress has been made towards all the stated goals.

By spending the winter of 2008 at Mawson Station we had access to the emperor penguin colony at Auster. We successfully sampled 400 adults and 200 chicks as stated in the proposal. We now have the samples back in Australia and analyses are beginning. No sample analysis for disease could be undertaken while still in Antarctica.

The samples will 1) give us a determination of the prevalence of IBDV antibodies (also some other disease viruses) for both adults and chicks. 2) One of our sampling periods was a repeat of the sampling conducted by Gardner et al. so we can compare the prevalence of IBDV antibodies in chicks from 2 different years and relate that to the prevalence in adults. 4) We conducted our sampling at four different times during the winter so that we were able to sample chicks before any other species visited the colony, then sample them again 6 weeks after skuas and giant petrels were in the area. 5) In order to determine the source of IBDV we want to determine its RNA sequence. To that end, a full set of samples have been sent to Dr. Daral Jackwood at Ohio State University, a colleague and IBDV expert. He has just begun to analyse the samples to isolate and sequence the IBDV RNA. 6) We monitored chick mortality with visits to the colony on average once per week. We noted approximately 800 dead chicks and collected 120 of the chicks for field necropsies. They mostly died of starvation with a few exceptions. We found parasites in one dead chick. We also collected 9 carcasses of adult emperor penguins. Eight of the 9 were females who all died with complications of egg laying. 7) This goal will require the completion of all the analyses for us to make conservation recommendations.

This collection of files represents the data (including samples) collected for Project 2954 on E...

Metadata record for data from ASAC Project 419 See the link below for public details on this project.

From the abstracts of some of the referenced papers:

The population size and breeding success of Emperor Penguins (Aptenodytes forsteri) at the Auster and Taylor Glacier colonies were estimated during the 1988 breeding season. At Auster a total of 10963 pairs produced about 6350 fledglings for a breeding success of 58%. At Taylor Glacier about 2900 pairs raised 1774 fledglings for a breeding success of 61%. Fledglings left Taylor Glacier over a period of 33 days at a mean mass of 10.56kg.

The accuracy of the tritiated water (HTO) and sodium-22 (22Na) turnover methods as estimators of dietary water and sodium intake was evaluated in emperor penguins fed separate diets of squid and fish. Emperor penguins assimilated 76.2% and 81.8% of available energy in the squid and fish diets, respectively. Both isotopes had equilibrated with body water and exchangeable sodium pools by 2h after intramuscular injection. The tritium method yielded reliable results after blood isotope levels had declined by 35%. On average the tritium method underestimated water intake by 2.9%, with a range of -10.3% to +11.1%. The 22Na method underestimated Na intake on average by 15.9% with the errors among individuals ranging from -37.2% to -1.8%. Discrepancies with 22Na turnover were significantly greater with the squid diet than the fish diet. The results confirm the reliability of the tritium method as an estimator of food consumption by free-living emperor penguins (provided seawater and freshwater ingestion is known) and support the adoption of the 22Na method to derive an approximation of seawater of seawater intake by tritiated emperor penguin chicks and by tritiated adults on foraging trips of short duration.

The diet composition of Emperor Penguin Aptenodytes forsteri chicks was examined at Auster and Taylor Glacier colonies, near Australia's Mawson station, Antarctica, between hatching in mid-winter and fledging in mid-summer by 'water-offloading' adults. Chicks at both colonies were fed a similar suite of prey species. Crustaceans occurred in 82% of stomach samples at Auster and 87% of stomachs at Taylor Glacier and were heavily digested; their contribution to food mass could not be quantified. Fish, primarily bentho-pelagic species, accounted for 52% by number and 55% by mass of chick diet at Auster, and squid formed the remainder. At Taylor Glacier the corresponding values were 27% by number and 31% by mass of fish and 73% by number and 69% by mass of squid. of the 33 species or taxa identified, the fish Trematous eulepidotus and the squid Psychroteuthis glacialis and Alluroteuthis antarcticus accounted for 64% and 74% of the diets by mass at Auster and Taylor Glacier, res pectively. The sizes of fish varied temporally but not in a linear manner from winter to summer. Adult penguins captured fish ranging in length from 60 mm (Pleuragramma antarcticum) to 250 mm (T. eulepidotus) and squid (P. glacialis) from 19 to 280 mm in mantle length. The length-frequency distribution of P. glacialis showed seasonal variation, with the size of squid increasing from winter to summer. The energy density of chick diet mix increased significantly prior to 'fledging'.

Abstract: The emperor penguin, Aptenodytes forsteri, is the premier avian diver and a top predator in the Antarctic ecosystem. The routine occurrence of 500-m diver during foraging trips to sea is both a physiological and behavior enigma. The objectives of this project address how and why emperors dive as deep and long as they do. The project examines four major topics in the diving biology of emperor penguins: pressure tolerance, oxygen store management, end-organ tolerance of diving hypoxemia/ischemia, and deep-dive foraging behavior. These subjects are relevant to the role of the emperor as a top predator in the Antarctic ecosystem, and to critical concepts in diving physiology, including decompression sickness, nitrogen narcosis, shallow water blackout, hypoxemic tolerance, and extension of aerobic dive time. The following hypotheses will be tested: 1) Prevention of nitrogen narcosis and decompression sickness in emperor penguins is achieved by inhibition of pulmonary gas exchange at depth. 2) Shallow water black out does not occur because of greater cerebral hypoxemic tolerance, and, in deep dives, because of resumption of pulmonary gas exchange during final ascent. 3) The rate of depletion of the blood oxygen store is a function of depth of dive and heart rate. 4) The aerobic dive limit (ADL) reflects the onset of lactate accumulation in locomotory muscle, not total depletion of all oxygen stores. 5) Elevation of tissue antioxidant capacity and free-radical scavenging enzyme activities protect against the routine ischemia/reperfusion which occur during diving. 6) During deep dives, the Antarctic silverfish, Pleuorogramma antarcticum, is the primary prey item for emperors. In addition to evaluation of the hypotheses below, the project has broader impacts in several areas such as partnership with foreign and national institutes and organizations (e.g., the National Institute of Polar Research of Japan, Centro de Investigacioines del Noroeste of Mexico, National Geographic, the University of Texas Southwestern Medical Center, and Sea World). Participation in National Geographic television documentaries will provide unique educational opportunities for the general public; development of state-of-the-art technology (e.g., blood oxygen electrode recorders, blood samplers, and miniaturized digital cameras) will lay the groundwork for future research by this group and others; and the effects of the B15 iceberg on breeding success of emperor penguins will continue to be evaluated with population censuses during planned fieldwork at several Ross Sea emperor penguin colonies.

Emperor penguins (Aptenodytes forsteri) and leopard seals (Hydrurga leptonyx) are iconic, top predators in Antarctica. Understanding their physiological ecology is essential to the assessment of their adaptability to the threats of climate change, pollution, and overfishing. The proposed research has multipronged objectives. Prior results suggest that Emperor penguins have flexible (vs. static) aerobic dive limits (ADL) that vary with the type of dive, and that the role of heart rate in utilization of oxygen stores also varies with dive type. A series of physiological measurements are proposed with backpack electrocardiogram recorders, that will allow further delineation of patterns and interrelationships among heart rate, dive behavior, and oxygen stores. Importantly, the research will be done on free diving emperors, and not individuals confined to a dive hole, thereby providing a more genuine measure of diving physiology and behavior. A separate objective is to examine foraging behavior of leopard seals, using a backpack digital camera and time depth recorder. Leopard seal behavior and prey intake is poorly quantified, but known to be significant. Accordingly the research is somewhat exploratory but will provide important baseline data. Finally, the P.I. proposes to continue long term overflight censuses of Emperor penguin colonies in the Ross Sea. Broader impacts include collaboration with National Geographic television, graduate student training, and development of sedation techniques for leopard seals.

Metadata record for data from ASAC Project 484 See the link below for public details on this project.

---- Public Summary from Project ---- Emperor penguins are the only birds that breed in the Antarctic winter. They feed mainly on fish and squid but also ingest krill. Changes in food availability due to oceanographic or climatic factors, or to the extent of sea ice (through the processes of global warming) will have a direct impact on the breeding success and population size of the penguins. By counting the number of males that incubate at mid-winter each year, we can monitor trends in their population size. Counts of fledglings in spring (November) tell us how successful the penguins bred.

The download file contains an excel spreadsheet which presents a summary of known Emperor Penguin colonies in the area of the Australian Antarctic Territory (AAT), and a file which details counts of male emperor penguins at the Taylor Glacier colony.

A description of the column headings used in the spreadsheet is below.

Colony: Colony name

lat, long: latitude and longitude of colony

discovered: date colony was discovered

current est pop (BP): Current estimated population size in breeding pairs - current as at date the colony was last seen

last seen: date the colony was last seen

counting method: method used to count the breeding pairs in the colony

comments: any applicable comments

reference: references relating to the colony

Taken from the 2009-2010 Progress Report: Public summary of the season progress: Population size of colonies fluctuates which is why long term monitoring studies are necessary to detect trends. At the emperor penguin colony at Taylor Glacier, monitored continuously since 1988, a slight downward trend is apparent but is not (yet?) statistically significant. The colony was visited three times: once in winter to obtain an estimate of the number of adults in the colony (roughly equivalent to the number of breeding pairs), and twice during the late chick rearing season to estimate breeding success. The count of adults in 2009 was the lowest on record. Reasons for this are still unknown.

Understanding the boundaries of breeding populations is of great importance for conservation efforts and estimates of extinction risk for threatened species. However, determining these boundaries can be difficult when population structure is subtle. Emperor penguins are highly reliant on sea ice, and some populations may be in jeopardy as climate change alters sea-ice extent and quality. An understanding of emperor penguin population structure is therefore urgently needed. Two previous studies have differed in their conclusions, particularly whether the Ross Sea, a major stronghold for the species, is isolated or not. We assessed emperor penguin population structure using 4,596 genome-wide single nucleotide polymorphisms (SNPs), characterized in 110 individuals (10–16 per colony) from eight colonies around Antarctica. In contrast to a previous conclusion that emperor penguins are panmictic around the entire continent, we find that emperor penguins comprise at least four metapopulations, and that the Ross Sea is clearly a distinct metapopulation. Using larger sample sizes and a thorough assessment of the limitations of different analytical methods, we have shown that population structure within emperor penguins does exist and argue that its recognition is vital for the effective conservation of the species. We discuss the many difficulties that molecular ecologists and managers face in the detection and interpretation of subtle population structure using large SNP data sets, and argue that subtle structure should be taken into account when determining management strategies for threatened species, until accurate estimates of demographic connectivity among populations can be made.,Emperor penguin neutral SNP datasetEP_final.vcf

The research will examine blood and muscle oxygen store depletion in relation to the documented aerobic dive limit (ADL, onset of post-dive blood lactate accumulation) in diving of emperor penguins. The intellectual merits of this proposal involve its evaluation of the physiological basis of the ADL concept. The ADL is probably the most commonly-used, but rarely measured, factor to interpret and model the behavior and foraging ecology of diving animals. Based on prior studies, and on recent investigations of respiratory and blood oxygen depletion during dives of emperor penguins, it is hypothesized that the ADL is a result of the depletion of myoglobin (Mb)-bound oxygen and increased glycolysis in the primary locomotory muscles. This project will accurately define the physiological mechanisms underlying the ADL through 1) evaluation of the rate and magnitude of muscle oxygen depletion during dives in relation to the previously measured ADL, 2) characterization of the hemoglobin-oxygen dissociation curve in blood of emperor penguins and comparison of that curve to those of other diving and non-diving species, 3) application of the emperor hemoglogin-oxygen dissociation curve to previously collected oxygen and hemoglobin data in order to estimate the rate and magnitude of blood oxygen depletion during dives, and 4) measurement of muscle phosphoocreatine and glycogen concentrations in order to estimate their potential contributions to muscle energy metabolism during diving. The project also continues the census and monitoring of the emperor colonies in the Ross Sea, which is especially important in light of both fisheries activity and the movement of iceberg B15-A. Broader impacts of the project include: 1) technological development of microprocessor-based, 'backpack' near-infrared spectrophotometer, which will be applicable not only to other species, but also to other fields (i.e., exercise physiology), 2) collaboration with the Department of Anesthesia at the U.S. Naval Hospital in San Diego in the training of anesthesia residents in research techniques, 3) the training and thesis research of two graduate students in these techniques and in Antarctic field research, and 4) a better understanding of the ADL concept and its use in the fields of diving behavior and physiology. In addition the annual census of emperor penguin colonies in the Ross Sea, in conjunction with the continued evaluation of previously developed remote cameras to monitor colony status, will form the basis of a new educational web site, and allow development of an educational outreach program to school children through SeaWorld of San Diego.

Percentage of time spent in each activity between departure from the colony and arrival at the ice edge for emperor penguins at Cape Washington in the Ross Sea, Antarctica.

The spreadsheet lists positions of 27 emperor penguin colonies in East Antarctica (Umebosi to Yule Bay) based in Sentinel-2 images. Records are based on all images available throughout the breeding seasons 2018-2023. See https://browser.dataspace.copernicus.eu/ The period covered is 2018-2023.

As a species highly reliant on stable fast ice as a breeding platform, emperor penguins are increasingly challenged in their breeding attempts due to changes in fast ice conditions. We collated habitat information of 27 emperor penguin colonies in East Antarctica (43–167°E) from 2018 to 2023 using European Space Agency Sentinel-2 satellite images. Our objective was to examine the variability in habitat and ice conditions and associated repercussions for colony movements and breeding success. Variables, such as location, colony movement and inter-annual variability in these parameters, were used to assess the adaptability of emperor penguins when local conditions change markedly. The major challenge emperor penguins currently face throughout Antarctica is untimely loss of breeding habitat resulting in increased or complete breeding failure, as observed in 8 colonies at least once during the study. One small colony at the West Ice Shelf lost its breeding area and has not been seen since 2021. The inter-annual movement of some colonies demonstrates the species' adaptability and the need for ongoing monitoring of the global emperor penguin population using satellite imagery. We highlight caveats, such as availability of suitable satellite images and movement of colonies, that need to be accounted for to ensure sound interpretation of the monitoring findings. Ongoing Antarctic-wide monitoring is essential to quantify the impact of changing fast ice conditions on emperor penguins and also the cumulative impacts of other threats such as disease. The information presented is to provide background and empirical data for researchers, policy makers and managers.

Comparison between at-sea-ecological studies that equipped emperor penguins over the last 30 years.

MEE_SPOT_Fig5_ColonyLocomotionMeteorological data and time lapse image recordings (04/02/2013 to 04/07/2013) used to evaluate the influence of wind speed and wind direction on the position of the Atka Bay emperor penguin colonyMEE_SPOT_Fig6_SingleLocomotionVideo (4008x2672, 5 fps, 60s) recorded on 07/22/2013 at 11:40:47 UTC used to evaluate the movement characteristics of single emperor penguins at the huddle boundariesMEE_SPOT_Fig4_AbundanceHigh resolution panoramic images for 04/01/2014 to 04/21/2014 used to evaluate emperor penguin numbers and arrival pattern