Subject: Louisiana Hummingbird Banding - Winter 2004-2005
From: Nancy L Newfield nancy@CASACOLIBRI.NET
Date:Thu, 14 Apr 2005
 

Louisiana Hummingbird Banding - Winter 2004-2005

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 2004-2005 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 the Shreveport area and even wandered east to Oak Grove in extreme northeastern Louisiana. These northern reaches of the state have 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, 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 Louisiana list of hummingbirds was 5 species in 1974. There are now 12 species on the Louisiana list!
 
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 most exciting bird of this season was a first state record Magnificent Hummingbird in Slidell that avoided capture for almost three weeks in November. The long-overdue occurrence of this splendid immature male was well-documented by photographs and videos. The bird appeared at the feeder only sporadically, sometimes skipping days, and he never remained in the yard through the day. The bird apparently had other food sources, but those could not be located.
 
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 a few new birds appeared in March and early April so banding efforts continued longer than usual. .
 
Totals for the 2004-2005 season are:
Broad-billed Hummingbird
Buff-bellied Hummingbird
Ruby-throated Hummingbird
Black-chinned Hummingbird
Calliope Hummingbird
Broad-tailed Hummingbird
Rufous Hummingbird
Allen's Hummingbird
2
23 [+ 9 returnees]
79 [+ 4 returnees]
84 [+ 10 returnees + 1 foreign re-encounter]
4 [+ 4 returnee]
1 [+2 returnees]
158 [+ 80 returnees + 10 foreign re-encounters]
4 [+ 2 returnees]
Total = 355 individuals of 8 species [+ 111 returnees & 11 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 several birds banded during the season that were re-encountered elsewhere as the season progressed.
 
The number of wintering hummingbirds banded [354] falls far short of the totals of the past four years, yet it exceeds counts of the 1980s and 1990s. The total of returnees and foreign re-encounters, highest ever, raises the total of birds handled to 476, still considerably fewer than in several previous seasons. 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.
 
It is not clear whether the number of hummers spending the winter months in Louisiana is increasing over all or not. The drop in numbers for the winter of 2004-2005 was certainly disappointing after several years of increases. Our methods of finding wintering hummers continue to improve. An increase in the number of banders permits better coverage. The concepts of "better networking" versus "actual increase" can be debated endlessly without resolution. Both factors are probably at work. 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.
 
As usual, Rufous accounted for the largest number of individuals ­ both new bands and returnees. This season was no exception. However, in recent years, Rufous totals have run about 65% of the total while this season, the number of new Rufous banded is only slightly more than 50% in spite of a record number of returnees. In assessing our records, it appears that young Rufous were in particularly short supply.
 
The shortage of young birds is especially troubling given the species’s status as “declining” according to data from Breeding Bird Surveys. In discussions with other hummingbird banders, we have been told that the 2004 nesting season was poor on the eastern slope of the Rocky Mountains because of climatic factors though breeding was thought to be excellent elsewhere. The only recovery of a Louisiana-banded Rufous [in 2001] was from British Columbia rather than from the eastern slope. However, that single data point is not sufficient to suggest that all or even most of our Rufous originate there.
 
If the bulk of the Louisiana winter population of Rufous originates in areas that experienced poor nesting seasons, then numbers of young birds should begin to rebound as soon as breeding conditions improve. Much more study will be required to find out if this decline is part of a population cycle or if more sinister factors are in play. Numbers of Calliope and Broad-tailed were also down, but the population of those species in Louisiana is never large enough to give us an established trend. [To read previous Louisiana Hummingbird Banding Winter Reports, log on to http://losbird.org/ and scroll down to “Hummingbirds”.] The diversity of species banded was the same as in the previous winter season.
 
The banding of a female Calliope in Keithville, near Shreveport, documented that species in the far northwestern portion of the state for the first time. The bird appeared about Thanksgiving time and it remains at the time of this writing.
 
Ruby-throated numbers were among the highest we’ve recorded and the tally for Black-chinned set an all-time record, both in the number of new birds and in the number of returnees. Buff-bellied numbers were about average while the Allen’s tally was down from that of recent seasons. Two Broad-billed were good. For the fifth consecutive season, no Anna’s were banded and none were authoritatively reported.
 
Banders elsewhere in the southeast found 5 Louisiana-banded birds. Madison, Mississippi, hosted a Rufous that had been banded as a youngster the previous season in Baton Rouge. A Rufous that was already an adult when banded in Shreveport in November 2003 was captured in Hattiesburg, Mississippi, in December 2004. Dothan, Alabama, hosted a female Rufous banded in Thibodaux in January 2002. The bird was young at the time of banding. A male Ruby-throated that was banded in Covington in early January 2004 was found in Chatom, Alabama. He was immature when banded. A female Rufous banded in Slidell in January 2004 was found dead in North Carolina sometime early in 2005.
 
By many measures, the season was disappointing. However, our purpose is to document and monitor the hummingbirds that spend their winter season and we know that there cannot be perpetual growth.
 
Even in a poor season, we find interesting occurrences. After the aforementioned Magnificent, the most exciting find was an immature female Rufous in Baton Rouge that had been banded in Lebanon, Indiana, in early September 2004. This was the first time a Rufous banded in migration outside the Deep South was captured the same season in Louisiana. The record is but a single data point demonstrating a migration route by which a Rufous arrived in Louisiana. While there are likely several routes by which Rufous reach the Gulf Coast, this record lends strength to the theory that some migrate eastward through the Great Lakes region before traveling southward to their ultimate destinations. We can only hope we find more pieces to this puzzle.
 
Other out of state foreigners included 3 Rufous banded in previous seasons in Mississippi [Bay St. Louis (2), Pascagoula], 1 from Alabama [Mobile], and 2 from the Florida [both Pensacola]. One of the Florida Rufous was apparently en route to its breeding territory when it was caught in early March 2005 in Thibodaux. This male was a youngster when banded in November 2001. It was recaptured near its original winter home in the falls of 2002 and 2004.
 
Another male Rufous was banded in Metairie in October 2002, when he was immature. He was caught this season in Slidell in late January. The bird had been present for a couple of months. However, the previous winter he was captured in Biloxi, Mississippi.
 
A couple of in-state foreigners were noteworthy. A male Rufous that was immature when banded in Thibodaux in February 2003 was found in Baton Rouge in January 2005.
 
The only non-Rufous foreigner was a female Black-chinned that was already an adult when she was banded in Houma, Louisiana, in February 2002. She was re-encountered in Baton Rouge almost exactly 3 years later. Although the distance is only 65 miles, it is clear that this bird traveled many more miles in her trips between wintering and nesting grounds.
 
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 flew to reach our area.
 
Same season re-encounters support a theory that not all hummers establish territories on their wintering grounds but rather drift about filching nectar from the territories of other hummers. There is often movement between sites during the season. Two Black-chinneds were caught at different sites each of which was approximately 15 miles from the original site. One of these birds moved to a third site before returning to the original site temporarily. One Rufous moved to a site 6 miles from the place where it was banded but it remained at the second site and established a territory. Several other marked birds could not be recaptured to verify their identities.
 
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. For the first time, we had returnees of 7 species! A record number of 111 far surpassed the previous season’s 85! Northwestern Louisiana recorded its first ever proven returnee, a female Rufous.
 
Last season’s longevity record Rufous “Old Mama” did not return. She was an adult when banded in January 1997. Thus, she would have hatched in the 1995 or earlier breeding season. She had returned to the same beautifully landscaped yard in Abita Springs every year. Using the standard Bird Banding Laboratory method for calculating age, she was at least 8 years 9 months old when captured in March 2004. This age surpassed the longevity record for Rufous posted on the BBL web site and established a new record for the species, a record that only stood for a few weeks as another old Rufous was reported from the breeding grounds shortly after the recapture of “Old Mama”.
 
There were no new longevity records this season. The oldest birds were 3 Rufous and a Buff-bellied that had been adults when banded in February 2000. Their putative hatching years would be 1998 or earlier. Another Rufous returnee from February 2000 was an immature when originally handled. That bird hatched in 1999 so its age is firmly established. Several returnees from the 2000-2001 season are lining up to give additional longevity data as well.
 
The number of returnees was actually higher than our figures show. Nearly a dozen known or suspected returnees could not be caught for verification of their band numbers. Some of these birds, especially Buff-bellied, become extremely adept at avoiding the traps after a few encounters. One Buff-bellied that was documented had not been recaptured in 5 years though he was almost certainly present each intervening season.
 
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 several scheduled trips had to be postponed because driving conditions were hazardous. Part of the region experienced an unexpected Christmas Day snowfall of as much as 4 inches. The same weather system produced a hard frost that destroyed nectar-producing flowers throughout much of the state excepting the New Orleans area and the citrus-growing region south of the city. After that, hummers were somewhat more dependent on feeders and thus were more readily caught. Insects seemed to be available at all times.
 
The Louisiana Winter Hummingbird Project has benefited from the enthusiastic assistance and generous financial support of numerous people. Many hummerhosts opened their doors at ungodly hours and sustained us with strong coffee, juice, breakfast and lunch. Several maintained a running tally of birds in their cities or towns and set up banding schedules for us. Others wrangled equipment, trapped birds, and recorded data. We thank Frank Arthur, Lynn Becnel, Laurie Binford, Winston Caillouet, Olga Clifton, Paul Conover, Miriam Davey, Dennis Demcheck, Bill Fontenot, Bob Jumonville, Gwen Kaiser, Bill Lawrence, Beth and Sammy Maniscalco, Craig and Megan Mineo, 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, Tom Sylvest, Mike Taylor, Dan Webb, and Chris and Satya Witt for the many hours they have invested in this project. We appreciate their special help very much.
 
Like tots awaiting Christmas, Louisiana’s hummingbird banders are looking forward to the next season ­ just 3 1/2 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]. Mark Myers: birds@AudubonInstitute.org phone 504-861-5124 [work], 504-836-2871 [home], 504-416-6618 [cell]. Nancy Newfield: nancy@casacolibri.net phone 504-835-3882.
 
Nancy L. Newfield
 
HummerQuest 2005 information http://www.casacolibri.net/hummerquest2005.php
 
*****************************
Nancy L Newfield
Casa Colibrí
Metairie, LA USA
nancy@casacolibri.net
*****************************