The Eagle Eye Winter 2015-2016

The Eagle Eye Winter 2015-2016 Bald Eagle Watching Days Set for January 15-16 Preparation for the 29th annual Bald presentations will be made. Frank at the River Arts Center Gallery form Eagle Watching Days (BEWD) is near- LaCour and his grandchildren will tell 8 a.m. to 3 p.m., staffed by representa- ly complete with a new birds of prey the story of Old Abe, the Wisconsin tives from the Bureau of Natural Her- show locked in for three shows on Jan Civil War Eagle. LaCour's family in the itage conservation and Ferry Bluff Ea- 15-16. Eau Claire area bought the young eagle gle Council. The Schlitz Audubon Nature Center from Chippewa Indians and then gave FBEC also will sell raffle tickets at of Milwaukee will bring its inter-active it to the local military unit preparing to the River Arts Center throughout the raptor show to the River Arts Center- go into the Civil War. Cathy Frasier, a day Saturday, with the drawing after for a show at 7 p.m. Friday, Jan. 15, Ferry Bluff Eagle Council member, 3:30 p.m. Prizes include a spotting plus two more shows on Saturday also will share some of her experiences scope and a pair of binoculars donated morning and again in the afternoon. as a chat room moderator for the Dec- as well as some framed pictures. Win- All shows are free and open to the orah eagle cam project. ners need to be present to pick up public. An eagle release by Marge Gibson their prizes at the River Arts Center on Joining the Audubon Nature Cen- of Raptor Education Group Inc. Saturday. ter on the program will be David (REGI) is being explored as well. Ea- A complete list of the program and Stokes, the highly entertaining and in- gle releases area always dependent on events is posted on the website and formative naturalist with his "Laughing the availability of rehabilitated eagles Facebook pages of the Ferry Bluff Ea- with Animals" show on Saturday and positive local conditions. If a re- gle Council. The website address is morning. lease is made, it will be at 1 p.m. Satur- www.ferrybluffeaglecouncil.org, or At the Tripp Heritage Museum on day at the VFW Park in Prairie du Sac. on Facebook search for Ferry Bluff Saturday morning, two small-venue Activities for kids will be available Eagle Council. include eagle habitat year round instead of just focusing on FBEC Mission Expanded To wintering eagles. The changes also give the Council flexibility Recognize Eagles Year Round to network with other wildlife oriented organizations and to address other bird species on special occasions. When Ferry Bluff Eagle Council was founded three Finally, the revision allows the Board to add or consoli- decades ago, wintering eagles were all that lived in the area. date committees, to accommodate the evolving needs of the The eagles came in December and left by March. That is no organization. A pilot study of a new set of committees will be longer is that the case. With the successful expansion of eagle conducted this year, with a final re-alignment coming in a territories across the state, eagles can be seen in the Sauk year. Prairie area all year long. At least a dozen eagle nests have The revised committee realignment will provide new op- been identified in the area, including a new one built this portunities for people to volunteer and become involved in spring across the river from Sauk Prairie. FBEC. Anyone interested should contact Mike Kierski, Recognizing the shift in eagle demographics, Ferry Membership Chair, at mkierski@exponent.com. Bluff Eagle Council (FBEC) revised its mission this year to 1 returning to a winter area likely means that birds will look in the same winter areas for food in subsequent years. Finding no food, they would presumably move on to search new areas. Finding food, they would presumably remain. This inference is similar to the argument made regarding food abundance and food availability. The difference is that philopatry refers to multiple-year importance of these pat- terns of change in winter habitats rather than changes that might occur within one year. FBEC had the good fortune to test this hypothesis of winter philopatry in eagles by teaming with REGI. The eagles that Marge Gibson rehabilitates are usually recovered from vari- ous places in Wisconsin and even farther afield in the Mid- Coming Home: What Resources west. After their recovery, however, Marge would release some of these birds in the Sauk Prairie area. In contrast, the Allow Eagles to Gather Here? eagles captured in the telemetry study were all captured in By Jeb Barzen Sauk City. The distinction between the rehabilitated eagles Over the past many winters I have mused on how food that Marge released in Sauk Prairie and the eagles that we abundance and food availability affect wintering eagles in the captured in Sauk Prairie is that the captured birds chose to be Sauk Prairie area. Today I want to briefly explore eagle be- in Sauk Prairie whereas the rehabilitated eagles did not. To havior that may interact with food abundance and availabil- REGI’s knowledge, none of the rehabilitated eagles had ity, but not directly and not immediately. Philopatry de- come from the Sauk Prairie area before becoming injured scribes an animal’s tendency to return home. In the case of and going to REGI. If philopatry was important to eagles wintering eagles, philopatry refers to the propensity of eagles we hypothesized that rehabilitated eagles released in Sauk to return to the same winter area repeatedly over many win- Prairie, in contrast to eagles captured in Sauk Prairie, would ters. FBEC research projects have measured eagle winter not have a high return rate in subsequent winters. philopatry in two interesting ways – through monitoring the For this experiment, we put radios on five of Marge Gib- frequency that eagles return to the same winter area that son’s eagles that were released in the Sauk Prairie area and they were captured in, and through an experiment done in tracked these birds during similar time periods as compared conjunction with Marge Gibson’s Raptor Education Group, to our captured eagles. In contrast to captured eagles, only Inc. (REGI). one of five rehabilitated eagles returned to the study area in In the FBEC telemetry project, 14 of 17 eagles that we cap- the winter subsequent to their release. The sole returning tured (81.4%) were tracked in the year they were captured bird was briefly detected in Baraboo and then not detected and during at least one subsequent winter beyond their capture again. Birds that were released in Sauk Prairie did not return year (Table 1). This is a very high return rate for eagles. If in subsequent winters. Philopatry is, therefore, an important any of our telemetered eagles died after they left Sauk Prairie behavioral mechanism to improve eagle’s efficiency of locat- before the next winter, this return rate would be even high- ing food in a variable environment and helps us to under- er. We only know of one eagle death during our study (eagle stand winter eagle ecology. An eagle’s tendency to return to 629-23482; Table 1), but recoveries of dead eagles are rela- winter areas that it knows also means that they are seeking tively rare. Interestingly, 10 of 17 eagles (58.8%) were important resources they require. Finding none, the birds tracked or detected in the Sauk Prairie study area at least two will choose other places to winter but not before exploring winters subsequent to their capture. Finally, 4 of 10 eagles the winter areas that are familiar to them. (40%) were captured and tracked for 4 years, their year of These results provide both good news and bad news for us. capture and for three subsequent winters. Only the 10 birds cap- The high degree of philopatry in eagles means that disturb- tured in the winter of 2002-03 could be tracked for the 4 ance that forces eagles out of a winter area can have a tem- winters of our study. No eagles skipped a winter using Sauk porary effect on eagles if the disturbance is stopped. Eagles Prairie (NT in Table 1), and then returned to the area that will return, if not in the same winter (should other environ- we could detect. mental conditions allow) then in subsequent winters. The Philopatry to winter areas by eagles is high but not 100%, bad news in these results is that, if disturbance continues especially when measured over several years. Ecologically, unabated among multiple years, eagles may abandon the area 2 altogether. How we approach disturbance can therefore be count results from this past winter (2014/2015: Table 2) not flexible within any one year but must also careful avoid only reflect that continued learning but they also reflect that more chronic disturbances that occur over multiple years. continued involvement by volunteers like you. If you have- n’t been able to get involved, now is the time to start! As always, your involvement is critical to improving our Counts for next winter (2015/2016) are: Dec. 6, 2015; Dec. understanding of eagles and how that knowledge can be 20, 2015; Jan. 3, 2016; Jan. 17, 2016; Jan. 31, 2016; Feb. 14, used for the conservation of these magnificent birds. The 2016; Feb. 28, 2016 2004-2005 Pre- 2001-2002 2002-2003 2003-2004 sent in Study USFWS Capture Weight at Age at Cap- Number of Number of Number of Area at Least Number Date Capture (kg) Gender ture Locations Locations Locations Once? 62923482 24-Jan-2003 4.68 Female 1-2 years NA 33 NT Found Dead 62923484 20-Feb-2003 3.91 Male 1-2 years NA 35 69 Yes 62923485 8-Mar-2003 3.12 Male 1-2 years NA 17 106 Yes 62923483 18-Feb-2003 6.15 Female Adult NA 39 139 Yes 62923471 8-Feb-2002 5.95 Female Adult 22 130 51 Yes 62923469 8-Feb-2002 4.28 Male Adult 45 81 NT No 62943498 31-Jan-2002 5.02 Female 3-4 years 15 23 2 No 62943500 31-Jan-2002 5.05 Female 4-5 years 15 8 7 No (No Antenna) 62943499 31-Jan-2002 4.62 Male 4-5 years 5 10 97 Yes 62943491 10-Jan-2002 6.35 Female 2-3 years 22 NT* NT No 62943495 17-Jan-2002 3.63 Male 1-2 years 9 4 NT No 62943496 17-Jan-2002 5.59 Female 3-4 years 13 NT NT No 62943493 17-Jan-2002 3.66 Male Adult 99 59 190 Yes 62943494 17-Jan-2002 4.59 Male 3-4 years 10 5 NT No 62943492 16-Jan-2002 4.22 Male 4-5 years 8 25 7 Yes 62944681 3-Feb-2003 3.97 Male 1-2 years NA 44 1 No 62923481 9-Jan-2003 4.45 Male Adult NA 55 35 Yes Table 1.

Load more