Post-fledging Wandering by Hatching-year Purple Martins: A Color-banding Study

Reprinted from: Update 10(4)
Henry D. Miller
2399 T.R. 406
Sugarcreek, OH
44681

Jonas M. Miller
3173 T.R. 414
Dundee, OH
44624

James R. Hill, III
Purple Martin Conservation Association

Fig. 1. A sample of the red and blue metal leg bands used in 2000 and 2001 in the Ohio Purple Martin color-banding project. Orange metal bands with letters and numbers (i.e., alphanumerals) were also used. Each band has a unique code, such as X464 or A851. (Please note: the letters can fall in the first, last, or second position.) These band numbers are easily read with a high-powered spotting scope at distances up to 100 feet away. Observers record the age and sex of the bird, the complete code on the band, the color of the band, which leg the color band is on, the date and time of the observation, and the geographic location of the sighting. 13,271 martin nestlings have been banded to date in central Ohio as part of this ongoing study.

For a martin landlord with a productive colony site, the end of summer is a bit of a circus. Fledged martins, now called "hatching-year birds" (HY's), are everywhere, and like a house full of teenagers, things can get kind of hyper, even chaotic. These young martins have trouble landing and also poke their heads into any available cavity. Subadult martins are often seen harassing and chasing these youngsters away. Nearly all landlords assume that these naive and rowdy fledglings putting on a show at their colony sites are birds fledged from their very own yards. Now, this large-scale, color-banding project has revealed that over 50% are not.

The Ohio Purple Martin Color-banding Project

Since the summer of 1999, four Amish martin landlords in central Ohio have color banded 13,271 nestling martins at their own colony sites and up to 51 other colony sites in the five surrounding counties. The banders were: Henry D. Miller of Sugarcreek, OH; Jonas M. Miller of Dundee, OH; Leroy A. Erb of Dundee, OH; and Robert Hershberger of Millersburg, OH. These four men and their assistants banded 2731 nestling martins at 25 different colony sites in 1999; 5298 nestling martins at 48 different sites in 2000; and 5242 martins at 55 different sites in 2001. All of the banders were licensed subpermittees of master bird bander, Mark Shieldcastle, of the Black Swamp Bird Observatory. The banders found landlords willing to participate in their banding project through word-of-mouth, and by having cooperator applications available at the annual Eastern Bluebird and Purple Martin Seminar, which is put on by Morris Yoder the last Saturday each February at the Mt. Hope, Ohio, auction barn. This day-long gathering often attracts over 700 attendees from the states of Indiana, Ohio, and Pennsylvania, most of whom are Amish folks who host martins and bluebirds. Volunteer participants in the Ohio Purple Martin banding project had to have accessible gourds and/or houses, plus be willing to keep accurate nest records. In the first three years of the project, participants lived in one of the five Ohio counties near the banders (i.e., Holmes, Tuscarawas, Wayne, Coshocton, or Ashland). The project will expand into other counties in the coming years.

The banders in this project sought the appropriate Federal and State permits to legally band and auxiliary mark Purple Martins because they wanted to learn what percentage of banded nestlings would return to breed at their natal sites the following year, how long they might live, and how far they would disperse between hatching and breeding locations. The banders had no idea that having a large population of color-banded martins would lead to other unforeseen discoveries, such as the one reported in this paper (i.e., post-fledging wandering). Nor did they foresee that many hundreds of their banded fledglings would wander northeast over 140 miles to join the huge migratory roost at Presque Isle State Park in Erie, Pennsylvania (but this is a future Purple Martin Update article).

How the Martins Were Banded

Fig. 1 shows a sample of the red and blue metal leg bands used in the Ohio Purple Martin color-banding project during 2000 and 2001. Orange metal bands with letters and numbers were also used. Each band has a unique code, such as X464 or A851. The letter can fall in the first, second, or forth position. These band numbers are easily read with a high-powered spotting scope at distances up to 100 feet away. In 1999, the banders used plain, plastic leg bands, a different color on a different leg for each of the 25 colony sites banded that first year.

As stated, to date, 13,271 martin nestlings have been band-ed as part of this ongoing study in central Ohio. How do four banders band so many nestlings in just three summers? They worked in two teams. One team did the colony sites to the north, the other team did the sites to the south. Since the banders were Amish and didn't own cars, drivers with vans volunteered to take them to the 55 banding sites. And since they all have other jobs, they did this work in the evenings and on Saturdays, or took vacation days. In the days prior to each banding visit, they let the landlords know they were coming in order to coordinate their arrivals and to enlist the help of the landlord. The banders also took along volunteer assistants that brought them the birds to band, returned the banded nestlings to the correct nest cavities, and helped with all the detailed paperwork.

The banders visited each colony site at least twice each summer; once early in the breeding season to band the nestlings of adult pairs, then about three weeks later to band young from subadult pairs, and adult pairs renesting after earlier nest failures.

Results

After color-banded martins started to fledge, banders Henry Miller and Jonas Miller started reading the band numbers on the fledglings at their sites. To their surprise, many of the banded fledglings they were seeing were foreign visitors, birds visiting from other colony sites where the men had banded. Combining the data from 2000 and 2001, Jonas Miller of Dundee, Ohio (see Figs. 2 and 3), saw 108 banded fledglings from 41 colony sites other than his own. The average distance to the colony sites these banded fledglings wandered from was 8.2 miles away. The nearest hatching site of a visitor was 0.24 miles away; the farthest banded fledgling visitor came from the colony site of Ken Fecker of Waldo, Ohio, 70.32 miles away (the Fecker bird was banded by PMCA personnel as part of a different banding study).

Fig. 2. The Dundee, Ohio, colony site of martin landlord, Jonas M. Miller. Jonas is one of four landlords that have banded 13,271 Purple Martins in Ohio during the last three breeding seasons. All his housing cranks up and down, and is accessible. Fig. 4. The Sugarcreek, Ohio, colony site of Henry D. Miller. For the past three summers, Henry and 54 other martin landlords in five Ohio counties took part in a color-banding Purple Martin project under the guidance of the Black Swamp Bird Observatory. Over 13,271 martin nestlings were banded as part of this study.

Similarly, combining the data from 1999, 2000, and 2001, Henry Miller of Sugarcreek, Ohio (see Figs. 4 and 5), saw 92 band-ed fledglings from 38 colony sites other than his own. The average distance these banded fledglings wandered was 6.34 miles from their natal colony sites. The nearest site was just 0.8 miles away; the farthest was 17.59 miles. Some of the banded visitors each man saw were observed on multiple, consecutive days; four to five days in some cases.

Henry Miller and Jonas Miller live only 2.99 miles apart. Combining both men's results, the average wander distance of the 200 banded fledglings they had visit their colony sites was 7.24 miles. Both men only had limited time to do scope work, so many bands likely went unsighted. They also reported that only about 40-45% of the fledglings they saw were banded, indicating that 55-60% of the birds they saw came from outside of their local area (as indicated by the Fecker bird showing up from 70 miles away), or from unbanded colonies within the study area. This demonstrates that independent, hatching-year (HY) martins explore widely before migrating south for the winter.

Discussion

The surprising results of this banding study underscore the previously-unknown fact that once Purple Martin fledglings reach independence, they start to wander, and they clearly wander in every direction to visit other active colony sites and to search for rich food sites. The relatively short average wander distance (7.24 miles) reported in this study is clearly just the result of the clustered nature of the 55 banding sites used. No other significant color-banding of Purple Martins was conducted in Ohio outside of the five county area in this study, except the 60 nestlings color-banded in 2000 at Ken Fecker's colony site approximately 70 miles away. One of those fledglings did show up at Jonas Miller's site. Plus, several hundred other color-banded nestlings from this study did wander the 140 miles to join the roost at Presque Isle State Park in Erie, Pennsylvania, in 1999, 2000, and 2001. Clearly, it can be stated that Purple Martin nestlings wander hundreds of miles in every direction prior to their southward migration to Brazil at season's end. Why? Perhaps they are searching for future breeding sites, or maybe they are just looking for areas of high food abundance so they can put on weight prior to their 4000-5000 mile southward journey to their wintering grounds.

The next obvious question is, did any of these color-banded nestlings return the following year as subadults to any of the sites where they were spotted as visitors? The surprising answer is no. Many color-banded subadults did return to breed within the study area (only about 4% of the nestlings banded in this study returned to their natal sites as subadults), but none of the returning subadults were observed at the colony sites where they were seen the year before as post-fledgling wanderers. Why not? Perhaps because approximately 60% of fledglings don't survive to return as subadults, or perhaps because they chose to nest at one of the many other sites they likely visited during their widespread post-fledging wanderings. Indeed, several of the nestlings banded in this study were reported breeding outside the banding area in Ohio and in western Pennsylvania. In any case, this study has revealed some very interesting results that would not have been possible without the valuable tool of color banding.

One additional phenomenon revealed itself during this study. One landlord, on doing a routine nest check of his T-14 martin house, discovered 19 dead fledgling martins in just two of his house cavities; 9 in one, 10 in the other. The bands on the legs of these 19 birds revealed that they were from 10 different nest cavities! What were fledglings from 10 different nests doing roosting together? And why did they die? The birds did not appear to be undernourished and the weather was stable during the period. The birds were not checked for pesticide poisoning. So, this phenomenon remains a mystery, but banding made this observation possible and certainly more intriguing.

We strongly encourage all landlords to watch closely for bands on their martins. Bird banding is one of the most useful tools in the modern study of wild birds. We are listing a few things to remember when reading bands: 1. Note which leg has the Federal aluminum band and read its 9-digit number (example 1751-12345). 2. Note which leg has the colored band, what color it is, and its 4-digit alphanumeric code. The placement of the letter on the color band is important to note (example A123, 1A23, or 123A). [Note: martin bands used in other studies could have 1-4 digits]. In addition, observers of banded martins are asked to record the age and sex of the bird, the date and time of the observation, and the geographic location of the sighting. If you find a banded Purple Martin and can read the complete band, please call the Bird Banding Laboratory at 1-800-327-BAND, or go to their website at <www.pwrc.usgs.gov/bbl/>. Information from band reports provides valuable data on the distribution and movements of martins, their relative numbers, annual production, life-span, and causes of death. Such information increases our knowledge and understanding of martins and their habits, and assists in their management and conservation.

D. Miller lives in Sugarcreek, Ohio, and is a maintenance supervisor with Hiland Wood Products. In 2001 he hosted 34 breeding pairs of martins. Jonas M. Miller lives in Dundee, Ohio, and is a craftsman with Trailway Wood. He hosted 68 pairs of Purple Martins in 2001. James R. Hill, III, is Founder and Executive Director of the Purple Martin Conservation Association. He color bands Purple Martins in Ohio, Pennsylvania, and New York, as part of ongoing research projects.

D. Miller lives in Sugarcreek, Ohio, and is a maintenance supervisor with Hiland Wood Products. In 2001 he hosted 34 breeding pairs of martins. Jonas M. Miller lives in Dundee, Ohio, and is a craftsman with Trailway Wood. He hosted 68 pairs of Purple Martins in 2001. James R. Hill, III, is Founder and Executive Director of the Purple Martin Conservation Association. He color bands Purple Martins in Ohio, Pennsylvania, and New York, as part of ongoing research projects.


Copyright 1998 by Purple Martin Conservation Association. All Rights Reserved.

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