![rufus hummingbird rufus hummingbird](https://www.centralcoastbiodiversity.org/uploads/1/4/9/9/14993002/2465421_orig.jpg)
Spring temperatures have increased in the past century in much of this region, and birds arrived earlier in years with warmer spring temperatures to suggest that migratory advances are climate-related.
![rufus hummingbird rufus hummingbird](http://fieldguidetohummingbirds.com/wp-content/uploads/2014/07/HB-plate-sample.jpg)
Fewer days were noted between arrivals in more northerly areas in the recent time period suggesting that birds may now be migrating faster than in the previous time period. 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. Historical arrivals were reported through the North American Bird Phenology Program, and recent arrivals were estimated from temporal occupancy patterns using eBird checklists. Here, I compare mean first arrival dates of the Rufous Hummingbird ( Selasphorus rufus), a prolific pollinator and long-distance migrant with the northernmost breeding range of any North American hummingbird, between 1895–19–2015 at eight observation locations in Oregon, Washington, and British Columbia. Problems may arise ecologically if birds arrive or depart before or after associated food resources such as plants or insects reach critical lifecycle stages. Warming temperatures have been linked to advancing spring migration dates of birds, although most studies have been conducted at individual sites.