MONTANA OWL WORKSHOP APRIL 20–25, 2018 LEADERS: DENVER HOLT & MATT LARSON LIST COMPILED BY: DENVER HOLT VICTOR EMANUEL NATURE TOURS, INC. 2525 WALLINGWOOD DRIVE, SUITE 1003 AUSTIN, TEXAS 78746 WWW.VENTBIRD.COM MONTANA OWL WORKSHOP APRIL 20–25, 2018 By Denver Holt The winter of 2017/2018 was once again a harsh one in western Montana. Once it started, winter snow was almost continuous. In fact, record amounts covered the mountains and valleys. And, as I write this report on May 10, much of the snow pack above 5,000 feet is just beginning to melt. In fact, normally at this time of year we can drive to most of our Boreal Owl nest boxes; however, this year we are still using snowmobiles. Winter numbers of vole-eating owl species started out good, but as spring approached, owl numbers declined, and nest numbers were few. It appeared that prey populations must have declined rapidly, and many owl species had left the area. Also, like last spring, we found dead Barn, Great Horned, Long-eared, and Short-eared owls. For those that nested, they laid fewer eggs AND experienced nest failures. Yet, despite this second consecutive harsh winter, some owls did manage to survive and begin breeding. Species that have a more diverse diet, or do not specialize on voles, did okay. For example, in our first year of Great Horned Owl nest study, we found 50 nests. We also found a few Saw-whet and Pygmy-owl nests, but no Boreal as of writing. Nonetheless, our group was able to find and observe or hear, Western Screech, Great Horned, Northern Pygmy, Great Gray, Northern Saw-whet, Long-eared, and Short-eared owls. We also had one of the best Short-eared Owl courtship flight displays in many years. Although we searched for Barn and Boreal owls, none were found. Perhaps the highlight was observing the nesting Great Gray Owl. All of the participants got wonderful looks at this obliging female. It was a great trip, and I’m looking forward to next year’s tour! BIRDS: COMMON NAME SCIENTIFIC NAME Waterfowl Anatidae Canada Goose Branta canadensis x Gadwall Mareca strepera x American Wigeon Mareca americana Mallard Anas platyrhynchos x Northern Pintail Anas acuta x Green -winged Teal Anas crecca Canvasback Aythya valisineria x Victor Emanuel Nature Tours 2 Montana Owl Workshop, 2018 Redhead Aythya americana x Ring -necked Duck Aythya collaris x Lesser Scaup Aythya affinis Bufflehead Bucephala albeola x Common Goldeneye Bucephala clangula x Barrow's Goldeneye Bucephala islandica Hooded Merganser Lophodytes cucullatus x Common Merganser Mergus merganser x Ruddy Duck Oxyura jamaicensis Pheasants, Grouse and Phasianidae Allies Gray Partridge (I) Perdix perdix x Ring -necked Pheasant (I) Phasianus colchicus x Ruffed Grouse Bonasa umbellus x Grebes Podicipedidae Pied -billed Grebe Podilymbus podiceps Horned Grebe Podiceps auritus x Red -necked Grebe Podiceps grisegena x Eared Grebe Podiceps nigricollis Western Grebe Aechmophorus occidentalis Pigeons and Doves Columbidae Rock Pigeon (I) Columba livia x Eurasian Collared -Dove (I) Streptopelia decaocto x Mourning Dove Zenaida macroura x Rails, Gallinules and Coots Rallidae Virginia Rail Rallus limicola Sora Porzana carolina x American Coot Fulica americana x Cranes Gruidae Sandhill Crane Antigone canadensis x Stilts and Avocets Recurvirostridae Black -necked Stilt Himantopus mexicanus x American Avocet Recurvirostra americana Plovers and Lapwings Charadriidae Killdeer Charadrius vociferus x Sandpipers and Allies Scolopacidae Long -billed Curlew Numenius americanus x Long-billed Dowitcher Limnodromus scolopaceus Wilson's Snipe Gallinago delicata x Spotted Sandpiper Actitis macularius Victor Emanuel Nature Tours 3 Montana Owl Workshop, 2018 Gulls, Terns and Skimmers Laridae Ring -billed Gull Larus delawarensis California Gull Larus californicus x Loons Gaviidae Common Loon Gavia immer x Cormorants Phalacrocoracidae Double -crested Cormorant Phalacrocorax auritus x Pelicans Pelecanidae American White Pelican Pelecanus x erythrorhynchos Herons, Egrets and Bitterns Ardeidae Great Blue Heron Ardea herodias x New World Vultures Cathartidae Turkey Vulture Cathartes aura x Osprey Pandionidae Osprey Pandion haliaetus x Hawks, Eagles and Kites Accipitridae Bald Eagle Haliaeetus leucocephalus x Northern Harrier Circus hudsonius x Sharp -shinned Hawk Accipiter striatus x Cooper's Hawk Accipiter cooperii x Northern Goshawk Accipiter gentilis Swainson's Hawk Buteo swainsoni x Red -tailed Hawk Buteo jamaicensis x Golden Eagle Aquila chrysaetos x Owls Strigidae Western Screech -Owl Megascops kennicottii x Great Horned Owl Bubo virginianus x Northern Pygmy -Owl Glaucidium gnoma x Burrowing Owl Athene cunicularia Great Gray Owl Strix nebulosa x Long -eared Owl Asio otus x Short -eared Owl Asio flammeus Boreal Owl Aegolius funereus Northern Saw -whet Owl Aegolius acadicus x Woodpeckers Picidae Lewis's Woodpecker Melanerpes lewis Red -naped Sapsucker Sphyrapicus nuchalis Downy Woodpecker Picoides pubescens x Hairy Woodpecker Picoides villosus Northern Flicker Colaptes auratus x Pileated Woodpecker Dryocopus pileatus x Falcons and Caracaras Falconidae American Kestrel Falco sparverius x Merlin Falco columbarius Victor Emanuel Nature Tours 4 Montana Owl Workshop, 2018 Peregrine Falcon Falco peregrinus Prairie Falcon Falco mexicanus x Tyrant Flycatchers Tyrannidae Say's Phoebe Sayornis saya x Western Kingbird Tyrannus verticalis Eastern Kingbird Tyrannus tyrannus Crows, Jays and Magpies Corvidae Gray Jay Perisoreus canadensis Steller's Jay Cyanocitta stelleri x Blue Jay Cyanocitta cristata x Clark's Nutcracker Nucifraga columbiana Black -billed Magpie Pica hudsonia x American Crow Corvus brachyrhynchos x Common Raven Corvus corax x Larks Alaudidae Horned Lark Eremophila alpestris Swallows Hirundinidae Tree Swallow Tachycineta bicolor x Violet -green Swallow Tachycineta thalassina x Northern Rough-winged Stelgidopteryx x Swallow serripennis Bank Swallow Riparia riparia Cliff Swallow Petrochelidon x pyrrhonota Barn Swallow Hirundo rustica x Chickadees and Tits Paridae Black -capped Chickadee Poecile atricapillus x Mountain Chickadee Poecile gambeli Nuthatches Sittidae Red -breasted Nuthatch Sitta canadensis x White -breasted Nuthatch Sitta carolinensis Pygmy Nuthatch Sitta pygmaea Creepers Certhiidae Brown Creeper Certhia americana Wrens Troglodytidae House Wren Troglodytes aedon Pacific Wren Troglodytes pacificus Marsh Wren Cistothorus palustris Dippers Cinclidae American Dipper Cinclus mexicanus Kinglets Regulidae Victor Emanuel Nature Tours 5 Montana Owl Workshop, 2018 Golden -crowned Kinglet Regulus satrapa Ruby -crowned Kinglet Regulus calendula x Thrushes and Allies Turdidae Mountain Bluebird Sialia currucoides x Townsend's Solitaire Myadestes townsendi Swainson's Thrush Catharus ustulatus American Robin Turdus migratorius x Varied Thrush Ixoreus naevius Mockingbirds and Mimidae Thrashers Gray Catbird Dumetella carolinensis Starlings Sturnidae European Starling (I) Sturnus vulgaris x Waxwings Bombycillidae Cedar Waxwing Bombycilla cedrorum x Old World Sparrows Passeridae House Sparrow (I) Passer domesticus x Wagtails and Pipits Motacillidae American Pipit Anthus rubescens Siskins, Crossbills and Fringillidae Allies House Finch Haemorhous mexicanus x Cassin's Finch Haemorhous cassinii Red Crossbill Loxia curvirostra x Pine Siskin Spinus pinus American Goldfinch Spinus tristis New World Sparrows Passerellidae Spotted Towhee Pipilo maculatus Chipping Sparrow Spizella passerina x Clay -colored Sparrow Spizella pallida Vesper Sparrow Pooecetes gramineus Savannah Sparrow Passerculus x sandwichensis Song Sparrow Melospiza melodia x White -crowned Sparrow Zonotrichia leucophrys x Dark -eyed Junco Junco hyemalis Troupials and Allies Icteridae Yellow-headed Blackbird Xanthocephalus x xanthocephalus Western Meadowlark Sturnella neglecta x Bullock's Oriole Icterus bullockii Red -winged Blackbird Agelaius phoeniceus x Brown -headed Cowbird Molothrus ater Brewer's Blackbird Euphagus cyanocephalus x Victor Emanuel Nature Tours 6 Montana Owl Workshop, 2018 New World Warblers Parulidae Northern Waterthrush Parkesia noveboracensis Orange -crowned Warbler Oreothlypis celata x MacGillivray's Warbler Geothlypis tolmiei Common Yellowthroat Geothlypis trichas Yellow Warbler Setophaga petechia Yellow -rumped Warbler Setophaga coronata x Townsend's Warbler Setophaga townsendi Wilson's Warbler Cardellina pusilla Cardinals and Allies Cardinalidae Western Tanager Piranga ludoviciana Black-headed Grosbeak Pheucticus melanocephalus Lazuli Bunting Passerina amoena MAMMALS Squirrels, Prairie Dogs & Sciuridae Marmots Eastern Fox Squirrel Sciurus niger x Red Squirrel Tamiasciurus hudsonicus x Yellow -pine Chipmunk Tamias amoenus x Least Chipmunk Tamias minimus Red -tailed Chipmunk Tamias ruficaudus Columbian Ground-Squirrel Spermophilus x columbianus Golden-mantled Ground- Spermophilus lateralis Squirrel Richardson's Ground-Squirrel Spermophilus richardsonii Hoary Marmot Marmota caligata Yellow -bellied Marmot Marmota flaviventris x Beavers Castoridae American Beaver Castor canadensis Rats & Mice Muridae Common Muskrat Ondatra zibethicus x Porcupines Erethizonitidae North American Porcupine Erethizon dorsatum Victor Emanuel Nature Tours 7 Montana Owl Workshop, 2018 Rabbits & Hares Leporidae Mountain Cottontail Sylvilagus nuttallii Snowshoe Hare Lepus americanus White -tailed Jackrabbit Lepus townsendii Cats Felidae Mountain Lion (Puma) Puma concolor Bobcat Lynx rufus Dogs Canidae Coyote Canis latrans x Red Fox Vulpes vulpes Bears Ursidae American Black Bear Ursus americanus Brown Bear Ursus arctos Weasels Mustelidae Northern River Otter Lontra canadensis American Marten Martes americana Short -tailed Weasel Mustela erminea x Long -tailed Weasel Mustela frenata Skunks Mephitidae Striped Skunk Mephitis mephitis x Raccoons Procyonidae Northern Raccoon Procyon lotor Deer Cervidae White -tailed Deer Odocoileus virginianus x Mule Deer Odocoileus hemionus x Pronghorn Antilocapridae Pronghorn Antilocapra americana Bison, Sheep & Goats Bovidae American Bison Bison bison x Mountain Goat Oreamnus americanus Bighorn Sheep Ovis canadensis Victor Emanuel Nature Tours 8 Montana Owl Workshop, 2018 .