Olive-sided Flycatcher Migration & Breeding

The Olive-sided Flycatcher (Contopus cooperi) is a migratory landbird in steep decline. An estimated 78% population loss of this species has occurred in North America over the past 40 years. Our research seeks to reduce Olive-sided Flycatcher decline in Alaska and propose management solutions for recovery. There are two notable ways in which decline may occur:

Migration

Adults undertake one of the longest migratory journeys of any North American songbird. Adult mortality during migration likely exacerbates decline, as this species has one of the lowest reproductive rates of any North American songbird. Using cutting-edge technology (tags weighing <1gram) we have documented the first-ever migratory route of this species. Alaska breeders exhibit a remarkable ~20,500 km (12,700 mile) annual journey! This knowledge enables Alaska to work with other managers in the U.S. and internationally to identify and maintain habitat at important stops along the way. This ensure adults successfully return to nest in Alaska, some from as far south as Bolivia!

Breeding

Our studies revealed that Alaska exhibits one of the highest known rates of nest success for this species in North America. Approximately 75% of Alaska nests rear one or more chicks, compared to ~53% of nests in the Pacific Northwest. We have increased existing knowledge of Alaska nests by revealing characteristics associated with nest success and survival (e.g. habitat features, insect diet). The data will inform strategies to conserve or enhance breeding areas to restore populations.

Click on the link below to learn more about the biology and identification: www.allaboutbirds.org/guide/Olive-sided_Flycatcher/id

Video

Parent feeding four large chicks in tree top nest.
Parent feeding four large chicks in tree top nest.

A parent stops by briefly to feed them. The spruce tree, nest, and chicks are blowing in the wind– don’t get seasick! (Video: N. Newberry, ADFG)

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Adult perched on tree top giving alarm
Adult perched on tree top giving alarm "pip-pip" call.

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Audio

Olive-sided Flycatcher Audio from ADFG

Gallery

Olive-sided flycatcher atop a dead tree snag in boreal habitat, central Alaska. Photo: J. Hagelin, ADFG - Alaska Department of Fish and Game (ADFG) Olive-sided Flycatcher with light-level geolocator on its back. Photo: J. Hagelin, ADFG - Alaska Department of Fish and Game (ADFG) Olive-sided Flycatcher in the hand (Photo: J. Hagelin, ADFG) - Alaska Department of Fish and Game (ADFG) Two Olive-sided Flycatcher nestlings. Broods usually contain 2-4 eggs and chicks. Alaska nests are often built in black spruce habitat in live trees. Nests constructed of sticks and lined with lichen. - Alaska Department of Fish and Game (ADFG) - Alaska Department of Fish and Game (ADFG) After an OSFL territory with a singing bird is located, we set up several mist nets, often in a V-shaped pattern. Mist nets are very tall, attached to poles and vertical to the ground. Mistnets are made of fine material similar to a hair net and are especially made for trained scientists to safely capture songbirds. We also set up a bird decoy (center) attached to an upright stick and play bird song with a device hidden in the brush directly below the decoy. The territory owner views the decoy as a singing intruder! When the territorial bird comes close to investigate, it is safely captured in a mistnet. In 10-20 minutes, the bird is banded, measured, and has a small tag attached to track its migratory route, before it is released. Photo: E. Allaby, ADFG - Alaska Department of Fish and Game (ADFG) Adult bird in hand, sealing the ends of plastic leg bands that are uniquely color coded to the individual. This enables us to identify individuals when they return, and continue to re-sight them over the years. Resight data helps us estimate rates of adult mortality. Photo: J. Hagelin - Alaska Department of Fish and Game (ADFG) We sometimes hike into the field with plenty of gear, including (sometimes) a collapsible ladder! This helps us gain access to a few nest trees that are relatively low to the ground to understand characteristics of successful nests. Photo: E. Allaby, ADFG - Alaska Department of Fish and Game (ADFG) Not all OSFL nests are low to the ground, but some in central Alaska often occur in small trees, which are accessible with a telescopic ladder. This enables us to measure chicks and nest characteristics (once chicks depart). Both types of data helps us understand reproductive success in Alaska. Photo: J. Hagelin, ADFG. - Alaska Department of Fish and Game (ADFG) Parents rear ~2-4 OSFL young in ~20 days. This chick is ~12 days old. Young were gently removed from nest, placed in cotton drawstring “bird bag” (in background), in order to safely and quickly bring them down for measuring and banding. Each receives a uniquely numbered metal (Federal) bird band and is carefully put back. Contrary to urban myth, scent of human handling does not impact chicks– parents readily accept and feed their young when placed back in the nest. Photo: E. Allaby - Alaska Department of Fish and Game (ADFG) Begging chick that is ready to fledge (~20 days old) still in its nest (the others have just left, and this one is about to leave, too!). Note the mouthparts are particularly bright/colorful in young birds. Photo: E. Stacey. - Alaska Department of Fish and Game (ADFG) ADFG Wildlife Biologist Julie Hagelin handling an an Olive-sided Flycatcher that has just returned to Alaska from its year-long migratory journey to South America (Photo: E. Stacey, ADFG). - Alaska Department of Fish and Game (ADFG) - Alaska Department of Fish and Game (ADFG) - Alaska Department of Fish and Game (ADFG) - Alaska Department of Fish and Game (ADFG) - Alaska Department of Fish and Game (ADFG) Male OSFL in typical location– acting as 'lookout' on his territory, typically from a dead-topped tree. Birds also catch insects on the wing from these perches, given their diet specializes in aerial insects. If you zoom in and look closely on bird’s right leg, you can BARELY see a yellow band right next to its belly. This demonstrates the challenges of detecting individually-color-banded birds from year to year. It takes patience to properly ID a returning migrant! Photo: N. Newberry. - Alaska Department of Fish and Game (ADFG) Date scrolling across the top for a mated pair (male and female) that nested in central Alaska. Data from light-level geolocators look like a daily 'cloud' of data, with the most probable location of bird in center. If we compile these daily clouds, we can reveal migratory route, and get a sense of where birds slowed or stopped along the way. These light-level geolocator data differ from GPS data. Light-level geolocators give a coarse estimate of a bird's location. GPS units provide pinpoint accuracy, but are heavier and currently do not yield daily measures for songbirds the size of OSFL over an entire year. 4) During the fall and spring Equinox (and several days on either size of each equinox), you may notice the data clouds appear 'smeared'. The birds are not actually travelling in this manner! When light levels are similar across the globe and it is simply harder to determine the location of a bird wearing a light-level geolocator. - Alaska Department of Fish and Game (ADFG) Overlay all daily location estimates for all birds in our study, count up when multiple birds overlap, generate a heat map. Enable us to static snapshot compare differences in fall and spring migration routes, as well as where overlap of Alaska breeders is greatest.Important locations in spring, you might want to focus conservation efforts in Pacific NW and BC. But year-round, clear corridor over smaller land mass in S. mexico and central America is important. - Alaska Department of Fish and Game (ADFG) Static map of migration for a single bird. Male F202 spent 71 days breeding in Anchorage, Alaska, before moving south in the fall, which included crossing the Gulf of Mexico. (Colored points indicate most likely location at he center of a gray 'data cloud'). F202 wintered for 177 days in Ecuador and/or Northern Peru, then returned in the spring to Anchorage again, where its data tag was collected within 10 yards of where it was deployed the previous year! - Alaska Department of Fish and Game (ADFG) Photo by Kerry Howard - Alaska Department of Fish and Game (ADFG)
Partners/Acknowledgements
US Fish and Wildlife Service, Migratory Bird Management, Region 7
Tetlin National Wildlife Refuge
Bureau of Land Management, Eastern Interior Field Office, Fairbanks, AK
University of Alaska Fairbanks, Museum of the North
Smithsonian National Zoological Park, Conservation Biology Institute
University of Alaska Anchorage
University of Alberta
Environment and Climate Change Canada
Yukon College
American Bird Conservancy
Biodiversity Research Institute (BRI)
Center for Environmental Management Military Lands (CEMML), Colorado State University
U.S. Army Garrison Alaska
Joint Base Elmendorf-Richardson's 673 CES/CEIS