North Atlantic Right Whale Calving Season Produces Highest Number of Births Since 2009

Special to the Transcript

The North Atlantic right whale calving season has come to a close with the highest number of calves recorded since 2009.

The annual calving season in the southeastern United States, which runs from mid-November until mid-April, produced 23 mother-calf pairs, the fourth-highest count ever. It’s positive news for the critically endangered species with an estimated population of about 380.

Scientists with the Anderson Cabot Center for Ocean Life at the New England Aquarium have been tracking the season closely and were pleased to see shorter intervals between calving for the majority of the whale moms.

“While a healthy right whale can give birth every three to four years, we had been seeing nearly 10 years between calves for some females. Many of this year’s moms have had shorter intervals—18 of them previously gave birth within the last six years—giving us hope that they may be healthier and can help grow the population faster,” said Amy Warren, Scientific Program Officer in the Aquarium’s Anderson Cabot Center.

Aerial survey teams from Florida, Georgia, and the Carolinas conducted regular flights on the calving grounds throughout the season. By the end of the calving season, most of the right whales had begun migrating north. At least 18 of the 23 mother-calf pairs have been seen in Massachusetts waters so far this spring. Research teams from the New England Aquarium’s Anderson Cabot Center have documented over one-third of those pairs in Cape Cod Bay this past month.

There are three first-time mothers this season: “Callosity Back” (Catalog #3760), “Mirror” (Catalog #4617), and unnamed right whale Catalog #4610. Two of these moms, Mirror and Catalog #4610, are just 10 years old, which is the age scientists expect females to begin calving. This contrasts with Callosity Back who, like many other right whales in recent years, was nearly 20 years old before having her first calf. This season’s moms also include two elder right whales, “Juno” (Catalog #1612) and “Ghost” (Catalog #1515), who are both at least 40 years old and have now given birth to at least nine calves each—just one calf shy of the current calving record.

“This year’s multi-generational cohort is a great example of the breadth of the information in the North Atlantic Right Whale Catalog. ‘Mantis’ (Catalog #1620) and her adult daughter ‘Squilla’ (Catalog #3720) are both moms this year. ‘Bocce’ (Catalog #3860) and ‘Millipede’ (Catalog #3520) are sisters, and their aunt ‘Slalom’ (Catalog #1245) is also a mom this year. We have other aunt-niece pairs and even a great aunt. These extensive family trees and life histories would not be possible without the contributions of the broader right whale research community,” Warren said.

In collaboration with a network of individuals and research organizations along the eastern seaboard, scientists in the Aquarium’s Anderson Cabot Center curate the North Atlantic Right Whale Catalog, an extensive photo-identification database that allows them to track right whales’ life stories including births, injuries, migration patterns, and age to create detailed histories of each individual whale. Scientists use this information to create a detailed list of mom-calf pairs with biographical information each calving season. This season’s list is available on the Aquarium’s website.

“It is hopeful to see 23 new calves born this year, but their survival into adulthood is still a long journey ahead in an ocean with many dangers and obstacles,” Warren added.

Right whales are experiencing an Unusual Mortality Event precipitated by increased injuries and deaths from human impacts, which is affecting the animals’ ability to survive and reproduce. While conservation and management efforts have progressed, the critically endangered species still faces threats including fishing gear entanglements and vessel strikes.

The New England Aquarium is a nonprofit research and conservation organization that has protected and cared for our ocean and marine animals for more than 55 years. We provide science-based solutions and help shape policies that create measurable change to address threats the ocean faces. We inspire action through discovery and help create engaged, resilient communities.