16 December 2011

Black-headed Gulls Like Ring-billeds

The 2011 Fall season is proving to be a great one for Black-headed Gulls in the Eastern United States. Between the Great Lakes region and the Northeast, there's been at least one Black-headed report every week for the last 8 weeks. Interestingly, 5 of these reports have been of Black-headeds associating with Ring-billeds. So, what's this "small" gull doing hanging out with the comparatively larger Ring-billed? Aren't Black-headeds supposed to be in Bonaparte's flocks? Yes and no...more on this later...

Here's the most recent example of this season's incursion of Black-headed Gulls:
Adult-type Black-headed Gull. Baltimore County, Maryland. 14 DEC 2011. by Amar Ayyash

This BHGU has been in the company of 40+ Ring-billeds at the Hunt Valley Mall in Baltimore County, MD. It was first noticed on 10 December 2011 by Russ Ruffing who momentarily thought he had a Bonaparte's in a Best Buy parking lot. After admiring the red bill, Russ did a double-take and properly identified it as a Black-headed (C. parkin lotus).

Chris West and I observed this larid early Wednesday morning after having driven overnight from the Chicago area. We watched it for about an hour before it picked up and flew a mile east to the Papermill Flats. We refound it on a small pond at Papermill, which coincidentally, held a Black-headed in December of 2010 and then another in February of 2011.

Black-headed Gulls are intermediate in size between Ring-billeds and Bonaparte's. Upperpart coloration matches Ring-billed but with a more silvery look. Although BHGUs closely resemble Bonaparte's, there are some obvious key-features that distinguish the two, especially adults. In addition to the reddish bill, note the blackish underprimaries that adult Bonaparte's never show:


Although outsized and outnumbered, the Black-headed did not have any problem competing for handouts in the mall parking lot:

In the Old World, Black-headed's demeanor is described as "not shy", and so its presence in a mall parking lot in the United States shouldn't be too confounding. Interestingly, David McGrath from the UK recently sent me this note: "Ring-billeds here also hang out in car parks chasing chips/bread often with Black-headed Gulls rather than Common Gulls, to which they are probably more closely related".  Both Black-headed and Ring-billeds naturally scavenge for food and readily gravitate towards humans. Unlike Bonaparte's, Ross's and Little Gull, these two embrace anthropogenic elements very well. Ecologically, Black-headed is very much a Ring-billed/Laughing Gull type larid.

I recently learned of a couple of breeding colonies in Western Newfoundland where 20-25 pairs of Black-headeds are nesting in mixed colonies with Ring-billeds (p.c. Dave Brown). Although the two don't overlap seasonaly in St. John's, when they do come into contact, they have no problem feeding side-by-side at sewage outflows. I'm convinced that Black-headeds are just as likely - if not more likely - to be found with Ring-billeds as they are with Bonaparte's; this seems to be the current trend and I imagine this association will only continue to increase. Thinking back to my lifer Black-headed, it too was an adult that spent the winter associating with Ring-billeds along the Chicago lakefront.

I can't help but wonder what sort of Black-headed numbers we'll see in the United States in the distant future. Although not yet with a prevailing presence in the states, it does seem to be increasing much faster than the still "vague" Little Gull.

I was able to capture a couple of amature videos of this bird. Note its kek-kek call which is considerably different than the smaller Bonaparte's:

Edit: it should be noted that individuals found in the St. John's area do not allow close approach by humans and are rarely found at the local landfill (p.c. Dave Brown).

05 December 2011

Little Gull and Lake Charleston, IL

Not too long ago, Little Gull was considered rare but annual in Illinois. I'm told that with enough effort, diligent birders were able to observe this species every Fall along the lakefront up until the early 1990s. Subsequently, lakefront records were supplanted by increased sightings on large lakes in the central and southern portion of the state. Lakes such as Clinton Lake became the more expected site for Little Gull, although its status was never elevated beyond rare to very rare.

Fall records have always been more numerous than Spring, and so when "zero" birds were documented in the Fall of 2000, Little's provisional status was revisited. Due to the paucity of records around the turn of the century, the IORC placed Little Gull back on the Review List in 2002 (click here for this list).

2010 and 2011 sightings from Lake Charleston in Coles County, IL - records pending.

As a whole, diminished sightings across the western Great Lakes region are said to be a result of a shift in breeding sites. The closest documented nesting site with respect to Illinois is Manitowoc County in Wisconsin - breeding has not been confirmed here for several years now. For reasons not fully understood, Little Gulls have minimal site tenacity in North America; rarely are they found nesting at the same location for more than several years.

With that said, this alluring, tern-like larid, has flared into a "nemesis" species for many listers. The ABA classifies it as a Code 3 species (this is the same code assigned to Ross's and Ivory Gull). It then comes as no surprise that tens of birders recently flocked to Lake Charleston in Coles County Illinois to observe this accommodating adult:

Photograph courtesy of Ron Bradley. Note the silvery primaries, faded black cap and pink suffusion to the underparts.
Ron Bradley found this bird the day before Thanksgiving on 23 November 2011. It was observed every day up until the 30th of November. Little Gulls are usually found associating with Bonaparte's and this individual was no different. I had the opportunity to observe it on 27 November and then again on 30 November where I consistently watched it catch and swallow up to 5 shads in the course of 30 minutes. Coincidentally, this was the last day birders saw it on the lake.

For me, the most intriguing aspect of this sighting is that an adult Little Gull was observed here last year as well! Yes, not many Illinois birders know of this record, but an adult was found here on 5 December 2010 by Jack Stenger. At the time, Jack was visiting Charleston Illinois with his fiance from Ohio. You can imagine his excitement when he stumbled upon a Little Gull during his first visit ever to this small lake that's no more than 350 acres in size. Jack reported his sighting on IBET that same night. I contacted him offline and got details - his description was exactly what I was hoping to hear. I got out there the next morning before sunrise and waited for my Illinois Little Gull.

Sure enough, at the crack of dawn, the Little Gull showed off its unmistakable underwings as it made a few rounds along the north side of the lake. It was in a tight flock of Bonaparte's that all moved harmoniously. I watched it for no more than one minute before it flew out of view. It came back into view for a few more seconds and then disappeared again. I never did see it after this despite hours of searching. It picked up and left along with 30+ Bonaparte's at sunrise. Suddenly the lake became desolate with very few small gulls at all. I distinctly remember telling birders who arrived afterwards that the absence of the Bonies was a really bad sign, and that proved to be true. Since then, I've gained a greater appreciation for Bonaparte's as with them come and go these rarer gems.

Adult Little Gull; NOV 2011. Lake Charleston, IL. Photo by Ron Bradley.
I jokingly requested that Ron send out invitations next year when the Little Gull returns, insinuating the 2011 bird may very well be the same individual from 2010. My simple mind is triumphed when I try to imagine that two "different" Littles visited this lake for two consecutive years. You never know...

03 December 2011

Montrose Lesser Black-backed and Glaucous Gulls

Chicago's lakefront received its first notable installment of northern gulls on Friday, 2 December 2011. A 2nd cycle Glaucous Gull was found at Monroe Harbor by Ari Rice and then shortly after, a 2nd cycle Lesser Black-backed Gull was found by Steve Spitzer at Montrose Beach. I arrived at Montrose around 2:00 p.m. hoping to photograph the LBBG, but immediately found a 1st cycle Glaucous Gull instead.

1st cycle Glaucous Gull. Montrose Beach. Chicago, IL. 2 DEC 2011. Photo by Steve Spitzer.
I ran into Leo Miller on the pier who was also looking for the Lesser Black-backed. I could see several large gulls feeding along the shore towards the Dog Beach and so we made our way down there. To our delight, the LBBG was still there with several Herrings:

2nd cycle Lesser Black-backed Gull. Montrose Beach. Chicago, IL. 2 DEC 2011. Photo by Amar Ayyash.

This fellow was on the large end, matching or exceeding most of the surrounding Herrings in body size. I recently wrote a piece on Lesser Black-backed's status in North America and speculated that if this species is found breeding in the states, it would do well side-by-side with American Herring. I stand by that statement and feel Lessers are more than capable of competing with that species. In fact, the only known nesting occurrences of LBBG in the United States is that of hybrid pairings with American Herring.

I recorded an amateur video of this individual fending off a handful of Herring's as it fed on a dead fish along the shore:

26 November 2011

Ohio Black-tailed Gull: Take Two.

Every birder has experienced it - you score a life bird but know in your heart of hearts that the looks you got were "crappy", bordering on unidentifiable were it not for expectations. On Sunday, November 20th, I drove out to Ashtabula Ohio for their first state record of Black-tailed Gull (Larus crassirostris). It was found by Ohio birder Craig Holt a few days prior on 16 November. I got to Ashtabula and found the bird around 8:00 a.m. YES! LIFE BIRD! The looks I had were very brief as I watched it preen in the water for about one minute, standing from an elevated bridge, looking into a channel some 400 yards away.

I was really excited when it got up as the black tail sealed the ID for me, but it continued in the opposite direction. It flew off to the northwest. I knew I was in trouble as this bird had the habit of disappearing early in the morning with no particular pattern. This sort of birding is agonizing. If one misses that short window in the morning, they may be "tethered" to that site for the rest of the day. I waited for it to return for almost 3 hours before I gave up and moved on. I bummed around various harbors and river mouths in the area and then drove home, a drive a little less than 6 hours. The entire experience was bittersweet: "I'm not happy with those looks", I thought.

I decided to go back 4 days later, but this time, I took the advice of Ohio birder Jen Brumfield, who advised we get there before first light. We did. Andy Sigler, Chris West and myself got there about an hour before sunrise and waited. We started scanning the channel, literally, at the crack of dawn. It was still dark out but we were able to make out the silhouettes of perhaps 2,000 gulls in the channel to the north. A Carolina Wren gave a morning murmur from the overgrowth below the bridge. Within a few minutes, the gulls started to move over the bridge and into the marina area along the river. I walked down the bridge and situated myself at the marina where I began chumming. The Ring-billeds responded well. I thought that if the Ring-billeds caused enough commotion, the Black-tailed would fly in to investigate.

Sure enough, less than 10 minutes later, Chris West skillfully spotted the bird in flight. It flew over the bridge and landed at the river mouth with the hordes of Ring-billeds. Chris shouted maniacally, waving and pointing to where I presumed he had the bird. I couldn't make out what he was saying nor could I see the bird, although it wasn't too difficult to tell that he had good news! He ran down to where I was and quickly relocated the bird a second time for me. Once I got on it, I kicked myself for not being able to see it. It sat in the water about 200 ft away and never showed any interest in my bread offerings. My mind was expecting a larger and darker bird but this was not so:

Adult Black-tailed Gull with Ring-billed. Ashtabula, Ohio; 24 NOV 2011.
I'd like to share a few identification notes here. Notice how the body size matches Ring-billed, almost exactly. Lesser Black-backeds are notably larger, but admittedly, this point could be useless if there isn't another gull nearby for comparison. The upperparts are typically a shade paler than Lesser Black-backed but could easily show some overlap. Black-tailed Gull is unarguably darker than the darkest California Gull. Keep in mind the ramifications of lighting when it comes to upperpart coloration. The wing extension is long and sleek like Lesser Black-backed but the bill is closer to that of California Gull. Note the long, parallel-edged look to the bill with a black subterminal tip. Better photos would reveal a significant amount of red on the very tip of the bill. I think the bill on this species is just as important an ID point as the tail. The clean white head pattern on this individual is a bit unusual. Most Black-taileds observed in North America have moderate streaking towards the back of the head. Here's a diagnostic shot of the tail:

Black-tailed Gull. Note the significant width of the white terminal edge to the tail.
 Photo by Chris West.

We spent the rest of the day birding various lakefront sites with Lorain Harbor being the highlight. Lorain is credited with Ohio's only Heermann's Gull and Tufted Duck records. We had hoped for a Little Gull or Black-headed but shamefully couldn't find one in the oodles of Bonaparte's. We estimated the massing at about 10,000 - that's 3,000 less than what was reported the day before:

The waters of Lake Erie are a major staging area for Bonaparte's in the fall. Numbers peak in late November where aerial surveys have estimated 100,000+ of these tern-like gulls over the lake (McCormac, 2011). This is much different than the western Great Lakes: Superior and Michigan. The reason for this huge gathering of Bonaparte's is no other than an abundant supply of shiners and shad which are commonly found at the mouths of rivers as they feed into the lake.

1st cycle Bonaparte's. Lorain Harbor, Ohio. 24 NOV 2011.

Most entertaining was watching an adult with a full hood. It's not unheard of to see an adult with a mixed up molt schedule, although this was my first time personally observing a full hood in the fall:

Adult Bonaparte's with full hood in November.
It didn't take too long for it to swallow this entire shad.
Other birds of note here included a first cycle Franklin's, an adult Thayer's, an adult Lesser and up to 10 Great Black-backeds.

We then drove to Huron Harbor which is a fun little site with enough birds to hold its own. Huron Harbor has attracted a nice list of rarities in the past, including Spotted Redshank and Northern Gannet. There were "only" about 1000 Bonaparte's here with a few Lessers mixed in (two 2nd cycles and a 1st cycle).

2nd cycle LBBG. Huron Harbor, Ohio; 24 NOV 2011.

Of great interest to me was this adult Ring-billed with orange patagial tags:

Huron Harbor, Ohio; 24 NOV 2011.
This bird was tagged at Dime Pier in Chicago in 2007. To read more about these patagial tags, click here. Whether this bird spent the summer in Chicago or on Lake Erie is a mystery, but I recently found out that some of these Chicago Ring-billeds have been seen on Lake Erie before.

Same bird as above.

All and all, it was a fruitful day with better looks at my "lifer" Black-tailed and hordes of gulls everywhere we went. Something tells me I'll be going back to Lorain soon!

16 November 2011

Color-tagged Ring-billeds in Chicago

In the spring of 2007, the City of Chicago and the USDA Wildlife Services conducted a study on two Ring-billed Gull colonies in Chicago, IL. The study was an egg-oiling project initiated by the City. The goal was to determine whether oiling eggs during the nesting season would reduce the number of gulls on local beaches. Ordinary corn oil is one way to prevent oxygen from penetrating the eggshell, thus preventing the young from ever hatching. Adult parents continue to incubate and invest energy in nesting, but to no avail. This is, as one of my friends put it "murder in a non-lethal way".  

What would be the rationale in decreasing the number of Ring-billeds on the lakefront?

The primary reason given by the City of Chicago is that fecal deposits of gulls have long been one of the causes for increased E.coli levels in near-shore waters along the lakefront. The aim was to track the movements of birds that had their eggs oiled (or not) and to determine if they would abandon their respective colonies.

During the nesting season of 2007, some gulls were part of a control group (eggs not oiled) and some were given treatments (eggs oiled). Colored wing tags (patagial tags) were attached to both wings of 724 gulls from the Dime Pier colony (approximately 3,100 nests) and the Lake Calumet colony (approximately 31,400 nests). From the Dime Pier colony, 94% of the nests were oiled (7,396 eggs) and from the Lake Calumet colony, 48% of the nests were oiled (41,753 eggs). The tags attached to the local Ring-billeds consisted of four different colors: blue, green, yellow or orange.

Adult Ring-billed. Montrose Beach. Chicago, IL; 2 November 2010.
This individual had its eggs oiled at the Dime Pier colony (directly south of Navy Pier). Photo by Amar Ayyash.

I've summarized the project's methods in the tables below:

Lake Calumet Colony

Tag Color
Blue (eggs not oiled)
Yellow (eggs oiled)
Dime Pier Colony

Tag Color
Green (eggs not oiled)
Orange (eggs oiled)

Same adult as above.  The irony of this sighting is that this bird was found just miles from where it once attempted to nest. Even more interesting is that it was found along the lakefront more than 3 years later. So technically, it could be safely aged to "at least" 6 years old.

The findings of this study were not instantaneous since subsequent hatch-year numbers had to be reviewed. Data was collected by biologists with the USDA Wildlife Services from April of 2007 through April of 2009. During this time, the public was called on to report any tagged gulls. The USDA used press releases and online announcements to garner the input of many birding organizations. Resightings were reported from some twenty different states (and one Canadian province). Unsurprisingly, many of the winter resightings came from the Gulf Coast states; this agrees with earlier studies regarding the movements of Ring-billeds on the Great Lakes (Gabrey, 1996). Also of interest to me is that no tagged RBGUs were reported in Chicago during the winter seasons. This reinforces my suspicion that Chicago Ring-billeds are replaced by a different population during the winter months.   

Resightings of tagged birds:
Tag Color
% of total tagged birds
% of total tagged birds
% of total tagged birds
Interestingly, there was approximately a 3 to 1 ratio of yellow and orange-tagged resightings over blue and green-tagged birds. Why this color bias existed is still unknown.The biologists and volunteers who conducted regular spot counts at the breeding colonies (at least twice per week) also recorded a similar color bias.  

Having reported two of these tagged gulls myself, I felt obligated to get details about this program and so I contacted the Supervisory Wildlife Biologist from the USDA, Thomas W. Seamans. It seemed odd to me that a relatively small percentage of the control group was reported, while a much, much, greater amount of resightings came from the treatment group. This struck me as backwards! Seamans admitted that "there is a problem with this marking technique [patagial tags] that could really cause a misinterpretation of data collected by biologists". He also added that "if we had been looking at long term movements then it [the tagging program] would have been a problem".

It's important to keep in mind that no hatch-year birds with wing-tags were reported during the breeding season of 2007 (nor were any reported the following year when they could still be distinguished from adults by plumage). In fact, not one tagged subadult was ever reported by the public or recorded by the Wildlife Services team throughout the entire project.

Incidentally, Steve Ambrose and I found an adult with a blue tag last weekend at Monroe Harbor in Chicago. Blue-tagged birds were part of the control group with no oiled eggs. I proudly reported this bird to Seamans and he was, as usual, very helpful in entertaining my questions. My resighting was only the eighth report this year and the fact that I found a blue tagged bird "makes for a rather rare sighting"! Naturally, as time progresses, less and less of these birds are being reported - some are losing their tags and some are perishing. 

Monroe Harbor. Chicago, IL. 12 November 2011. The tag on the right wing was missing. This individual could have been a hatch-year bird when it was tagged or an adult. The swollen left tibia and notably short legs make for a somewhat abnormal looking Ring-billed.
Over 97% of the nests with oiled eggs from the 2007 breeding season effectively failed. Nests that were not oiled did not suffer any "complete" clutch loss (Rader, 2008). One might argue that the City of Chicago was not trying to eliminate the entire population of both colonies but I would beg to differ. The only reason why a good percentage of nests were left unoiled in the Lake Calumet colony is because the City would have exceeded the Federal and State permits for the project (the City underestimated the number of nests on its permit application).  

I personally think the City acted disingenuously. Were they really interested in "understanding" the movements and/or reactions of the gull colonies during the breeding season of 2007? My feeling is that they wanted a quick fix to eradicate the RBGU numbers along the lakefront and they partially succeeded in doing that, but only temporarily. Their decision was rash, insensitive and ultimately a waste of taxpayer dollars. No gulls were tagged during the 2008 and 2009 breeding season and it seems like no follow-up was given to the "study". 

I'll leave my readers with one last thought from the Wildlife Services' report: "Negative effects on tagged individuals or response to tag color by conspecifics will contribute to biased results and, possibly, poor management decisions" (Seamans et al., 2010). 

I'd like to thank Thomas W. Seamans for all of his helpful information and feedback. Tom was very forthcoming and open about these findings.

12 November 2011

A Tail of Two Streamers

A couple of years ago, I noticed a 1st cycle Bonaparte's Gull with what appeared to be longer central tail feathers - longer than the rest of the rectrices. I figured this was just a unique case but kept note of it. With time, I began noticing more and more of these individuals that show this excess length. This slight protrusion sort of resembles the short streamers found on some juvenile jaegers. Here's an example:

1st cycle Bonaparte's Gull. Carlyle, IL. 14 Nov 2010.

I found it odd that the width of this excess feathering was unlike the rest of the thin, white, terminal edge to the tail. I thought that perhaps this was a trait found on some, but not all, 1st cycle Bonaparte's. I speculated that the central tail feathers grew out longer so as to "maybe" act as coverts for the closed tail from above. Afterall, these tail feathers have to last for almost an entire year.

Then, last week, I found an adult with this tail pattern at Calumet Park along the Chicago lakefront:

 Calumet Park. Chicago, IL. 5 Nov 2011.
For a fraction of a second, one has no choice but to associate this tail pattern with that of Ross's Gull. I tried finding a description or illustration of this phenomenon in the literature, but nothing. How could Dwight, Grant, Howell & Dunn, and Olsen & Larsson all have missed this? It was then brought to my attention that the Crossley ID Guide shows an alternate adult Bonaparte's with this pattern. Whether Crossley intentionally inserted this image in his guide is unknown, but the individual shown shows a pattern much similar to Ross's; had I been doing a "tail quiz", I seriously would identify it as the tail of a Ross's. Also, one can see that on that bird the outer tail feathers are quite worn and this adds to the "wedge-shaped" pattern.

Killian Mullarney from Ireland suggested that what I'm seeing may actually be the longest undertail coverts as he has seen Black-headed Gulls like this before. Incidentally, while out photographing gulls yesterday, I came across this 1st cycle Bonaparte's:

1st cycle Bonaparte's. Hammond, IN. 11 Nov 2011
Note how the undertail coverts (white) line up with the edge of the tail, overlapping with the black tailband.
The contrasting black tailband and white undertail coverts are easily delineated. From this photo, it's not very difficult to believe that the, central, undertail coverts could grow out pass the tail. This delineation would not be as clear with an adult (or 2nd cycle) since the rectrices are all white by then:

2nd cycle BOGU. Note how the center of the tail shows a protrusion - this is a result of the longer undertail coverts.

  So, I went back and reviewed more photos of the adult from 5 November 2011:

All of the rectrices are easily seen here except for the two central feathers. The undertail coverts (utc) are doing exactly what coverts do: they're covering the bottom of the tail.
The undertail coverts clearly project pass the terminal edge of the tail. From above, the straightened tail looks like this:

Undertail coverts projecting pass the two central tail feathers. This gives the impression that the central tail feathers are longer than the rest of the rectrices, although this is not the case.
I'd like to thank those who emailed me with comments on this topic, especially Killian Mullarney. My next question is: "Do Ross's Gulls, to some degree, exhibit a similar pattern"? 

Please feel free to email me your comments and observations: amarayyash@yahoo.com