2020-21 abundance estimate
In 2020 DOC and Ministry for Primary Industries, in collaboration with Auckland and Oregon State Universities, began a repeat of the abundance estimate of Maui dolphins.
The revised population estimate was carried out over two summer seasons, 2020 and 2021. The 2020 and 2021 field reports are available below.
- The abundance of Maui dolphins over 1 year of age was estimated to be 54 with a 95% confidence interval of 48 to 64 (this means that the researchers are 95% confident that there are between 48-64 Maui dolphins over the age of 1 year within the survey area).
- Over both years a total of 84 biopsy samples were collected from a total of 43 individual dolphins.
- 22 of these individuals were females
- 13 individuals were sampled in both years
- 41 individuals were identified as Maui dolphins
- 2 individuals (one male and one female) were identified as Hector’s dolphins, both sampled in 2020 and not resampled in 2021. The female Hector’s dolphin was first identified in 2010, while the male had not been sampled previously.
The 2020 and 2021 field seasons were successful in matching the effort of the 2010/2011 surveys and the 2015/2016 surveys, with a comparable number of surveys, duration of the survey period and coverage of the primary known habitat for Maui dolphins.
Estimating the abundance and effective population size of Māui dolphins in 2020 – 2021 using microsatellite genotypes, with retrospective matching to 2001:
Māui dolphin biopsy sampling survey field reports and preliminary results:
Previous abundance estimates