Thursday, October 17, 2013

Surveying Birds along the Lower Colorado River, 2013

The spring of 2013 was an amazing field season on the Lower Colorado River.  This past season we had our largest crew on record, with 17 people!    We were very lucky to have a group of highly qualified ornithologists.  The first month of the season, as always, was spent sharpening our bird skills, learning our survey methods, as well as clearing trails to our survey plots.  Driving routes and trails need to be established to all our bird plots that were randomly selected for the season.  This is no easy task considering this past year we surveyed approximately 250 plots.  Trail clearing can be rough work, but it definitely helps the crew to bond as we spend the entire month working together. Once the first month is finished up, the crew splits off to their respective field sites and surveys begin.   This year we had four field houses spanning the length of our study area from southern Nevada to the international boundary with Mexico. 

Photo by Alicia Arcidiacono

To survey for birds, we use an area search or spot-mapping survey approach.  For this method, our surveyors are given an aerial image of their survey plot superimposed with a UTM grid. The surveyor walks systematically passing within 50m of all points on their survey plot.  During this time the surveyor records all birds seen and heard on their maps and any evidence of breeding. Surveys begin at, or a half hour before, sunrise and usually last several hours. 

The crew had a fantastic season recording approximately 200 different species of birds. Additionally over 21,000 individual locations of birds were mapped and entered into GIS.  Our crew also documented a large number of rarities, including the first breeding record of a Nutting’s flycatcher in the US.  We also recorded Rufuous-backed Robin, Palm Warbler, and Baltimore Oriole; all of which are rare birds within our study area.   

In addition to birds, other wildlife species were plentiful in our study area. We observed bobcats, mountain lions, several species of rattlesnake, javelina, badgers, skunks, bighorn sheep, and much more.  Throughout this past season we had many great adventures and made some lasting friendships.  With another season wrapped on the LCR, I am left in disbelief how quickly the time passed.  Thanks crew of 2013 for making it one of our best seasons on record!  Looking forward to 2014!   

- Dawn

Tuesday, October 8, 2013

Warm Springs Natural Area Species List, September 28 - October 2

Warm Springs Natural Area, from near the entrance gate
So here’s the list of the birds recorded during my surveys at Warm Springs.  (The surveys were randomly located on the property, not designed to hit hot spots.)  I described a few of my highlights here.  The most commonly-recorded species were (in order): White-crowned Sparrow, Gambel’s Quail, House Finch, Red-winged Blackbird, Abert’s Towhee, Mourning Dove, Turkey Vulture, Western Scrub-Jay, and Yellow-rumped Warbler.  For comparison, my highlights from the 2012 surveys are here

  1. Gambel's Quail
  2. Turkey Vulture
  3. Sharp-shinned Hawk
  4. Red-tailed Hawk
  5. American Kestrel
  6. Virginia Rail
  7. Eurasian Collared-Dove
  8. Mourning Dove
  9. Greater Roadrunner
  10. Belted Kingfisher
  11. Lewis's Woodpecker
  12. Red-naped Sapsucker
  13. Red-naped Sapsucker x Red-breasted Sapsucker
  14. Ladder-backed Woodpecker
  15. Northern Flicker
  16. Say's Phoebe
  17. Vermilion Flycatcher
  18. Loggerhead Shrike
  19. Cassin's Vireo
  20. Western Scrub-Jay
  21. Common Raven
  22. Barn Swallow
  23. Verdin
  24. Bushtit
  25. Cactus Wren
  26. Rock Wren
  27. Bewick's Wren
  28. House Wren
  29. Marsh Wren
  30. Ruby-crowned Kinglet
  31. Blue-gray Gnatcatcher
  32. Black-tailed Gnatcatcher
  33. Northern Mockingbird
  34. Crissal Thrasher
  35. European Starling
  36. Phainopepla
  37. Orange-crowned Warbler
  38. Common Yellowthroat
  39. Yellow-rumped Warbler
  40. Spotted Towhee
  41. Abert's Towhee
  42. Brewer's Sparrow
  43. Lark Sparrow
  44. Unidentified “Sage” Sparrow
  45. Song Sparrow
  46. Lincoln's Sparrow
  47. White-crowned Sparrow
  48. Summer Tanager
  49. Red-winged Blackbird
  50. Western Meadowlark
  51. House Finch
  52. Lesser Goldfinch

Happy birding!

Sunday, October 6, 2013


Whew.  In late September, I hacked apart the chain tethering me to my laptop and the joys of proofing data, and headed southward to the Warm Springs Natural Area for a few days to collect some data.  Free at last!  I’m still in the process of getting the survey data entered, so I’ll leave the full species list for a later post, but I thought I’d share some highlights and a few photos.  I didn’t see anybody particularly unexpected, but one of my favorite things in wildlife biology is delving into what is expected, where, and why!

  • Western Scrub-Jays.  My goodness, the Scrub-Jays.  We tend to run into a few in mid-April, but we hadn't had any fall records in our dataset until this visit.  Plus Flickers.  They were EVERYWHERE, and apparently had just arrived en masse … not to mention a Lewis’s Woodpecker or two.

Red-naped x Red-breasted Sapsucker
  • I was really excited to see sapsuckers: Red-naped and Red-naped x Red-breasted hybrids.  So far, in my September forays to Warm Springs, several of the Red-naped/Red-breasted/hybrid Sapsuckers have been young-of-the-year, and at least half have been hybrids.  Has anyone else noticed this pattern in that part of the state/at that time, or is it just a function of my small sample size?  I’d be really interested to hear, either way!

  • Not that these guys are that uncommon, but I enjoyed my 4-wren day, with Bewick’s Wrens, Marsh Wrens, House Wrens, and a Cactus Wren (!) hanging out in the riparian area within a space of about 300 meters.  It's not that Cactus Wrens are unknown from the area, but I have to admit that I was a little startled to have one poke its head out from the palm fronds, rasping its song.

  • Summer Tanagers.  Any day I see a Summer Tanager is a good day in my book, and I had 3 days of them pitucking from among the palm fronds and cottonwood leaves.

    The Bee Nest Tunnels are these dark spots on the ground surface
  • The Phainopeplas are back, “hoyting” from the top of mesquites.

  • A particularly fun discovery was a colony of native ground bees: maybe alkali bees?  There is an alfalfa field only a couple hundred meters away.  SO cool.  [As an aside, if you’re interested in books on pollinators, Stephen Buchmann and Gary Paul Nabhan’s The Forgotten Pollinators is one of my favorites.] 

  • I found a few unidentified Sage Sparrows (but nothing like the winter numbers) darting into the shrubbery, thwarting my attempts to determine whether they were Bell’s or Sagebrush Sparrows!

  • Lots of Sharp-shinned Hawks, too.  I tried to get some photos, but ended up with some fantastic pictures of branches instead.

  • Warbler-wise, it’s a little late, so I was limited to Yellow-rumped (all Audubon’s), Orange-crowned, and Common Yellowthroats.  Again, I tried to get some photos of the Yellow-rumps, and ended up with yet more pictures of branches!

Lincoln's Sparrow
  • By far the most abundant species I found, though, was the White-crowned Sparrow, who were packed into the former pastures now filled with sunflowers.  There were so many of them, and they were moving around so much, it was difficult to pick out the occasional Lincoln’s and Song Sparrows.  House Finches were also found here in large numbers, but at least they perched on the tops of the sunflowers, making them easy to see; plus they called almost incessantly.  The Lincoln’s and Song Sparrows were mostly on the ground, where they alerted me to their presence by the scratching sounds as they foraged - along with the occasional call note.

  • I watched a Loggerhead Shrike manipulate a large green grasshopper with its beak, finally impaling it onto the broken stub of a mesquite branch.

  • Last but not least: Monarch butterflies.  I didn’t see nearly as many of them this year as I did in 2012 (from what I understand, last year was a particularly good year for them in Nevada), but I saw quite a few scattered through the area.

Well, that’s it for now, I think.  I’ll try to get the rest of the data finished up soon, so I can put up the full species list.

Happy birding!