BECHERVAISE ISLAND
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Adelie penguin foraging trip duration records for Bechervaise Island, Mawson since 1991-92. Data include average male and female foraging trip durations for both the guard and creche stages of the breeding season. Data based on records of tagged birds crossing the APMS for in and out crossings. Durations determined from difference between out and in crossings in conjunction with nest census records. Data included only for birds which were known to be foraging for a live chick. This work was completed as part of ASAC Project 2205, Adelie penguin research and monitoring in support of the CCAMLR Ecosystem Monitoring Project. The fields in this dataset are: Year trip duration (hours) Mean , standard error, count and standard deviation for male and female foraging trips during guard and creche stages of the breeding season.
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Adelie penguin breeding success records for Bechervaise Island, Mawson since 1990-91. Data include counts of occupied nests and chick counts when either 2/3 of the nests have creched or when all nests have creched. Breeding success values are calculated as the number of chicks per occupied nest. Breeding Success = the number of chicks raised to fledging per nest with eggs Breeding success is calculated from four different whole island counts: 1) the number of incubating nests (i.e. the number of nest with eggs) - 'incubating nest count' 2) the number of brooding nests (i.e. the number of nests brooding chicks) - 'brooding chick count' 3) the number of chicks present when 2/3 of the nests have creched their chicks - '2/3-creche count' 4) the number of chicks present when all the nests have creche their chicks - 'fully-creche count' Each colony on the island is manually counted by field observers, using 'counters', three times each. Counts within 10% of each other are used to average the number of nests or chicks for each colony and then in later calculations to determine breeding success. Incubating nest counts are conducted on or about 2nd December; Brooding chick counts are conducted on or about the 7th January; 2/3-creche counts on or about the 19th January; and Fully-creche chick counts on or about 26th January. Whole island 2/3-creche and fully-creche chick count dates are determined from calculating when 2/3 and all study nests in the census area (study colonies) have creche their chicks. This work was completed as part of ASAC Project 2205, Adelie penguin research and monitoring in support of the CCAMLR Ecosystem Monitoring Project. The fields in this dataset are: Year Breeding success Occupied nests
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This indicator is no longer maintained, and is considered OBSOLETE. INDICATOR DEFINITION Demographic parameters for the Adelie penguin at Bechervaise Island near Mawson. TYPE OF INDICATOR There are three types of indicators used in this report: 1.Describes the CONDITION of important elements of a system; 2.Show the extent of the major PRESSURES exerted on a system; 3.Determine RESPONSES to either condition or changes in the condition of a system. This indicator is one of: CONDITION RATIONALE FOR INDICATOR SELECTION The Adelie penguin is a relatively long lived sea bird dependent on krill. It is expected that major changes in the availability of food (krill) to sea birds will be reflected ultimately in recruitment into the breeding population. Causes of changes in the availability of krill relate directly to changes in both the biological and physical environment brought about by man made or natural means. Ageing populations may give an outward appearance of stability in terms of numbers at a breeding colony but such a condition may mask a decline in recruitment. To determine whether there are environmental influences on the population it is necessary to undertake detailed demographic studies. Demographic studies carried out over many years on animal populations comprising known age cohorts are required to determine those factors responsible for any observed changes in recruitment and/or mortality. Population reconstruction techniques provide estimates of recruitment and mortality and relate these functions to population size and/or population trends. These studies may alert us to possible changes in the ecosystem particularly related to the availability of food to the penguins or changes to the physical environment. The identification of the cause of changes must come from detailed investigations of food availability and the environment carried out at the same time. Annual breeding success at Bechervaise Island (eggs laid to chicks fledged) varies enormously from 0 in catastrophic years to above 1 for good seasons. The population at Bechervaise Island near Mawson has been monitored since 1990 as part of the CCAMLR Ecosystem Monitoring Program. Chicks and adults have been tagged annually. The number of breeding pairs has increased slightly between 1990-2001, but changes in the non -breeding population are unknown. Demographic studies based on the return rate of birds tagged as chicks provide information on trends in the overall population and the net rate of recruitment. Since it is intended that this program be undertaken indefinitely it makes this population an excellent subject for monitoring in the context of the SOE. DESIGN AND STRATEGY FOR INDICATOR MONITORING PROGRAM Spatial Scale: Restricted to the Mawson region. Similar studies are carried out by other national research programs at Terra Nova Bay (Italy) and on the Antarctic Peninsula (USA). Frequency: Annual Measurement Technique: The Adelie penguin population at Bechervaise Island consists of approximately 1800 breeding pairs. Each breeding season since 1990/91 in excess of 250 chicks have been given implanted electronic identification tags. The return of birds to their natal colony has been detected automatically by the Automated Penguin Monitoring System (APMS)or by checking all birds with a hand held tag reader. Additional and associated biological data as prescribed by CCAMLR (1997 are collected to aid interpretation of demographic and other trends. To detect trends in the population size and in demographic parameters, particularly of recruitment, it will be necessary to maintain an annual tagging program of chicks and recording of all tagged birds. RESEARCH ISSUES comprehensive analysis of the data collected over the duration of this study is required to determine natural variation and potential anthropogenic influences affecting Adelie penguin population dynamics. LINKS TO OTHER INDICATORS Sea-ice extent and concentration.
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Intermittent Adelie penguin population counts for Bechervaise, Verner and Petersen Islands, Mawson since 1971. Data include counts of occupied nests for the post 1990/91 data conducted on or about 2nd December. Data collected prior to this were obtained from ANARE Research Notes or field note books. These counts may not have been performed at the 'optimal' time for occupied nests counts, and when this is the case have been adjusted according to a 'correction' factor. The post 1990/91 data were completed as part of ASAC Project 2205, Adelie penguin research and monitoring in support of the CCAMLR Ecosystem Monitoring Project. The fields in this dataset are: Year Bechervaise Island Counts Verner Island Counts Petersen Island Counts Date Season occ nests (occupied nests)