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From the abstract of the referenced paper: Satellite telemetry data are a key source of animal distribution information for marine ecosystem management and conservation activities. We used two decades of telemetry data from the East Antarctic sector of the Southern Ocean. Habitat utilization models for the spring/summer period were developed for six highly abundant, wide-ranging meso- and top-predator species: Adelie, Pygoscelis adeliae and emperor, Aptenodytes forsteri penguins, light-mantled albatross, Phoebetria palpebrata, Antarctic fur seals, Arctocephalus gazella, southern elephant seals, Mirounga leonina, and Weddell seals, Leptonychotes weddellii. The regional predictions from these models were combined to identify areas utilized by multiple species, and therefore likely to be of particular ecological significance. These areas were distributed across the longitudinal breadth of the East Antarctic sector, and were characterized by proximity to breeding colonies, both on the Antarctic continent and on subantarctic islands to the north, and by sea-ice dynamics, particularly locations of winter polynyas. These areas of important habitat were also congruent with many of the areas reported to be showing the strongest regional trends in sea ice seasonality. The results emphasize the importance of on-shore and sea-ice processes to Antarctic marine ecosystems. Our study provides ocean-basin-scale predictions of predator habitat utilization, an assessment of contemporary habitat use against which future changes can be assessed, and is of direct relevance to current conservation planning and spatial management efforts. The data files provided here comprise the model predictions of the preferred habitat for each of the six species listed above, as well as the overlap results obtained by combining these six sets of results. See the paper for methods used to generate the model predictions and to combine the individual species results. File names for individual species are of the form results_SPP_TYPE.asc, where SPP is one of "afs" (Antarctic fur seal), "ap" (Adelie penguin), "ep" (emperor penguin), "lma" (light-mantled albatross), "ses" (southern elephant seal), or "ws" (Weddell seal. TYPE is either "mean" (mean estimate of habitat preference) or "iqr" (inter-quartile range of uncertainty in the estimate; see paper for details). Data values for individual species results are percentiles of the study area, so that values of 90% or higher are pixels corresponding to the most important 10% of habitat for that species, values of 80% or greater are the top 20% of habitat, and so on. The overlap results files are named overlay_results_mean.asc and overlay_results_iqr.asc. Values in these files represent the average of the top four individual species results in a given pixel (see paper for details).
Metadata record for data from ASAC Project 106 See the link below for public details on this project. From the abstracts of some of the referenced papers: This paper reports the results of the first aerial photographic survey of Adelie penguin colonies in the Prydz Bay region. The area surveyed extended from the northern Vestfold Hills to the Publications Ice Shelf. More than 325,000 pairs of Adelie penguins were estimated to be breeding in this region in 1981/82. The great majority of breeding Adelie penguins occurred in the northern half of the region surveyed, in the Vestfold hills and Rauer Islands, where most colonies were located. This is probably due to the typical pattern of summer sea-ice dispersal, which usually results in sea-ice leaving the northern areas of the coast first. Prydz Bay supports nine seabird species that breed on the Princess Elizabeth Land coast: two penguins, six Procellariiformes and one skua. Information on their diet is reviewed. Apart from the scavenging South Polar Skua Catharacta maccormicki and Southern Giant Petrel Macronectes giganteus, three diet types were distinguished. First, the Emperor Penguin Aptenodytes forsteri ate almost exclusively fish; secondly the Adelie Penguin Pygoscelis adeliae, Cape Petrel Daption capense, and Wilson's Storm Petrel Oceanites oceanicus consumed at least 60% euphausiid, the remainder largely fish; and thirdly, a diet of greater than 60% fish, the rest euphausiids, was taken by the Southern Fulmar Fulmarus glacialoides, Antarctic Petrel Thalassoica antarctica and Snow Petrel Pagodroma nivea. Seasonal fluctuation in composition of Adelie Penguin, Cape Petrel and Southern Fulmar diet suggested either fluctuating foraging ranges or movement of Euphausia superba inshore during summer months. Annual fluctuation in diet composition was correlated with seabird reproductive success. When E. crystallorophias dominated the euphausiid component of Adelie Penguin diet, reproductive success was high; when E. superba was scarce in Prydz Bay, Antarctic Petrel and Southern Fulmar productivity was low. Breeding phenology, success and nest attendance of Antarctic Petrels Thalassoica antarctica and Southern Fulmars Fulmarus glacialoides at the Rauer Group, East Antarctica, are discussed. Most data were collected on Hop Island in January and February 1988, and from December 1988 to March 1989. Observations extended from the late stages of incubation to post-guard or fledging periods. Some annual breeding indices collected from 1983 onwards at census sites are compared with meteorological data and the extent of fast ice for the nearby Davis Station. Both species had a restricted hatching period, reflecting a brief and synchronised egg-laying period, reflecting a brief and synchronised egg-laying period, typical of other southern fulmarine petrels. Antarctic Petrel chicks hatched from 4 January (1989) and c. 90% appeared by 16 January (both years). Southern Fulmar hatching began on 21 January (1988) and almost all chicks appeared by 6 February (both years). Adult attendance at nests declined with increasing chick age. For Antarctic Petrels, this was most marked at about 11 days; no chicks had continuously attendant adults after 24 days, although adults returned to feed them. Incubation shifts following hatching and the post-guard period started, on average, 13 days after hatching. Egg and chick losses varied between years and sites. The South Polar Skua Catharacta maccormicki was apparently involved in the majority of losses. Nest sites of both species resemble those elsewhere: Southern Fulmars may require steeper sites, allowing a fall away from colonies. Antarctic Petrels are less affected by accumulation of snow or ice and shelter from katabatic winds may be important. Although weather may modify breeding success locally, annual success must depend on the ability of parents to produce eggs and feed chicks: this may be moderated by the extent and persistence of pack ice. Annual chick productivity and breeding success, recorded at four Adelie penguin, Pygoscelis adeliae, colonies at Magnetic Island in eastern Prydz Bay, are presented for the seven breeding seasons 1981/82 to 1987/88. The adult breeding population remained relatively stable during the first 4 years of the study, and increased in hte last 2 years. Substantial annual variation in breeding success occurred over the study period, ranging between an estimated 0.69 and 1.33 chicks surviving until late creche stage per nest for seasons 1985/86 and 1982/83 respectively. Annual patterns of chick productivity in southern fulmar, Fulmarus glacialoides, and Antarctic petrel, Thalassoica antarctica, populations within Prydz Bay were synchronous with those of Adelie penguins. In the years of highest and lowest reproductive performance, prey abundance within the likely foraging areas was correspondingly high and low. Reproductive performance was greatest in years when fast-ice breakout occurred before the end of December (1981/82, 1982/83. 1986/87 and 1987/88) and lowest when the breakout was after (1983/84, 1984/85 and 1985/86) and pack-ice cover persisted within the foraging range of the birds during the chick-rearing period.
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 2010-2011 season.
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 2011-2012 season.
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 Emperor Penguins. This project was based on collecting samples from Emperor penguins throughout the winter season. There were 5 sets of samples. 1-Adults during courtship in May 2-Adults during hatch period in early August 3-Chicks at ca 5 weeks of age--soon after leaving the constant care of their parents 4- Adults in early summer (mid-November) 5-Chicks in early summer (late November) Sampling at these intervals it was hoped we would be able to discriminate when or how the IBD antibodies appear in this population. The files are: 1) Project 2954-Emperor IBD Antibodies PrevalenceSummary This is a summary file of all the Virus Neutralization tests to determine the presence of antibodies to Infectious Bursal Disease (IBD) in the 5 groups of Emperor Penguins. 2) Project 2954-Emperor IBD summary graph This is a graphical representation of the summary information for IBDV antibodies 3) Project 2954-Emperor Penguin Egg Samples-2008 This is a listing of the abandoned eggs collected over the winter. The eggs were weighed and measured. Many were sampled. We took 5ml of yolk and stored the samples in -80 C for future analysis. 4) Project 2954-Emperor Penguin sampling2008 This is the master file of sampling. Each penguin we handled was given a sample identification (but no permanent identifying marks). Each was weighed, measured, inspected for ticks and samples taken. This file identifies which samples were obtained. In addition it represents some analyses. The sexes of many of the penguins have been determined genetically with PCR. That is included in the file. 5) Project 2954-Emperor Penguin Serology NDV and AI 2008 This file is a listing of all the serum samples and the results of Hemagglutination Inhibition test (HAI) for antibodies to Newcastle Disease Virus (NDV) and an antibody ELISA test for Avian Influenza. No sign of any exposure to NDV or AI in Emperor penguins. 6) Project 2954-Disease Status Poster-Peng Conf 2010 This Powerpoint file is a single oversized page that presents much of the results that we have to date. It was presented at the 7th International Conference on the Biology of Penguins, in Boston USA, Sept 2010 7) Project 2954-Searching for IBDV in Emperors with RT-PCR This MS WORD file is the summary of methods and results of testing tissue samples from chick carcasses found at the colony. Bursa and spleen tissue was preserved and sent to Daral Jackwood in Ohio USA. He conducted real time Reverse Transcriptase PCR on the samples to try to find the IBD virus. That is essential for the full identification of the source of antibodies in these penguins. Unfortunately all results were all negative. We hope with a new proposal to expand our testing to find this virus.
Metadata record for data from AAS (ASAC) Project 3024. Public The proposed research will derive improved estimates of East Antarctic fast-ice extent and thickness, and their variability, from satellite data. These will be used to explicitly test relationships between fast ice/other environmental parameters and Emperor penguin population dynamics. We shall also combine observations with a wave-ice shelf-sea ice interaction model to test the hypothesis that catastrophic ice shelf break-up events on the E. Antarctic Peninsula are linked to increased ocean wave energy associated with sea-ice extent anomalies (driven by atmospheric anomalies), and/or long-period swell from far-remote storms. This work will aid comprehension of processes responsible for recent rapid ice-shelf demise. Project objectives: 1. To measure and monitor East Antarctic fast ice areal extent and thickness, and their spatio-temporal variability, using satellite remote sensing. 2) To analyse the impact of fast ice variability on the breeding success of Emperor penguins (Aptenodytes forsteri). 3) To investigate the potential impact of sea ice on recent ice shelf break-up breakup on the Antarctic Peninsula. Taken from the 2008-2009 Progress Report: This project has shown a strong correlation between interannual fast ice variability and Emperor penguin breeding success at Dumont d'Urville, and has produced satellite-based maps of East Antarctic fast ice (radar snapshot mosaics from November 1997/98 and 20-day composite images for 2005-2008, extending back to 2000). Secondly, significant progress was made towards implicating an atmospherically-driven anomalous lack of sea ice in recent Antarctic ice-shelf disintegrations. Finally, new research highlights a previously-overlooked mechanical coupling between the floating Mertz Glacier tongue and very thick (greater than 25m) and old (greater than 20yrs) fast ice attached to it, with important implications for ice-sheet margin stability. Taken from the 2009-2010 Progress Report: Progress against objectives: 1) To measure and monitor East Antarctic fast ice areal extent and thickness, and their spatio-temporal variability, using satellite remote sensing. Considerable progress has been made against this objective, building on last year's publication of the first detailed "snapshot" maps of landfast sea ice (fast ice) extent around the East Antarctic coast from 75 degrees E-170 degrees E for the Novembers of 1997 and 1999 using RADARSAT satellite ScanSAR images (see Giles et al., 2008). The main achievements are: * The development of an improved semi-automated method to successfully derive fast ice extent (and pack ice motion) from time series of Envisat Advanced SAR images (Giles et al., in prep.), via a project with the European Space Agency and the International Space Science Institute (Berne, Switzerland). Fast ice is identified as regions of zero motion in the cross-correlation analysis of carefully co-registered pairs of satellite SAR images. * Significant progress in the PhD project (Alex Fraser) aimed at deriving longer and near-continuous time series of fast ice extent from time series of NASA MODIS visible and thermal IR imagery at 1 km resolution. A major challenge has been to address the problem of effectively 'removing' persistent cloud cover from the images. This has been achieved by compositing many thousands of MODIS images to create 20-day composite images of the entire East Antarctic coastal zone from 10W to 170E. This technique was showcased at the prestigious International Geoscience and Remote Sensing 2009 conference in South Africa in July 2009 (Fraser et al., 2009a), with subsequent publication by Fraser et al. (2009b). During the year, this work resulted in an important new time series of fast ice extent that runs from 2000 to 2008 inclusive (Fraser et al., in prep.), with techniques being described in Fraser et al. (in press). This unique dataset represents by far the most detailed estimate of East Antarctic fast ice and its spatio-temporal variability to date. It furthermore represents an important new baseline against which to gauge change, given that Antarctic fast ice is a key yet poorly understood component of the global cryosphere (and ocean freshwater budget), is of immense ecological significance (see 2 below), and is a sensitive indicator of climate change/variability. This baseline is directly comparable to the more familiar overall sea ice (pack ice) extent product. Work is underway to determine why large regional differences occur in fast ice distribution and behaviour, including analysis of the role of bathymetry, grounded icebergs and changes in wind patterns. This work also provides crucial regional-scale fast ice information in support of detailed localised fast ice measurements carried out within the Antarctic Fast Ice network at Casey and Davis (AAS 3032). * A collaborative project has been established with Drs Fricker (USA) and Legresy (France) to estimate the thickness of a large region of perennial fast ice adjacent and attached to the Mertz Glacier Tongue. This has been achieved by combining satellite imagery with surface elevation data from the NASA's ICESat laser altimeter satellite, although current unknowns include the thickness and density of the overlying snowcover. The results suggest that this fast ice is extraordinarily thick i.e. greater than 25 m, and may be at least 20 years old (Massom et al., subm., a). Work examining the glaciological significance of this extremely thick fast ice is described in 3 (below). Work is also underway to evaluate the impact on this and regional fast ice of the major calving of the Mertz Glacier in February 2010. 2) To analyse the impact of fast ice variability on the breeding success of Emperor penguins The first element of this multi-disciplinary, international study was completed last year i.e. a case study showing strong links between Emperor penguin breeding success at Dumont d'Urville and fast ice distribution along the Adelie Land coast of East Antarctica and its variability due to variability in the regional wind field. Results were published in Marine Ecology Progress Series (Massom et al., 2009a), and were also presented in a keynote address to the Xth SCAR International Biology Symposium in September 2009. Work is underway to extend this study both temporally and to other species and regions, using the new MODIS-derived time series of 20-day composite maps of fast ice extent (see 1 above). This work will include a comparison of the fast ice information with new data from French penguin scientists (Drs Barbraud, Ancel and LeMayo) on Emperor penguin mortality and other demographic parameters, with a view to discovering links between the penguin demographics and fast ice variability due to changing weather patterns. Further work is in its initial stages to study the impact of fast ice variability on i) Weddell seal foraging behaviour (with Dr Hindell's group at the Univ. of Tasmania), ii) Adelie penguin breeding success and foraging behaviour (with Drs Southwell and Emmerson, AAD), and iii) other Emperor penguin colonies in East Antarctica (with Dr Wienecke, AAD). Ongoing/future work will also evaluate the impact of abrupt change on the seals and penguins at Dumont d'Urville following the Mertz Glacier calving in February 2010.
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'.
This dataset contains data revealing the incidence of bacterial, viral and parasitic disease causing agents in Antarctic bird populations. Samples for disease analysis have been collected from various species of Antarctic birds during the course of ASAC project 953 and are stored at the Department of Microbiology, University of Western Australia and CSIRO Australian Animal Health Laboratories (AAHL). All analysis is being performed at the Department of Microbiology, University of Western Australia. A summary of samples collected and stored for each species is listed below. Adelie penguin (Pygoscelis adeliae): Serum (blood) and faecal (cloacal) swabs were collected from chicks and adults in the Mawson station area, the Vestfold Hills and Terra Nova Bay. Samples from approximately 1200 birds have been stored. Tissue samples have been collected from chick carcasses found in the Vestfold Hills area. Carcasses were collected on an opportunistic basis. Emperor penguin (Aptenodytes forsteri): Serum (blood) and faecal (cloacal) swabs were collected from chicks at Amanda Bay, Auster and Cape Washington. Tissue samples have been obtained from 20 chick carcasses collected from Auster Rookery. South polar skua (Catharacta maccormicki): Serum (blood) and faecal (cloacal) swabs were collected from 125 adult birds in the Vestfold Hills area. This project has close ties with ASAC project 1336 (ASAC_1336 - South polar skuas as vectors of disease). See that metadata record for related datasets. The fields in this dataset are: Infectious bursal disease virus Avian influenzae Avian adenovirus Sample Species Age Year Region Colony Location Stage of Breeding Season Blood Sample Cloacal Swab Serum
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