West Coast Martin Trends 21 July 2000
by Stan Kostka (updated
top photo: Lynn Schmidt scoping for banded Purple Martins at Elk Plain, WA, July 2003, Bottom photo: Purple Martins using a multi-compartmented, eastern-style martin house in Elk Plain, WA; all photos by Stan Kostka
Several hours were spent this afternoon and evening observing an upland (450 feet) Purple Martin colony, in a residential area just beyond the eastern edge of the Fort Lewis Military Reservation. Elk Plain is about four miles southeast of Spanaway Lake, and roughly fourteen miles from the inland marine waters of the Nisqually Delta to the west, and Commencement Bay to the north. This site is unusual compared to most other Purple Martin colonies in Washington State. Being somewhat skeptical of the initial report, I contacted the property owner there who responded affirmatively to my repeated inquiry of "Are you sure they are Purple Martins?" Kelly McAllister of WDFW confirmed it a month ago, and posted the following observations to Tweeters online birding digests.
Subject: Purple Martins - an exception to the rule? 20 Jun 2000.The dogma is something like "Purple Martins in the Pacific Northwest nest in boxes or other cavities over interior marine waters or, less commonly, over lakes and marshes". I know that there are records of Purple Martins nesting (in the last decade) in more upland localities but they are pretty rare. Today, I visited a home in Spanaway (east of Tacoma)
where four pairs of Purple Martins are nesting in boxes on 4X4 posts in a backyard. There is a pond about 100 yards away and the area with the boxes is pretty wide open, mostly mowed lawn and vegetable gardens… a standard subdivision of nicer new homes on lots of probably five acres.
I watched some skirmishes between the martins and the Violet-green Swallows that are trying to complete their nesting cycle in boxes in the same yard. The two species don't seem to get along. For me, the sight of Purple Martins in this environment really blew my conceptions of suitable habitat conditions here. Maybe our martins are evolving to be more like their Midwest counterparts.
The martins have been coming to this location for 3 years. The homeowners are as surprised as anyone. Personally, I think that Fort Lewis, which is nearby to the south, has been producing so many martins from their successful nest box program that there were many birds returning to the general area just looking for new places to nest. So, a cavity in a wide open setting which allows lots of overhead space for patrolling, was good enough for these martins needing a home. I really think that nest box programs started in marine shoreline, lake or marsh environments are the most likely to be successful, but once the martins are established, lots of colonizers can be expected in areas that are less ideal but still offer a cavity in a wide open setting.
Washington Department of Fish and Wildlife
One month later, additional observations by Stan Kostka
Eleven martins were observed overhead at the site today (21 July 2000). At one time nine were perched on the nestboxes . Four ASY males, two ASY females, two SY males, and two SY females were identified. One ASY female is aluminum banded on the right. Five separate birdhouses with two inch round cavity entrances in single, duplex, four-plex, and six-plex configurations are more or less ten feet off the ground, which consists of mowed lawn with a few small trees and a vegetable garden. There are twelve cavities in all available with 2 inch round holes, and others with smaller holes for Tree and Violet Green swallows. Active martin compartments are each on separate poles and range approximately 45 to 150 feet from the two story residence, are 35 feet from a garden shed, 30 feet from a dog kennel, and 15 feet from the edge of a basketball court. Basketball games and lawn mowing reportedly disturbed the martins early on in the season and they left temporarily during these activities, but as of late they have been staying to watch some of the basketball games. Almost always the martins seem to come and go from the direction of the Fort Lewis Military Reservation.
Nestchecks today revealed four clutches of nestlings ranging in age from hatching day to ten days. All nests were receiving regular visits from feeding parents and several fecal sac removals were observed . No confirmed count of nestlings was made. Eighteen eggs numbering 4,4, 5, and 5 were confirmed before hatching began. Several unused nests have been built in adjacent compartments . The martins seemed to use apple leaves exclusively from one nearby sapling to line nests.
Some notes of interest concerning the martins nesting closest to the residence: A month ago the martins were in contest for this box with violet green swallows even though none of the four nestboxes had entrances large enough to accommodate a martin. At times the
investigating martins were driven down to the ground by the much smaller violet green swallows. At Kelly's suggestion one of those four holes was enlarged and subsequently the martins shared that four-plex with the violet greens, this in spite of the fact that another single nestbox was available further out in the yard . This contradicts the generally accepted notion that martins and violet greens will not nest in close proximity. Perhaps the nesting violet green swallows played a role in attracting the martins to this site. Also of interest is the fact that a small maple tree which is taller than this nestbox is only twenty feet away directly outside the entrance the martins are using, this in spite of the fact that the other single nestbox further out in the yard has a much more open flyway. This contradicts the generally accepted notion that martins require an open flyway, especially at new sites.
23 July 2000. The banded female was hand-captured today by Hugh Messer the owner and manager of this site. As suspected, she was born nearby and banded as a nestling on the Fort Lewis military reservation by Sam Agnew and Dave Clouse.
With purple martin populations on the increase along the north Pacific coast region due to nestbox programs in Washington, Oregon, and British Columbia, the birds seem to be expanding into areas with topographical and land use characteristics much different from where the remnant populations have traditionally been found nesting in recent decades, that is, the inland marine shoreline. Once again we are reminded here that the primary factor that determines whether or not martins exist and persist in any area is access to suitable cavities. And they have shown they will share those cavities in close quarters with other secondary cavity nesting swallows.
2001-2004. Nesting cavities were added each year, and the site now has about 20 boxes and 8 gourds. After remaining a four pair colony for 2001, the site grew each subsequent year, doubling to eight pairs in 2003, and exploding to 18 pairs in 2004. 2003 and 2004 were very good years for Northwest martins, with large increases recorded elsewhere in the region, likely due the unusually warm and dry spring and summer weather.
The nearby Fort
Lewis military reservation continues to support martins, both in nestboxes and
tree snags. Reports of snag nesters have increased in the past couple years.
The lowland prairie habitat on the fort experiences frequent wildfires resulting
from training exercises, and snag retention has been part of timber salvaging
there since at least 1985. Trees on these prairies hold the oldest martin
records in the territory, dating back to the 1850s.
58 nestlings were color banded at Elk Plain in 2004, and hopefully they will help answer an important question in Western martin conservation. Will nestbox fledged martins return and breed in snags ? Common sense says they would, since it is known that martins do not absolutely imprint on cavity type. However, Purple Martins certainly seem imprinted on artificial cavities in their Eastern range, where natural habitat exists, but martins do not use it at all. Here in the Northwest, populations have increased following the introduction of nestboxes and gourds in the past few decades, but the overwhelming majority of martins now use these artificial cavities, often in very close proximity to humans. As the popularity of providing housing for martins increases in the Northwest, will snag nesters go the way of the Dodo, as they have in the East ?
There are currently no reports or records of banded (nestbox fledged) Purple Martins using tree snags. Hopefully that will change in 2005.
Stan Kostka 2004