Golden Eagle 42 Release

Telemetry: Bird 42

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Background and Release

Golden Eagle 42 was accidentally caught in a leg-hold trap November 6, 2008 in western Wisconsin and suffered leg injuries. After treatment at the University of Minnesota Raptor Center, we banded him and attached a satellite monitored radio (PTT) in order to monitor his migratory movements, determine his summer breeding area, and learn more about how he uses the Mississippi River Valley during the winter. (Read more about the Golden Eagle Project.)

Update maps on the eagle's roost sites are provided below. To see all the roost sites on an interactive Google Earth map, click here. (You will need a recent version of Google Earth to view this file. Download Google Earth for free.)

UPDATES:

Jan. 21, 2010 Map (PDF, 3 MB). It has been a few weeks since I last checked in with you and eagle42 apparently resented being ignored as he moved out of northern Trempleau County. On Jan 7 he started heading towards the Mississippi River and from the 8th through the 19th was around the City of Winona. He used the same woodlot for roosting on more than one night. On Jan 11 he crossed the river and spent the day in Minnesota. The past 2 evenings (Jan 20, 21) he has been roosting just outside Fountain City, WI.

Dec. 23, 2009 – Jan. 6, 2010 Map (PDF, 2.99 MB). Golden Eagle 42 has continued to focus his time in northern Trempleau County in the area around Independence, Arcadia, and Whitehall. His evening roosts shift from day to day but there seems to be a few favorites he does come back to. His movements during any given day also do not wander greatly from the roost areas. Woodlots and the valleys that cut through this part of Wisconsin are his favorite haunts.

Dec. 11–22, 2009 Map (PDF) – Golden 42 remains in northern Trempleau County, Wisconsin, were he has been since November 29. Since my last message he has not moved a great deal. He spent Dec 11 – 14 hanging around a small valley about 5 1/2 miles north of Independence, WI. On the 15th he moved about 6 1/2 miles to the west using another small valley until he moved a short distance to the SW on the 20th near Whitehall, WI. The past 3 days have found him moving around the area. A serious winter storm is expected to hit the area for the next 3 days, and it will be interesting to see if and how that affects him.

Dec. 5–10, 2009 Map (PDF, 2.14 MB). No big changes for Golden Eagle 42. During this time he was moving around the northern half of Trempleau County, Wisconsin. On Dec 5 he was just south of Strum and on the 6th near Pigeon Falls. The distances between his evening roosts were between 2 – 12 miles in any successive days. His evenings have been spent in or at the edge of woodlots. Maybe he is settling down for the winter.

Nov. 24–Dec. 4, 2009 Map (PDF, 2.12 MB). November 24 and 25 found Eagle 42 roosting in west central Dunn County, Wisconsin in the same woodlot he used on the 23rd. On Nov. 26 he moved 41 miles south to Buffalo County, WI and spent the 27th and the 28th near Nelson, WI using woodlots on the bluffs above the junction of the Buffalo and Mississippi Rivers. On the 29th he moved again, this time 25 miles west to the northwest corner of Trempleau County, WI. The evenings of the Nov 29–Dec 4 found him roosting in various woodlots no more than 8 miles apart in that part of Trempleau County.

Nov. 23, 2009 Map (PDF, 2.94 MB). Eagle 42 used the same woodlot for roosting from Nov 12–19. There was little daily movement from the are and it would seem that the deer carcasses in the corner of the lot are keeping him tied closely to that spot. On the 20th he roosted about 1 mile north and then moved another 10 miles N/NE on the 21st. He roosted for 2 evening in a wooded area in western St. Croix County and on the 23rd was about 1 mile S/SW in eastern Dunn County.

Nov. 11–17, 2009 Map (PDF, 2.83 MB). It appears that our eagle has found a place he likes. On Nov. 11 he moved 13 miles north into Dunn County. On the 12th he found a spot about 3 miles west of Menomonie, WI where he basically remained through mid-day on the 17th (which was the last data point we received). His evening roosts were all at the edge of the same field with the exception of the evening of the 14th when he roosted about 1 mile to the SW. Daytime tracking data shows him moving about although not any great distance. It appears that he has found a good source of food and has had no reason to move on. On the Nov. 11-17 map note that the location marked Nov 12 includes all his locations through the 17th with the exception of the evening of Nov 14.

Nov. 11, 2009 Map (PDF, 2.99 MB). Eagle 42 remains in western Wisconsin. After his return on Nov. 2 he moved to a spot in Trempealeau Co., where he hung out until the 7th. He moved about 5 mi to the SW and then on the 8th he went north about 35 miles into Dunn Co. As of last night he had moved a bit south into northern Pepin County.

Nov. 1-4, 2009 Map (PDF, 2.88 MB). He may be back on his wintering area! A 62 mile jaunt on Nov. 2 took our bird into Buffalo County, WI. On the 3rd he moved 21 miles to the NE, over the spot we released him in March and in the late afternoon settled in to a wooded area about 7 miles north where he remained through Nov 4.

Fall Migration 2009 Map (Oct 6-Nov 4) (PDF, 2.9 MB)
Google Earth Map

Golden Eagle 42 began his southward journey on October 7 covering 1,136 miles (1828 km) between Oct 7 and Oct 16. His daily travels (straight line between evening roosts) varied from 14 to 170 mi/day with a mean of 114 mi/d (183 km/d). During this leg he did not retrace his spring path but basically took a compass heading south. He slowed his southward journey quite a bit between Oct 17 – 20 traveling 127 mi (204 km) over those few days. He jogged east about 75 miles on the 17th, went about 70 miles south and then corrected his path traveling west on the 20th. As a result his actual southward progress was around 75 miles during this period. At this point he was about 200 miles north of the Minnesota/Canada border. He picked up the pace on the 21st and 22nd covering 226 mi (364 km) and spent his first night in MN, Oct 22, roosting on a bank of the Little Fork River about 3 mi. southeast of Little Fork in Koochiching Co.

The next 8 days (Oct 23-30) were spent in Minnesota travelling through Koochiching State Forest, the Chippewa National Forest, south of Hibbing and the down through Itasca and Aitken Countis. He roosted in or on the edge of wooded areas adjactn to bogs, fields, and woodlots. His total travel during this time was 168 mi. (270 km) which he covered at an average speed of 21 mi/d (34 km/d). He crossed into Wisconsin on Oct 31 from Pine into Burnett County. A 62 mile jaunt on Nov. 2 took the bird into Buffalo County, Wis. which ended his fall migration. The total distance covered during this migration was 1,750 miles (2,816 km) and took 26 days. His mean distance traveled per day was 67 mi (108 km) and ranged from 0.5 – 170 mi/d (.77 – 273 km/d)

Summer Migration 2009 Map (May 29-Oct 6) (PDF 2.54 MB)
Google Earth Map

The starting date of the summer period is somewhat arbitrary. There is no indication that the bird settled on a breeding territory so we have chosen the last part of May when his progress north slowed down considerably. Over the summer he made a series of moves north and west settling into various home range areas for periods of time before moving on.

Evening roosts from May 29–June 2 were all on Bibby Island on the western shore of Hudson’s Bay. His roosts, while different each evening, were no more than 1 – 1.5 miles apart between days. He left Bibby Island on June 2 traveling NW away from Hudson’s Bay then turned north on June 3 and headed in a northerly direction paralleling the western shore of Hudson’s Bay between approx. 62.1 to 64.4 lat. through June 9 covering 237 mi (382 km) most of it on the 7th, 8th, and 9th.

The evenings of June 9-24 were spent in an approx. 370 sq. mile area on a large peninsula on the west shore of Hudson’s Bay in Nunavut, Canada. He changed roosts every evening. On June 25 he moved 58 miles (94.5km) north and began to slowly travel to the west. From June 26–July 9 he moved 105 miles to the west in a slow, wandering path west of Wager Bay (an inlet of Hudson’s Bay). This put him above 66 degrees north.

On July 10 he made a 62 mi (100km) jump W/NW to an area in the Kitikmeot region of Nunavut, Canada. From July 10-16 he used a 30 mile stretch of a large river (Back River?) which drains into Franklin Lake. On the 17th he started moving north and by the 19th of July he was around 66.9 degrees north, near Franklin Lake which put him above the Arctic Circle. He spent the rest of the summer roosting within 20 miles of Franklin Lake except for a short trip back to the Back River area from Sep 11–13. He left on fall migration on Oct 6.

Spring Migration 2009 Map (Apr 26-May 29) (PDF, 2.79 MB)
Google Earth Map

The beginning and end dates for “spring migration” are a bit arbitrary. We have a couple of days of missing data (not sent by the PTT) on the front end, and since he did not appear to nest I cut off migration when he reached a northerly point on Hudson’s Bay when his daily distances slowed down dramatically. His travel during this period measured straight line between evening roosts was 2,382 mi. (3,832 km) for an average of 72 mi/d (116 km/d).

On April 26 he was near Duluth MN, and then true to form, he headed south and spent the evening of the 27th in Barron Co. Wis. before turning west and then north the next day. He traveled through north-central Minnesota (Itasca and St. Louis Counties) and crossed into Ontario on May 1, flew west to near St. Ignace Island on the north shore of Lake Superior and turned north at that point toward Hudson’s Bay on May 3. From April 28 – May 2 he covered 489 miles (786 km) at an average of 97.8 mi/d (157 km/d), range 12-157 mi/d (20-253 km/d).

On May 3 he traveled 193 mi., the most of any day during spring migration, crossing the tree line and continued moving north over the tundra. From May 3–6 he traveled a total of 447 miles (720 km) and on May 6 arrived at a point parallel to the top of James Bay. On May 7 he headed west and moved north again on the 8th and continued moving north parallel with, but not always near, the western shore of Hudson’s Bay. He arrived near Bibby Island on the western shore of Hudson’s Bay around May 27 at which time his daily movements slowed down considerably. It is at this point on May 29th that I have concluded is the end of spring migration.

Winter 2009 Migration Map (Mar 25 – Apr 26) (PDF, 2.95 MB)
Google Earth Map

He was released, and our tracking began on, the afternoon of March 25. He immediately began moving north and by March 28 was in northern Chippewa, Co, WI. At that point he turned around and headed back south toward his release site on March 29th and spent the next 6 days in Buffalo Co, WI including some time near the Mississippi River. On April 5 he headed further south traveling about 30 miles a day and ended up near Lansing, IA on April 8 at which point he again turned around and the next day headed back north. At this point we had cause for concern. The transmitter sent signals until about mid-morning April 10 indicating the bird was in Houston County, MN. No further data was transmitted until April 14 and showed the bird to be in the SW corner of Dunn County, WI. The transmitter continued sending data but for the next 3 days it indicated no change in location. This usually means the radio fell off or the bird was unable to move.

On April 21 we conducted a ground search of the area where the signals originated. Searchers included Scott Mehus and 12 volunteers from the National Eagle Center, Jess Carstens, WI DNR, and Patrick Auth the landowner. A very thorough search turned up no sign of the eagle or the transmitter. We did however find a well picked-over deer carcass with raptor feathers and droppings nearby. It is possible that the eagle was feeding on this carcass for a few days, thus accounting for the signals all originating from this site. In fact, the bird had begun moving on April 18 into northern Dunn County and then back south into Buffalo County.

Between April 23–26 (we have no data for that period) he moved north about 128 miles to a point on the WI/MN border about 13 miles outside of Duluth where he was on the evening of April 26.