Re: [cobirds] Yesterday's golden-plover event--and a question for Bryan Guarente
Sandra and others, In this case, it was because of the snowfall that made me focus in at a lower level. The snowfall drives the birds lower so they have more visibility to something on the ground (at least that is what is suspected). In the earlier times of this event, the 850 millibars (units of pressure abbreviated mb; approximately 1.5km up from sea level) was similar to the surface winds, so not too big of a difference. I appreciate you calling me out on this. It would have been better for me to say that I was looking at the surface information because of the snowfall associated with the system coming through. This may actually lead to other confusion for the birds parts and drive them closer to the ground making it more likely for them to descend earlier rather than later. I did evaluate where the precipitation was falling prior to the period I posted about and had been watching it throughout the event (for meteorological not ornithological reasons). The precipitation was falling behind this cold front ever since it was in Alberta, so it was a good bet that the birds would be flying lower to the ground. Ask anyone who monitors nocturnal migration, and you will find that more migrants are heard when the cloud cover is lower. This is true when there is precipitation as well, but there may be a bias in observers for comfort reasons. Hope that helps, and please feel free to keep asking more questions. There are more intricacies to this, but we only scratch the surface on COBirds. Thanks for calling me out. I appreciate the fact that this may have taken extra gumption to do in a public forum, and I deserved it. Bryan Guarente Meteorologist/Instructional Designer UCAR/The COMET Program Boulder, CO On Wed, Oct 17, 2018 at 9:46 AM Sandra Laursen wrote: > Bryan, > thanks for this analysis. One lesson I have absorbed from you in the past > is that it's not the surface-level winds that are important, but the wind > up a bit higher where the birds are migrating. Why do you focus on surface > winds this time? > > thanks > - Sandra Laursen > > > > On Monday, October 15, 2018 at 10:40:25 PM UTC-6, Bryan Guarente wrote: >> >> Cobirders, >> when Ted beckons... you get a really long email... >> >> So the question is: >> >>1. Why did this situation bring more birds to the Front Range? >> >> *TL;DR* (Too long; didn't read) -- Super-short snarky answer just for >> Ted: it was the wind! The weather had a lot to do with it and which end of >> the cold front Colorado ended up on helped dictate that flow of migrants. >> Based on percentage of the total flow area behind the cold front compared >> to the overall flow, it looked like a 30-40% chance that birds would end up >> in the Front Range due to funneling or convergence. >> >> *Full version:* >> >>- *Why did this weather situation bring more birds to the Front >>Range?* >> >> Let's look through the computer models because it is sexier, and makes it >> easier for everyone to understand because I can give you data everywhere on >> the globe. One could also do this with satellite imagery, but it is harder >> to get you to see what I want to see, so I will work with the easier >> option. >> >>- >> >> https://earth.nullschool.net/#2018/10/14/Z/wind/surface/level/orthographic=-105,40,1706/loc=-105.000,40.000 >> >> That animation of a single time gives you the idea of what is going on >> that made Colorado a hotspot for any migrants yesterday. Any bird trying >> to make its way to the southeast from Canada may have started out with good >> intentions, but depending on which side of the flow it started from or >> ended up in over time, it had a strong chance of ending up heading toward >> the Front Range. The cold front itself is the "blue" area with no wind >> that curves from Lake Nipigon down through Iowa, Nebraska, then curving >> into Colorado. All of the airflow behind that cold front (to the north and >> west) is what we want to focus on. The flow had multiple possible end >> points at that time: near Lake Nipigon, along the cold front just south of >> Lake Superior, along the cold front in Iowa, or into the Colorado Front >> Range. >> >> The highest likelihood location for the birds to end up was actually >> along the Front Range. The percentage of the total area of that flow >> behind the cold front that was showing a distinct convergence into the >> Front Range was about 30-40% (guesstimated). So any birds within that >> 30-40 percentage of the total area had a strong likelihood of ending up in >> Colorado's Front Range. That means that birds ranging from Alberta through >> Montana, North Dakota, Minnesota, and western Iowa and then everywhere >> southwest of that behind the cold front, had a strong chance of ending up >> in the Colorado Front Range. The door was wide open so to speak. The flow >> was broad initially, then came crashing in on itself converging into a >> small area (Colorado Front Range). So think
[cobirds] Re: RFI: Tropical Kingbird
Hello Paul, I *think* I may have briefly seen the Tropical Kingbird today. I saw the bird sitting on a wire just as I pulled into the entrance and parked in front of the sign for South Platte Park. It was a couple of wires below below several European Starlings. It was marginally larger than them, and had a long bill. It flew downward before I could get a photo. I stayed around the area for about 20 minutes and it didn't return. I checked all around the RPM building, and down the road just to the curve (where there are lots of Lesser Goldfinches). I can't be sure if I saw it, but if it's not too out of your way to Pueblo you could try to see it. On Wednesday, October 17, 2018 at 12:19:56 PM UTC-6, Paul Hurtado wrote: > > Hi all, > > I know it's a long shot, but I'll be in Denver this Saturday morning en > route to my 20th(!?) high school reunion down in Pueblo, and would love to > see that TROPICAL KINGBIRD (it's pretty rare for me to pick up new ABA > birds in CO since I've moved out of state!). > > So, while it seems to have moved on, I'd very much appreciate hearing from > anyone who goes looking for the bird. > > Thanks! > Paul Hurtado > Reno, NV (Pueblo, CO) > > -- > Paul J. Hurtado > http://www.pauljhurtado.com/ > -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to cobirds+unsubscr...@googlegroups.com. To post to this group, send email to cobirds@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/a39c602c-1271-4dbd-ae70-cb02f48ac8e1%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[cobirds] Colorado Rare BIrd Alert, 18 October 2018
Compiler: Joyce Takamine e-mail: RBA AT cobirds.org Date: October 18, 2018 This is the Colorado Rare Bird Alert for Thursday, October 18 sponsored by Denver Field Ornithologists and the Bird Conservancy of the Rockies. Note that the RBA is using the new AOU checklist. Rare and out of range species for the last seven days include: (*indicates new information on this species is new) Greater White-fronted Goose (Baca) Cackling Goose (*Boulder) Eurasian Wigeon (Montezuma) Storm Wigeon (Montezuma) Greater Scaup (Arapahoe) Surf Scoter (*Adams, *La Plata) Bufflehead (Adams, Baca, Boulder, Fremont, Jefferson, La Plata, Larimer, Rio Grande, Summit) Hooded Merganser (*Adams,* Boulder, Jefferson, *La Plata) Red-breasted Merganser (Boulder, Larimer) Ring-necked Pheasant (*Las Animas) Horned Grebe (Arapahoe, Denver, *La Plata, *Montrose) Common Poorwill (El Paso) White-throated Swift (Fremont, Garfield) Virginia Rail (Larimer) Sandhill Crane (El Paso, Fremont, Rio Grande, Teller) Black-bellied Pover (Boulder, *Larimer) American Golden-Plover (Arapahoe, *Boulder, Jefferson, Larimer, *Summit) Semipalmated Plover (Arapahoe, Boulder) Killdeer (Clear Creek) Stilt Sandpiper (Arapahoe, *Boulder) Sanderling (Boulder, *Jefferson, Montezuma) Pectoral Sandpiper (Boulder, Douglas, *Larimer) Short-billed Dowitcher (*Arapahoe, Boulder) Lesser Yellowlegs (*Arapahoe, *Broomfield) Willet (Summit) Wilson’s Phalarope (Jefferson) Red-necked Phalarope (Jefferson) Bonaparte’s Gull (Adams, Arapahoe, *Larimer) Laughing Gull (La Plata) Franklin’s Gull (Arapahoe, *Boulder, *Larimer, Rio Grande) Mew Gull (Arapahoe, *Boulder) WESTERN GULL (Arapahoe) Lesser Black-backed Gull (Larimer) Forster’s Tern (*Summit) Red-throated Loon (*Denver) Common Loon (*Adams, *Arapahoe) American White Pelican (Clear Creek) Snowy Egret (La Plata) Green Heron (*Arapahoe, Fremont) White-faced Ibis (Arapahoe) Osprey (Fremont, Ouray) HARRIS’S HAWK (Larimer) Lewis’s Woodpecker (*La Plata) Acorn Woodpecker (La Plata) Red-belllied Woodpecker (Larimer) Williamson’s Sapsucker (*Ouray) Red-naped Sapsucker (Larimer) Ladder-backed Woodpecker (*El Paso) Hammond’s Flycatcher (*La Plata, Montrose) Gray Flycatcher (El Paso, *Jefferson) Dusky Flycatcher (La Plata) Cordilleran Flycatcher (Larimer, Montezuma) Black Phoebe (La Plata) Eastern Phoebe (Jefferson) Scissor-tailed Flycatcher (*El Paso) Steller’s Jay (Boulder, Clear Creek, El Paso, Garfield, *Jefferson, Larimer, *Ouray) Woodhouse’s Scrub-Jay (El Paso, Garfield, *Jefferson, *La Plata) Clark’s Nutcracker (*Ouray) Common Raven (*Adams) Juniper Titmouse (*La Plata) Bushtit (*La Plata, Ouray) Rock Wren (Boulder, Larimer, *Montrose) Marsh Wren (Larimer) Bewick’s Wren (*Montrose) Blue-gray Gnatcatcher (El Paso) American Dipper (*Arapahoe) Ruby-crowned Kinglet (Adams, Clear Creek, *El Paso, Garfield, *Jefferson, *La Plata,* Larimer, Mesa, *Montrose, *Ouray, San Juan) Eastern Bluebird (Larimer) Western Bluebird (*Arapahoe) Mountain Bluebird (*Adams, *Arapahoe, Boulder, Clear Creek, *El Paso, Jefferson, *La Plata, *Larimer,* *Montrose,* Ouray, Teller) Hermit Thrush (Boulder, Denver, *El Paso, *Jefferson, *Larimer) Curve-billed Thrasher (El Paso) Sage Thrasher (Fremont, Mesa, *Montrose) Northern Mockingbird (*Las Animas) American Pipit (*Arapahoe, Clear Creek, El Paso, Jefferson, Larimer, *Montrose, Ouray, Summit) Sprague’s Pipit (Larimer) Lesser Goldfinch (Denver) McCown’s Longspur (Boulder) Green-tailed Towhee (*Jefferson, La Plata) Canyon Towhee (El Paso) Savannah Sparrow (La Plata, Larimer, Park) Grasshopper Sparrow (*Larimer) Brewer’s Sparrow (Clear Creek, *Montrose, Ouray) Vesper Sparrow (Jefferson) Lark Sparrow (Jefferson) Field Sparrow (Boulder) Sagebrush Sparrow (*Montrose, *Ouray) Fox Sparrow (*Boulder, Larimer, *Prowers) Lincoln’s Sparrow (Adams, *Arapahoe, Clear Creek, *El Paso, Jefferson, *Larimer,*Montrose, *Prowers, San Juan) Swamp Sparrow (Larimer) White-throated Sparrow (*Boulder, *Prowers, Saguache) Harris’s Sparrow (Boulder, El Paso) Brown-headed Cowbird (Teller) Tennessee Warbler (*Bent) Orange-crowned Warbler (Adams, *Arapahoe, Clear Creek, Douglas, *Larimer, Montrose, Ouray) Common Yellowthroat (Larimer, Mesa) Palm Warbler (*Boulder) Townsend’s Warbler (Gunnison, La Plata, Mesa, Pueblo) Black-throated Green Warbler (*Bent, Clear Creek) Wilson’s Warbler (Boulder, Eagle, La Plata, Larimer, Mesa, *Montrose) Western Tanager (Boulder, *Larimer, Pueblo) Rose-breasted Grosbeak (*Pitkin) ADAMS COUNTY: ---On October 15 at Ken Mitchell Park and OS, Adam Besely reported 5 Bufflehead and 2 Bonaparte’s Gull. ---On October 16 at Lowell Ponds (Clear Creek Valley Park), Gabriel Wiltse reported 6 Hooded Merganser and Orange-crowned Warbler. ---On October 17 at Rocky Mountain Arsenal NWR Mark Obmascik reported Surf Scoter, 6 Hooded Merganser, 28 Mountain Bluebird and Common Raven. ---On October 17 at McKay Lake, Tyler Wilson reported Common Loon. ARAPAHOE COUNTY: ---On October 15 at Cherry Creek SP Marina and nearby Dam
