The hummingbird feeders at Stokes Nature Center are a busy place this time of year. Little bullets of metallic green zoom in and out jockeying for position, while others rest or await their turn in the branches of nearby box elder trees. The birds are a great source of wonder and amusement for staff and guests alike.
June signals the start of nesting season for Utah hummingbirds. At this point in the year, the birds have mainly recovered from their lengthy migration from places as far away as Central America, and are ready to focus on their next set of challenges: establishing a territory, courtship, mating, and rearing young.
Hummingbird nests are a wonder all their own. Tiny and cup-like, they are generally found affixed to small branches near riparian areas. Nests are constructed primarily of plant materials and are lined with plant down such as the fluffy seeds produced by cottonwood trees. Materials used on the exterior of the nest vary from species to species. Black-chinned hummingbirds use leaves and flowers, while Broad-tailed hummingbirds are partial to decorating with lichens or shredded bark. Regardless of the exterior appearance, hummingbird nests have one important material in common – spider webs. Hummingbirds collect the webs and use them to plaster the outside of the nest, which serves two important purposes: acting as a glue that holds nest materials together while at the same time providing some flexibility that allows the nest to stretch and grow with the developing young.
Nests are occasionally constructed on the foundation of last year’s home, and two eggs around half-an-inch in length are laid and incubated by the female for about 16 days before hatching. Young will fledge and join their mother at your feeder about 20 days later. If nesting is successful, the family migrates south in the fall and will return to the same general area next May.
Finding food in early spring, however, is becoming more of a challenge each year to hummingbirds in the American West. A recent study published in the journal Ecology shows that hummingbird migrations and spring flower blooms are becoming out of sync. Broad-tailed hummingbirds in particular rely upon the nectar of petite, yellow glacier lilies – one of the first flowers to bloom in spring. Scientists have found that due to global temperature increases glacier lilies are blooming about 17 days earlier than they did in the 1970’s. The birds, however, haven’t altered their migration timing and so often arrive to find the flowers already in full swing. If this trend continues, scientists predict that within the next 20 years, the birds could miss the glacier lily bloom entirely. Hope lies in the hummingbirds’ ability to adapt– either by migrating farther north to places where lilies bloom later, or shifting their own migration time to match the changing bloom dates.
Photos of glacier lilies, Utah hummingbirds, and their nests, can be found on our website, www.wildaboututah.org. Thank you to the Rocky Mountain Power Foundation for supporting the research and development of this Wild About Utah topic.
For the Stokes Nature Center and Wild About Utah, this is Andrea Liberatore.
Images: Courtesy & Copyright 2010 Mike Fish
Courtesy & Copyright 2010 Andrea Liberatore
Courtesy & Copyright 2010 Lyle Bingham
Text: Andrea Liberatore, Stokes Nature Center in Logan Canyon.
Harrison, H. H. (1979) Peterson Field Guides: Western Birds’ Nests. Houghton Mifflin Co: Boston
Ehrlich, P.R., Dobkin, D.S., Wheye, E. (1988) The Birder’s Handbook: a field guide to the natural history of north American birds – The Essential Companion to Your Identification Guide. Simon & Schuster/Fireside Books: New York.
National Science Foundation press release, 05-30-2012, Where Have All the Hummingbirds Gone? Retrieved online at: http://www.nsf.gov/news/news_summ.jsp?cntn_id=124345&WT.mc_id=USNSF_51&WT.mc_ev=click
Live Webcam of black chinned hummingbird nest:
Nature News, Evolution News and Views, David Klinghoffer, The Genius of Birds: Watch a Hummingbird’s Tongue in Action – See more at: http://www.evolutionnews.org/2013/06/the_genius_of_b073491.html