Tuesday, February 17, 2015

Black-throated Valentine

Black-throated Sparrow, (c) & courtesy of Bill Schmoker
Who doesn’t love Valentine’s Day? It’s the day we officially get to celebrate romantic love with heart-shaped goodies, long-stem roses, candle-lit dinners, and all things milk-chocolatey. But for my wife and me, it’s become the day to celebrate the annual arrival of an old friend.

It all began a long, long, long time ago. February 14, 2014, to be exact. I was out in the field – somewhere – doing bird surveys when the wife texted me. Guess what? read the message, probably in those exact words. I stepped outside this morning and heard two sweet toots followed by a pretty trill. The black-throated sparrows are back!

This was indeed textworthy news. At our little slice of paradise in the Joshua tree forest of northwest Arizona where the Grand Canyon opens its craggy maw upon Lake Mead, Black-throated Sparrows share our two acres of pristine high desert for most of the year. But at some point in November, typically, they abandon us for a few months to head south for warmer climes. Our resident Cactus Wrens no doubt laugh at them. Our resident Black-tailed Gnatcatchers jeer: Wiimp wiimp wiimp wiimp wiimps!

It’s probably true that no one enjoys being mocked, so at some point in the waning days of winter, the blackthroats return – if for no other reason than to shut up the laughing ladderbacks. But when, exactly?

I think I now know. This year – 2015 – I happened to be home on the 14th of February. As is my wont, I awoke just before dawn and stepped outside onto the deck to check the temperature. Then I heard it. Two sweet woodwind toots followed by a piccolo trill. Black-throated Sparrow! First of season!

“Hey! Guess who’s back?” I whispered delightedly.

My wife guessed right. She was as excited as I was.

It was a great Valentine’s Day gift for us this year.  Truly memorable!

- Dave

Friday, February 6, 2015

Nevada Bird Count: Looking Back, Looking Forward

Truckee River
It’s February, and thoughts across the birding nation are focused on prepping for the coming field season.  I’m no exception!  During all this prep, though, I’ve been reflecting on last year’s incarnation of the Nevada Bird Count, and thought I’d pull together a map showing where we had surveyed point count transects last year.  We surveyed around 120 transects last year, some of them surveyed 2 or 3 times, along with fourteen area searches along the Truckee River, in the Pine Nuts, at Desert and Pahranagat National Wildlife Refuges, at Warm Springs Natural Area, and several locations within blackbrush and sagebrush habitats.  It definitely kept us hopping!  


Pine Nut Range


 

Central Nevada Sagebrush
This year the focus areas will be quite similar, with only a couple of changes: the Pine Nut and Shoshone ranges, Walker and Truckee rivers, Warm Springs Natural Area, and Ash Meadows National Wildlife Refuge are among the highlights.  There won’t be as many far-flung transects to explore, but we’ll get to dig our fingers in to several locations, and really get to know them well.  We’re still in the midst of the hiring process, so I’ve been talking with lots of great applicants - and getting even more psyched to get started!





Southern Nevada Blackbrush/Joshua Tree


Warm Springs Natural Area
In the meantime, though – it’s back to data processing and report-writing!  I’ll leave you with some pretty pictures from 2014, and a wish that you all have very

Happy birding,
Jen







Thursday, January 29, 2015

Bird adventures on Anaho Island



Cormorant nests
In January, we began our bird surveys on Anaho Island, to help document use of the island by birds other than colonial waterbirds.  Closed to the public, Anaho Island is both a National Wildlife Refuge managed by the US Fish and Wildlife Service, and a part of the Pyramid Lake Paiute Reservation, patrolled by the Tribe’s Pyramid Lake Rangers.  It was established to protect breeding colonies of waterbirds, particularly American White Pelicans – the pelican colony there is one of the two biggest in the western United States.  For now, our surveys extend across the entire island – as the breeding colonies of pelicans, cormorants, gulls and so on, re-establish themselves in spring, our survey area will shrink to only those areas where we cannot disturb them.

We completed our first winter survey in January – though given the blue skies, warm weather, and green grass, it didn’t feel too much like winter!  We didn’t see anything unexpected on this visit, but I certainly was impressed by the sheer numbers of Rock and Canyon Wrens.  We’re definitely looking forward to documenting the changes in the bird community here across the seasons - we’ll keep you posted!

Happy birding,
Jen


Sunday, December 28, 2014

From the Great Salt Lake to Las Vegas Wash: Pelicans

On October 31, at Las Vegas Wash, I spotted a small group of pelicans - two of which had been banded.  One of the bird's tags were readable - two numbers and a letter in white writing on a green tag.  It turns out it had been banded as a chick on July 23rd up in the Great Salt Lake.  Here's a short article that the Review-Journal published earlier this year on the banding there.  Keep your eyes peeled!  And remember, if you find banded birds (pelicans or otherwise), please do report their bands to the Bird Banding Lab here - though with the larger wing tags like those on these pelicans (since you're not likely to be seeing the leg bands), you'll have to use their email address.

Happy birding!
Jen

Tuesday, December 23, 2014

Fall/Winter 2014 Projects

View from Las Vegas Wash
It’s been a busy fall here at GBBO!  Much of what we’ve been doing is working through the piles of data accumulated during the breeding season – but we’ve managed to make it out into the field, as well.  Among our projects were:

Anaho Island – in January, we will begin a year-long project looking at non-colonial waterbird use of Anaho Island.  This October, we visited the island to scope out survey locations, and see where the American White Pelican colony was located.  Stay tuned!

Crescent Dunes, Tonopah - in September, we began a pilot monitoring season at the Crescent Dunes Solar Power Plant near Tonopah.  This plant is due to begin generating power in early 2015; we’ll be involved in biological monitoring here for the next few years to document bird use and potential mortalities.  This will help to ensure that any impacts are well-documented, and will contribute to the development of mitigation strategies to minimize impacts on birds.

Las Vegas Wash – in September, we started up year-round bird surveys:  every two weeks, one of our surveyors conducts point counts on the Wash.  In October, we attacked the vegetation survey portion of the project – many thanks to Kelly and Dave for their hard work and great attitude – there’s nothing quite like having to run out a measuring tape through 70 meters of solid quailbush!

Lower Colorado River Project – the LCR crew had a successful bird survey season this spring/summer, and followed it up with vegetation surveys throughout September and October.  Here’s a post from a previous year’s veg surveys along the LCR, showing what it’s like.  Intrepid souls, who always seem to find the fun – even in tamarisk!

Nevada Bird Count – while the bird surveys finished in early July, and our main crew left in late July, Kelly and Dave remained on the vegetation survey circuit into November, finishing up habitat surveys in blackbrush habitats within the Mojave Desert, and pinyon-juniper habitats within the Pine Nut Range, near Carson City.  Thanks, guys!

Warm Springs Natural Area – in September, we conducted our fall bird surveys, and in October/November, the final vegetation surveys were finished up.  Dave informs me that however impressed he was by his 70 meters of quailbush, he was even more impressed by his 50 solid meters of mesquite thicket.  He’s finishing up the data entry now – next month the habitat modelling begins!

Waterbirds –  we continued to monitor fish-eating waterbird numbers at Walker Lake and several other terminal lakes in western Nevada, including Pyramid Lake.  Due to continued declines in the water level and Walker Lake, and corresponding increases in dissolved solids in the lake water, fish populations have crashed and the avifauna of the lake reflects these changes, with fish-eating birds numbers reaching very low levels, and numbers of invertebrate feeders (notably the small grebes) reaching very high levels during parts of the year.  Continued bird monitoring will help to document improvements in the lake's ecology if current efforts to acquire more inflow are ultimately successful.  

As you can see, we’ve been keeping busy – and now prepping for the 2015 field season begins!  Have a wonderful holiday, and all the best for the New Year!

Jen




Tuesday, October 21, 2014

Breeding White-faced Ibis in Nevada

[Note: this spiel was written quite some time back, but I thought you might find it interesting all the same! -- Jen]

In 2009 through 2011, Great Basin Bird Observatory teamed with Nevada Department of Wildlife (NDOW) to survey colonial waterbirds throughout the state, including White-faced Ibis, as a part of a regional evaluation led by the U.S. Fish and Wildlife Service and American Bird Conservancy.  White-faced Ibis, dark-colored wading birds, have a long downwardly-curved bill with which they probe through the mud and debris of wetlands and agricultural fields in search of their prey – in the Great Basin, they feed mostly on earthworms and insect larvae.  

In the 1960s and 1970s, pesticides and habitat loss caused the ibis population to crash, across their range[i].  However, in the 1980s and 1990s, they began increasing again; now, the Intermountain West population is considered to be of only moderate conservation priority[ii].  While the regional trend is stable or increasing, there is concern that Nevada’s population may again be declining[iii].  Evaluating White-faced Ibis populations on a state-wide level can be difficult, however, since they are nomadic, with colonies moving as water levels fluctuate.  

The Lahontan Valley, particularly Carson Lake, has traditionally been one of the most important White-faced Ibis breeding areas within the Great Basin, and in high water years supports the bulk of Nevada’s breeding population.  Breeding numbers vary dramatically here, from 0 (e.g., 1974) to 9000 pairs (e.g., 1997)[iv].  Our results supported this pattern: in 2009, a low water year, NDOW recorded 100 breeding ibis; with the higher waters seen in 2011, 6940 breeding ibis were recorded.  The Humboldt River, Ruby Valley, and Quinn River also supported large numbers of breeding ibis, and formed the bulk of Nevada’s population during low water years in the Lahontan Valley.

While pesticide impacts have lessened in past years for the majority of the Intermountain West’s population, eggshell thinning as a result of DDT (and DDE, its metabolic byproduct) remains an important problem for Carson Lake’s ibis, particularly for those breeding early in the season.  While DDT was banned from use within the United States in 1972, DDE levels in Carson Lake ibis eggs have remained high over time[v].  Michael Yates and others[vi] reported that many of Carson Lake’s ibis winter in the Mexicali and Imperial Valleys of Mexico and California, and that these birds had high levels of DDE.  Unfortunately, White-faced Ibis appear to be physiologically susceptible to DDE/DDT, and their life history increases their chance of exposure: they tend to feed in agricultural fields that may have been subjected to past pesticide applications, and their favored prey are earthworms, which tend to bioaccumulate DDE from soils.  In addition, they tend to breed shortly after arriving on their breeding grounds, while their systems still contain DDE, which may explain why earlier nesting individuals tend to have greater eggshell thinning – individuals nesting later have been able to feed on uncontaminated prey, and their DDE levels and eggshell thinning are consequently reduced.

While our joint colonial waterbird project is over, NDOW continues to regularly survey the major White-faced Ibis colonies, including those in the Lahontan Valley, and we continue to maintain our statewide colonial waterbird database.  If you have information on breeding ibis colonies (or other colonial waterbirds), locations and/or numbers, we’d love to hear from you!  Many thanks to our partners at Nevada Department of Wildlife for sharing their survey results for this project, especially Brad Bauman, Pete Bradley, Jenni Jeffers, and Larry Neel.



[i] Ryder, Ronald A. and David E. Manry. 1994. White-faced Ibis (Plegadis chihi), No. 130.  The Birds of North America (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology.
[ii] Ivey, Gary, and Caroline P. Herziger.  2006.  Intermountain West Waterbird Conservation Plan.  Version 1.2.  February 2006.  A plan associated with the Waterbird Conservation for the Americas Initiative.  Published by U.S. Fish and Wildlife Service Pacific Region, Portland, Oregon.
[iii] Great Basin Bird Observatory.  2010.  Nevada Comprehensive Bird Conservation Plan, Version 1.0.  Great Basin Bird Observatory, Reno, NV.  Available online at www.gbbo.org/bird_conservation_plan.html
[iv] Ivey and Herziger 2006; Oring, Lewis W, Larry Neel, and Kay E Oring.  2001.  Intermountain West Shorebird Plan.  Version 1.0. 
[v] Henny, Charles J. 1997.  DDE still high in White-faced Ibis eggs from Carson Lake, Nevada.  Colonial Waterbirds 20(3): 478-484.
[vi] Michael A. Yates, Mark R. Fuller, Charles J. Henny, William S. Seegar, Jaqueline Garcia. 2010.  Wintering area DDE source to migratory white-faced ibis revealed by satellite telemetry and prey sampling. Ecotoxicology 19:1, 153-162.