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Title: CHANGES IN SPRING ARRIVAL DATES OF RUFOUS HUMMINGBIRDS (SELASPHORUS RUFUS) IN WESTERN NORTH AMERICA IN THE PAST CENTURY
Warming temperatures have been linked to advancing spring migration dates of birds, although most studies have been conducted at individual sites. Problems may arise if birds arrive or depart before or after associated food resources reach critical lifecycle stages. I compared mean first arrival dates of Rufous Hummingbird (Selaphorus rufus), a prolific pollinator and long-distance migrant, between 1895-1969 and 2006-2015 at eight locations in Oregon, Washington, and British Columbia. Historical arrivals were reported through the North American Bird Phenology Program and recent arrivals were estimated from temporal occupancy patterns using eBird checklists. Results indicated that hummingbirds arrived 8 and 11 days later in the recent time period in two coastal cities in Oregon and 7-17 days earlier in northern, more inland cities in Washington and British Columbia. Spring temperatures have increased in the past century in much of this region and birds arrived earlier in years with warmer spring temperatures, suggesting that migratory advancements were climate-related. Later arrivals reported in coastal regions of Oregon in the recent time period may suggest that Rufous Hummingbirds are bypassing coastal areas to take advantage of more predictable conditions along inland migratory routes, or are shifting their breeding ranges northward, notions both supported by declining population trends observed in Breeding Bird Survey data. My results provide justification for the investigation of the ecological impacts of climate change on birds in coastal vs. inland environments and a framework for comparing information from two extensive and emerging datasets to better understand the impacts of climate change on bird migration.  more » « less
Award ID(s):
1541342
PAR ID:
10025395
Author(s) / Creator(s):
Date Published:
Journal Name:
Wilson Ornithological Society Annual Meeting
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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