Jim: Thanks so much for asking these questions! The responses are very interesting, both from the standpoint of owl breeding biology, and from the aspet that we might enjoy their company this winter also. I hope they can find enough to eat here, and that we don't see as high a mortality rate as we did last year...
BTW: last night and this AM, I had at least two, possibly more Great Horned Owls calling near my house. I usually only hear them a couple of times during the year, usually at breeding season. This seems early for that, maybe they were just establishing territories... Fun to hear them, though!! Holly Peirson Forest Lake, Anoka Co. -----Original Message----- From: [email protected] [mailto:[email protected]]on Behalf Of Jim Williams Sent: Wednesday, November 09, 2005 8:49 PM To: MOU-net Cc: MnBird Subject: [mou] Great Gray Owls, remarks on 2005-2006 Today, I posed some Great Gray Owl questions to Dr. James Duncan, the Winnipeg owl researcher who also does work in Roseau County. Here is the exchange. Jim Williams Wayzata ==== Hi Jim, Good to hear from you. I attempted to answer your questions below in CAPS the best I can, recognizing that the information I am providing is not from the main MN owl invasion area. Things could be quite different there regarding great grays and meadow voles compared to Roseau County and southern Manitoba! Cheers, Jim ________________________________________ Dr. James R. Duncan, Manager Biodiversity Conservation Section Wildlife and Ecosystem Protection Branch Manitoba Conservation Box 24, 200 Saulteaux Crescent Winnipeg, MB R3J 3W3 Wildlife Web Site www.manitoba.ca/conservation/wildlife CDC Web Site http://web2.gov.mb.ca/conservation/cdc/ Can we expect the owls to return in numbers this winter? YES - OUR LONG-TERM WINTER DATA SUPPORT WHAT I CALL AN "ECHO EFFECT", IN WHICH THE ONLY SIGNIFICANT TIME SERIES CORRELATION IN WINTER NUMBERS OF GREAT GRAY OWLS FROM YEAR TO YEAR IS THAT IN THE YEAR IMMEDIATELY AFTER AN INVASION/IRRUPTION YEAR, THERE IS TYPICALLY HALF AS MANY GREAT GRAY OWLS AS THE INVASION/IRRUPTION YEAR. How did the owls fair on the breeding territories this spring and summer? Was their a normal pattern of breeding? Did the birds enjoy breeding success? NO GREAT GRAY OWLS NESTING IN THE NEST STRUCTURES I MONITOR IN MB AND ROSEAU COUNTY, MN, IN SUMMER 2005. How is the prey population for these birds, spring, summer, and present? I ONLY MONITOR SMALL MAMMALS ONCE A YEAR (OCTOBER) IN MY MB AND MN (ROSEAU COUNTY) STUDY AREAS, AND ONLY IN HABITATS WHERE GREAT GRAY OWLS ARE KNOWN TO HUNT. THE GREAT GRAYS IN MY STUDY AREA EAT >90% MEADOW VOLES, THEREFORE I AM COMMENTING ON NUMBERS OF THAT PREY SPECIES ONLY. THIS YEAR THE NUMBER OF MEADOW VOLES ON MY STUDY AREAS WERE STILL VERY LOW, BUT APPEAR TO INCREASING SLOWLY, A NORMAL PATTERN. I EXPECT MEADOW NUMBERS IN MY STUDY AREA TO BE MORE NUMEROUS NEXT YEAR, AND COINCIDENTALLY TO HAVE OWLS NESTING IN 2006. What other comments might you offer? THE RESULTS OBSERVED ON OUR STUDY AREAS SHOW A NORMAL CYCLIC PATTERN OF THE FLUCTUATIONS IN THE NUMBER OF BREEDING GREAT GRAY OWLS AND THEIR TYPICAL PREY, THE MEADOW VOLE. _______________________________________________ mou-net mailing list [email protected] http://cbs.umn.edu/mailman/listinfo/mou-net
