saguaro's Journal

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TYRANNIDAE

1) Empidonax tyrant-flycatchers | standard features: olive-brown upperparts, whitish throat, light gray to faint yellowish belly, short primary projection

• Alder/Willow Flycatcher (Empidonax alnorum/trailii) has ^' faint white eyering, ^' relatively short primary projection, and olive-brown upper coloration with ^' moderately distinct chest band
• Acadian Flycatcher (E. virescens) has distinct white eyering, ^' long primary projection, ^' and olive-brown upper coloration with ^' rather indistinct chest band
• White-throated Flycatcher (E. albigularis) has distinct white eyering, very short primary projection, and ^' drab grayish upperparts ^' and ^' distinct chest band forming a contrasting white throat
• Least Flycatcher (E. minimus) has distinct white eyering, very short primary projection, and ^' drab grayish upperparts ^' with ^' indistinct chest band
• Yellow-bellied Flycatcher (E. flaviventris) has distinct white eyering, short primary projection, and warm olive upperparts and chest including a ^' yellowish throat and belly

2) Contopus tyrant-flycatchers | standard features: dusky-brown upperparts, dark lores, white wingbars, and light gray belly

• Tropical Pewee (Contopus cinereus) has ^' pale lores ^' and ^' yellowish belly; ^' bill is orange with black tip, like Eastern Wood-Pewee
• Eastern Wood-Pewee (C. virens) has dark lores and pale belly; ^' bill is orange with black tip, ^' like Tropical Pewee
• Western Wood-Pewee (C. sordidulus) has dark lores and pale belly; ^' bill is mostly black, with orange base of lower mandible
• Dark Pewee (C. lugubris) has distinct crest, dark sooty appearance and no wing bars
• Olive-sided Flycatcher (C. cooperi) has unmistakable "vested" appearance and no wing bars
• Ochraceous Pewee (C. ochraceus) is unmistakable among its genus, but easily confused with the smaller, shorter-billed Tufted Flycatcher (Mitrephanes phaeocercus)

3) Myiarchus tyrant-flycatchers

• Great Crested Flycatcher (Myiarchus critinus) has strong chest-belly color contrast, bill with ^' orange-based lower mandible, ^' rather dark head and throat, and extensive white on inner tertials
• Nutting's Flycatcher (M. nuttingi) has weak chest-belly color contrast, an ^' all-dark bill, ^' lighter gray throat, and less white on inner tertials
• Dusky-capped Flycatcher (M. tuberculifer) is unmistakable by the sharp contrast between dark crown and gray throat
• Panama Flycatcher (M. panamensis) is unmistakable by the lack of rufous in wings and tail

4) Elaenias & Tyrannulets

• Southern Beardless-Tyrannulet is prominently crested and has indistinct white eyering, two buffy-white wingbars, and ^' white throat
• Yellow-bellied Elaenia (Elaenia flavogaster) is prominently crested and has white eyering, two white wingbars, yellowish wing edging, ^' light gray throat, ^' yellow belly, and grayish-olive-brown upperparts
• Lesser Elaenia (E. chiriquensis) is slightly crested and is almost identical to Yellow-bellied Elaenia (E. flavogaster) except has smaller crest and drabber yellow belly
• Greenish Elaenia (Myiopagis viridicata) is crestless and has ^' no wingbars ^', double-broken white eyering, whitish lores, light gray throat and breast, yellowish belly, and olive upperparts
• Mountain Elaenia (E. frantzii) is crestless and has faint yellowish eyering, ^' two whitish wingbars, ^' yellowish wing edging, and overall drab olivaceous appearance
• Torrent Tyrannulet (Serpophaga cinerea) is unmistakable due to riverine habitat
• Rough-legged Tyrannulet (Phyllomyias burmeisteri) is crestless and has ambiguous eyering, whitish lores often forming an eyeline, distinctive ^' black-and-yellow wings, ^' gray cap, olive back, and yellow belly
• Yellow-crowned Tyrannulet (Tyrannulus elatus) is crestless and has ambiguous eyering, contrasting gray head and olive-yellow underparts, stubby bill, faint dark eyeline and ^' two white wingbars
• Mouse-colored Tyrannulet (Phaeomyias murina) is crestless and has very faint eyering, thick whitish eyebrow, and ^' two thin whitish-cinnamon wingbars
• Yellow-olive Flycatcher (Tolmomyias sulphurescens) is crestless and has pale iris, prominent white eyering and supraloral stripe, ^' black-and-yellow wings ^' and relatively thick bill
• Mistletoe Tyrannulet (Zimmerius parvus) is unmistakable with dark cap and yellow wing edging
• Yellow-bellied Tyrannulet (Ornithion semiflavum) is unmistakable with distinctive gray cap, broad white supercilium, olive auriculars, bright yellow underparts, and thick vireo-like bill

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STRIGIDAE

4) Megascops screech-owls

• Bare-shanked Screech-Owl (Megascops clarkii) has rimless tawny facial disc and whitish-spotted underparts; largest screech-owl
• Tropical Screech-Owl (M. choliba) has black-rimmed light gray facial disc and "pattern of dusky, herringbone streaks on the underparts"¹
• Middle American Screech-Owl (M. guatemalae) has 2 morphs: brown morph is gray-brown to buff-brown on head & upperparts, with pale eyebrows, and the rufous morph has bright rufous coloration on head & upperparts
• Chocó Screech-Owl (M. centralis) is highly variable in coloration; very similar to Tropical Screech-Owl (M. choliba) but is smaller, darker, more mottled, and less definitely streaked"²

1. Greeney, H. F. and J. F. Freile (2020). Choco Screech-Owl (Megascops centralis), version 1.0. In Birds of the World (S. M. Billerman, B. K. Keeney, P. G. Rodewald, and T. S. Schulenberg, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA.
2. Ong, G. (2020). Tropical Screech-Owl (Megascops choliba), version 1.0. In Birds of the World (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA.

Monday, 1 July 2019
3:30 am - 6:00 am

Hiked the walls at the entrance to Kofa Queen Canyon until sunrise.

Tuesday, 3 July 2018
3:45 am - 8:00 am

I decided to explore an area of Sonoran Desert National Monument that I had not visited before, the uninhabited region bounded in its four corners by Gila Bend, Buckeye, Phoenix, and Casa Grande. The only road cutting through this desert is Maricopa Rd. I parked on the north side of the road about 12 miles out from Gila Bend and hiked my way along a path, which I soon left for an off-trail adventure. The night was warm, and the night sky unpolluted and brilliant.

Ground vegetation was sparse, and thus I decided to explore the more elevated areas. There were many crevices, mini-caves, and openings in the boulders that seemed to advertise the presence of life forms. I was not disappointed and soon came across Desert Woodrat (Neotoma lepida), calling Common Poorwill (Phalaenoptilus nuttallii), unidentified spiders, and Arizona Bark Scorpion (Centruroides sculpturatus). As I kept ascending the eastern horizon became brighter, and I began to see that I was not far from reaching the summit of my hill. I pushed on, reaching the peak at around 3:50 in the early morning light. The hill was much higher than I thought and was, in fact, a mountain ridge stretching northward; from my vantage I could see Gila Bend and part of Buckeye, while to the south and east stretched flat desert interspersed with isolated ranges.

The vegetation on the hills was sparse. Fishhook barrel (Ferocactus wislizeni) and buckhorn cholla (Cylindropuntia acanthocarpa) were the dominant cactus species, followed by saguaro (Carnegiea gigantea), Englemann hedgehog (Echinocereus engelmanni), and Graham's fishhook (Mammillaria grahamii). The saguaro flowers were just beginning to open and were frequented by bees. I found an Arizona Woodrat (N. lepida) pair using a slumped barrel cactus as a nest site, and they would quickly depart the cactus whenever I approached. Birdlife was relatively plentiful in the early hours; I heard Canyon Wren (Catherpes mexicanus) and Myiarchus sp. and saw Black-tailed Gnatcatcher (Polioptila melanura), Swainson's Hawk (Buteo swainsoni), Turkey Vulture (Cathartes aura), Lesser Nighthawk (Chordeiles acutipennis), Gila Woodpecker (Melanerpes uropygialis), groups of Cactus Wren (Campilorhynchus brunneicapillus), and at least three Gilded Flicker (Colaptes chrysoides). Warming temperatures led birds to give way to reptile activity, and I came across a number of Common Side-blotched Lizard (Uta stansburiana). I must develop a better grasp of lizard identification, as I cannot say for certain whether these were not Ornate Tree or Long-tailed Brush Lizard. I also found two Harris' Antelope Ground Squirrel (Ammospermophilus harrisii), which are common in the area. Seeing all these life forms from the vantage point of a high ridge was quite the unique experience.

I followed the crest northward almost to its endpoint, descending down the western (shaded) side along a comparatively easy slope. The heat was nonetheless oppressive by the time I'd reached the flatlands. This area was heavily dominated by teddy-bear cholla (Cylindropuntia bigelovii), replaced by brittlebush (Encelia farinosa) on the slopes. Here I saw Western Whiptail (Apidoscelis tigris) and Zebra-tailed Lizard (Callisaurus draconoides). I also noticed Pepsis sp. and photographed a Cream Grasshopper (Cibolacris parviceps) that identically resembled the nearby granite stones.

This ridge, albeit not lush or rich in flora, turned out to yield a surprising amount of life forms even in the middle of summer. I hope to make this one of the many sites in the desert that I periodically return to.