SONGS ON THE WIND: Bird Migration Into and Through The Grand Canyon Region By Bryan Brown The Red-necked (Northern) Phalarope and Swainson’s Hawk travel the longest distance of all Grand Canyon migrants, over 6,000 miles each way. Images courtesy The Birds of North America Categories of migratory birds at Grand Canyon: • Over 375 species of birds have been recorded at Grand Canyon. • Of these, about 135 are regularly-occurring seasonal migrants. Category # of species (approximate) Spring and fall only = “classic migrant” 23 Summer resident/visitor migrating into and out of region 70 Winter resident/visitor migrating into and out of region 12 Permanent resident with different winter and summer populations 30 TOTAL MIGRANT SPECIES 135 Other aspects to consider when categorizing migrants: • Short, medium, or long-distance migrant? • Diurnal or nocturnal migrant? • Passerine (songbird) or non-passerine? • If passerine, does it sing during migration? • Is it a Neotropical (“complete”) migrant? • Does it migrate singly, in single-species flocks, or in mixed-species flocks? At Grand Canyon, Wilson’s Warbler is a nocturnal, spring/fall only, passerine, Neotropical migrant that sings during migration and travels singly, in flocks, and in mixed-species flocks. Images courtesy The Birds of North America What are other generalized aspects of migration? • Do spring and fall migration differ? • What initiates migratory behavior? When to migrate? • How do migrants know where to go? How do they navigate? • Do migrants follow leading lines or exhibit broad-front movements? • Where do migrants get the energy to migrate? • Does a migrant make use of large-scale staging areas? • Is all migration north-south? • Do all age classes or sexes of a species migrate simultaneously? • What habitats do migrants use? Migrants exhibit a greater density and diversity in welldeveloped riparian habitat than adjacent desertscrub. B. Brown photo B. Brown photo Spring and fall only migrants at Grand Canyon: Non-passerines Passerines • White-faced Ibis • Northern Shoveler • Cliff Swallow • Northern Rough-winged Swallow • • • • • • • • • • • • • • • • • • American Wigeon Canvasback; Redhead Ring-necked Duck Osprey; Broad-winged Hawk Red-necked (Northern) Phalarope Black-necked Stilt American Avocet Solitary Sandpiper Willet Common Snipe Wilson’s Warbler MacGillivray’s Warbler Orange-crowned Warbler Nashville Warbler Townsend’s Warbler Hermit Warbler Lincoln’s Sparrow Yellow-headed Blackbird Spring and fall only migrants Passerine Non-passerine Images courtesy The Birds of North America Summer-resident (nesting) or summer-visitor species that migrate into and through Grand Canyon in spring/fall (n=70). Non-passerine Passerine Images courtesy U.S. Fish and Wildlife Service Southward migration of Burrowing Owls (n = 15) during fall 2014, as determined by geolocators monitored by The Global Owl Project. Map courtesy The Global Owl Project Winter-resident and winter-visitor species that migrate into and through Grand Canyon in spring/fall (n = 12). Non-passerines • Canada Goose • Northern Pintail • Lesser Scaup • Common Goldeneye • Bufflehead • Ruddy Duck • Bald Eagle • Rough-legged Hawk • Belted Kingfisher Passerines • Winter Wren • Cedar Waxwing • Oregon Junco (ssp. of Dark-eyed Junco) Winter-resident migrants. Non-passerine Image courtesy Gary Cascio Passerine Image courtesy The Birds of North America Permanent resident species (n = 30) with different summer and winter populations (species present all year but individuals migrate). Passerine Non-passerine • Photo of spotted towhee here Images courtesy Gary Cascio and The Birds of North America There are about 30 permanent resident species at Grand Canyon whose individuals do not migrate. Non-passerines Passerines Images courtesy NPS and The Birds of North America Neotropical migrants nest in North America but overwinter in Central and South America (approx. 30). Non-passerine Passerine Images courtesy The Birds of North America Hawkwatch International has surveyed migratory raptors in autumn at Lipan and Yaki Points since 1991. Image courtesy Grand Canyon River Outfitters Association and R. Stoner A small but regionally important staging area for migrant Bald Eagles existed along the Colorado River at the mouth of Nankoweap Creek from the 1970s through the early 1990s. B. Brown photo Image courtesy Tom Brownold Will global climate change influence bird migration into and through Grand Canyon? If so, what would these influences be? • Has global warming influenced bird migration? Are there examples of this influence at Grand Canyon? • Can distant changes influence bird migration at Grand Canyon? • Bird migration = natural change. B. Brown photo Images courtesy: • The Birds of North America • Gary Cascio/Late Nite Grafix • U.S. Fish and Wildlife Service • Bryan Brown • Grand Canyon River Outfitters Association/R. Stoner • The Global Owl Project • Tom Brownold • National Park Service B. Brown photo
© Copyright 2024