MONTANA OWL WORKSHOP APRIL 25–30, 2021 LEADER: DENVER HOLT 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 25–30, 2021 By Denver Holt The winter of 2021 was relatively mild, with only one big storm in October and one cold snap in February. In fact, Great Horned Owls began nesting at the onset of this cold snap. Our female at the ORI field station began laying eggs and incubating. For almost a week the temperature dropped from about 20 degrees F to 10, then 0, then minus 10, minus 15, and eventually minus 28 degrees below zero. Meanwhile, the male roosted nearby and provided his mate with food while she incubated eggs. Eventually, the pair raised three young to fledging. Our group was able to see the entire family. By late February to early March, an influx of Short-eared Owls occurred. I had never seen anything like it. Hundreds of Short-eared Owls arrived in the valley. Flocks of 15, 20, 35, 50, and 70 were regularly reported by ranchers, birders, photographers, and others. And, in one evening I counted 90, of which 73 were roosting on fence posts and counted at one time. By mid-to-late March, however, except for Great Horned Owls, other owl species numbers dropped significantly. We found only one individual Long-eared Owl and zero nests in our Missoula study site. It’s been many, many years since we have not found a nest in Missoula. Last year (2020) we had 15 nests. Nonetheless, our group was able to find a Northern Pygmy-Owl singing near a potential nest cavity. Although perched very high in the trees, we had some fine looks with the spotting scope. On one evening we went to survey for Western Screech-Owls. To our surprise, the owl was already singing when we arrived. The owl sang for about 15 minutes, but unfortunately, we never saw it. It was only the second time we have found this species on the workshop. During our day searching for cavity-nesting owls, we were lucky enough to see a female Northern Saw-whet Owl poke its head out of a nest hole. This cavity, made by a Pileated Woodpecker, is a common-sized hole for Saw-whet Owls in our area. Indeed, what a treat to see a Saw-whet in a natural cavity, as most studies use nest boxes. On another evening, we ventured out to observe the Short-eared Owl courtship flights, also known as sky dancing. We were rewarded with an outstanding show of Short-eared courtship flights hundreds, if not 1,000 feet above the ground. At one time, three Short-eared’s were courting at the same time. We also observed many territorial skirmishes between many males, which take place at lower altitudes. All of us were able to hear the courtship hooting and the wing-clapping sounds produced during the owls’ shallow dives. On our last day, our scouting team reported there were no Boreal Owls in our nest boxes—our traditional last day event. In fact, Boreal Owls have not nested in the last three years. So we took a chance, and as one participant noted, we did a “forced march” through the heart of Grizzly Bear habitat in search of Great Gray Owls. Our spring surveys suggested a potential nest area. Victor Emanuel Nature Tours 2 Montana Owl Workshop, 2021 We hiked for about 40 minutes through spruce bogs, marshes, and mucky habitat. The group looked and listened for signs of the owls. We scanned old stick nests, mistletoe configurations, and broken-topped old dead snags (trees). Soon, one of our group spotted an owl on top of a snag. Indeed, there was a nesting Great Gray Owl, and she had at least two chicks we could see. After 30 minutes of observations, we marched out. A great ending to a great trip! COMMON NAME SCIENTIFIC NAME 1 Waterfowl Anatidae 2 Snow Goose Anser caerulescens x 3 Ross's Goose Anser rossii 4 Canada Goose Branta canadensis x 5 Trumpeter Swan Cygnus buccinator x 6 Northern Shoveler Spatula clypeata x 7 Gadwall Mareca strepera x 8 American Wigeon Mareca americana x 9 Mallard Anas platyrhynchos x 10 Northern Pintail Anas acuta 11 Green-winged Teal Anas crecca x 12 Canvasback Aythya valisineria 13 Redhead Aythya americana x 14 Ring-necked Duck Aythya collaris x 15 Lesser Scaup Aythya affinis x 16 Bufflehead Bucephala albeola x 17 Common Goldeneye Bucephala clangula 18 Barrow's Goldeneye Bucephala islandica x 19 Hooded Merganser Lophodytes cucullatus x 20 Common Merganser Mergus merganser x 21 Ruddy Duck Oxyura jamaicensis x 22 Pheasants, Grouse & Allies Phasianidae 23 Ring-necked Pheasant (I) Phasianus colchicus x 24 Gray Partridge (I) Perdix perdix x 25 Ruffed Grouse Bonasa umbellus H 26 Grebes Podicipedidae 27 Pied-billed Grebe Podilymbus podiceps 28 Horned Grebe Podiceps auritus 29 Red-necked Grebe Podiceps grisegena 30 Eared Grebe Podiceps nigricollis 31 Western Grebe Aechmophorus occidentalis x 32 Pigeons and Doves Columbidae 33 Rock Pigeon (I) Columba livia x 34 Eurasian Collared-Dove (I) Streptopelia decaocto x 35 Mourning Dove Zenaida macroura 36 Swifts Apodidae 37 White-throated Swift Aeronautes saxatalis 38 Rails, Gallinules & Coots Rallidae 39 Virginia Rail Rallus limicola 40 Sora Porzana carolina 41 American Coot Fulica americana x 42 Cranes Gruidae 43 Sandhill Crane Antigone canadensis x 44 45 46 Stilts & Avocets Recurvirostridae 47 Black-necked Stilt Himantopus mexicanus x 48 American Avocet Recurvirostra americana x 49 Plovers and Lapwings Charadriidae 50 Killdeer Charadrius vociferus x 51 Sandpipers & Allies Scolopacidae 52 Long-billed Curlew Numenius americanus 53 Long-billed Dowitcher Limnodromus scolopaceus x 54 Wilson's Snipe Gallinago delicata x 55 Spotted Sandpiper Actitis macularius 56 Gulls, Terns & Skimmers Laridae 57 Ring-billed Gull Larus delawarensis x 58 California Gull Larus californicus 59 Caspian Tern Hydroprogne caspia x 60 Loons Gaviidae 61 Common Loon Gavia immer 62 Cormorants Phalacrocoracidae 63 Double-crested Cormorant Phalacrocorax auritus x 64 Pelicans Pelecanidae 65 American White Pelican Pelecanus erythrorhynchos x 66 Herons, Egrets & Bitterns Ardeidae 67 Great Blue Heron Ardea herodias x 68 New World Vultures Cathartidae 69 Turkey Vulture Cathartes aura x 70 Osprey Pandionidae 71 Osprey Pandion haliaetus x 72 Hawks, Eagles & Kites Accipitridae 73 Golden Eagle Aquila chrysaetos x 74 Northern Harrier Circus hudsonius x 75 Sharp-shinned Hawk Accipiter striatus x 76 Cooper's Hawk Accipiter cooperii 77 Northern Goshawk Accipiter gentilis 78 Victor Emanuel Nature Tours 4 Montana Owl Workshop, 2021 Bald Eagle Haliaeetus leucocephalus x 79 Swainson's Hawk Buteo swainsoni x 80 Red-tailed Hawk Buteo jamaicensis x 81 Rough-legged Hawk Buteo lagopus x 82 Owls Strigidae 83 Western Screech-Owl Megascops kennicottii H 84 Great Horned Owl Bubo virginianus x 85 Northern Pygmy-Owl Glaucidium gnoma x 86 Burrowing Owl Athene cunicularia 87 Great Gray Owl Strix nebulosa x 88 Long-eared Owl Asio otus x 89 Short-eared Owl Asio flammeus x 90 91 Boreal Owl Aegolius funereus 92 Northern Saw-whet Owl Aegolius acadicus x 93 Woodpeckers Picidae 94 Williamson's Sapsucker Sphyrapicus thyroideus x 95 Red-naped Sapsucker Sphyrapicus nuchalis x 96 Lewis's Woodpecker Melanerpes lewis 97 Downy Woodpecker Dryobates pubescens x 98 Hairy Woodpecker Dryobates villosus 99 Pileated Woodpecker Dryocopus pileatus x 100 Northern Flicker Colaptes auratus 101 Falcons & Caracaras Falconidae 102 American Kestrel Falco sparverius x 103 Merlin Falco columbarius x 104 Peregrine Falcon Falco peregrinus 105 Prairie Falcon Falco mexicanus 106 Tyrant Flycatchers Tyrannidae 107 Say's Phoebe Sayornis saya x 108 Western Kingbird Tyrannus verticalis 109 Eastern Kingbird Tyrannus tyrannus 110 Crows, Jays & Magpies Corvidae 111 Canada Jay Perisoreus canadensis x 112 Steller's Jay Cyanocitta stelleri 113 Blue Jay Cyanocitta cristata H 114 Black-billed Magpie x 115 Clark's Nutcracker Nucifraga columbiana 116 American Crow Corvus brachyrhynchos x 117 Common Raven Corvus corax x 118 Tits, Chickadees, & Titmice Paridae 119 Black-capped Chickadee Poecile atricapillus x 120 Mountain Chickadee Poecile gambeli x 121 Victor Emanuel Nature Tours 5 Montana Owl Workshop, 2021 Chestnut-backed Chickadee Poecile rufescens 122 Larks Alaudidae 123 Horned Lark Eremophila alpestris 124 Swallows Hirundinidae 125 Bank Swallow Riparia riparia 126 Tree Swallow Tachycineta bicolor x 127 Violet-green Swallow Tachycineta thalassina x 128 Northern Rough-winged Swallow Stelgidopteryx serripennis x 129 Barn Swallow Hirundo rustica x 130 Cliff Swallow Petrochelidon pyrrhonota x 131 Kinglets Regulidae 132 Golden-crowned Kinglet Regulus satrapa x 133 Ruby-crowned Kinglet Regulus calendula x 134 135 136 Nuthatches Sittidae 137 Red-breasted Nuthatch Sitta canadensis x 138 White-breasted Nuthatch Sitta carolinensis x 139 Pygmy Nuthatch Sitta pygmaea 140 Treecreepers Certhiidae 141 Brown Creeper Certhia americana 142 Wrens Troglodytidae 143 House Wren Troglodytes aedon 144 Pacific Wren Troglodytes pacificus x 145 Marsh Wren Cistothorus palustris 146 Dippers Cinclidae 147 American Dipper Cinclus mexicanus 148 Starlings Sturnidae 149 European Starling (I) Sturnus vulgaris x 150 Mockingbirds & Thrashers Mimidae 151 Gray Catbird Dumetella carolinensis 152 Thrushes & Allies Turdidae 153 Mountain Bluebird Sialia currucoides x 154 Townsend's Solitaire Myadestes townsendi 155 Varied Thrush Ixoreus naevius 156 Swainson's Thrush Catharus ustulatus 157 American Robin Turdus migratorius x 158 Waxwings Bombycillidae 159 Cedar Waxwing Bombycilla cedrorum 160 Old World Sparrows Passeridae 161 House Sparrow (I) Passer domesticus x 162