Monday, December 16, 2013

Pinyon Jay Project Update

GBBO has been continuing its work to better understand the causes behind the rapid, ongoing decline in Pinyon Jays.  This decline of 4-5% per year has been occurring over the last 30 years, and has been well-documented by BBS data. However, its causes have not yet been adequately explained, in part because Pinyon Jays have been a poorly studied species in much of their range and present many challenges for field biologists. Nevertheless, we have been successful in efforts to deploy radio tags on Pinyon Jays, and have over the past year conducted a detailed nest study and habitat use assessment in the Desatoya Mountains of western-central Nevada. 

Although data from the last year are still being analyzed, all of our findings to date are consistent with a picture of Pinyon Jays as a species that prefers transitional ecotones between pinyon-juniper woodlands and sagebrush.  Because many of these mixed-age, mixed-structure transitional areas have been supplanted over the last century by larger and denser pinyon-juniper woodland patches, we are hypothesizing that the Pinyon Jay's preferred landscape has been reduced in extent. This suggests a possible mechanism that may have contributed to the Pinyon Jay's documented declines, and one that has ramifications for current pinyon-juniper woodland management practices. GBBO will continue its efforts on behalf of Pinyon Jays, and we will be presenting our findings and recommendations in publications in the near future.

- John

Tuesday, December 10, 2013

Waterbird Surveys

Dennis and Bob surveying on Walker Lake
GBBO has been monitoring populations of fish-eating birds over the last year on several western Nevada lakes, including Walker Lake and Pyramid Lake. Our monitoring efforts occur year-round, although they are more intensive and frequent during the spring and fall migration periods. Our goals are to better understand how waterbird populations at Walker Lake have, and are, changing as the lake shrinks, as dissolved solids increase, and as fish populations decline. We are also interested in determining the extent to which other nearby lakes "take up the slack" and provide habitat for birds that formerly used Walker Lake during migration. 

At present, Walker Lake exhibits substantially reduced numbers of several fish-eating waterbird species, and very large populations of phalaropes and Eared Grebes, which feed on the aquatic invertebrates that thrive in saline lakes. In these respects, it is becoming similar to Mono Lake, but we consider the situation to be reversible if water deliveries to the lake increase again.  Our monitoring program will continue, and as efforts to increase inflows to Walker Lake bear fruit, we can document recovery of its fish-eating waterbirds.

- John

Thursday, November 28, 2013

Happy Thanksgiving!

In honor of Thanksgiving, I’d like to share a few fun photos of Wild Turkeys, brought to you by our friends at The Yurt, John Woodyard and Melissa Renfro!

One of their recent arrivals is a leucistic Turkey, below:  


Last, but not least, here's a cool video of a couple of toms duking it out in April:

Have a Happy Thanksgiving, everybody!

All pictures/videos on this post copyright and courtesy of John Woodyard.  Thanks!

Friday, November 22, 2013

Gray Vireos: A Coda

Gray Vireo, photo copyright & courtesy of Deb Vogt
Thanks, everyone, for the Gray Vireo emails and all the location info!  (Just so you know – I really use that location information, entering them into one of my databases – next year’s map will be including all of these new sites!) 

I wanted to share a few photos Deb Vogt sent me – in June, she found a pair of Gray Vireos and their nest down in southern Nevada.  She thought they were feeding a fledgling deep in the tree – one parent “cussed her out”, while the other sang.  I hadn’t seen a Gray Vireo nest before, so I was happy to finally get to see a picture, at least!  Thanks, Deb!

Happy birding,

Gray Vireo nest, copyright & courtesy of Deb Vogt

Wednesday, November 20, 2013

Gray Vireos: A Request To Keep Your Birding Eyes Peeled

An NBC point where Gray Vireos recorded

Gray Vireos are a favorite of mine (though, to be honest, there’s hardly a bird on Nevada’s species list I haven’t said that of, at one time or another!), breeding primarily within pinyon-juniper habitats in Nevada; juniper appears to be particularly important.  They’re also a species of conservation concern within the state, and Nevada supports an estimated 20% of the global population [1].

Another Gray Vireo location
These guys are ones I enjoy mapping, and every year, it seems I generate a “hmmm, let’s see what the data look like this year” map.   This morning, I was going through some data collected in the Pine Nuts earlier in the year, and saw that we have three more Gray Vireo records there.  So you can tell what’s coming next: my thoughts turned vireo-ward!  During the afternoon’s caffeine break, I dove into GIS, played with the data, and churned out the following maps.  The first one is of all our Gray Vireo locations recorded during the Nevada Bird Count (NBC) and Atlas [2] surveys, with confirmed breeding locations broken out.  

And yet another one!
You can see during the Atlas years all of the locations are down south and within the eastern mountains of the state.  During the past 10 or so years of the Nevada Bird Count, we’ve also been accumulating records within central/western Nevada, including along the Nevada/California border, north of the Mojave Desert.  The border locations are mostly from surveys completed during and after 2009.  The second map is of all of our NBC points and Atlas locations, for reference (including incidental locations). 

On to the request:  we don’t yet have confirmed breeding records for these northern/western locations, and I’m particularly interested in confirming the breeding status along the Nevada-California border.  We have probable breeding records in the north/central portion of the state, but the highest evidence we’ve so far recorded for the border mountains is singing and possible pairs.  If you find yourself hanging out in pinyon-juniper in May/June/July, keep your eyes and ears peeled for these guys -- and if you confirm breeding (e.g., carrying nesting material, nests/eggs/nestlings, parents carrying food/fecal sacs, recently-fledged juveniles), please do let me know!  … Then I’ll have a good excuse to make up another map!

Happy birding!

Gray Vireo Atlas and Nevada Bird Count locations, with confirmed breeding
Nevada Breeding Bird Atlas and Nevada Bird Count survey locations, including incidentals

[2]  Floyd et al. 2007.  Atlas of the Breeding Birds of Nevada.  University of Nevada Press, Reno.

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!

Sunday, September 8, 2013

Sagebrush and Bell's (canescens) Sparrows

In case you hadn't seen Peter Pyle's writeup on distinguishing Sagebrush and (canescens) Bell's Sparrows in fresh plumage (fall/early winter; the primary period when their ranges will be overlapping), you can find it here. What is particularly useful is that the writeup contains photos of study specimens from Berkeley's Museum of Vertebrate Zoology; most of these photo sets are comparing fresh plumage, but a few are of worn plumage.

Definitive Prebasic Molt (according to the Sage Sparrow Birds of North America (BNA) account) begins in June, finishing by mid-September (whether anyone has looked at timing differences etc by subspecies, I don't know). Records of arrivals of Sagebrush Sparrows onto territories range from late February to late April. In Mono County, canescens begins nest building in early March, and the final nests started in mid-late June. Southern populations of canescens may start up earlier (I haven't seen any data on it) but I suspect will at least skew to the early side of that range. At any rate, you can see that there will be worn Sagebrush Sparrows migrating northward through canescens territories!

As a note to make things more interesting for us all, the BNA account notes that migrating flocks of "Sage Sparrows" have been found containing both (canescens) Bell's Sparrows and Sagebrush Sparrows.

Hope you find it useful, too!

Friday, September 6, 2013

Territory Mapping

Vermilion Flycatcher female on nest in screwbean mesquite
I’ve had some folks ask me about territory mapping, so I thought I’d share a bit about how the Nevada Bird Count does it (the Lower Colorado River project does it slightly differently in order to meet their particular program goals – minor variations on the same theme!).   Territory mapping (we’ll often also refer to it as area searching or spot-mapping) is my personal favorite way to get acquainted with birds of a new region or habitat, and is a fantastic way to learn the natural history of bird and plant communities.  Nothing beats point count transects for the chance to hike and explore and get a wide breadth of understanding of your birds and habitat, and their variation across the landscape – but the area searches are a great way to get depth.  Our plots are of variable size – basically, we want a plot to be big enough that we’re able to have it covered by 9:30-ish in the morning, but small enough that we’re able to have it covered well, and aren’t glossing over sections to get them done on time.  Not surprisingly, therefore, our Mojave Scrub plots are going to be a larger size than our coniferous forest or riparian plots – the former have a lot less habitat structure and fewer birds, so we’re able to cover more ground.  A 300 x 300m plot is fairly typical in streamside vegetation, where there’s a lot of structure.  We visit each plot 8-10 times; often our Mojave Scrub or sagebrush plots are able to be thoroughly mapped within 8 visits, but those extra 2 visits can make a big difference in our more complex plots!

Another area search plot, Sandy Valley
Basically, our surveyors are given an aerial photo overlain with a UTM grid, and on each visit, they will walk through the plot in a different pattern, making sure that they get within 50m of every part of the plot on each walk-through.  The different routes ensure that each part of the plot will get surveyed during the best part of the birding morning on at least one occasion, so we don’t have one location that is always surveyed at 5:30 a.m. and one location always surveyed at 9.  We walk through the plot, looking at and listening to birds, watching their behavior, and marking down their locations on our aerial photo.  Once we’ve finished our initial walk-through, somewhere between 9 and 10am, then we’ll often head back to a perplexing area to spend some more time watching, listening, and mapping.   The 2 biggest things to remember are (1) following individuals and (2) simultaneous detections.  When we find an individual, it’s useful to spend some time with it, marking down the path of that individual’s movement, particularly if it’s a singing male or is exhibiting other territorial behavior.   Do we see any behavior indicating where the nest might be found?  Concurrently, you want to look and listen to determine whether you have any other individuals of that species, and if so, map them too.

Here's one of 3 maps that I filled in during a single visit of my area search plot

At the end of the survey, we’ll end up with a map of all of our bird locations, criss-crossed with lines – solid ones indicating the movements of a particular individual, dashed lines indicate that we had different individuals, along with a few scribbled behavioral notes.  The day’s not done yet, though!  We’ll transfer each species’ locations, lines and notes to a species-specific map, that will eventually encompass all of the data for that species from all of the visits.  Before each visit, we’ll scrutinize those maps, and figure out where the territory boundaries are unclear and where we need to spend some more time.  Then, at the end of our 8 to 10 visits, we’ll draw our territory boundaries, and summarize our findings.

If you squint, you can make out letters marking locations: the first visit is A, the 2nd visit, B, and so on.

The area searches are useful for a lot of purposes – they give us detailed natural history information, and because they provide such detailed location information, they’re excellent at monitoring changes in habitat and bird communities through time, so they’re incredibly useful to monitor habitat restoration projects.  Plus we’re able to use them to do some calibrating of our extensive program of point count surveys – by conducting point counts on the area search plots, we’re able to compare what our point count surveyors record to the mapped territories, which helps us determine detection rates.

You don’t need UTM grids and GPS units to do your own territory mapping, though.  Find your favorite park on (for example) google maps, switch to satellite view, zoom in, and print it out.  With a pencil and your binoculars, you’re now set to map out territories of the bird community – or just a species or two of interest.  When you’ve mapped out a territory, take a look at it  - what does it tell you about that species’ habitat/structural needs?  Where is the nest located relative to the territory boundary?  If a pair renests, with either a replacement clutch or a second brood, do their territory boundaries shift?   As they move along in breeding stages, how do their movements change?   Do their defended areas contract, or expand?  And of course, spot mapping doesn’t have to be limited to the breeding season, you can also see how birds’ uses of various habitats changes across the seasons.  All fun things you can explore with mapping! 

Happy birding,
- Jen

Sunday, August 11, 2013

Clark County Species List, 2013

Summer Tanager at Warm Springs
Ha! Look what I found!  Tucked into a 3 foot tall stack of data was the list of species my NBC crew recorded in Clark County this year, mid-April to mid-June.  It had hung on our field house's refrigerator and was carefully tended whenever folks returned.  Looking through it again, it brought back more than a few fun memories, and I thought some folks might be interested.  It’s certainly not an exhaustive list of what can be found down there  – we weren’t hitting hot spots in order to build a list, we were visiting random locations within the County, which sometimes took us to really birdy places, and other times took us to some barren creosote scrub with a couple of Black-throated Sparrows.  It was a lot of fun, but – as my crew can attest – there’s a lot of really tough terrain down there!  Anyway, here it is …

  1. Canada Goose
  2. American Wigeon
  3. Mallard
  4. Northern Shoveler
  5. Chukar
  6. Ring-necked Pheasant
  7. Gambel’s Quail
  8. Pied-billed Grebe
  9. Eared Grebe
  10. Western Grebe
  11. Clark’s Grebe
  12. Double-crested Cormorant
  13. Least Bittern
  14. Great Blue Heron
  15. Great Egret
  16. Snowy Egret
  17. Black-crowned Night-Heron
  18. White-faced Ibis
  19. Turkey Vulture
  20. Osprey
  21. Northern Harrier
  22. Sharp-shinned Hawk
  23. Cooper's Hawk
  24. Common Black-Hawk
  25. Swainson's Hawk
  26. Zone-tailed Hawk
  27. Red-tailed Hawk
  28. Virginia Rail
  29. Sora
  30. American Coot
  31. Snowy Plover
  32. Killdeer
  33. Black-necked Stilt
  34. American Avocet
  35. Spotted Sandpiper
  36. Ring-billed Gull
  37. Rock Pigeon
  38. Eurasian Collared-Dove
  39. White-winged Dove
  40. Mourning Dove
  41. Greater Roadrunner
  42. Barn Owl
  43. Western Screech-Owl
  44. Great Horned Owl
  45. Burrowing Owl
  46. Lesser Nighthawk
  47. Common Poorwill
  48. Vaux's Swift
  49. White-throated Swift
  50. Black-chinned Hummingbird
  51. Anna's Hummingbird
  52. Costa's Hummingbird
  53. Broad-tailed Hummingbird
  54. Belted Kingfisher
  55. Ladder-backed Woodpecker
  56. Hairy Woodpecker
  57. Northern Flicker
  58. Gilded Flicker
  59. American Kestrel
  60. Peregrine Falcon
  61. Prairie Falcon
  62. Olive-sided Flycatcher
  63. Western Wood-Pewee
  64. Willow Flycatcher
  65. Gray Flycatcher
  66. Dusky Flycatcher
  67. Black Phoebe
  68. Say's Phoebe
  69. Vermilion Flycatcher
  70. Ash-throated Flycatcher
  71. Brown-crested Flycatcher
  72. Western Kingbird
  73. Loggerhead Shrike
  74. Bell's Vireo
  75. Gray Vireo
  76. Plumbeous Vireo
  77. Cassin's Vireo
  78. Warbling Vireo
  79. Western Scrub-Jay
  80. Pinyon Jay
  81. Clark's Nutcracker
  82. Common Raven
  83. Horned Lark
  84. Tree Swallow
  85. Violet-green Swallow
  86. Northern Rough-winged Swallow
  87. Barn Swallow
  88. Mountain Chickadee
  89. Juniper Titmouse
  90. Verdin
  91. Bushtit
  92. Red-breasted Nuthatch
  93. White-breasted Nuthatch
  94. Pygmy Nuthatch
  95. Rock Wren
  96. Canyon Wren
  97. House Wren
  98. Marsh Wren
  99. Bewick's Wren
  100. Cactus Wren
  101. Ruby-crowned Kinglet
  102. Blue-gray Gnatcatcher
  103. Black-tailed Gnatcatcher
  104. Western Bluebird
  105. Mountain Bluebird
  106. Townsend's Solitaire
  107. Swainson's Thrush
  108. Hermit Thrush
  109. American Robin
  110. Northern Mockingbird
  111. Bendire's Thrasher
  112. Crissal Thrasher
  113. Le Conte's Thrasher
  114. European Starling
  115. Phainopepla
  116. Orange-crowned Warbler
  117. Lucy's Warbler
  118. Virginia's Warbler
  119. MacGillivray's Warbler
  120. Common Yellowthroat
  121. Yellow Warbler
  122. Yellow-rumped Warbler
  123. Grace's Warbler
  124. Black-throated Gray Warbler
  125. Townsend's Warbler
  126. Wilson's Warbler
  127. Yellow-breasted Chat
  128. Green-tailed Towhee
  129. Spotted Towhee
  130. Abert's Towhee
  131. Chipping Sparrow
  132. Brewer's Sparrow
  133. Black-chinned Sparrow
  134. Vesper Sparrow
  135. Lark Sparrow
  136. Black-throated Sparrow
  137. Song Sparrow
  138. Lincoln's Sparrow
  139. White-crowned Sparrow
  140. Dark-eyed Junco
  141. Summer Tanager
  142. Western Tanager
  143. Black-headed Grosbeak
  144. Blue Grosbeak
  145. Lazuli Bunting
  146. Bobolink
  147. Red-winged Blackbird
  148. Western Meadowlark
  149. Yellow-headed Blackbird
  150. Great-tailed Grackle
  151. Brown-headed Cowbird
  152. Hooded Oriole
  153. Bullock's Oriole
  154. Scott's Oriole
  155. Cassin's Finch
  156. House Finch
  157. Pine Siskin
  158. Lesser Goldfinch
  159. American Goldfinch
  160. House Sparrow

Happy birding!