SFGATE: The Secret Sex Lives of Harbor Porpoises Under San Francisco's Golden Gate Bridge
- Behavior
- Natural history
The species has a “funnel of love” below the city's most well-known landmark.
Published in SFGATE: December 7, 2023
Bill Keener’s eyes widened as he peered through his binoculars and spotted the dark, shiny dorsal fins swiftly bobbing along the surface of San Francisco Bay. “There’s three of them coming right at us,” he said.
It was a drizzly Tuesday morning in November, and the Marine Mammal Center field researcher and I had been wandering along the pedestrian walkway on the Golden Gate Bridge for about an hour. Cars whooshed past us as we dodged bicyclists and paused at lookout points, keenly peering over the steel railing toward the murky turquoise water about 200 feet below. We were hoping to catch a glimpse of the species he’s been closely tracking for decades: the harbor porpoise, a shy yet charismatic creature that nearly disappeared from the bay altogether.
Harbor Porpoise Research at The Marine Mammal Center
Harbor porpoises have returned to San Francisco Bay after an absence of approximately 65 years. The Center's Cetacean Field Research Team is conducting a multi-year assessment to document this population’s abundance and distribution, as well as to examine their social behavior and calving success.
{"image":"\/Animals\/Wild\/Harbor porpoise\/cropped-images\/harbor-porpoises-aerial-view-badge-by-marc-webber-c-the-marine-mammal-center-0-88-1280-999-1618509985.jpg","alt":"Harbor porpoises seen from above","title":"Coevolution of Asymmetric and Spiraled Genitalia with Unique Mating Behavior","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/coevolution-of-asymmetric-and-spiraled-genitalia-with-unique-mating-behavior","label":"Research Paper","type":"publication"}
Coevolution of Asymmetric and Spiraled Genitalia with Unique Mating Behavior
Read More{"image":"\/Animals\/Wild\/Harbor porpoise\/harbor-porpoise-shutterstock-2.jpg","alt":"harbor porpoise","title":"Harbor Porpoises Catching and Handling Large Fish","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/harbor-porpoises-catching-and-handling-large-fish","label":"Research Paper","type":"publication"}
{"image":"\/Animals\/Wild\/Harbor porpoise\/cropped-images\/harbor-porpoise-by-bill-keener-c-the-marine-mammal-center-309-73-1207-943-1610670087.jpg","alt":"Harbor porpoise surfacing in the water","title":"The Sex Life of Harbor Porpoises: Lateralized and Aerial Behavior","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/the-sex-life-of-harbor-porpoises-lateralized-and-aerial-behavior","label":"Research Paper","type":"publication"}
{"image":"\/Animals\/Wild\/Harbor porpoise\/cropped-images\/harbor-porpoises-foraging-by-marc-webber-c-the-marine-mammal-center-4-0-1276-996-1618438446.jpg","alt":"harbor porpoises eating a large fish","title":"Prey-Related Suffocation in Harbor Porpoises","link_url":"https:\/\/www.marinemammalcenter.org\/publications\/prey-related-suffocation-in-harbor-porpoises","label":"Research Paper","type":"publication"}
Yes, I want to save a life!
Yes, I want to save a life!
You’ll be giving sick and injured animals the best possible care at the Center’s state-of-the-art hospital. With your gift today, you are giving a patient a second chance at life in the wild.
See Our Latest News
{"image":"\/People\/Action\/Veterinary care\/cropped-images\/dane-whitaker-and-emily-whitmer-vaccine-trial-by-bill-hunnewell-49-0-1270-992-1757364612.jpg","alt":"Two veterinarians collect a blood sample from an elephant seal in a rehabilitation pen.","title":"Bird Flu Vaccine Trial May Offer Hope for Protecting Hawaiian Monk Seals","link_url":"https:\/\/www.marinemammalcenter.org\/news\/bird-flu-vaccine-trial-may-offer-hope-for-protecting-hawaiian-monk-seals","label":"News Update","date":"2025-09-09 09:13:00"}
Bird Flu Vaccine Trial May Offer Hope for Protecting Hawaiian Monk Seals
September 9, 2025
Read More{"image":"\/Animals\/Patients\/Elephant seals\/2025\/cropped-images\/es-vaccine-trial-satellite-tag-by-bill-hunnewell-218-0-1270-992-1757432410.jpg","alt":"Northern elephant seal","title":"The New York Times: Scientists Begin Testing Bird Flu Vaccine in Seals","link_url":"https:\/\/www.marinemammalcenter.org\/news\/the-new-york-times-scientists-begin-testing-bird-flu-vaccine-in-seals","label":"In the News","date":"2025-09-09 02:00:00"}
The New York Times: Scientists Begin Testing Bird Flu Vaccine in Seals
September 9, 2025
Read More{"image":"\/Animals\/Patients\/Sea otters\/2025\/cropped-images\/so-mooring-release-2-laurie-miller-c-the-marine-mammal-center-USFWS-permit-MA101713-1-80-0-1270-992-1757003194.jpg","alt":"A southern sea otter rests in the ocean after being released from rehabilitative care.","title":"Entangled in Ocean Trash, Sea Otter Mooring Gets a Second Chance at Life","link_url":"https:\/\/www.marinemammalcenter.org\/news\/entangled-in-ocean-trash-sea-otter-mooring-gets-a-second-chance-at-life","label":"Patient Update","date":"2025-09-05 02:00:00"}
Entangled in Ocean Trash, Sea Otter Mooring Gets a Second Chance at Life
September 5, 2025
Read More{"image":"\/Animals\/Patients\/Harbor seals\/2025\/cropped-images\/denali-hs-photo-by-clive-beavis-c-the-marine-mammal-center-79-0-1270-992-1756314221.jpg","alt":"2026 marine mammal center calendar cover star","title":"Pacific Harbor Seal Denali Chosen as the 2026 Calendar Cover Star","link_url":"https:\/\/www.marinemammalcenter.org\/news\/vote-for-your-favorite-marine-mammal-to-be-the-2026-calendar-cover-star","label":"News Update","date":"2025-08-04 02:00:00"}
Pacific Harbor Seal Denali Chosen as the 2026 Calendar Cover Star
August 4, 2025
Read Morenatural history
Bill Keener
Harbor Porpoise