Northern harriers, long-winged rodent-hunting hawks, make impressive migrant journeys. Research by UC Davis’ Hull Lab sheds new light on these journeys. Harriers are a familiar sight in California’s wetlands, especially in winter. Researchers captured fifteen female harriers–ten in winter, five in spring–in Suisun Marsh and equipped with 14-gram GPS backpack transmitters, too heavy for use with the smaller males. Telemetry data from seven of the ten winter females revealed migrations of up to 600 miles, to nesting sites from the San Joaquin Valley to Washington State and Idaho.  The eighth, nicknamed Blanca for her pale yellow eyes, flew through British Columbia and Alaska all the way to the Arctic tundra, a 7,000-mile round trip that set a distance record for her species. She and her fellow travelers used wildlife refuge wetlands as stopovers. The five spring-caught females stayed closer to Suisun. Lead researcher Joshua Hull plans to use newly available 10-gram transmitters to track male harriers.  The project will help wildlife managers better understand the habitat needs of this raptor, a California Species of Special Concern whose numbers in Suisun Marsh and elsewhere have declined. 

Read More Hull Lab Harrier News

Plus Three Great Migration Stories by Joe Eaton. 

Pearls in the ocean of information that our reporters didn’t want you to miss

Migrations

Northern harriers, long-winged rodent-hunting hawks, make impressive migrant journeys. Research by UC Davis’ Hull Lab sheds new light on these journeys. Harriers are a familiar sight in California’s wetlands, especially in winter. Researchers captured fifteen female harriers–ten in winter, five in spring–in Suisun Marsh and equipped with 14-gram GPS backpack transmitters, too heavy for use with the smaller males. Telemetry data from seven of the ten winter females revealed migrations of up to 600 miles, to nesting sites from the San Joaquin Valley to Washington State and Idaho.  The eighth, nicknamed Blanca for her pale yellow eyes, flew through British Columbia and Alaska all the way to the Arctic tundra, a 7,000-mile round trip that set a distance record for her species. She and her fellow travelers used wildlife refuge wetlands as stopovers. The five spring-caught females stayed closer to Suisun. Lead researcher Joshua Hull plans to use newly available 10-gram transmitters to track male harriers.  The project will help wildlife managers better understand the habitat needs of this raptor, a California Species of Special Concern whose numbers in Suisun Marsh and elsewhere have declined. 

Read More Hull Lab Harrier News

Plus Three Great Migration Stories by Joe Eaton. 

Photo: Harrier courtesy Hull Lab, UC Davis


Senior Editor: Cariad Hayes Thronson

Social Media Editor: Sierra Garcia

Ideas for Pearls: Contact [email protected]com

About the author

Ariel Rubissow Okamoto is both today’s editor-in-chief and the founding editor of ESTUARY magazine (1992-2001). She enjoys writing in-depth, silo-crossing stories about water, restoration, and science. She’s a co-author of a Natural History of San Francisco Bay (UC Press 2011), frequent contributor of climate change stories to Bay Nature magazine, and occasional essayist for publications like the San Francisco Chronicle (see her Portfolio here). In other lives, she has been a vintner, soccer mom, and waitress. She lives in San Francisco close to the Bay with her architect husband Paul Okamoto.

Related Posts

subisdence on 4 delta islands map

Asked to suggest an appropriate future for four Delta islands owned by the Metropolitan Water District, it’s difficult not to want the moon.

Why not richer rice fields, more wetlands, better boat launches, extended trails, even eco-tourism? ? A new survey for the Delta Islands Adaptation Project, funded by a Prop 1 Watershed Restoration Grant, wants the public’s opinion on the importance of 10 possible land-use objectives leading to the selection of one...
chart by Hutton

An examination of 50 years of records reveals an apparent seasonal bias in estimates of freshwater flow from the Delta to the San Francisco Estuary.

The seasonal bias suggests flows were overestimated during the summer months and underestimated during the winter. Estimates of Delta outflow use a measurement called net Delta outflow index (NDOI), which is determined by taking the amount of Delta inflow, from sources such as the Calaveras, Sacramento, and San Joaquin rivers,...
diagram of fish net trawl

Fish monitoring surveys in the San Francisco Estuary net different numbers of different fish species depending upon when and how they sample.

According to a new study published in San Francisco Estuary and Watershed Science, even surveys that target the same part of the water column can come up with significantly different catches. The study’s authors analyzed decades worth of data from the California Department of Fish and Wildlife (CDFW) Fall Midwater...