Louisiana Hummingbird Banding - Winter 2005-2006

The following is a summary of the hummingbird banding activities of Dave Patton, Linda Beall, Mark Myers, Paul Dickson, Steve Locke, and Nancy Newfield over the course of the 2005-2006 winter season in Louisiana. Patton, Beall, and Newfield are self-employed, permitting some flexibility in scheduling. Myers is the curator of birds at the Audubon Zoo. Dickson manages a large business. Locke is a University of New Orleans graduate student in biology who worked in tandem with Newfield some of the time.
Most hummingbirds were banded in the southern third of the state, roughly the area south of Interstate 10/12. Patton covered the area from Baton Rouge westward, while Newfield and Locke banded from Baton Rouge eastward, excepting St. Tammany Parish, which was primarily handled by Beall. Beall and Newfield both banded in Baton Rouge and probably caught only a fraction of the hummers around. Myers covered scattered areas around New Orleans. Dickson examined a small pocket of wintering hummers in Shreveport. This northern region of the state typically hosts fewer wintering hummers, but the area has been little studied, so generalities may not be valid
The Louisiana Winter Hummingbird Project differs substantially from passerine migration banding studies. Most sites host only a few hummers, so efforts must be made to catch individuals rather than mist-netting whichever birds might pass through during a specific time period. Most captures are made using cage wire traps placed around feeders. Electronic remote-control releasers permit the operation of several traps at one time and they allow the bander to watch from an indoor location, making inclement weather less of a factor. Mist nets and other types of traps are occasionally employed. Because of the dispersed distribution of the birds, operations must be completely portable.
Almost all birds were color-marked using specially-colored, water-soluble Liquid Paper on their crowns. Color-marking allowed us to avoid repeatedly capturing the same birds and it permitted hummerhosts to specifically identify each individual. Color-marking enabled the hosts to distinguish look-alikes and to notice new, unbanded birds as they arrived. Color-marked birds are more noticeable as they moved from one site to another as well. In several locations, we found more individuals present than had been originally tallied by the hosts. In most locations, the roster of individual hummers did not remain constant. Instead, while many individuals defend territories throughout the winter, others seem to be trap-lining over a fairly large area. This required the banders to make two or more visits to a number of sites as unbanded birds replaced individuals that had already been banded.
The project was initiated in 1979 as a means of documenting the numbers and species assortment of hummingbirds that spend the winter months in Louisiana. Traditional wisdom of the 1970s was that any hummers occurring in Louisiana during the winter months were vagrants or they were Ruby-throated Hummingbirds that forgot to migrate after the nesting season. Our banding studies have shown that the breeding population is almost completely gone by mid-August, so those that crowd feeders in late August and September are most certainly migrants. The 1974 edition of Louisiana Birds by George H. Lowery, Jr., lists 5 species of hummers. The state list currently stands at 12 species!
In the 1970s, most guides to hummingbird feeding dictated that feeders be removed by early September so that the ready availability of nectar would not cause hummingbirds to linger too long into the fall. At that time, it was thought that nearly all hummers that attempted to spend the winter in the area perished in cold weather and therefore spending the winter months in Louisiana was not a good strategy for survival. However, we have not found any Ruby-throateds banded during the usual period of breeding or of southward migration to remain for the winter. Therefore, members of Louisiana’s only nesting species that arrive in late autumn belong to other, as yet unknown populations.
The season, as we define it, begins with the arrival of the first non-Ruby-throated Hummingbird in mid summer. Typically, the first arrivals are adult Rufous Hummingbirds in August and most of those are returnees from previous seasons. During the early part of the season, we primarily attempt to verify returning hummers. Later, as several birds stake out territories at a site, we try to capture and band as many as possible. We also attempt to capture marked birds that have moved in from other sites.
Because the last stage of Ruby-throated southward migration may extend well into December, it is very difficult to categorize individuals of that species as winterers or migrants early in the season. Therefore, we arbitrarily define wintering for Ruby-throateds as those we encounter on or after 15 November, though some of those birds may actually be tardy migrants. Some that occur earlier may well be winterers.
The winter banding season peaks in January and February, when maximum numbers are present at the various sites. The season usually ends in late February or early March as wintering birds begin leaving and summer resident Ruby-throateds begin arriving. At that time, wintering birds become more difficult to catch and banding trips become less productive. However some wintering birds stay well into April or even early May. This season wintering birds seemed more difficult to catch than ever before. However, a few new birds appeared in March and April so banding efforts continued longer than usual.
Totals for the 2005-2006 season are:
Broad-billed Hummingbird
Buff-bellied Hummingbird
Ruby-throated Hummingbird
Black-chinned Hummingbird
Anna’s Hummingbird
Calliope Hummingbird
Broad-tailed Hummingbird
Rufous Hummingbird
Allen's Hummingbird
Unidentified Selasphorus
21 [+ 11 returnees]
46 [+ 6 returnees]
52 [+ 12 returnees + 2 foreign re-encounters]
5 [+ 1 returnee]
5 [+ 1 foreign re-encounter]
157 [+ 47 returnees + 4 foreign re-encounters]
Total = 301 individuals of 9 species [+ 77 returnees & 7 foreign re-encounters].
Explanation of terminology: Bird banders often use specialized terminology when discussing their favorite subject. Returnee – a bird that has returned to the specific wintering site where it was banded after having been away for its putative breeding season. Foreign Re-encounter – any subsequent capturing of a banded bird after it leaves the 10-minute block in which it was banded. A foreign re-encounter can be the capturing of one of our own birds at a distant site within Louisiana or one banded outside the state. The total of foreign re-encounters does not include birds banded during the season that were re-encountered elsewhere within our area as the season progressed.
The number of wintering hummingbirds banded [301] falls far short of the totals of the seasons from 2000-2001 through 2003-2004. Even compared to the disappointing season of 2004-2005, numbers were down. The total of returnees and foreign re-encounters raises the total of birds handled to 385, 92 individuals fewer than the previous season and 217 fewer than the greatest year. The previous high count of newly banded hummers, documented in 2003-2004, was 510 individuals of 8 species [+ 85 returnees + 7 foreign re-encounters] for a total of 602 birds handled. The amount of effort of the banders was similar to that of the previous few seasons, so the reduced tally cannot be attributed to a change of methods or lack of attention on the part of the banders.
The drop in numbers for the winters of 2004-2005 and 2005-2006 is certainly disappointing after several years of increases. Our methods of finding wintering hummers continue to improve. The network of hummingbird hosts has expanded greatly and the practice of creating habitat for wintering hummers has become very popular in southern Louisiana. Few Louisiana hummerhosts rely on feeders alone. Better communications, particularly through the listserv Humnet, has given us the means to reach more people interested in hosting hummingbirds during the winter months. Yet, many hummerhosts reported fewer birds than usual.
It would be easy to blame the damage from Hurricanes Katrina and Rita for the dearth of hummers. Several known and suspected returnee Rufous disappeared with the storms. Quite a few of our productive sites were lost either permanently or temporarily as homeowners either moved away or were preoccupied with rebuilding their lives. Still, one known returnee Rufous survived tremendous devastation in Covington.
Surely, the greatest impact of the two storms was upon Ruby-throateds migrating through Louisiana on their journey south for the winter. They were abundant at feeders immediately afterwards, probably a result of loss of natural sources of nectar. There is no way to determine the number of birds that might have been killed by the storms or that might have starved from reduced natural nectar sources afterwards.
We suspect several additional factors could be involved in the low numbers of the season. The previous season’s shortage of immature Rufous surely translates to a smaller breeding population the following nesting season. Although the number of Rufous was much smaller than in several past seasons, the percentage of young birds among the newly banded seemed healthy. Perhaps a population cycle reached its low point and numbers will rebound after a few seasons.
In spite of low numbers, Rufous still accounted for the largest number of individuals – both new bands and returnees. In recent years, Rufous totals have run about 65% of the total. However, this season, as last, the total of newly banded Rufous was only slightly more than 50%. Among returnees, Rufous accounted for close to 65%.
Ruby-throated and Black-chinned numbers typically fluctuate greatly. This season’s totals were solid but well below record numbers. Near equal numbers of the two species did not show any trend. About twice the number of Black-chinneds returned as did as Ruby-throateds.
Numbers of Buff-bellieds, both new bands and returnees, remained fairly constant. Allen’s numbers were about average. Always exciting and unexpected, Broad-billed numbers were average so to speak. The banding of 6 Anna’s brought the species diversity up to 9 species, one more than in any season since 1999-2000. Two Anna’s arrived, at the same River Ridge home, after many of the winterers had already departed.
Calliope and Broad-tailed numbers were down, but the populations of those species in Louisiana are never large enough to demonstrate an established trend. [To read previous Louisiana Hummingbird Banding Winter Reports, log on to http://losbird.org/ and scroll down to “Hummingbirds”.]
The season was very disappointing in many ways. Nevertheless, our purpose is to document and monitor the hummingbirds that spend their winter season in Louisiana and we know that each season has different attributes. Even in a poor season, we find interesting occurrences. Every band applied offers the possibility of discovering just one more data point to fill in the huge puzzle that the picture Louisiana hummingbirds has become!
One good reason to band is to find out where our birds go after they leave Louisiana. Astonishingly, an adult male Broad-billed that was banded in New Iberia in December 2005 was captured near Colorado Springs, Colorado, in April 2006 – a distance of 957 miles. It is a third record of the species for Colorado. Curiously, the first Broad-billed documented in Colorado [2002] had also been banded in Louisiana!
Banders elsewhere in the southeast found 4 Louisiana-banded hummers. In November 2005, Brandon, Mississippi, hosted a male Rufous that was already an adult when he was banded in January 2005 in Thibodaux. A male Rufous that was a youngster when banded in Covington in January 2005 was captured in Silverhill, Alabama, in January 2006. Georgia hosted 2 Rufous; one in Suwanee in January 2006 was an adult when banded in Covington in January 2004. Another in Decatur in January 2006 had been a young bird when it was captured in Baton Rouge in December 2003.
Over the summer of 2005, we learned belatedly that a Rufous that had been banded in Covington early in 2003 was captured in southwestern Alberta, Canada, in July the same year. The re-encounter site is nearly 2000 miles from the banding site. This is the second Louisiana-banded Rufous to be found in western Canada.
We caught 4 out of state foreigners this season. An adult female Black-chinned caught in Pearl River proved to be one banded as a youngster in Fort Grant, Arizona, in late September 2004. That banding site is approximately 1200 miles due west of the re-encounter site. This is the first southwestern-banded hummer ever caught in Louisiana! A young female Black-chinned banded near Raisin, Texas, in October 2005 was found in Lutcher on January 2006, 397 miles from the banding site.
Both out of state Rufous were originally caught in Pensacola, Florida. An adult male, banded as a youngster in mid-November 2001, was caught in Thibodaux on January 2006. He has spent the past 5 winters in Pensacola and he was previously caught in March 2005 at the same location in Thibodaux. In late January 2006, the same Thibodaux yard also attracted a young female that had been banded in Pensacola only about a month before. Both individuals were no doubt en route to their natal environs. The distance between Pensacola and Thibodaux is 222 miles.
One in-state foreigner was noteworthy. An adult male Broad-tailed captured in March 2006 in St. Francisville proved to be the same individual banded as an immature in Covington in November 2002. We can only speculate on where he has been all this time.
A few individuals banded in previous seasons returned to Louisiana, but they chose different sites. Most of these were within 10 miles of the original site. We can only speculate on the reasons these birds changed sites. However, the small distances are probably not significant, especially considering the distance these birds fly to reach our area. One female Ruby-throated was banded as an adult in December 2001 in Mandeville. She returned for the next two seasons. Then she skipped the following one before being captured again at the original site in 2005. However, in the 2005-2006 season, she was found 11 miles away in Abita Springs.
Returnees are resourceful birds that prove winter survival and exhibit an uncanny navigational ability when they are able to relocate their previous winter home after flying hundreds, if not thousands, of miles. Long-term returnees provide longevity data and attest to the value of created or enhanced habitats.
There were no new longevity records this season. The oldest birds were 2 Rufous banded as youngsters in the 2000-2001 season and the adult female Ruby-throated banded in December 2001. These birds would have hatched no later than the 2000 breeding season. Using the Bird Banding Laboratory formula for establishing age, each would be approximately 5 ½ years old.
A banded adult female Rufous was thought to be the same individual that had held the same territory in Baton Rouge since February 2000. She was an immature when originally handled. That bird hatched in 1999 so her age is firmly established. However, despite several attempts, she could not be caught for verification.
Winter weather is seldom extreme in Louisiana, but weather can play a significant role in this project. We do not band during subfreezing temperatures or during heavy rain, but neither was a major factor this winter. Dense fog can impede travel and scheduled trips may be postponed because driving conditions are hazardous. However, the only effect of weather in the winter of 2005-2006 was difficulty in catching hummers because of a lack of cold weather. Floral nectar was abundantly available throughout the southern part of the state throughout the entire winter so hummers were not at all dependent on handouts from humans. In fact, in some gardens, flowers are much preferred over feeders.
The Louisiana Winter Hummingbird Project has benefited from the enthusiastic assistance and generous financial support of numerous people. Many hummerhosts welcomed us with strong coffee, juice, and breakfast at unbelievably early hours. Several maintained a running tally of birds in their cities or towns and they set up banding schedules for us. Others wrangled equipment, trapped birds, and recorded data. We thank Frank Arthur, Lynn Becnel, Laurie Binford, Olga Clifton, Paul Conover, Miriam Davey, Dennis Demcheck, Bill Fontenot, Erik Johnson, Bob Jumonville, Beth and Sammy Maniscalco, Kevin Morgan, Rose and Jack Must [Wild Birds Unlimited, Lafayette], John and Margaret Owens, Mike and Sue Roberts, Cheryl Stanbury, Ron Stein, Melanie and Pat Stephens, Gene and Edna Street, and Tom Sylvest for the many hours they have invested in this project with us. We appreciate their special help very much.
Already, Louisiana’s hummingbird banders are looking forward to the next season – just a few months away! We are always searching for new sites where hummers reside during the winter months. Please contact us if you host wintering hummers or know someone who does. Dave Patton: wdpatton@cox.net phone 337-232-8410. Linda Beall: hummbander@yahoo.com phone 985-893-5150 [home], 504-231-5150 [cell]. Nancy Newfield: nancy@casacolibri.net phone 504-835-3882.
Nancy L Newfield
Casa Colibrí
Metairie, LA USA