Royal Penguins at Macquarie Island
All Royal penguin colonies on Macquarie Island have been surveyed, and the method used judged as the most effective method of estimating the total abundance. Two methods were used for the survey depending on the terrain on which a colony was established. Method 1 (Ground survey method): In topograph...
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| Format: | Dataset |
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Australian Ocean Data Network
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| Online Access: | https://researchdata.ands.org.au/royal-penguins-macquarie-island/686783 https://data.aad.gov.au/metadata/records/AADC-00032 http://data.aad.gov.au/aadc/portal/download_file.cfm?file_id=1201 http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=AADC-00032 |
| Summary: | All Royal penguin colonies on Macquarie Island have been surveyed, and the method used judged as the most effective method of estimating the total abundance. Two methods were used for the survey depending on the terrain on which a colony was established. Method 1 (Ground survey method): In topographically regular areas, the area of the colony was surveyed during the winter when birds were absent. The colonies were viewed again in the following spring, when penguins were on their nests, in order to check for any major discrepancies between the area surveyed and that occupied by nests. The nest densities were obtained from two 10m by 10m plots staked out in the lower Sandy Bay colony. The plots were photographed in early November when only females were present at the nests and few failures would have occurred. Enlarged photographs of each plot was divided into four 5m by 5m sections and nest counts were made in each of them to obtain the mean number of nests per square metre and the standard deviation. The mean number of nests in the lower Sandy Bay plots was 2.43/m^2 (range at 95% confidence limits 2.32-2.54). In a few cases where pairs were evident they were counted as one nest. Areas within colonies with badly drained ground or large boulders were estimated separately with a slightly lower nest density per square metre. The number of nests was estimated by multiplying the mean nest density by the area of each colony. The range in the number of nests is given by 95% confidence limits of +/-2SE of the mean density. Method 2 (Estimates): The colonies on irregular sites (most of the west coast colonies) were visited in spring or early summer when birds were present. Upper and lower estimates of the number of breeding pairs were made. Breeding penguins were allocated to one of 57 colonies identified by location. Where two or more colonies were in the same general area each was recorded separately. Small groups of birds in close proximity to larger colonies (less that 250m away) were treated as satellite groups and included with the nearest large colony. Irregularities at the edges of the colonies and major changes of slope were allowed for when marking the colony outer limits with stakes. The areas occupied by vegetation 'islands' and rock stacks were deducted from the colony area. This dataset contains the results from surveys of Royal Penguins (Eudyptes schegeli) on Macquarie Island. The surveys were conducted between May 1984 and January 1985. The total number of Royal penguins breeding on Macquarie Island is estimated at 848,719 pairs (+/-10.5%). The sizes and locations of all 57 colonies are given. The results are listed in the documentation. All Royal penguins breeding at Macquarie Island were allocated to one of 57 colonies identified by locations and varying in size from 75 breeding pairs to over 160,000 breeding pairs. The mean number of nests in the Lower Sandy Bay plots was 2.43/m2 (range at 95% confidence limits 2.32-2.54). The occupied area given for Hurd Point colony has been reduced by 5% from that surveyed to allow for two areas included in the survey which were subsequently found not to be used by breeding birds in the 1984-85 season. The variation in the difference between the lower and upper estimates of individual colonies given in Table 2 ranges from 17% to 50%. This was mainly due to the extreme variability of the terrain and/or the degree of association with Rockhopper penguins. The number of breeding pairs calculated for the colonies surveyed through the winter was 487,932 (range 465,838 - 510,014). The total estimated for the unsurveyed colonies was 360,787 (range 294,100 - 427,475) breeding pairs. The total estimated number of breeding pairs of Royal penguins on Macquarie Island is 848,719 +/- 10.5% (range 759,938 - 937,489). The dataset includes two text files (csv format) detailing the number of breeding pairs at each colony, and an sketch map of Macquarie Island detailing the locations of the colonies. The fields in this dataset are: Colony Area Range Breeding Pairs |
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