Wednesday, October 31, 2007

Green-breasted Mangos in North America

Green-breasted Mango Anthracothorax prevostii

This species is not included in the Sibley Guide to Birds because at the time that I was planning the book there were only two records north of Mexico. By the time I had finished the book there were 7 records (enough to warrant inclusion, if only I had known sooner!). Records have continued to increase with the total as of today up to at least 16 in Texas (through 2006) and single records in NC, WI, and GA. The WI and GA records are both in fall 2007, prompting this summary. Obviously it's a species that should be watched for all over the US.

Identification
A report by John Arvin on identification of Mango Hummingbirds from the minutes of the 1995 Texas Bird Records Committee meeting:
Arvin discussed his findings regarding identification of immature/female Mango sp. hummingbirds of Central America and northern South America. Arvin has now visited 3 of the 4 major North American collections with numbers of Mango specimens (LSU, Smithsonian, and Field Museum of Chicago; American Museum of Natural History specimens have not been examined). He examined all specimens of the 3 mainland Mango species which are possibly confused:
- GBMA - Green-breasted Mango (Anthracothorax prevostii)
- GTMA - Green-throated Mango (A. viridigula)
- BTMA - Black-throated Mango (A. nigricollis)
A brief summary of distinctive aspects follows:
GTMA is a scarce hummer of n.e. S. Am. It is rare in collections. Fem/imms are easy to separate because the dark stripe on the center of the underparts is short, extending barely past the throat.
BTMA occurs in humid tropical lowlands. Fems/imms are very similar to GBMA except that the central dark stripe NEVER shows any blue or green iridescence; it is flat black.
GBMA is highly migratory at least in the northern part of its range. GBMA fem/imms have varying amounts of color in the central dark stripe but: No GBMA failed to show at least a little blue or green color (at least a few metallic feathers) in the stripe. Thus, IF a mango is a fem/imm and IF any blue/green iridescence is seen in the dark belly stripe, it is a confirmed Green-breasted Mango. If no color is seen, it may be accepted at least as a mango sp. Based on geographic probability, and the fact that the northern pops of GBMA are migratory and no other pops of any of the other spp. are, it is a virtual certainty that any mango sp. in Texas is a GBMA (barring escaped captive). TBRC members may continue to make their own decisions on how conservative they may choose to view records in which no color in the central stripe is seen.
Arvin could find no other plumage differences that would be useful at distinguishing fem/imm GBMA and BTMA. Apparently the amount of rufous/rusty on the sides of the neck does NOT help; it is quite variable within and between these two species.
North American Records:

Texas 1) - 14-23 September 1988. One female or immature was at Brownsville, Cameron Co, TX. Originally accepted only as Mango species (Anthracothorax species) this record was later accepted as a Green-breasted Mango based on geographic probability after a pattern of other documented records developed. the first record of its genus in the United States.

Texas 2) - 6-27 January 1992. One female or immature in Corpus Christi, Nueces Co, TX.
photo here and here. From TBRC 1993 report.

Texas 3) - 22-27 September 1993. One female plumaged bird, in Falfurrias, Brooks Co, TX. 1995 TBRC report

Texas 4) - 18-20 August 1993. One immature was photographed at Santa Ana NWR, Hidalgo Co, TX. 1996 TBRC report

Texas 5) - 17-20 August 1996. Up to two were at San Benito, Cameron Co, TX, 1997 TBRC report

Texas 6) - 3-8, and 21 November to 21 December 1997. One at Corpus Christi, Nueces Co, TX, 1998 TBRC report

Texas 7) - 22-23 May 1999. One at Los Fresnos, Cameron Co, TX. 2000 TBRC report

North Carolina 1) - 12 Nov - 4 Dec 2000. One immature male in Concord, Cabarrus Co, NC. Article in The Chat here (pdf) photos here and here

Texas 8) - 1-8 February 2001. A male at McAllen, Hidalgo Co, TX,

Texas 9) - 10 July-15 August 2001. A female or immature at Pharr, Hidalgo Co, TX,

Texas 10) - 28 September-18 October 2001. A male at McAllen, Hidalgo Co, TX, TBRC 2002 report

Texas 11) - 23 November 2001-12 February 2002. A male at McAllen, Hidalgo Co, TX,

Texas 12) - 9 September- 23 October 2002 The same male returned to McAllen, Hidalgo Co, TX, TBRC 2003 report

Texas 13) - 22 August-5 December 2004. One adult male at McAllen, Hidalgo Co, TX, photos here

Texas 14) -
20 September 2004-25 January 2005. One (or possibly two) adult male(s) at McAllen, Hidalgo Co, TX, photo here and here and here (labeled Pharr, TX?) and here

Texas 15) -
18-20 June 2005. An imm. bird at San Benito, Cameron Co, TBRC 2005 report

Texas 16). 8-9 July 2006. An imm. bird at San Benito, Cameron Co, TX, TBRC 2006 report

Wisconsin 1) - early Sep - 5 Nov+, 2007. Immature or female at Beloit, WI; photos here and here and here. This bird was captured on 5 Nov 2007 and taken into captivity, details here.

Georgia 1) - 25 Oct - 11 Nov+, 2007. One immature or female at Dublin, Laurens Co. GA; photos here and here and here


References:
TBRC annual reports and minutes can be found here

10 comments:

Chris said...

FWIW, I have seen a photo of one from Indiana I believe around the same time as the NC bird. I do not know if it was ever published, but the photo (even in it's exceedingly poor fax quality) clearly showed a fem/imm mango (presumed GB).

slybird said...

Great post! I have a question (I feel I should know this given how long I've been birding)... where do you compile these records from? When we talk about first US records, etc... what database are we drawing from?

Thanks,
Nick

David Sibley said...

Chris,

Thanks for the info, but I never heard of an Indiana record and don't see any mention of an Indiana mango photo on the state Bird Records Committee site. Are you sure the photo you saw was real and from Indiana?

David Sibley said...

to Nick (slybird),
I rely on the state bird records committees for this info. This species is pretty easy since most of the records are from Texas and conveniently summarized in the TBRC annual reports, which are all online. The other three records are easily found online.

A species like Eurasian Kestrel, with records more scattered, would be more of a challenge to track down, although the ABA and AOU checklists do include summaries of records of such rare species.

Patrick Belardo said...

Hi David,

I believe the Veraguan Mango (A. veraguensis) was split from Green-breasted Mango, but I don't believe it is migratory. I think it is restricted to Panama (with a few records from surrounding countries), but I couldn't find much info. I just wanted to throw that out there. I can't wait for a mango to show up in NJ!

Chris said...

I'm sure it was a real photo. It was a fax of a photo (and a poor one at that), but it was shown to me by a birder from Indiana and it was unmistakably a mango. I obviously can't verify where it was taken, although I have no reason to distrust the location as reported to me by the guy who got the fax. I seem to recall that he actually spoke with the host and found out that the bird was gone, but this was several years back so I don't recall the details.

Don said...

Chris (and David),

I think there might be some confusion/miscommunication about an Indiana record for Green-breasted Mango. I have been the chair of the Indiana Bird Records Committee for the past five years. Before me, Phil Kelly served in that post for about three years. No person in Indiana has ever publicly reported having a mango present. I am confident even if there was a rumor about such a sighting I would have heard about it. The confusion might arise because Phil Kelly of Indiana went to North Carolina in 2000 to see the Green-breasted Mango. He obtained photos of the bird http://www.pjkelly.net/gallery/gbma.htm and at least one of these photos has been used in The Chat http://www.carolinabirdclub.org/chat/issues/2005/v69n2greenbreastedmango.pdf

Chris, if you think a mango might have been seen in Indiana, I would be eager to get any details of the sighting. I am betting in the end the photo was of the NC bird taken by Hoosier Phil Kelly rather than being in Indiana.

cyberthrush said...

It's always wonderful to see out-of-range birds, but the Texas occurrences of the Mango are only slightly out of its established range; the single Georgia occurrence is more interesting. And I've long suspected (but of course can't prove) that the NC and WI. instances were nothing more than hummers that flew into the back of trucks loaded with tropical foliage plants headed north (there are LOTS of such truckloads), and then released when the back door opened upon destination arrival; i.e. not true migratory occurrences.
Anyway, my point is that as interesting as the GB Mangos are, true western hummers that are clearly moving long distances for their Eastern appearances are probably of greater interest for study.

Chris said...

I will try to track down the guy who showed me the picture. As I said, I have no first hand knowledge of the sighting, except that I was unequivocally told that the photo was taken at a feeder in Indiana but was already gone by the time the guy got the fax of the picture. But, who knows. It is certainly possible, and perhaps even likely, that he was mistaken or had been given bad information as well.

David Sibley said...

Cyberthrush,

I think these mango records also fit a larger pattern of many southern birds moving north,and are probably also part of the pattern of increasing vagrant hummingbirds in the east (with the increase in hummingbird gardens and feeders, and increased awareness). Bird distribution is always changing in response to habitat changes and other things, and it's exciting to watch all of these changes and wonder what's next.

The idea that birds are accidentally transported in shipments of tropical plants has been suggested before, but it has never been plausible. First, I can't imagine how a bird could be loaded onto a truck and trapped, and if that happened it's very unlikely that a hummingbird could survive the journey. If this was happening I would expect to see lots of other species transported, and not the same species over and over (e.g. why aren't Bananaquits - tame and abundant nectar-feeders - transported accidentally with tropical flowers?)

We can't absolutely rule out the possibility of accidental transport, but there is no evidence for it, and with each new record the distribution of mangos looks more like a natural pattern of vagrancy.