Tuesday, March 27, 2012

Hurricane Irene and swifts -with a look at the possibility of displacement of Caribbean Black Swifts

As the upcoming report of the Massachusetts Avian records Committee (MARC) should be coming out in a month or so I thought I would delve into greater detail on one of the reports I submitted this year.  I will review my other submissions after the latest report comes out but wanted to take this time before the report is issued to look at my report of a large swift species seen following Hurricane Irene.  I will look at the various reports of large swift species seen during and after Irene as well as a few other reports related to other storms.  I will look at the possibility of these large swift species being the Caribbean subspecies of Black Swift (Cypseloides niger niger). 
I submitted my report to MARC as a large swift species which was seen on August 29, a day after the passage of Irene.  I cannot say with certainty what species of swift it was beyond it was not a Chimney Swift and given the hurricane and other reports of large swift species it is possible (perhaps probable) it was a Black Swift from the Caribbean population that was displaced by Irene.  The eBird Hurricane Irene wrap up summed up these swift reports nicely:
·         A large swift, now believed to be Black Swift (very likely of the Caribbean population, which may represent a species distinct from western North American ones), was seen and photographed at Cape May. Most agree it was not a European Apus swift (e.g., Common Swift), so whatever it is, it will represent a new record for the East Coast (the nearest Black Swift is from Point Pelee, ON). See Tony Leukering's report.
·         Large swifts or suspected large swifts were reported from three other locations, but not conclusively documented. These were seen off Manhattan 28 Aug; at Charleston, SC, 30 Aug (two birds); and in western Massachusetts, moving south with nighthawks (!), on 29 Aug. It seems possible, if not likely, that a decent number of Caribbean Black Swifts were displaced by this storm!

A bit of additional information regarding the possibility of Black Swifts of the Caribbean subspecies being displaced by Irene is in order at this time.  As mentioned in the eBird wrap up of the storm there was a minimum of four separate locations that reported either a possible Black Swift or a large swift species with only one of those documented with photographs (an additional sighting following TS Lee is included also).   The locations and dates of sightings followed the path of the storm and will be detailed here. 

Aug 28                Cape May, NJ                1
Aug 28                Manhattan, NY               1
Aug 29                Belchertown, MA            1
Aug 30                Charleston, SC               2
Using eBird I researched these sightings more in depth and found the following information.  As far as the Cape May sighting is concerned here is the eBird list report submitted by several people viewing in Cape May, NJ (specifically Cape Island-Sunset Beach).  The report from eBird shows the following observers present including David La Puma, Glen Davis, Louise Zemaitis, Michael Fritz, Michael O'Brien, Samuel Paul Galick, Tom Johnson, Tony Leukering.  Here is the eBird report of the sighting of this individual:
large swift sp.
Pix at flickr.com/photos/bonxie88; Around 2:24 pm, I was standing in the parking lot in front of the Sunset Grille when I noticed a dark, long- and narrow-winged bird north of the gift shop across the parking lot from the Grille that I first thought was a small falcon. However, I quickly realized that it was a SWIFT. Wow, a two-swift day! I turned and shouted for everyone to "GET ON THIS BIRD!" This big, apparently-all-dark swift with very long wings that were pinched in at the base, an attenuated rear end, and a flaring and notched tail exhibited wing beats that were quite slow and deep for a swift as it was drifted north away from us by the wind. Our collective opinion was that the bird was probably either a White-collared Swift (Streptoprocne zonaris) or a member of one of the species of Old World swift in the genus Apus. Alpine Swift (Apus melba) has occurred on Bermuda, so that was in the mix, but that species sports a bright white throat and belly. Though none of us had experience with Old World swifts, most Apus have more-deeply notched tails than exhibited by the Sunset Beach swift. Those of us with Middle American experience all considered that the bird was not inconsistent with an identification of White-collared Swift, a species with a few ABA-area records, including one from the northern Lower Peninsula of Michigan. Tom Johnson obtained a number of semi-reasonable pictures of the bird that we have sent off to various experts for their thoughts. The pictures prove that the bird was not an adult White-collared Swift, but the white on juveniles is restricted to the nape. Personally, until I hear otherwise, I consider the bird to most likely be referable to White-collared Swift. Should that ID be correct and should the New Jersey Bird Records Committee accept the record, it would be a first for the state and for the northeastern United States. ADDENDUM: various reviewers (including Steve Howell, Marshall Iliff, and Brian Sullivan all question the tentative ID and, though none are willing to ID specifically, question whether Black Swift is ruled out by pix.

The only photographs of any of these large swift species were taken by Tom Johnson at Cape May and can be found at the following link. 
The second sighting was from Charleston, SC (specifically Eastwood, James Island on the south side of Charleston Harbor).  There were two large swift species noted from that location in the company of Chimney Swifts.  Here is the eBird report of that sighting submitted by Dennis Forsythe:
large swift sp.
At Sunrise Park at harbor.2 all dark, large swifts with Chimney Swift, much larger than
Chimney Swifts, "cigar butt" shape, and a uniform all black, flew NW with Chimney Swifts out of sight.. Wings did a slight flutter when flapping. Viewed for less than 1 min with 10.5x40 bino in good light.Thanks for the reply. After reviewing my notes and memory, I would feel more comfortable with changing the sighting to "large swift sp" The birds were seen about 8AM EDT, with good light. While the color was a uniform black seen as they flew left with the sun to the right, I only saw the front for a split second and had more time ca. 30sec look after the birds flew past and had the best views when they were flying away. I did not notice a white color but I only had a brief view so I could have missed that. The birds seems a uniform black on top and bottom w/o any noticeable color differences. And I did not notice any fork in the tail as it was closed the whole time. They flew "purposefully" away from me with shallow strokes and a slight "flutter" in the outer 1/3 of the wings once or twice.with sickle shaped all dark wings. I am not confident to add any additional details w/o additional notes or memories of the sighting. Let me know what to do with these sighting. I think these were Caribbean race Black Swifts cf. Cape May, NJ record during Hurricane Irene.

The sighting from Manhattan I could not find further information on at this point.
The final sighting of a large swift species either during or immediately after Irene comes from myself and occurred at Herman Covey WMA in Belchertown, MA.  Here is my eBird report of the sighting:
large swift sp.
I was standing at the edge of a marsh area and had a group of Common Nighthawks moving from north to south at 9:40am. I would estimate them at a few hundred feet. After snapping a few photos of the lead birds I put the camera down and noticed three more birds appear. Two were nighthawks but the other immediately struck me as odd. It had the typical swift shape but the bird was quite bulky and I would estimate the size as about 1/2 to 2/3 that of the nighthawks. The tail was longer than a Chimney Swift and the wings were much bulkier. I got no color beyond dark overall. The wing beats to me were slower than a Chimney Swift and then it was in a glide as it went over top of me. The bird was in view for only a few seconds and then it disappeared behind trees. It did fly directly overhead of me. I was unable to get the camera up quick enough. I hobbled out to a more open area beyond the tree line but I could not relocate it. I really do not know what to make of the bird beyond it being a different swift. I looked for the bird for the rest of my time there but had no luck.

I have included my submitted report to MARC regarding this bird.  As I have had no prior experience with Black Swifts I cannot say for sure that was the species and I felt uneasy at the time as submitting it as anything other than a large swift species.  As I have stated previously I can be 100% certain the bird I saw was not a Chimney Swift and was not a swift species I was familiar with.   Following the submission of my report I was able to view White-collared Swifts in Costa Rica and the swift I saw was smaller than these swifts but certainly different in size and behavior to a Chimney Swift.  Here is my report submitted to MARC.

Rare Bird Report

Species:  Large swift species                                        Sex: unknown                                                   Age: unknown

Date of initial sighting: 9/1/2011

Time of initial sighting: 9:40am                                               

Date and Time of additional sightings:  N/A

Location: Herman Covey WMA, Belchertown, MA

Discovery info:  Bird seen flying with Common Nighthawks

Other observers: None

Complete narrative: 

I was standing at the edge of a marsh area and had a group of Common Nighthawks moving from north to south at 9:40am. I would estimate them at a few hundred feet. After snapping a few photos of the lead birds I put the camera down and noticed three more birds appear. Two were nighthawks but the other immediately struck me as odd. It had typical swift shape but the bird was quite bulky and I would estimate the size as about 1/2 to 2/3 that of the nighthawks. The tail was somewhat broad and was neither forked nor tapered. The tail did seem to me to be a little longer than Chimney Swifts would be in relation to the body. The wings were bulkier and the bird overall was just more solid looking. I got no color beyond dark overall. The wing beats were slower than a Chimney Swift and did not seem as deep.  The bird was in a glide as it went over top of me. The bird was in view for only a few seconds (approx 5 seconds) and then it disappeared behind trees.  I was unable to get the camera up quick enough to get a photo. I moved about 75 feet to a more open area beyond the tree line but I was unable to relocate it.  I continued to look for the bird following the initial sighting but had no luck.  I believe Black Swift comes the closest to matching the bird I was but I cannot say for certain.  Given the hurricane that had moved through on Aug 28 the possibilities are many.

Nearby species: It was moving with a group of Common Nighthawks as well as at least one Chimney Swift.  There were also Tree Swallows in the general area.

Vocalizations: None

Habitat and behavior:  seen over marshy area moving north to south moving with Common Nighthawks.

Other species considered and reasons for eliminating them:

As I’m not sure what the bird was I cannot eliminate several possible species.  I considered several swift species such as White collared Swift but the tail was not right and the color was dark overall.    Common Swift also does not match the bird in overall shape.  Black Swift is certainly a good candidate as it matches several attributes of my bird but I cannot be certain.

I wish I would have gotten a longer look at the swift I saw and managed a photo but it all happened so fast and I was unable to get any photos.  It will likely be one of the best birds I ever came across while birding in western Massachusetts that I was unable to conclusively identify. 
A further report of large swift species around the time of Irene comes from Derek Aldrich at Reedy River Falls Park, Greenville County, SC on September 7, 2011 following the passage of the remnants of Tropical Storm Lee. Here is Derek Aldrich’s eBird report:

large swift sp.
Seen during the remnants of Lee passing through. Both were larger than the nearby swifts with similar structure. I had no binoculars or camera and they were gone back in the clouds not to be seen again. The first thing to stick out was their size.

2011 hurricane season tracks (Lee-yellow and Irene-red)
I have included a map of the course taken by Lee as well as tropical storms for a few weeks previous that may have had an impact on the sightings of the large swift species.  The course of Lee does not lend itself to displacement of Black Swifts from the Caribbean.  However given the proximity in dates of Irene and Lee perhaps the large swift species seen here were indeed holdovers from Irene displacement and only discovered by coincidence after the passage of the remnants of Lee.  Again determining the exact species of this large swift species is difficult if not impossible at this point but there is at least a strong possibility that these two birds could also have been Black Swifts.
Black Swift is noted as a common breeder on various islands in the northern Caribbean including several islands that were impacted by Irene.  As this species is noted as highly aerial and migratory they are certainly a species that could be displaced by a strong hurricane and seems likely that at least several large swifts, likely Black Swifts, were displaced by Irene.  According to worldbirdinfo.net the typical departure dates for Black Swifts from Puerto Rico is between August 16-September 5 which would correspond with the dates of Irene and would lend to the maximum number of available birds available for displacement as it right at the end of breeding season. The question now becomes can the specific species be determined to any great confidence?  There are several other large swift species that could be possible but Black Swift seems the most likely candidate. 

Hurricane Irene track with strength

Although there are few hurricanes/tropical storms that have taken the exact route of Irene and impacted the east coast as heavily, there have been many storms taking the same route as Irene in the Caribbean and then impacting further south then Irene did but where there are other documented reports of large dark swifts.  As I searched through the other bird records committee’s of the various states with reports of large dark swifts following other hurricanes the following info came to light.
There are at least two more state reports of large swift species in Massachusetts with one seen following the passage of Hurricane Bertha.  As mentioned in the post below there is also a report from Florida (Dry Tortugas) of a sighting in the eye of a hurricane of several large swift species that may also have been Caribbean Black Swifts.  The hurricane in Florida that led to this sighting was Hurricane Inez that formed in late September and tracked through Greater Antilles then south of Puerto Rico through the southern side of Haiti, then Cuba and finally Florida.   The storm passed over the Dry Tortugas in early October.  Below is the route map of Hurricane Inez.
Hurricane Inez route map

Here is the report from “Field Notes” from 1996 relating to the swift species seen in Massachusetts related to Hurricane Bertha.
Field Notes, Winter 1996, Vol 50, Number 5 by Wayne R Petersen

The  most unusual and problematic report of the season was of a large, dark, forked-tailed swift seen and photographed at Cape Pogue, C Chappaquiddick I., M.V., July 14 (G.Daniels, A. Keith, V. Laux, P. Nden et al.). Discovered the morning after the passage of hurricane Bertha, a storm whose track included the Greater Antilles, the bird apparently showed many of the characteristics of a Black Swift, a polytypic Cypseloide species that maintains a Caribbean subspecies (C. n. niger}.  Based upon body and wing shape, tail configuration, an apparently dark throat, and at least one observer's impression of white frosting on the forehead, some observers were convinced that the swift could only be a Black Swift, most probably of Caribbean origin. Perhaps not surprisingly a 1966 sight report of several large, dark swifts seen in the eye of a hurricane over Florida's Dry Tortugas was also thought to pertain to C. n. niger (Robertson & Woolfenden1, 992, Florida Bird Species).  Observers  watching the Massachusetts swift later the same day, however failed to note white about the forehead and lores and had the impression that the bird's shape, proportions and behavior were more like those of a swift in the genus Apus, possibly A . apus,  the wide-ranging Com.Swift of the Old World, for which there is an accepted Alaskan vagrant record and a questionable sight record from Barbados (A.O.U. Checklist, 1983). Based upon the difficulty of distinguishing certain large swift species, especially in this case the Caribbean race of the Black Swift, as well as the disparity in the impressions of the various experienced observers who saw the M.V. bird, at the moment the report is most conservatively categorized as "a large swift, almost certainly belonging to the genus Cypseloides or Apus" Detailed original notes and photos of the swift are being circulated among a number of authorities, whose collective knowledge will hopefully shed further light on the correct identification of this remarkable vagrant. In any event, the M.A.R.C. really has its work cut out on this one!

The MARC has reviewed the above report on a few occasions with the first review in report #4 (Feb 2000).  The report was accepted as follows:
Large, fork-tailed swift, #96-21, Chappaquiddick Is. (Dukes), 14 July, 1996 (A. Keith, G. Daniels, et al), This intriguing bird was seen by a number of experienced birders, yet there was no consensus as to species. The original observers identified it as a Black Swift (Cypseloides niger) of the West Indian subspecies, but later observers believed it to be an apus swift, most probably Common Swift (Apus apus). Photos were taken, but the Committee felt there was not enough resolution in the photographs to make a clear identification. This record remains frustrating, since whatever species was involved, it was clearly new to Massachusetts
The MARC reviewed the same report in a subsequent report and made the following observations:
Apus species, #96-21R, July 14, 1996, Chappaquiddick (Dukes), resubmitted by W. Petersen. (Third ballot. 8-1). This controversial record involved a large swift seen and photographed at the lighthouse on Chappaquiddick Island in the wake of Hurricane Bertha. The bird was originally accepted as a “Large, fork-tailed swift species” (see Report Four), but further analysis of the photographs revealed a tail shape that eight Committee members believed could only be that of an Apus swift. Common Swift (Apus apus) has been recorded from St. Pierre et Miquelon and quite likely was represented by this record; however, the Committee could not rule out Pallid Swift (Apus pallidus).

In the end the report from July 1996 will likely never be conclusively identified beyond a large species of swift. 
Here is the route map for Hurricane Bertha:
Hurricane Bertha route map
The tracks of Hurricane Inez (category 4), Bertha (category 3) and Irene (category 3) were all very similar in that they tracked through the breeding area of Black Swifts and likely displaced these birds.  I have included tracks of these three hurricanes for comparison.  All three of these hurricanes were major hurricanes with Inez reaching category 4 status and Bertha and Irene both peaking at category 3 storms.   Typically displacement of birds occurs more readily with more severe storms and all three of these storms reached ‘major’ hurricane status (category 3 or above).  Although these three storms all produced reports of large swift species there are other storms with similar tracks that did not produce reports of unidentified swifts…why?  There are probably a variety of reasons.  Some of the storms on similar tracks were even more powerful and created such devastation birders were not able to get out to the same degree as in less destructive storms.  There are more birders out and about looking before, during and after storms than ever before and they are more connected now with cell phones, internet, etc.  Perhaps some of these swift reports were overlooked as identification of various swift species can be quite difficult even under adequate viewing conditions.

There certainly is a history of swifts being blown off course by hurricanes.  One great (but sad) example can be found at the following link:   http://iles-et-ailes.pagesperso-orange.fr/2005/Martinets1.htm  , http://iles-et-ailes.pagesperso-orange.fr/2005/Martinets4.htm and    http://iles-et-ailes.pagesperso-orange.fr/2005/Martinets2.htm  The text is French but the photos speak volumes.  The photos certainly illustrate the potential for swifts to be displaced by hurricanes.  The article mentions the arrival of hundreds of Chimney Swifts blown to the isles of Saint-Pierre et Miquelon off the Canadian coast as well as to Nova Scotia and other areas of Canada following Hurricane Wilma in late October and November of 2005.  The storm formed in the Gulf of Mexico travelled across Florida and then off the east coast before landfall in Canada.  These swifts were likely transported a long distance by Wilma before being dumped out by the storm along the Atlantic provinces of Canada.

Given all this information can an accurate conclusion be reached regarding these birds?  Perhaps but we cannot be certain of the exact species of these various sightings.  Swifts can be difficult birds to identify even in good light and if you have time to study them but many of these sightings occurred in less than ideal conditions and were short in duration.  The circumstantial evidence is certainly there pointing toward the identification of these swifts being Black Swift of the Caribbean subspecies.  It will be interesting to see how the various state bird record committees handle these reports.  Certainly better photographic documentation would help but in the latest storm only a handful of photo were obtained of one of the birds so the committees will have to rely on the written description of the birds in question.  I would certainly love to have one of the only records of Black Swifts in the eastern US but I’m not entirely certain we will ever be able to determine the exact id of the bird with any true confidence. 

If anyone has any comments, questions, additional information or other observations please feel free to leave it below.
I would like to thank the creators of eBird for providing the ability to research these various reports.  I would also like to acknowledge the information I found on the MARC website, the SORA website, Weather Underground website, The Weather Channel website, and other sources mentioned within the article.

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