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 Wagtails & Pipits Motacillidae 163 American Pipit Anthus rubescens 164

Victor Emanuel Nature Tours 6 Montana Owl Workshop, 2021 Finches, Euphonias & Allies Fringillidae 165 House Finch Haemorhous mexicanus x 166 Cassin's Finch Haemorhous cassinii H 167 Red Crossbill Loxia curvirostra H 168 Pine Siskin Spinus pinus x 169 American Goldfinch Spinus tristis 170 New World Sparrows Passerellidae 171 Chipping Sparrow Spizella passerina 172 Clay-colored Sparrow Spizella pallida 173 Dark-eyed Junco Junco hyemalis x 174 White-crowned Sparrow Zonotrichia leucophrys x 175 Vesper Sparrow Pooecetes gramineus 176 Savannah Sparrow Passerculus sandwichensis 177 Song Sparrow Melospiza melodia x 178 Spotted Towhee Pipilo maculatus 179 180 181 Troupials & Allies Icteridae 182 Yellow-headed Blackbird Xanthocephalus xanthocephalus x 183 Western Meadowlark Sturnella neglecta x 184 Bullock's Oriole Icterus bullockii 185 Red-winged Blackbird Agelaius phoeniceus x 186 Brown-headed Cowbird Molothrus ater 187 Brewer's Blackbird Euphagus cyanocephalus x 188 New World Warblers Parulidae 189 Northern Waterthrush Parkesia noveboracensis 190 Orange-crowned Warbler Leiothlypis celata x 191 MacGillivray's Warbler Geothlypis tolmiei 192 Common Yellowthroat Geothlypis trichas 193 Yellow Warbler Setophaga petechia 194 Yellow-rumped Warbler Setophaga coronata x 195 Townsend's Warbler Setophaga townsendi 196 Wilson's Warbler Cardellina pusilla 197 Cardinals & Allies Cardinalidae 198 Western Tanager Piranga ludoviciana 199 Black-headed Grosbeak Pheucticus melanocephalus 200 Lazuli Bunting Passerina amoena 201 202 203 204 205 ADD ONS 206 Blue-winged Teal x 207

Victor Emanuel Nature Tours 7 Montana Owl Workshop, 2021 Cinnamon Teal x 208 Turkey x 209 Evening Grosbeak x 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 MAMMALS 227 Squirrels, Prairie Dogs & Marmots Sciuridae 228 Northern Flying Squirrel Glaucomys sabrinus 229 Eastern Fox Squirrel Sciurus niger x 230 Red Squirrel Tamiasciurus hudsonicus x 231 Yellow-pine Chipmunk Tamias amoenus 232 Least Chipmunk Tamias minimus 233 Red-tailed Chipmunk Tamias ruficaudus 234 Columbian Ground-Squirrel Spermophilus columbianus 235 Golden-mantled Ground-Squirrel Spermophilus lateralis 236 Richardson's Ground-Squirrel Spermophilus richardsonii 237 Hoary Marmot Marmota caligata 238 Yellow-bellied Marmot Marmota flaviventris x 239 Beavers Castoridae 240 American Beaver Castor canadensis 241 Rats & Mice Muridae 242 Common Muskrat Ondatra zibethicus x 243 Porcupines Erethizonitidae 244 North American Porcupine Erethizon dorsatum 245 Rabbits & Hares Leporidae 246 Mountain Cottontail Sylvilagus nuttallii x 247 Snowshoe Hare Lepus americanus 248 White-tailed Jackrabbit Lepus townsendii 249 Cats Felidae 250

Victor Emanuel Nature Tours 8 Montana Owl Workshop, 2021 Mountain Lion (Puma) Puma concolor 251 Bobcat Lynx rufus 252 Dogs Canidae 253 Coyote Canis latrans x 254 Red Fox Vulpes vulpes 255 Bears Ursidae 256 American Black Bear Ursus americanus 257 Brown Bear Ursus arctos 258 Weasels Mustelidae 259 Northern River Otter Lontra canadensis 260 American Marten Martes americana 261 Short-tailed Weasel Mustela erminea 262 Long-tailed Weasel Mustela frenata 263 Skunks Mephitidae 264 Striped Skunk Mephitis mephitis 265 Raccoons Procyonidae 266 Northern Raccoon Procyon lotor 267 268 269 270 271 Deer Cervidae 272 White-tailed Deer Odocoileus virginianus x 273 Mule Deer Odocoileus hemionus x 274 Pronghorn Antilocapridae 275 Pronghorn Antilocapra americana 276 Bison, Sheep & Goats Bovidae 277 American Bison Bison bison x 278 Mountain Goat Oreamnus americanus 279 Bighorn Sheep Ovis canadensis 280 281 ADD ONS 282 Elk x 283 284 285 REPTILES & AMPHIBIANS SCIENTIFIC NAME 286 Water Turtles Emydidae 287 Painted Turtle (western) Chrysemys picta x 288 Snakes Serpentes 289 Western Terrestrial Garter Snake Thamnophis elegans x 290

Victor Emanuel Nature Tours 9 Montana Owl Workshop, 2021