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09 October 2009

Autumnal Martin Migration Remarkably Different in 2009 at Omaha

The southerly migration of Purple Martins through midtown Omaha was remarkably different in 2009 compared to 2008. Gathered martins were noted by the end of June, the numbers peaked earlier when there were a few thousand more than the peak count in 2008, the counts of thousands occurred earlier and the birds were completely gone at least two weeks earlier.

There was no apparent reason for the differences. The dichotomy of the two years influenced the people watching the martins, but as for what it indicated for the martins is not known.

Birds on the Wires

The clue to finding the roosting of the martins was once again based on noting species in the skies while looking for Chimney Swift activity at a couple of magnanimous and appreciated chimneys along Izard Street at 43rd Avenue. The swifts were present in the evening using a prominent chimney, and while lingering in the area, martins were noted. As there aren't any breeding facilities for the purple birds, there was an inclination to check the roost locality for any activity a couple of days later.

There were hundreds of birds gathered on the power lines just south of Dodge Street, and just west of 40th Street, a locale a block or two northeast of the roost site utilized in 2008. Once the martins were known to be present, further visits were made to determine numbers and any particular habits.

The rest of the season flew along. The first birds were counted as they gathered along the power lines. In latter July, the first action at the roost site was documented. By the end of the month, the martineers had gathered - these being Dennis Devine, Justin Rink and myself - to observe the situation.

This basic pattern continued for the next few days, with a constant bunch of people appreciating the activities of the martins as they gathered in the aerial realm and then swooped into the trees at the roost along 44th street, just south of Farnam Street, on the campus of the Nebraska Medical Center.

Towards the end of August, a reporter for the local newspaper was present, taking notes and then arriving again to get notes for a story. When a photographer arrived on August 31, there was a lesser number of martins, but Kent Sievers was able to use his horde of equipment to get a couple of pictures used in an article published in the Omaha World-Herald on September 2nd, with a headline of "A purple blizzard" describing the birds' antics as appreciated by observers, appending a bunch of generic details for roosts as known for other roosts in the eastern United States.

The front-page story brought more watchers, with 25 counted on the evening when the story was featured. These numbers continued, with Justin Rink present each evening to inform people about martin behavior and to answer any questions which may have arised.

By September 9th, the birds had moved their primary roosting a bit to the north. This caused some confusion to the "martineers" as it seemed to indicate that the birds had perhaps moved elsewhere. When the birds started to prefer the trees along Farnam Street, efforts were taken to look around the area to see if they were using other trees. There was no other roosting site found, and eventually it was understood that the gathering had just decided to shift northward.

The trees along Farnam continued to be the primary roosting site for the rest of the time when martins were present.

2009 Autumnal Season

Martins were present at the midtown roost area from June 29 to September 13, 2009. This is a summary of the dates when the number of martins were specifically noted, with ancillary notes. Each count is based on personal observations, with important assistance in determining numbers provided by Justin Rink, for the August 17th count, and subsequent dates.

Date

Number

Species Notation

06/29/2009

600

roost activity done at 9:30 p.m.

06/30/2009

600

roost activity done at 9:30 p.m.

07/01/2009

750

roost activity done at 9:30 p.m.

07/04/2009

500

a basic count of the birds on the wires

07/21/2009

1000

to start, group of 150 on wires; extensive swarming by 9 p.m. with peak for next ten minutes

07/24/2009

1500

7-800 on wires; overall ca. 1500 soaring and flying about at 9 p.m.

07/25/2009

2000

several hundred on wires; then bunches at roost action

07/28/2009

5000

ca. 1000 on wires; then bunches at the roost trees

07/31/2009

7500

number noted with Rink and Devine - the three martineers

08/03/2009

10000

during the evening visit to watch the birdly activities

08/17/2009

25000

this number or more; peak 8:15 to 8:45 when it was all finished

08/20/2009

25000

flocking started at 8:19 p.m.

08/23/2009

25000

approximate number flocking at 8 p.m. - done by 8:35; 14 adults watching; carcasses of 36 dead noted; one injured noted, present previous day; two strikes; couple of others bounced off walkway

08/24/2009

22500

15 watchers, including reporter for local newspaper; mostly done by 8:30; about a half-dozen bunches of 15-20 birds straggled in after this time

08/27/2009

30000

12 watchers; swarming at 8:08, with sunset at 8:06; four strikes - two known fatalities; one dead carcass at Saddle Creek and Farnam in the morning

08/28/2009

40000

three watchers; 11 skywalk strikes; two dead in streets; what a maelstrom of martins

08/29/2009

35000

10 watchers; 12 dead under trees; done about 8:20 p.m.; cat arrived a bit of time later

08/30/2009

17500

approximate count, as there certainly were fewer birds; 13 watchers; flocking ca. 7:55; basically done at 8:20; one dead due to strike

08/31/2009

8000

seven watchers; one OWH photographer; two martineers; 2-300 at 7:32, arriving earlier than usual; done by 8:15; two dead under trees

09/01/2009

12000

nine watchers including one from West Virginia that came with a friend; two martineers; only 1/4 of number noted in sky used the usual roost; done by ca. 8:10 pm

09/02/2009

12000

more than 25 watchers due to news article; two martineers; survey number based on an aerial estimate, and ca. 1/4 of this number noteably seen to use the 44th street and Farnam street trees; despite biking about, no other roost locality located

09/06/2009

8000

approximate number given as 8-10000; more than 25 observers counted at the scene

09/09/2009

1200

count on a clear evening; very little martin activities to observe; watchers: 13 adults with 2 young childs; three martineers; birds roosting along Farnam Street

09/10/2009

200

seven watchers, two martineers

09/13/2009

5

going easterly; eight watchers hoping for thousands, and two martineers

The profound situation of the gathered martins was a migratory spectacle consistently enjoyed by numerous watchers, and was readily compared to the spring migration of Sandhill Cranes along the Platte River. It should be noted that watching martins was much easier and more comfortable than trekking to a some riverside place, as in midtown Omaha, it was a so simple matter of driving to 44th street, parking and then walking a few hundred feet to a spot suitable for watching. Some of the regular watchers brought along a lawn-chair so they could sit while observing.

Julian Date

2008

2009

180

na

600

181

"

600

182

"

750

185

"

500

202

"

1000

205

"

1500

206

"

2000

209

"

5000

212

"

7500

215

"

10000

229

"

25000

232

"

25000

235

"

25000

236

17500

22500

237

17500

-

238

18500

-

239

-

30000

240

-

40000

241

-

35000

242

25000

17500

243

-

8000

244

-

12000

245

-

12000

246

35000

-

249

-

8000

250

15500

-

252

10000

1200

253

-

200

254

12500

-

256

10000

5

257

7500

-

258

1100

-

259

1100

-

260

7500

-

261

1000

-

262

1000

-

263

1000

-

264

1000

-

265

500

-

266

500

-

267

500

-

268

125

-

269

65

-

270

65

-

271

5

-

Comparing 2009 to 2008

Hundreds of martins were noted in 2009 more than 50 days prior to the discovery of the roost activity in 2008.

The peak in the estimated number of martins was six days earlier in 2009, when ca. 40,000 martins were present on August 28th. In 2008, the peak number present was September 2nd.

In 2009 - when there were still several thousand present in 2008 - numbers were already decreasing and only a couple of hundred or fewer were present.

Martin watchers were disappointed because of the variance in when martins were present. On days when last year there could have been thousands of birds, there were very few present in 2009, and although people enjoyed seeing any activities, the flight behavior conveyed by the multitudes could not be appreciated. It was the aerial antics which were most enjoyed by the people which gathered on the sidewalk to watch.

There is no known reason for the dramatic differences in the roosting schedule when comparing the two years. Clues may become apparent if information on an additional season of roosting can be documented.

Martin Fatalities

There were half-as-many known occurrence of martins striking the glass exterior of the Kiewit-Clarkson skywalk or south Kiewit-Clarkson skywalk in 2009 as there were in 2008.

Date Located

Aug 2008

Sep 2008

Jul 2009

Aug 2009

07/25/2009

1

08/01/2009

1

08/23/2009

3

08/23/2008

4

08/25/2008

5

08/26/2008

3

08/27/2009

4

08/28/2009

12

08/28/2008

3

08/30/2009

1

09/04/2008

5

09/05/2008

1

09/07/2008

4

09/08/2008

8

09/09/2008

3

09/13/2008

9

The first instance of a martin mortality was on July 25, 2009. This was on a Saturday, and reported to officials of the Nebraska Medical Center on Monday. A followup contact was made on Tuesday, and by Friday, banners and decals meant to make birds aware of the glass had been put in place along the north skywalk

There were subsequent strikes in 2009, especially on August 28, when the peak number of martins was present. Of the dozen instances, eight resulted in mortality with the others temporarily disabled. When the disabled birds were noted, and as appropriate, the birds were moved from the street beneath the skywalk so they could recover in a safe place and then fly away when they were ready to do so.

In some cases, the strikes were only a brief impact and the birds were stunned for a short time, and were able to continue along, despite a fall to the ground from the elevated skywalk.

The predominant feature for the strike situation was that officials of the Nebraska Medical Center reacted with a few days to the report of mortality on Monday, and by Friday had put in place banners and decals that would address the situation.

This reaction is unique in how officials in Omaha have addressed being informed of deadly bird strikes at their buildings.

Martin Appreciation

The martin mecca midtown has been appreciated by a great number of people during the past two years. Personal reasons for visiting the roost site may vary, according to comments heard during the watch season, but it is obviously the wonderful natural display given by the birds that is the attraction.

Martin enthusiasts at the midtown roost, September 2009.

The autumnal migration of the species is a unique facet of migration along the Missouri River. It provides a special and comfortable time to watch a bunch of birds and enjoy a dramatic spectacle that is unique for the central Great Plains. No where else in the state of Nebraska, or Iowa or other adjoining states is their such a huge roost of martins which gather in the autumn - ignorant of any human considerations - but which none-the-less provide so much for passive watchers to enjoy and ponder.

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