Tuesday, February 27, 2018

Nazca Booby, Life Bird, San Diego, CA, February 2018


With business trips to southern CA and the San Francisco Bay area on consecutive weeks, I decided to stay out in CA and take the weekend “off” instead of flying back and forth both weeks.  Not only would it save my company some money, but it would also give me some birding time in the region.  For a few years I’ve been thinking of adding some vacation time to a southern CA trip to head to the Las Vegas area to work on my NV list, and this would be the ideal opportunity.  I set up an eBird Needs Alert for NV and there were indeed lots of possibilities for my NV list.  Things were coming together.

But just as I was starting to plan for NV I remembered seeing reports of Nazca Booby’s somewhere in southern CA.  With a bit of research on the eBird Rarities Alerts I found daily sightings of up to 4 Booby’s in San Diego Bay.  And then I noticed multiple sightings of Streak-backed Oriole in Tucson.  Both would be life birds for me.  Could I make a giant loop south to San Diego, east to Tucson, north to Las Vegas, and then back toward Los Angeles to fly north to SFO?  I wouldn’t be proud of my carbon footprint, but it was all possible if I made it a 3-day weekend, though I wouldn’t have much time in NV.  And of course it would help if my key targets (the Booby and Oriole) were cooperative.  So I started planning for all 3 parts of my trip.

Birders were principally reporting the Nazca Booby’s while standing at 3 locations on the west side of San Diego Bay, with sightings from land mostly being pretty far away.  The prime location to look for the birds seemed to be from Attu Avenue.  Given the distant views, some birders were renting boats to get closer looks at the birds.  The Booby’s were often reported perched on buoys, especially buoy #34, rather than in flight.  So with these details, and daily positive reports, I was optimistic that I could see one or more birds quickly with an early morning stop, and then head to Tucson for the Oriole.

Then again, the Oriole was a different story.  It was coming to a feeder in a suburban yard, but not very reliably.  In fact one birder posted that he finally saw the bird on his 11th try!  That post made me dig a bit deeper and I was able to start to find negative eBird reports for that hotspot.  As my trip neared I saw no positive reports for the 5 days before my birding weekend, and several negative posts.  Typically birders will post if they see the target, but often won’t post if they miss it.  So no positive reports at all was probably bad news, especially for several days in a row.  Should I pass on the Oriole and “just” make it a San Diego and Las Vegas trip?  I waited until the last night of work but again only saw negative posts.  So at that point I revised my itinerary to head out early morning to San Diego, and then make my way to Las Vegas, skipping a try for the Oriole.

I arrived at Attu Avenue on the west side of San Diego bay as it was just starting to get light, and then made the short walk to the shore.  The bay was full of waterfowl – diving ducks, Brant, Aechmophorus grebes, and more.  But I was there for the Booby’s, so I quickly focused my attention on finding the buoys that were their preferred roosts.  From what I could tell from the eBird posts, the buoys would be northeast of my location, and likely on the far side of the bay.  Plus recent photos of the birds’ favorite buoy 34 had the broadside of a large gray ship in the background.  So I started to scan in that general direction and began to find buoys in the area, but it was still pretty dark so I wasn’t seeing numbers on them.  Then as I continued to pan a bit farther to the north I came upon a ship that looked like the one in the photos.  And sure enough there was a buoy in front of it.  I was in the right general area.

As I started to settle in and wait for sunrise I relooked at that buoy in front of the ship – wasn’t there a large pale bird on the lower level of the buoy?  I zoomed in to the fullest extent of my 50x eyepiece, and sure enough it looked like I might have my target bird roosting right there on the buoy.  But it was really far away (I later estimated 1.25 miles), and still pretty low light so I couldn’t be sure - basically I was seeing little more than a white dot in an all dark background.  But a couple minutes later the bird stretched its wings and I could see the diagnostic white body and leading edge of the wings, with black wingtips and trailing edges.  It was indeed a Nazca Booby!  Or maybe more accurately, either a Masked or Nazca Booby.

I continued to watch the buoy and could see the Booby move around a bit.  And then a bit later it was finally light enough for me to see the number on the buoy – it was #34 – its favorite.  A bit later the Booby stretched again, and then took off flying south down the far side of the bay low over the water.  As I continued to stay with the bird a second Booby joined it.  It must have been perched on another buoy nearby.  I watched them both for the next several minutes, diving a couple times, and generally making their way south.  Eventually both birds disappeared to the south at the closed end of the bay.  I decided to head down that way to Grand Caribe Shoreline Park hoping to re-find them perched closer nearby, but I could not relocate them.  Perhaps they headed out to the open ocean for their breakfast.  Or perhaps they had turned around and headed back north.  I thought about heading back to Attu Ave. to try to see if they had returned there, but given my plans for NV, I decided to make an early exit and head off to the Las Vegas area. 

But then again, with success finding the Booby’s so quickly, should I head to Tucson for the Oriole after all?  I quickly checked all the websites – there were no updates on NARBA, eBird, or the AZ listserve.  So although I was disappointed to pass on another possible life bird, it was indeed on to NV.

As I started the drive from San Diego I started to reflect a bit on my Booby sighting.  The key field mark to tell Nazca from Masked Booby is the bill color – orange to red for Nazca and more yellowish for Masked.  It was certainly not possible to see bill color when I had the one bird perched on the buoy.  And even though the 2 birds were a bit closer when they flew by, they were still maybe three quarters of a mile away at their closest point.  So I still couldn’t see bill color even then.  Other birders seemed to lament the same issue in their reports on eBird, which although the listed ID was Nazca Booby, several included comments that indicated bill color couldn’t be determined.  At least there were some photos of the birds seen at close distance with definitive IDs (when birders were on a boat out in the bay).  And there were no Masked Booby’s reported in the bay.  So although I couldn’t eliminate Masked Booby, I guess I could go with the Nazca Booby ID as many other birders did at least based on strongly circumstantial evidence. 

Nazca Booby was my Continental ABA bird #751 and Lower 48 #730.  And I can’t forget it was a new statebird for me in CA - #390.

And although I’ve never been to Attu (in Alaska), I guess I can now say at least I’ve birded Attu Avenue…

No comments:

Post a Comment