American Robins Robins are arriving earlier than before, often before the snow has even melted. They have to wait out the snow in order to eat and breed. In Colorado, robins are migrating from low to high elevations where they breed two weeks earlier than they did in the 1970’s. (Tangley)

Mexican Jays In southern Arizona, the breeding season of Mexican Jays is as much as 10 days earlier now than in the 1970’s. The change correlates with higher spring temperatures, which rose nearly 4.5  F. (Tangley)

Red-Winged Blackbirds Red-winged blackbirds are arriving at breeding grounds in Michigan nearly 20 days earlier than the 1960’s. (Tangley)

Prothonotary Warblers These birds have been returning to breeding grounds in Virginia from South America and the Caribbean a day earlier for the past 20 years. (Tangley)

Loggerhead Sea Turtles Loggerhead sea turtles are coming ashore to lay their eggs about 10 days earlier than During this same time period, temperatures have increased by 1.5  F. Warmer temperatures are also affecting the sex of sea turtles because the gender of these reptiles is determined by sand temperature. (Tangley)

Red Squirrels Red squirrels are now bearing young about 18 days sooner This makes it the first known mammal to be evolving its phenology in response to global warming (Tangley)

Oaks Oaks are leafing out eight days earlier for every degree Celsius increase in temperature (Jensen)

Ash Ash trees are only leafing half as fast as the oaks (Jensen) Back to Student 10 Home