13 November 2017

Chronology of Autumn Turkey Vulture Movement at Valentine

Turkey Vultures are a common summer resident in the vicinity of north Valentine, and the number present increases as fall migration occurs. By mid-summer of 2017, there were more than 100 that would congregate in tree snags at the western extent of Government Pond, immediately west of the Valentine Fish Hatchery.

From mid-September through early October, once the vultures left the roost in the morning, a group of them would soar westerly along the ridge of the Minnechaduza Creek valley. With their regular occurrence, several days were spent recording how many vultures were seen and the time of their occurrence. Details were also occasionally kept on local weather conditions, notably temperature, wind speed and its direction.

Information was derived from 88 records of observation as designated to a particular 15-minute period of time (i.e., all records between 10:30 to 10:44 within period for 10:30) for the same vantage point a bit more than one mile westward of the vulture night roost. Birds were denoted when they passed a particular line of demarcation of the landscape. A few of the records were associated with the nearby Valentine Mill Pond and the city of Valentine.

Regarding general bird movement, for most of the morning observations the vultures were going westerly. Those associated with late day times were going easterly, likely returning to the roost site.

In general, vultures would not occur until after 9 a.m. When there were windy conditions early in the morning, there would be vultures earlier than on calm days. If there had any precipitation or extensive dew, the vultures would also be seen flying at a later time.

These are a couple of examples of details associated with sightings of a greater number of vultures on a particular morning:


  • 09/27/2017: one soaring westerly at 1004
  • one soaring westerly at 1009
  • three soaring westerly at 1012
  • two soaring westerly at 1024
  • one soaring easterly at 1042; a bird returning easterly was not typical for the morning observations
  • one seen at 1110; calm winds with a few wispy clouds; temp at 59o
  • one at 1141 soaring above in slight winds less than 5 mph

Since an overall tally for a period of time was not determined, the difference in birds going westerly or easterly does not influence the extent of overall occurrence numbers as that particular detail was not determined.

  • 09/29/2017: ten in an obvious bunch moving westward above the pine-clad ridge; northeast wind at 6 mph, temp 54o and partly cloudy; the ten occurred at ten at 1004 and then another one at 1008 a.m.

Later in the day, there was a flock of 27 seen at the North Park Ridge, a prairie area just to the north of the roost site. Notations indicate: at 1640, soaring above the hills with some others above the heart city; what a magnificent sight; sunset near 7:30 p.m.

This is an example of a sightings on the morning of October 1st:

  • three at 9:45
  • one at 0950
  • three at 9:54; going westerly; at 10 a.m. 62o, winds ssw at 12 mph with gusts up to 18 mph
  • six soaring about above the ridge at 1008
  • one at 1010
  • one at 1012
  • two at 1017
  • two at 1020

The records kept indicate that the vultures set flight and were moving in small groups and from 915 to 1045 a.m.

Daytime Chronology of Turkey Vultures at the North Lake Shore Hills and Valentine
Time of Day 9/17 9/19 9/20 9/21 9/22 9/24 9/26 9/27 9/28 9/29 10/1 10/3 10/4
815 - - - - - - - - - - - 2 -
900 - - - - 3 - - - - - - - -
915 - 7 - 12 2 - - - - - - 1 -
930 - 6 - 5 - - - - - 1 - - -
945 - 5 - 2 - - 2 - - 6 8 - -
1000 - 1 5 3 - 1 1 5 2 11 8 - -
1015 - - - 3 - - - 2 2 - 4 - 1
1030 1 1 1 2 - - - 1 13 4 - - -
1045 4 3 - - - - - - - - - - -
1100 2 - - - - - - 1 - - - - 1
1130 - - - - - - 8 1 - - - - -
1300 - - - - 1 - - - - - - - -
1330 5 - - - - - - - - - - - -
1430 2 - - - - - - - - - - - -
1600 - - - 10 - - - 2 - - - - -
1615 - 2 - - - - - - - - - - 1
1630 - - - - - - - - - 27 - - -
1645 - - - - - - 1 - - - - - -
1700 - - - - - - 1 3 - - - - -
1730 - - - - - - - 1 - - - - -
1815 - - - - - - 1 - - - - - -
1830 - - - - - - 2 - - - - - -
1915 - 1 - - - - - - - - - - -

With only a relatively lesser percentage of the vultures noted going westerly along the Minnechaduza valley ridge, obviously many of the vultures went elsewhere. On occasion they could be seen going southwesterly. The destination for others is not known.

If there was one mystery for the breeding season occurrence of a few vultures and then the migratory season congregation, what did they eat? The carcass of a fox was placed at a spot visible to the soaring vultures, but it was never even visited.

Most of the roost trees used by the vultures are pine tree snags that are the result of a wild fire in 2012. The extent of these trees has decreased through the years as the trees rot and eventually fall to the ground. Eventually the snag trees now present will be gone so the vultures will have to find an alternative roosting site.