22 Updated Cetacean Red List Assessments Published in December 2020

Between 2018 and 2020, the Cetacean Specialist Group has undertaken a re-assessment of all cetacean species, a task that is now virtually complete. The 2020-3 edition of the Red List, which was published in December 2020, included 22 assessments or reassessments of cetacean species, subspecies or populations and included almost all of the beaked whales. This is in addition to 3 assessments published earlier in 2020, 6 in December 2019, 2 in July 2019, 5 in March 2019, 35 in November 2018, 10 in July 2018, and 19 in November 2017. A total of 102 updated or new cetacean assessments have been published in the last 2 ½ years.


The updated assessments included almost all of the beaked whales many of which moved out of the Data Deficient category to Least Concern, while Perrin’s beaked whale (Mesoplodon perrini) is now Endangered, and Stejneger’s beaked whale (Mesoplodon stejnegeri) and a newly described species, Sato’s beaked whale (Berardius minimus), are both Near Threatened. Most of the changes for beaked whales resulted from the IUCN Guidelines changing the definition of Data Deficient and thus are not necessarily genuine changes in conservation status. To remain as Data Deficient, a species had to plausibly belong in any category from Critically Endangered to Least Concern.


Besides the beaked whales, the South American freshwater dolphin Sotalia fluviatilis, commonly known as the tucuxi, was reassessed and moved from Data Deficient to Endangered (Table 1). This change was due in large part to improved data and analyses. Re-assessments of the common dolphin (Delphinus delphis) and northern bottlenose whale (Hyperoodon ampullatus) will be published in the next Red List edition in 2021. Work on the two cetacean species that still require reassessment, and on some of the more out of date subpopulation and subspecies assessments, will begin in 2021.


Table 1 – Summary of updated assessments and new assessments published in the 2020-3 edition of the Red List. (NT = Near Threatened, DD = Data Deficient, CR = Critically Endangered, EN = Endangered, LC = Least Concern).

# Species/Subspecies Common name Taxonomic level Category Status change
1 Berardius arnuxii Arnoux’s beaked whale Species (global) LC DD -> LC
2 Berardius bairdii Baird’s beaked whale Species (global) LC DD -> LC
3 Berardius minimus Sato’s beaked whale Species (global) NT New listing
4 Hyperoodon planifrons Southern bottlenose whale Species (global) LC No change
5 Indopacetus pacificus Longman’s beaked whale Species (global) LC DD -> LC
6 Mesoplodon bidens Sowerby’s beaked whale Species (global) LC DD -> LC
7 Mesoplodon bowdoini Andrews’ beaked whale Species (global) DD No change
8 Mesoplodon carlhubbsi Hubbs’ beaked whale Species (global) DD No change
9 Mesoplodon densirostris Blainville’s beaked whale Species (global) LC DD -> LC
10 Mesoplodon europaeus Gervais’ beaked whale Species (global) LC DD -> LC
11 Mesoplodon ginkgodens Ginkgo-toothed beaked whale Species (global) DD No change
12 Mesoplodon grayi Gray’s beaked whale Species (global) LC DD -> LC
13 Mesoplodon hectori Hector’s beaked whale Species (global) DD No change
14 Mesoplodon hotaula Deraniyagala’s beaked whale Species (global) DD No change
15 Mesoplodon layardii Strap-toothed beaked whale Species (global) LC DD -> LC
16 Mesoplodon mirus True’s beaked whale Species (global) LC DD -> LC
17 Mesoplodon perrini Perrin’s beaked whale Species (global) EN DD -> EN
18 Mesoplodon peruvianus Pygmy beaked whale Species (global) LC DD -> LC
19 Mesoplodon stejnegeri Stejneger’s beaked whale Species (global) NT DD -> NT
20 Mesoplodon traversii Spade-toothed beaked whale Species (global) DD No change
21 Sotalia fluviatilis Tucuxi Species (global) EN DD -> EN
22 Ziphius cavirostris Cuvier’s beaked whale Species (global) LC No change


The Red List status and documentation for 89 (of the 90 currently recognised) cetacean species as well as 12 subspecies and 28 subpopulations can be found on the IUCN Red List website (redlist.org). Of the 89 species, 35% are assigned to a threatened category (i.e. CR, EN, VU, NT) and 12% are considered DD (Table 2). It should also be emphasized that there is strong interest in completing additional assessments of subpopulations that are known or thought to be at higher risk than the species as a whole (e.g. Killer Whales, Belugas, Dusky Dolphins).


Table 2. Summary information on Red List status as of December 2020.

Category Species Subspecies Subpopulations Total
Critically Endangered 4 4 14 22
Endangered 11 4 7 22
Vulnerable 7 4 5 16
Near Threatened 9 0 0 9
Least Concern 47 0 0 47
Data Deficient 11 0 2 13
Total 89 12 28 129


Secured By miniOrange