Heermann’s Gull
Larus heermanni

The Heermann’s Gull’s story, along with the Elegant Tern’s, is closely linked to a small, 142 acre island in the Gulf of California, called Isla Raza. Studies show nearly 95% of all Heermann’s Gulls are born there.
Humans have been the biggest threat to survival for the Heermann’s Gull. Population declines reached their low point in 1975, when their numbers fell to 55,000 pairs. Pesticide levels in their flesh reached high levels. Mexican fishermen poached eggs in large quantities, introduced mammals such as Black Rats (Rattus rattus) and House Mice (Mus mus) wreaked havoc on the remote islands they nested on, commercial fishing of sardines, anchovies, and other prey fish affected the nesting success for these gulls.
Things turned for the better in 1964 when the Mexican government established Isla Rasa as a seabird sanctuary. The rat and mouse invaders were eradicated in 1975. Pesticide levels in their tissue have been reduced in more recent years, and the current population is estimated at 350,00 individuals. Recently, nesting colonies have spread north, some even off the California coast.
Taxonomists regard the Heermann’s Gull as monotypic (i.e. there are no subspecies).
Most of my encounters with these gulls have come from the rocky cliff shoreline near La Jolla (California), my father’s birthplace. He was born in 1927, when La Jolla was a sleepy village with cobblestone streets. Life then was simpler, and little pressure from humans was put on wildlife. I worry today, as the wealthy upper-class continue building larger homes, and creeping ever closer to the shore.
Areas like the La Jolla Cove can attract seasonal congregations of bird and mammal sea life, and the aroma can become quite strong. Eventually storms wash all the decaying organic material out to sea, and clear the air. But during those pungent periods, I have heard locals bitching and moaning, claiming ‘someone should do something‘ to get rid of the birds. But California Sea Lions are likely the worst offenders leaving obnoxious organic deposits. But Brandt’s Cormorants nest on these cliffs. And Brown Pelicans, multiple gull species (including our Heermann’s), terns, and shorebirds frequently rest on cliff ledges.
15 Photos

Heermann's Gull(Larus heermanni) |
Description: The channel entering Morro Bay is a great place to meet Sea Otters and many birds. San Juis Obisbo County California. |
Date Taken: 2017:09:17 14:09 |
Location:
Morro Bay |
Camera Information: NIKON D5, 800 mm, f/8.0, 1/2500 |
File Name: HeermannsGull_D5X4319-MorroBay |
© 2017 Jack Daynes, shadeTreeImaging.com |


Heermann's Gull(Larus heermanni) |
Description: 2018-12-17: At the Cove in La Jolla. San Diego County, California (USA) |
Date Taken: 2018:12:17 12:54 |
Location:
La Jolla Cove |
Camera Information: NIKON D500, 400 mm, f/8.0, 1/1600 |
File Name: HeermannsGull_D506047-La-Jolla-Cove |
© 2018 Jack Daynes, shadeTreeImaging.com |


Heermann's Gull(Larus heermanni) |
Description: Near The Cove. La Jolla, California. San Diego County. |
Date Taken: 2012:02:16 14:00 |
Location:
La Jolla |
Camera Information: NIKON D3X, 800 mm, f/5.6, 1/1600 |
File Name: D3X7211-HeermannsGull |
© 2012 Jack Daynes, shadeTree-Imaging |


Heermann's Gull(Larus heermanni) |
Description: Loafing at the Tijuana River Mouth in Imperial Beach, California. San Diego County. |
Date Taken: 2012:09:08 10:10 |
Location:
Border Field |
Camera Information: NIKON D3X, 800 mm, f/5.6, 1/2000 |
File Name: D3X8690-HeermannsGull |
© 2012 Jack Daynes, shadeTreeImaging.com |


Heermann's Gull(Larus heermanni) |
Description: Immature bird at the Cove. La Jolla, California. San Diego County 2012-03-02. |
Date Taken: 2012:03:02 13:14 |
Location:
La Jolla Cove |
Camera Information: NIKON D3X, 800 mm, f/5.6, 1/2000 |
File Name: D3X7603-HeermannsGull |
© 2012 Jack Daynes, shadeTreeImaging.com |


Heermann's Gull(Larus heermanni) |
Description: Near The Cove. La Jolla, California. San Diego County. |
Date Taken: 2012:02:16 14:06 |
Location:
La Jolla |
Camera Information: NIKON D3X, 800 mm, f/5.6, 1/3200 |
File Name: D3X7233-HeermannsGull |
(C) 2012 Jack Daynes, shadeTree Imaging |


Heermann's Gull(Larus heermanni) |
Description: The beach by Border Field and the Tijuana River Mouth in Imperial Beach, California. San Diego County. |
Date Taken: 2013:08:23 9:52 |
Location:
Border Field |
Camera Information: NIKON D3X, 800 mm, f/5.6, 1/3200 |
File Name: D3X1719-HeermannsGull |
© 2013 Jack Daynes, shadeTreeImaging.com |


Heermann's Gull(Larus heermanni) |
Description: Juvenile at the beach by Border Field and the Tijuana River Mouth in Imperial Beach, California. San Diego County. |
Date Taken: 2013:08:23 9:52 |
Location:
Border Field |
Camera Information: NIKON D3X, 800 mm, f/5.6, 1/3200 |
File Name: D3X1721-HeermannsGull |
© 2013 Jack Daynes, shadeTreeImaging.com |


Heermann's Gull(Larus heermanni) |
Description: The beach by Border Field and the Tijuana River Mouth in Imperial Beach, California. San Diego County. |
Date Taken: 2013:08:23 9:55 |
Location:
Border Field |
Camera Information: NIKON D3X, 800 mm, f/5.6, 1/5000 |
File Name: D3X1727-HeermannsGull |
© 2013 Jack Daynes, shadeTreeImaging.com |


HeermannsGull(Larus heermanni) |
Description: This bird has molted several flight feathers. Hartford Pier at San Luis Bay in San Luis Obispo along the coast of Central California. |
Date Taken: 2019:07:28 15:48 |
Location:
San Luis Bay |
Camera Information: NIKON D5, 800 mm, f/8.0, 1/2000 |
File Name: HeermannsGull_D5X9646-SanLuisObisbo |
© 2019 Jack Daynes, shadeTree Imaging |


Heermann's Gull(Larus heermanni) |
Description: Part of the collection at the Western Foundation of Vertibrate Zoology in Camarillo, California. |
Date Taken: 2011:11:02 9:09 |
Location:
W. Fdn. of Vertibrate Zoology |
Camera Information: NIKON D3X, 105 mm, f/8.0, 1/5 |
File Name: HeermannsGull_D3X4611-Eggs |
© 2011 Jack Daynes, shadeTree Imaging |


Heermann's Gull(Larus heermanni) |
Description: Part of the collection at the Western Foundation of Vertibrate Zoology in Camarillo, California. |
Date Taken: 2011:11:02 9:07 |
Location:
W. Fdn. of Vertibrate Zoology |
Camera Information: NIKON D3X, 105 mm, f/8.0, 1/5 |
File Name: HeermannsGull_D3X4610-Eggs |
© 2011 Jack Daynes, shadeTree Imaging |


Heermann's Gull(Larus heermanni) |
Description: South parking area of the Elephant Seal Viewing Area at Piedras Blancas north of San Simeon and south of Big Sur California. San Luis Obisbo County. |
Date Taken: 2017:09:16 9:10 |
Location:
Piedras Blancas |
Camera Information: NIKON D5, 800 mm, f/18.0, 1/800 |
File Name: HeermannsGull_D5X3013-PiedrasBlancas |
© 2017 Jack Daynes, shadeTreeImaging.com |


Heermann's Gull(Larus heermanni) |
Description: Adult bird near The Cove. La Jolla, California. San Diego County. |
Date Taken: 2008:09:10 11:58 |
Location:
La Jolla |
Camera Information: NIKON D2X, 800 mm, f/5.6, 1/640 |
File Name: jcd0426HeermannsGull |
© 2008 Jack Daynes, shadeTree Imaging |


Heermann's Gull(Larus heermanni) |
Description: Early morning at the La Jolla Cove with Royal Tern. San Diego California. |
Date Taken: 2018:07:15 9:06 |
Location:
La Jolla Cove |
Camera Information: NIKON D500, 800 mm, f/8.0, 1/1250 |
File Name: HeermannsGull_D504514-LaJolla |
© 2018 Jack Daynes, shadeTree Imaging |

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