Phainopepla Fables

Inland Seabirds

Posted on August 7, 2013 by David Vander Pluym

On August 5 Lauren and I made a mad dash down to Mittry Lake after Bobby Wilcox found Arizona’s potential second state record of a Sooty Shearwater and the first one found alive (though see below about a third individual)! With strong winds out of the Gulf of California we had hopes the bird might stick. On the drive down I even had thoughts of the bird arcing over the lake! Unfortunately it did not stick around and was not relocated. While trying to relocate it, though, I discovered a Brown Booby, which was a nice consolation prize! Though the booby did not stick around long, several of us (Lauren, Henry and Suzanne Detwiler) were present and able to see it. The booby seemed to have just arrived when I found it, decided the water it was on wasn’t deep enough and moved on. Two rare seabirds arriving in the same area on the same day is amazing, but with no storms about what conditions might have brought them?

I discovered this Brown Booby in the area just south of Imperial Dam on 5 Aug 2013. This represents the 10th state reccord and only the second since 1991. Copyright (c) 2013 David Vander Pluym

I discovered this Brown Booby in the area just south of Imperial Dam on 5 Aug 2013. This will represent the 10th state reccord if accepted and only the second since 1991. Copyright (c) 2013 David Vander Pluym

This Brown Booby was in the area just south of Imperial Dam on 5 Aug 2013. Note the pale belly strongly contrasting with the darker chest and the paler underwing coverts. The photo is underexposed and the belly appeared slightly paler than these photos indicate. Note also the two generations of primaries indcating a second-year bird. Copyright (c) 2013 David Vander Pluym

When one thinks about seabirds in the interior desert southwest one tends to immediately think of tropical storms blowing seabirds up out of the gulf. That has happened with most recently Tropical Storm Nora dumping hundreds of storm petrels on Lake Havasu; see Storm Birding for more info on storm related birds. However these are rare events and most records of seabirds, whether they are tubenoses or boobies, are not related to storms! They do however all follow a pattern. The vast majority come from the “warm season” late April into November with most tubenose records coming from July (late April-September), while boobies and frigatebirds tend to be August-September (mid June-November). Even Storm-Petrels have been found at the Salton Sea not in association with storms! Interestingly most of the Laysan Albatross records are earlier than the average, from May, a time when they are moving north in the eastern Pacific.

Sooty Shearwater on Monterey Bay, Monterey Co, Cali, on 1 Aug 2009. See on a Shearwater Journey's pelagic, I was a leader on. With only one prior record for Arizona (from 1971) Bobby Wilcox report of one at Mittry Lake Yuma, Az got us moving south in a hurry! Missing the shearwater we had to settle instead with a Brown Booby! Copyright (c) 2013 David Vander Pluym

Sooty Shearwater on Monterey Bay, Monterey Co, Cali, on 1 Aug 2009. Seen on a Shearwater Journey’s pelagic. With only one prior record for Arizona (from 1971) Bobby Wilcox’s report of one at Mittry Lake Yuma, AZ got us moving south in a hurry! Missing the shearwater we had to settle instead with a Brown Booby! Copyright (c) 2013 David Vander Pluym

So we have a pattern of when, but why do they occur during these times? During the warmer months the temperature difference between the colder Pacific Ocean and the warmer Gulf of California decreases and seabirds that don’t breed in the gulf may move north into it. Once there they may move north up the gulf. Aided by the northward moving monsoonal winds an adventurous bird may ride these winds up the river or into the Salton Sink. In fact when the shearwater and booby were found there were ~10mph winds straight out of the gulf and most records of tubenoses come during such conditions. Both boobies and frigatebirds tend to fly higher and can be more readily blown north by these winds, likely the reason there are far more records of these species than of tubenoses.

I discovered this Brown Booby in the area just south of Imperial Dam on 5 Aug 2013. Note the dark brown evenly colored upperparts. Copyright (c) 2013 David Vander Pluym

In total 9 species of tubenose have previously been recorded between the Salton Sink (8 species) and the LCRV (6 species). The LCRV had one prior record of Sooty Shearwater, a bird flying along the river at the Palo Verde Dam north of Blythe 19 May 2001, and though not submitted as being in Arizona, must have passed through! The other prior AZ Sooty Shearwater was just outside of the LCRV in Wellton, Yuma County, 6 Jun 1971. Brown Boobies (and Blue-footed) have occurred more regularly inland, though numbers have decreased since the 80’s with this only being Arizona’s second since 1991! I believe the Salton Sink has also only had 2 Brown Boobies since 1990. Magnificent Frigatebirds were formerly more regular as well and now they are rare enough, that while that is still the most likely species to occur, other species need to be considered and ruled out!

Cook's Petrel off Santa Cruz Co, Cali on 1 Aug 2009. See on a Shearwater Journey's pelagic, I was a leader on. With 3+ records for the Salton Sink this is my pick for the next tubenose in the LCRV. Copyright (c) 2013 David Vander Pluym

Cook’s Petrel off Santa Cruz Co, Cali on 1 Aug 2009. Seen on a Shearwater Journey’s pelagic. With 3+ records for the Salton Sink this is my pick for the next new tubenose in the LCRV. Copyright (c) 2013 David Vander Pluym

Though the focus of this has been on tubenoses, boobies, and frigatebirds, I want to mention a couple other species that could occur in the LCRV because of the summer monsoons. Yellow-footed Gull moves up into the Salton Sink in the hundreds during the monsoons, but despite this there is no record that I am aware of for the LCRV! Laughing Gull and Gull-billed Tern are two other species that could be found at this time of year, and in fact the past several years have had several reports of Laughing Gull. September is the period generally thought of for jaegers, but most records of Pomarine from the Salton Sink are from the summer months. Summer is also a time when numbers of South Polar Skuas have been found in the northern part of the gulf and could ride the winds up the valley or over to the Salton Sea!

With the Laguna/Imperial Dam area being the closest to the gulf (just under 100 miles straight or just over 100 river miles), this is your best bet for these species (especially non storm related tubenoses). Lots of lakes in this area could hold goodies, though, you could spend several hot days without seeing much of anything! Visiting on days when the wind is blowing out of the south will increase your chances of finding an inland seabird, but wind can make it hard to bird. Another difficulty is that there are lots of small lakes that are inaccessible and even the bigger ones in that area can be hard to view. For more info on birding this area check out http://southwestbirders.com/

I discovered this Brown Booby in the area just south of Imperial Dam on 5 Aug 2013. Copyright (c) 2013 David Vander Pluym

Though most people bird the LCRV in the cooler months, and the summer can be a bit boring for the birds, the possibilities of a mega keep me going out there even in 122F heat!

For more information check out Patten, M. A., et al. 2003. Birds of the Salton Sea: Status, Biogeography, and Ecology and Rosenberg, et al. 1991. Birds of the Lower Colorado River Valley. Also if you can find it (which I have not yet) Patten and Minnich 1997 Souhwest Naturalist.

-DVP

Posted in Imperial County, LCRV, Migration, Vagrants, Yuma County | Tagged Brown Booby, Gulf of California, Salton Sink, Seabirds, Sooty Shearwater, Tubenoses | 5 Comments

Least Tern, Lake Havasu City

Posted on August 4, 2013 by Lauren Harter

David and I had a nice surprise today in the form of a text message from John West, saying that he had just found a Least Tern at Rotary Park! This being a state bird for both of us, we rushed down to the sweltering beach (113 F) and were happy to see the little elf still there.

Least Tern is one of several species that presumably wander to Arizona from populations along the upper Gulf of California, but are much more regular in central and southeastern Arizona than here in the LCRV. I believe there are fewer than 10 records.

I haven’t spent much time with Least Terns, especially in recent years, so it was fun to watch and study this bird. It was still quite young, with a bit of brown remaining on the scapulars and pale tips to some of the wing coverts. When it spread its wings, the white triangle on the inner wing formed from bright white outer secondaries and greater coverts and inner primaries contrasted with the rest of the wing, forming a shadow of a dark “M” pattern. Most striking, of course, was the diminutive size. A rare Snowy Plover was on the beach with it; the two were about the same size, but I would guess the Snowy Plover was heavier. The Least Tern was dwarfed by Forster’s Terns and Killdeer, and it may as well have been a speck of sand next to a Caspian Tern.

The light wasn’t great, but I took a video of the bird loafing on the beach. (I recommend changing the quality to high def.) Check out the size comparison with a diminutive Snowy Plover!

[http://www.youtube.com/watch?v=p4A9p9IFBQs]

John got some great photos before we arrived, but David got some too.

Least Tern by David Vander Pluym

Posted in Lake Havasu, LCRV, Mohave County, Vagrants | Tagged Least Tern, Rarities, Twitching | 2 Comments

Sound Recordings from the Spring

Posted on July 31, 2013 by Lauren Harter

After making good use of my recording equipment this spring, the summer has been much slower for sound recording. I blame the heat, both because it keeps me inside much more often and because I don’t like to take the mic out in extreme heat. I’ve been plenty busy with other projects, though, so I haven’t had much of a chance to process and post my recordings from the spring. I took the opportunity today to do so.

If this grackle could get out of the heat, he’d do it too.

I processed 22 recordings today (plus some really junky ones that I didn’t save), of which I posted 14 on Xeno-Canto. Below are a few of my favorites.

I’ve always been kind of enchanted by the songs of Anna’s Hummingbirds, and lately I’ve been trying to record them. In particular I’m curious about geographic variation in the song. The dive display of the males is especially cool: he dives down in a J, terminating the dive just above the object of his attention (female, rival, human head…). As he ends the dive he gives a loud squeak. There are actually three parts to the squeak; the first two parts of the sound are made by the wings, but the loud last part is made by the tail. Immediately after ending the dive, he will pull back up again, hovering well above The Object as he sings, but only the first part of a typical song. Then he rises straight up until he’s a speck in the sky, and repeats the dive display. I was fortunate to be able to record a displaying male back in March: listen to it here.

An owling trip to the California side of Lake Havasu in early April turned up only two species, Great Horned and Western Screech-Owls. Still, we got some good eBird data out of it and I managed to get a decent recording of a singing Western Screech-Owl.

The next afternoon, David and I found ourselves in central Phoenix with some time to spare. So we stopped by Encanto Park, our favorite hotspot for Rosy-faced Lovebirds, which I had wanted to record. This was one of the more challenging times I’ve had while recording birds. Recording in a popular urban park, near a busy street, on a Saturday afternoon is not easy! Still, my lovebird recordings came out better than I expected. Listen to them here and here.

The next day, we visited the Hassayampa River Preserve for its bird-banding program. I also took the time to record a few birds. My favorite of these was an agitated Northern Cardinal. It’s difficult to hear in the recording, but between typical call notes he was giving faint song-like notes.

Don’t mess with the cardinal.

I’m feeling accomplished right now, but I still have plenty left from the spring, plus a few really good ones from the summer!

Posted in LCRV, Sound Recordings | Tagged Anna's Hummingbird display, Bird recordings, Bird song, Encanto Park, Hummingbird noises, Lovebird calls, Lovebirds in Arizona, Northern Cardinal, Northern Cardinal call, Peach-faced Lovebird, Rosy-faced Lovebird, Screech Owl song, Western Screech Owl, Xeno-Canto | 1 Comment

Photo Study: Two Second-Cycle California Gulls

Posted on July 22, 2013 by Lauren Harter

Phainopepla Fables has been on the back-burner lately as field work has kept us busy, and we’ve spent the past month or so catching up. We hope to update the blog more regularly now as we should have a little more free time. Bonus: fall migration is on, and the monsoon has started!

Yesterday, with a storm rolling in from SSE, I decided to head out ahead of the storm and see what was on the beach at Rotary Park. A whole lot of Not Much, as it turned out, but soon I spotted this bully coming in with a fish, and decided to spend some time photographing it.

This is a second-cycle California Gull, one that was hatched last year (2012 model). Note that it is molting inner primaries: the fresh, not-yet-grown inner primaries contrast strongly with the full-size but very worn juvenile outer primaries. This bird is undergoing its second prebasic molt.

This individual is still heavily marked with muddy or dusky brown, and could be mistaken for a juvenile with a passing glance. Juveniles are just starting to appear in this area this fall, and are still strikingly fresh, cleanly barred, with a more or less all-dark bill. This bird is much more patchy-looking, with a nice bicolored bill. The bill base and legs are sickly gray in color, and many of the wing coverts have been replaced with clean gray feathers. Remember also the extremely worn juvenile outer primaries, feathers that would be crisp and fresh on the young juveniles.

This bird was working very hard to swallow this fish, and failed in quite a few attempts as I snapped photos. Eventually it got the fish down and appeared in the gull flock with a grotesquely bulging throat, but all I photographed was the struggle…

My attention was quickly diverted from the fish swallow-regurgitate cycle when this beast flew in.

This is another second-cycle California Gull. It is at about the same stage of flight-feather molt as the first bird, creating the same odd wing shape. This bird, however, is much more worn and bleached than the first bird. Its overall whitish body plumage gives it more of an adult-like aspect.

Note that the bird’s overall structure and the color of the bare parts are more or less the same as the first bird. The plumage, though, is strikingly different, even though these birds are at the same stage in life.

Check out this close-up of that striking wing pattern. Some scapulars and coverts have been replaced, but many of the coverts have worn away to almost nothing. The secondaries have bleached white at the base.

Here are some more flight shots. The pattern of wear and molt combine to make a striking wing pattern not normally associated with the large white-headed gulls!

This guy really stands out among the adult Ring-billed Gulls.

California Gulls are four-year gulls, meaning they take four plumage cycles to attain adult plumage. First-cycle California Gulls are a common enough sight in western Arizona: barred or mottled brown overall, with a bicolored bill by winter, becoming more muddied by late winter. These second-cycle gulls are a less common sight, and third-cycle birds rarer still. By the time they complete the second prebasic molt, they will have mostly gray mantles, more adult-like flight feathers, and a little more white in the tail.

Note: I referenced Howell and Dunn’s excellent book Gulls of the Americas (2007) for this post and highly recommend it for further reading on the subject. I also referenced the gull and molt expertise of David Vander Pluym.

Posted in Identification, Lake Havasu, LCRV, Mohave County, Molt, Species Profiles | Tagged California Gull, Gull molt, Gull plumage, Second-cycle gulls | 2 Comments

Is Nutting’s Flycatcher actually two species?

Posted on May 18, 2013 by David Vander Pluym

Lauren Harter and I have been very busy with work lately and haven’t had the time to update the blog as much as we like (but we do have some interesting stuff that we will hopefully finish and post soon!). Today however I had a second to spend at the computer and catch up on reading some e-mails and checking various things posted when I came across something interesting on the AOU webpage.

This baby Nutting's Flycatcher 21 Apr 2013 in the BWR NWR, Moh Arizona was born in an area where Ash-throated Flycatchers are common, a good indication that Ash-throated and Nutting's Flycatcher tend not to hybridize. Copyright (c) 2013 David Vander Pluym

This baby Nutting’s Flycatcher 21 Apr 2013 in the BWR NWR, Moh Arizona was hatched in an area where Ash-throated Flycatchers are common, a good indication that Ash-throated and Nutting’s Flycatcher tend not to hybridize. Copyright (c) 2013 David Vander Pluym

Recently the AOU has posted a batch of pending proposals. Among others that caught my eye was a proposal to split Nutting’s Flycatcher into two species. Since Lauren Harter and I discovered the Nutting’s Flycatcher at Mosquito Flats BWR NWR back in Dec 2011 our interest has been piqued by the species and when we have had a chance we have tried to read up as much as possible on the species as well as watching it in the field. Listening to recordings, we had noticed vocal differences between Nutting’s Flycatchers that have been found in the US, those from central and southern Mexico (Myiarchus nuttingi inquietus) and those in southern Mexico to Costa Rica (M. n. flavidior), and we had heard some discussion about the status and the differences between these taxa. I know nothing about the nominate taxa which occurs in the interior of southern Mexico to Nicaragua, except that the genetics align it with inquietus. Listening to the various calls and songs of each taxa on Xeno-canto and Macaulay Library really gives you an appreciation for just how different they are! Take this recording from Costa Rica for example: I have heard nothing like it from the Bill Williams birds or any recordings of northern Nutting’s. Compare for yourself with vocalizations of Nutting’s Flycatcher from the Bill Williams River or elsewhere in west Mexico. I know that I would not be able to identify one of these southern birds as a Nutting’s Flycatcher if I were to hear it out birding!

Given how different the vocalizations are it is not surprising that a recent paper found that the two taxa differ significantly at the genetic level as well. This change in both vocalizations and genetics is apparently very abrupt with birds on the coastal plain of southern Mexico differing from those in the nearby hills. The two taxa are said to be similar in appearance and it will be interesting to sort out field identification. A quick google search of Nutting’s Flycatchers from Costa Rica indicates that identification may not be as difficult as northern Nutting’s vs. Ash-throated, which are very similar despite not being closely related.

Speaking of how similar Nutting’s is to Ash-throated it may surprise some to learn that when Nutting’s Flycatcher was first described it was a controversial species. At first given the similarity of Nutting’s and Ash-throated (especially when you could only work with specimens) as well as variation within the tail pattern of each taxa, that the two were considered one species with widespread intergradation. It was not until 1961 when a paper published by Wesley E. Layon put this notion to rest. Combining both field work and examining a large number of specimens he was able to show that there was likely little if any hybridization and that plumage and vocalizations conformed to species. I highly recommend this paper as it is still considered to be the best for identification criteria for Nutting’s Flycatcher vs. Ash-throated. As an aside, if there ever was a chance of hybridization between the species it was in the Bill Williams when in March 2012 the Nutting’s was hanging out with an Ash-throated before being driven away by a second Ash-throated. Now instead of hybrids we have a pure pair breeding!

This Nutting's Flycatcher has been observered by many, but perhaps you have also seen "Nutting's" Flycatchers in Costa Rica? If so you may have actually seen a different species. Here 19 Jan 2013 BWR NWR LP Copyright (c) 2013 David Vander Pluym

This “Phillips’s” Flycatcher has been observed by many, but perhaps you have also seen “Nutting’s” Flycatchers in Costa Rica? If so you may have actually seen a different species. Here 19 Jan 2013 BWR NWR LP Copyright (c) 2013 David Vander Pluym

If the split is accepted the issue of naming will come up and if you are interested in that I would strongly suggest reading the proposal as perhaps instead of seeing a Nutting’s Flycatcher you actually saw a Phillips’s Flycatcher or a Ridgway’s Flycatcher.

Though unlike several of the other proposals a split is unlikely to give most birders a new tick, it is still an interesting split and helps to illustrate the importance of vocalizations in species limits. Humans are very visual animals, and because of this we often forget that for other animals this might not be the most important aspect for them in finding a mate.

-DVP

Posted in Bill Williams, Identification, Species Profiles | Tagged AOU, Costa Rica, flycatcher, Mexico, Nutting's Flycatcher, Taxonomy | Leave a comment

Nutting’s Flycatcher Confirmed Breeding!

Posted on April 21, 2013 by David Vander Pluym

With only four previous records for the United States, Lauren Harter’s and my discovery of a Nutting’s Flycatcher in the Bill Williams River NWR in the winter of 2011-2012 was a shock, though there was a prior record (Sept 2008) for the Bill Williams. When it was rediscovered returning the next winter we were surprised but not shocked. Though there had been reports of two birds during the first year and speculations about it being the same bird as the one in 2008 it seemed like it was one bird that was wintering in the Mosquito Flats area and then leaving for the summer.

Nutting’s Flycatcher sitting in a Palo Verde. Note the gray chest contrasting with the yellow belly, the very brown back and crown (lacking gray tones) as well as the secondary panel and tail pattern. Note also the worn tail on this individual. BWR NWR 20 April 2013 Copyright (c) 2013 David Vander Pluym

This past winter, though there were reports of the bird at Mosquito Flats into March, the last fully documented report was from 10 Feb so it seemed in all likelihood that it had left. Fast forward to 8 April and we are in full work mode for GBBO doing riparian bird surveys, when Lauren Harter heard and recorded a Nutting’s Flycatcher on the north side of the Bill Williams River (North Burn) about ~1km from the Mosquito Flats (which is about how far it moved its first year). A couple days later on 11 April Oscar Johnson discovered a calling Nutting’s Flycatcher 3 km away from the previous sighting. We all assumed it was the same individual wandering around, but we questioned this assumption when Oscar had it again in the same location 16 April. The possibility exists that Oscar’s birds are different from the North Burn bird, but until we are able to get back to North Burn this can only be speculation.

On 19 April Lauren went out to investigate what was going on and saw an adult carrying something to the same patch of tamarisk twice. This definitely got us excited, assuming the bird had a nest, but who was the mate? Both Oscar and Lauren had thought they heard and recorded two birds but were unable to confirm this. On 20 April I decided to head out and try to see if I could add another piece to the puzzle. After waiting I was able to see that the bird had a regular circuit of stops it would make. At one of the stops of the circuit a territorial dispute broke out with three birds at least one of which was a Nutting’s Flycatcher and one possibly an Ash-throated. Later in the morning I heard counter calling Nutting’s Flycatchers from the same area, all very interesting but not the hard breeding evidence I wanted. Suddenly the bird flew off the cliffside carrying something in its beak. As it flew directly to a spot I had seen it visit on several occasions I decided that I should follow! After about 100 meters of belly crawling and negotiating through mesquite and tamarisk (boy is that stuff dense!) I popped out at an opening where I suspected the birds were going. As I sat down to wait I starting hearing soft wheeping coming from a dense cluster of tamarisk. I sat and waited and soon heard soft wheeping from some dense tam and as I suspected that might be where a nest was, I investigated. As the wheeping became more agitated and as I was unable to find the bird I decided to retreat back to the opening and see if I could see anything from there. As I was backing out I flushed the bird and briefly it landed in the open where I could clearly see it was a fledgling Nutting’s Flycatcher!!!!!!! I was shocked and before I could get my camera up, the bird gave one last soft wheep, disappeared into the dense tam and stopped calling. Still shocked, I suddenly noticed an adult fly in and land, softly calling, right where the fledgling had been. I quickly grabbed my camera and got a few photos of the bird carrying an insect before it noticed me and quickly swallowed the insect. As it was starting to get warm and I found myself being a disturbance to the birds I decided to head out.

Nutting's Flycatcher carrying food. Note again the worn tail. BWR NWR 20 April 2013 Copyright (c) 2013 David Vander Pluym

Nutting’s Flycatcher having just swallowed the prey item it was carrying. Many species of birds will swallow food meant for nestlings when seen by potential predators (e.g. humans) as a way of trying to hide nearby young. BWR NWR 20 April 2013 Copyright (c) 2013 David Vander Pluym

Note the nicer looking tail on this 2nd adult Nutting's Flycatcher BWR NWR 20 April 2013 Copyright (c) 2013 David Vander Pluym

I still wanted to get photos to document this first United States nesting record and confirm that the parents were both Nutting’s Flycatchers, so of course Lauren and I went out there early this morning 21 Apr, hoping to be rewarded! How quickly those rewards came! Since we had an idea of the area being used by the birds, we were able to keep a lower profile and completely avoided disturbing the birds. We soon had first one adult in the area, and based off of the feather wear of the tail, we were able to confirm it was a second bird, different from one I photographed yesterday. Soon though we had even better proof in the form of two adults sitting together on the edge of our little opening!

Yes it is a bad photo but it does show the two adult Nutting's Flycatchers! They just did not want to sit right next to each other. BWR NWR 20 April 2013 Copyright (c) 2013 David Vander Pluym

As soon as the first adult came in, we could hear the fledgling calling from the dense tamarisk. The adults would drop down into it likely feeding the young! When the adults left we were able to quietly investigate and I quickly discovered a fledgling sitting on a branch!!! I softly got Lauren’s attention and while I was able to snap off a couple photos she was able to get recordings of the bird calling. As the calling continued we realized we could hear a second youngster as well and were even able to get a quick look at it! After a passing Lucy’s Warbler startled one into moving away from us and a parent arriving with food beckoned the youngins deeper into the tamarisk, we decided to head out, fully satisfied with our day. We did try to get over to the North Burn area, but gave up after finding the “shortcut” trail overgrown and under water and the day getting late. Will have to check another time when our busy schedule allows. Given that this a first breeding record for the United States, the three of us plan on submitting a manuscript for publication!

Lauren was able to get several recordings today and on the 19th of these birds. Below are links to the recordings in xeno-canto, with descriptions of the different calls and timestamps. Enjoy!

April 19, single adult calling: here and here.April 21, interaction calls of two adults: here and here.
Adults and fledglings here; a similar recording here but with probable begging calls.
Perhaps the best one is here, with all four individuals calling together. Be sure and check out all of these recordings.

Fledgling Nutting's Flycatcher the first nesting record for the United States! BWR NWR 20 April 2013 Copyright (c) 2013 David Vander Pluym

As if the day’s excitement wasn’t enough, just before I arrived at the car I had a nice reminder that rattlesnakes don’t want to bite you if they don’t have to, after I put my foot down a foot from a coiled one!

-DVP

Edited 24 Apr: slight change to the wording to better clarify the events of 20 Apr.

Posted in Bill Williams, LCRV, Mohave County, Vagrants | Tagged LCRV, Mosquito Flats, Nutting's Flycatcher, Nutting's Flycatcher breeding | 21 Comments

Mew Gull in Lake Havasu City

Posted on March 24, 2013 by Lauren Harter

From a birder’s perspective, one particularly nice aspect of living in Lake Havasu City is the chance to just swing by Rotary Park on the way to the grocery store. I’ve had a cold the past few days and haven’t been out birding as much as I’d like, so a quick trip to the store seemed like the perfect chance to check the beach for gulls or early migrants.

When I walked onto the beach, I soon noticed a gull flock. When I walked closer, one of the first gulls I laid eyes on was surprisingly dark-mantled. A second glance revealed its small, unmarked bill. A Mew Gull!

Mew Gull at Rotary Park, Lake Havasu City, 24 March 2013

I shot a few pictures with my iPhone, then contacted David as well as Oscar Johnson, Bob Baez, and Tim Schreckengost. All soon showed up, and we enjoyed long looks as the bird preened and loafed on the beach. It was even a lifer for Tim! Most of us were able to take photos and/or videos at leisure.

EDIT: Check out Tim’s commentary plus photos and video by Tim, and photos by Oscar, here!

Since seeing my first Arizona Mew Gull two years ago, I’ve seen a few more birds in the state, but this is my first adult. Most Mew Gulls to occur in Arizona are young birds. Reports have greatly increased in the past few years with increased coverage of the Colorado River corridor (including Lake Powell), but this species is still a very rare visitor. If accepted by the ABC, this will be roughly the 22nd record for Arizona. Interestingly, there were no records between 2000 and 2010!

It can be difficult to pick out an adult Mew Gull from a flock of Ring-billed Gulls. The mantle is darker, contrasting more with the white scapular and tertial crescents. The bird is smaller overall with a more rounded head and “cute” appearance; the small, slender, unmarked bill also contributes to this appearance. This individual shows a distinct grayish basal half of the bill, an interesting but fairly common variation.

The tattered appearance of the bird led several of us to believe that it likely wintered in the harsh conditions of Baja. With this bird’s appearance and the early arrival of Franklin’s Gulls, who knows what will be next? Iceland Gull, perhaps?

Posted in Lake Havasu, LCRV, Mohave County, Vagrants | Tagged Adult gulls, Birding, Gull, Gull identification, Lake Havasu City Arizona, Mew Gull, Ring-billed Gull | 4 Comments

Species Profile: Franklin’s Gull

Posted on March 23, 2013 by David Vander Pluym

The Franklin’s Gull is an attractive member of one of my favorite groups. It is also always one of the highlights of spring waterbird migration in the LCRV. With a black hood and a pink blush to the chest even those who have not yet come around to liking gulls have to admit this is an attractive species.

Franklin's Gull in alternate is a pretty attractive gull with the black hood and pink flush to the chest. It is also one of the easier gulls to id in this plumage note the large white eye arcs, red bill, dark mantle, and large white apical spots on the tips of the primaries. This individual was at Rotary Park, Lake Havasu City Az on 26 Apr 2012. Copyright (c) 2013 David Vander Pluym

Franklin’s Gull in alternate plumage is a pretty attractive gull with the black hood and pink blush to the chest. It is also one of the easier gulls to ID in this plumage; note the large white eye arcs, red bill, dark mantle, and large white apical spots on the tips of the primaries. This individual was at Rotary Park, Lake Havasu City AZ on 26 Apr 2012. Copyright (c) 2013 David Vander Pluym

A widespread breeder across the northern Great Plains and local in the northern Rockies and Great Basin regions, this species forms huge colonies where it is a raucous and conspicuous species. It primarily migrates across the Great Plains to its wintering grounds in western South America, however the species moves across much of the western US as a low density migrant where it is rare to uncommon in spring and generally rare in fall.

Franklin's Gull is a colony species and in the summer of 2010 Lauren and I did survey's for colonial marsh nesting species including Franklin's Gull for the Klamath Bird Observatory. Here is a distant photo of a mixed colony of White-faced Ibis and Franklin's Gull from 30 June 2010 Malheur NWR, Oregon. Both species are sensitive to intrusion, hence the distant photo. Copyright (c) 2013 David Vander Pluym

Franklin’s Gull is a colonial species and in the summer of 2010 Lauren and I did surveys for colonial marsh nesting species including Franklin’s Gull for the Klamath Bird Observatory. Here is a distant photo of a mixed colony of White-faced Ibis and Franklin’s Gull from 30 June 2010 Malheur NWR, Oregon. Copyright (c) 2013 David Vander Pluym

The following video, shot by Lauren at Malheur NWR, shows just how raucous a Franklin’s Gull colony can be:

Birds of the LCRV (Rosenberg et al 1991) cites only 25 records (of 40 individuals) for the LCRV with slightly more than half coming from fall (particularly late Oct-Nov). In recent years, with an increase in coverage of the spring waterbird migration on Lake Havasu, the species has been shown to be a regular migrant, usually in singles or small groups, but with a high count of 32, in spring primarily mid-April to mid-May. On the other hand, it has been rare but regular in fall with ~2 typically reported. In recent years the species has primarily been recorded around Lake Havasu, particularly during morning lake watches from Cape Havasu. Likely this is primarily coverage and the species can be expected anywhere along the river/lakes in the valley as well as marshes and flooded fields. One of the higher counts comes from Rotary Park in Lake Havasu City, but not from the beach, the birds were actually on the golf course!

Franklin’s Gull is a long distant migrant, breeding colonially across the northern Great Plains and locally south to the northern Great Basin. Look at how worn the flight feathers are on this individual at Malheur NWR Oregon, 22 July 2010. Not surprisingly this species molts on the breeding grounds in the fall. Copyright (c) 2013 David Vander Pluym

Interestingly, this species is one of only two that are found in the US/Canada that have two complete molts a year. The other species is the Bobolink. No one is quite sure why Franklin’s Gulls undergo a complete molt in spring, but it likely helps that they winter along the food rich Humboldt Current. Typically adults are more likely to undergo a complete spring molt than immatures and during bad food years few individuals may undergo a complete molt. Even in good years, a few individuals may not fully complete the molt, retaining the outer primaries.

As mentioned before Franklin's Gull molt on the breeding grounds. This molt into basic plumage aspect is complete and startson the breeding grounds. In this photo you can see P4 growing in and that the outer primary coverts are worn conrasting with the inner primary coverts. This individual was at Malheur NWR Oregon 22 Jul 2010. Copyright (c) 2013 David Vander Pluym

Franklin’s Gulls begin the prebasic molt on the breeding grounds. In this photo you can see P4 growing in and that the outer primary coverts are worn, contrasting with the inner primary coverts. This individual was at Malheur NWR Oregon 22 Jul 2010. Copyright (c) 2013 David Vander Pluym

This year the species has been on the move early across the western United States, with some people reporting that this beats their previous early record by a month! It is interesting how widely scattered these reports are with reports coming from Site Six in the LCRV, the Salton Sea, Sedona Az, Nevada, and even Wyoming among other places. All of these birds have been reported as adults in alternate and clearly they could turn up anywhere in the west right now. It would be great to get the data of this early push into one place and ebird.org is a great spot to do this. It will be interesting to see how this season shapes up in comparison to recent years here on the LCRV!

This group of Franklin's Gull were at the mouth of the Rio Lluta north of Arica, Chile 7 Jan 2004, roughly the middle of there wintering range along the coast of western South America. Note the different age classes with several first cycle birds showing brown coverts while the adults show slightly smaller white apical spots on the primaries in comparision to birds in alternate. Given the date most of these birds are likely undergoing the prealternate molt which is typically complete, one of only two species in the United States and Canada to have two complete molts a year (see text). Copyright (c) 2013 David Vander Pluym

This group of Franklin’s Gulls were at the mouth of the Rio Lluta north of Arica, Chile 7 Jan 2004, roughly the middle of their wintering range along the coast of western South America. Note the different age classes with several first cycle birds showing brown coverts while the adults show slightly smaller white apical spots on the primaries in comparison to birds in alternate. Given the date, most of these birds are likely undergoing the prealternate molt which is typically complete, one of only two species in the United States and Canada to have two complete molts a year (see text). Copyright (c) 2013 David Vander Pluym

-DVP

Literature Cited:
Rosenberg, K.V., et al. 1991. Birds of the lower Colorado River Valley. The University of Arizona Press, Tuscon, Az.

Posted in Identification, Lake Havasu, LCRV, Migration, Molt, Species Profiles | Tagged Franklin's Gull, LCRV | 1 Comment

Viewing the LCRV Swallow Spectacle

Posted on March 15, 2013 by David Vander Pluym

I love spectacles of migration, huge numbers of animals moving; no photos can do it justice. I have been lucky to have had the opportunity to see some of these amazing sights. Hundreds of thousands of Sooty Shearwaters off the California coast, thousands of warblers passing by Higbee Dike at Cape May, and tens of thousands of swallows along the Colorado River. Most of us know about the first two spectacles, but what about the third? The sight of thousands of swallows, a giant ball seeming to ebb and flow and then suddenly cascading from the sky into a marsh, must be one of the most amazing wonders of the world.

A lone Tree Swallow in Tillamook Oregon 17 May 2009, beautiful even when not in a huge flock. Copyright (c) 2013 David Vander Pluym

Though it has been known for a long time that large numbers of swallows move through the LCRV (the high count in Rosenberg, et al 1991 being 750,000!), recent years have brought a renewed attention to the spectacle from both birders and ornithologists.
Lauren wrote a bit about our viewing experiences with the swallows last year, where we were able to witness tens of thousands at Martinez Lake. Even more amazing was the sight of an estimated 1.2 million swallows on 8 May 2011 over Mittry Lake reported in the AZFO seasonal report. I cannot even imagine what that must have been like!

It is likely that a large portion of the western populations of Tree Swallows use the LCRV during spring migration. Not surprisingly, biologists have also been looking into the use of the LCRV by Tree Swallows. In other regions, such as California’s Central Valley, researchers were able to use radar to find where large numbers of Tree Swallows were. This can help to identify areas that are important for staging swallows as well as getting population estimates. An interesting paper on this can be found here. This link references a talk given that indicated that attempts in the mid 2000’s to find roosts using radar out of Yuma failed. Unfortunately the link to the reference was dead and as of this posting I was unable to find more information on these attempts. However in the past few years attempts were renewed to track Tree Swallow migration by radar out of Yuma by the Arizona Department of Game and Fish and a poster was presented on this at last year’s AZFO meeting. If you missed the meeting you can read the abstract to the poster here. This use of radar to track migrants is an interesting field and has the potential to greatly increase our understanding of migration. Radar can also be helpful to birders as you can check radar stations to see if large numbers of birds are on the move in your area. For those interested in using radar, check out this video tutorial for more information and if you want to try it yourself you can check out this page to view radar.

Barn Swallows (here 23 July 2009 at Malheur NWR Oregon) occur in the thousands in the LCRV in fall, but as yet we have not seen them form the spectacular roosting flocks that Tree Swallows form in the spring. Copyright (c) 2013 David Vander Pluym

Here in the LCRV, the Cliff Swallows are back and building nests, Violet-green Swallows are starting to move and today while trail clearing every time I looked up I would see a steady stream of Tree Swallows flying over. Clearly it is swallow season! Many people wonder when is the best time to see the swallows. There is no way to say for sure if your visit will produce hundreds of swallows or tens of thousands or even a million swallows, but you can maximize your chances by being there at the right time. Though fall can produce good numbers of swallows of multiple species (Barn and Tree can move in the hundreds or even thousands), the real spectacle is the Tree Swallows moving through in spring. The peak time for Tree Swallows is mid March to late April. However as hundreds winter on Lake Havasu and around Martinez Lake, good numbers can be seen in late February and by early March migration is under way. Formerly only a few stragglers would occur into May in the past, however in 2011 the highest known count for the LCRV occurred on 8 May when 1.2 million were estimated at Mittry Lake. At this time it is unknown if this is a regular occurrence or was just a rare occurrence as it was a cold wet year and a lot of birds moved through later than average. In recent years it is not unusual to have groups of several hundred into early May. During the evenings the swallows swarm and flow and then fall into the marsh in a spiral. This is typically done in the evenings right around sunset, but the timing can vary so get there early and be prepared to wait until dark watching the swallows. It can be a good idea to bring lawn chairs, scope, and insect repellent as you are at a marsh! Be sure and scan with your binoculars over the marsh as the swallow flocks may be distant as well as high up.

Violet-green Swallows are primarily a migrant in the LCRV and most of those that occur are the widespread nominate subspecies thalassina (such as this bird here in Tillamook Oregon 1 Jun 2009). However there is a small breeding population in the Bill Williams River NWR and along the Parker Strip, though there are no specimens they are believed to be an intergrade population between the nominate subspecies and brachypetera which breeds in Mexico. Copyright (c) 2013 David Vander Pluym

Finally, where can you view these roosts? Below I have screenshots of google maps to areas that I have found to be good places to view along with more information on them. They are arranged from south to north. It should be noted that calm conditions are usually better for viewing.

Mittry Lake: I haven’t visited this site for the swallow migration, but 1.2 million! Tree Swallows were estimated from here 8 May 2011. I also don’t know if they were roosting or feeding over it. More details on birding this site can be found here.

Martinez Lake area: Perhaps the best spot in the LCRV is Fisher’s Landing and Martinez Lake. This location is also all around good birding so be sure and get there early so you can scan the lake or check out Imperial NWR. Rarities are always possible and both Brown and Blue-footed Boobies have been found here! To get to this spot from highway 95 north of Yuma turn left onto Martinez Lake Rd. Follow it toward Fisher’s Landing, but just before you get there turn right onto Red Cloud Mine Rd toward the Imperial NWR and Martinez Lake. Next turn left onto Joe Young Dr and park before the buildings where you can overlook the marsh and wait for the swallows. Be sure and listen for Black Rails as well!

An overview of both Ferguson and Martinez Lakes. Ferguson is rarely visited as it is down a long dusty road with lots of private property around it. Swallows may roost there but overall Martinez Lake offers better views and is easier to get to. The blue marker represents a good place to view from. See also the next map.

From the road to Fisher’s Landing, right before entering the landing proper turn right onto the Red Cloud Mine Rd/Wildlife Refuge Rd and then a left on Joe Young Rd. Park off the road at the edge of the marsh where the blue marker is. This has been our best viewpoint for watching the swallows and be sure and listen for Black Rails!

Ferguson Lake likely has swallow roosts, but I have not been there at dusk to find out. It is a long and dusty road coming out of Bard California and is rarely visited (though it has the potential for rarities; for example Lauren Harter and I found a Red-throated Loon there in Dec 2010 and others chasing the loon found a Gilded Flicker). There is also a lot of private property around the lake so if you go it is a good idea to scout out the best place to view it without trespassing. Coming from Laguna Dam you head north on Imperial/Laguna Dam Rd (the name changes depending on what stretch you are on), and turning left onto the first turn for Senator Wash Rd and then make a left onto Ferguson Rd following it to the lake. You can also sort of see if they are roosting there with a scope from Martinez Lake.

Cibola Lake, Cibola NWR:

Following the levee south toward Cibola Lake, at the south end there is a road up the hill for an overview of the lake. This is a great spot to watch the river of swallows at dawn moving north off their roost sites. Check out the Cibola NWR for more info on how to get here.

Blythe area and the Parker Valley: The next day after viewing the swallows coming into roost or that morning after viewing them leaving a roost you might want to take a spin through the Blythe area or the Parker Valley and watch the swallows foraging. Though you want see a single concentration of swallows they can be everywhere feeding and it is a good chance for something rare. I picked Mangrove Swallow as a next ten for Arizona and it would be on my top ten list for California if I did one. To watch the swallows feeding just following any road through the agriculture areas.

Bill Williams Delta: Viewing from the NWR HQ you can often see good numbers of swallows descending into the marshes. However most recent counts here have been in the neighborhood of 20000, still spectacular, but not the numbers seen elsewhere. Good place to view in windy conditions as it is somewhat protected.

North end of Lake Havasu: Viewing from Cape Havasu can produce amazing numbers (I have seen up to 100000 Tree Swallows dropping into the marsh). The problem with this spot is that the swallows are usually distant and a scope is very helpful. There are points that are closer both on the California and the Arizona side, however I have not actually been to these sites to see how the view is for the swallows. They are worth checking out and I hope to be there this spring to check it out. Castle Rock on the Arizona side and north of Havasu Landing on the California side take you much closer to the marshes and probably give you better views. To access Castle Rock go north of Cape Havasu along London Bridge Road and north of Desert Hills make a left on Crystal Beach Rd. Follow this to the end and at the end of the road head left to the end of this road, park and walk through the gate and out onto the bluffs. From here you have a good view of a wide area of marshes. For Havasu Landing you have to access from the California, heading north from Havasu Landing you have to find access between private property, be sure and scout it out well in advance. UPDATE: 16 Mar 2013 The swallows were landing in the southeast most reed island and were easily visible from Cape Havasu and would not have been visible from Castle Rock or the northern most part of Havasu Landing. The area off Sunset Trail north of Havasu Landing may however have given good views. Again be aware of private property. Castle Rock and the northern portion of Havasu landing would be good places for watching the dawn fly out.

Castle Rock is the blue pin on the east side of the river while one of the possible access points for Havasu Landing is on the west side. See text for details.

Havasu NWR and north: the previous high count of 750000 was during a traveling count over part of the Mohave Valley north to Bullhead City of foraging swallows, obviously foraging swallows can be anywhere!

Hopefully this will help people time their trip to the LCRV to see the swallows and help to direct you to the best site. It is a spectacular sight!

-DVP

Literature Cited:
Rosenberg, K.V., et al. 1991. Birds of the lower Colorado River Valley. The University of Arizona Press, Tuscon, Az.

Posted in Birding Locations, La Paz County, Lake Havasu, LCRV, Migration, Mohave County, San Bernardino County, Techniques, Yuma County | Tagged Colorado River, Lake Havasu, LCRV, Martinez Lake, Mittry Lake, Tree Swallow | 1 Comment

Spring Changes

Posted on March 10, 2013 by David Vander Pluym

Warming temperatures and changes in the bird life are always a good sign that spring is here around Lake Havasu. Spring means not only changes in the bird life in the LCRV but also the start of the field season for us with long days working in the field. We are hoping to keep up with our budding blog even with the long hours so stay tuned for some great stuff! Last week was spent trail clearing in the Overton Nevada area and it was great to visit the Overton Wildlife Management Area where the Common Crane was this winter. Waterfowl migration was evident with good numbers present and we even found a rare Mexican Duck! Though it was great exploring this area we were away from internet and fell behind on a lot of things.

This Red-tailed Hawk at the Overton Wildlife Management Area 8 Mar 2013 was wet and annoyed that we had accidentally flushed it from it's American Coot prey. Copyright (c) 2013 David Vander Pluym

We are back in Lake Havasu and today 10 March, Tim Schreckengost of Thermal Birding and I spent a couple hours checking up on the rare wintering waterfowl on Lake Havasu. We had a successful time of it! Though numbers were down there were still large numbers of Greater Scaup in the Bill Williams Delta as well as a few Barrow’s Goldeneyes, the Long-tailed Duck, and 3 White-winged Scoters, as well as a Red-throated Loon, 3 Pacific Loons, and 2 Horned Grebe. Not a bad time at all!

This Common Loon is transitioning into its alternate plumage. 10 Mar 2013 at Havasu Springs, LP, Arizona. Copyright (c) 2013 David Vander Pluym

At the Havasu Springs Resort we enjoyed listening to loon vocalizations as well as the two Horned Grebes calling to each other and appearing to engage in some courtship displays. It was interesting that one was still largely in basic plumage while the other was largely in alternate. March is always fun to see the loons and grebes molting into alternate plumage which can also provide a different set of ID problems from birds in basic. One of the Pacific Loons was also in alternate, but too distant to photograph.

These two Horned Grebes were actively calling and engaging in the start of courtship. Though one is largely in basic plumage and the other is largely in alternate note that they share the same structure of thick necks and bills, helpful for IDing birds in transitional plumages. These birds were at Havasu Springs Resort, LP, Arizona. Copyright (c) 2013 David Vander Pluym

Tim and I next moved up to Site Six to check on the Shad Run. We had good numbers of birds including two Pacific Loons and my FOS 2 Bonaparte’s Gulls. Bonaparte’s is an species whose perception of rare has changed for us in the LCRV, as they were formerly considered to be very rare in spring, but in the past two springs they have passed through in good numbers (50+) in one or two pulses.

Notice the shad in this Bonaparte's Gull bill. At Site Six, MOH, Arizona, 10 Mar 2013 Copyright (c) 2013 David Vander Pluym

Though some of the Spring Break image of Lake Havasu was in evidence today it didn’t distract from a great day out in the field checking on wintering birds and seeing what changes have occurred in the past week on Lake Havasu. To end I want to mention that generally the spring break “crowd” on Lake Havasu should NOT affect the birding on the lake enough to keep you from visiting and checking out what is going on. Even on weekends the North End of Lake Havasu can still be a great place to bird on a spring morning!

-DVP

Posted in Lake Havasu, LCRV, Molt, Nevada | Leave a comment