Date: 12/24/18 7:31 am From: Bill Volkert <billvolkert11...> Subject: [wisb] Re: Canadians - what do they know?
Sandy: Sorry to provide such a lengthy answer to your question, but watching Canada geese for well over 30 years at Horicon Marsh and working with the very people who studied them so intensively in order to resolve management issues, I have learned a lot about these birds and often find it hard not to go into some detail about their behavior and life history. So here is a long way of answering why these birds may be flying south at this time.
Canada geese are very winter hardy birds. I have seen them standing on the ice at Horicon Marsh at temperatures well below zero. Like most birds, its not the cold that forces them to fly south, but what the cold brings with it; frost, snow and ice. This is what either eliminates the food supply (such as frost killing insects or forcing them into dormancy), or limits access to food as with snow and ice. Geese will remain, for the most part, as long as there is a lack of snow. Ice can also be a factor since it allows the coyotes to chase after geese while they are roosting, but as long as we have less than about 4 to 6 inches of snow Canada geese can find plenty of food.
I recall the Horicon Marsh CBC's, which I participated in or compiled between 1976 and 2010, varying between no geese in years when we had 12 to 18 of snow and one particular year when we still had 124,000 geese on the marsh. There always is a cohort of geese that tends to move before the winter weather forces them south while others stay as long as they can. The first migrant geese usually arrive at Horicon between September 15 and 20. The fall weather usually isn't that severe in the sub-arctic at that time to force them south, but these birds seem to leave in anticipation of the coming snow. We usually hit peak numbers around the end of October to early November, but this can vary from year to year. This is when snow accumulates on the nesting ground and forces the remaining birds to fly south.
Likewise, the migrants will usually begin to depart around early to mid-December no matter what the weather while others will remain as long as they can - until we have a good snow cover. I often was asked by visitors why they were seeing geese fly north in October and November when it was the fall migration. I would explain that true migration is not regularly observed and tends to occur with the passing of cold fronts. Geese will be observed thousands of feet up and at times may be so high that people might not even notice them. However, the flocks that stage at places like Horicon Marsh will remain for weeks or even several months and use the marsh only as a roost site. They fly out each day to feed and may go in any direction to find food, so this is not an indication of migration.
When geese are making daily feeding flights they usually fly between 100 and 500 feet high. The farther they are flying from one site to another, the higher they will fly. However, when geese are truly migrating they will fly 2,000 to 5,000 feet high, depending on favorable winds, and have been recorded flying as much as 10,000 feet up. (as an aside, the bar-headed goose of Asia flies over the Himalaya Mountains every year and is regularly observed at 25,000 feet or more. Canada geese also could probably fly that high, but our landscape doesn't demand that).
I am guessing that you were probably watching birds making their daily feeding flights, but there also is a chance that some of the birds simply decided that the weather would eventually turn and without any particular reason headed toward Illinois. This, of course, would be determined simply by how high they were flying (hundreds of feet, or thousands of feet high). The geese that stage at Horicon Marsh nest in the lowlands around James and Hudson Bay and winter in southern Illinois and western Kentucky and Tennessee, around the confluence of the Ohio and Mississippi Rivers. In years of mild winter weather some geese will stay at Horicon or simply move to southern Wisconsin or northern Illinois. Basically, many of these birds fly only as far as they need to and I have watched flocks of Canada geese remain at Horicon until the last opportunity and head south with the passing of a severe snowstorm. The numbers that arrive on the traditional wintering grounds in southern Illinois varies with the winter weather in Wisconsin. For many years I used to receive phone calls from hunters in southern Illinois and in particular on person in St Louis who would inquire about our weather and goose counts so that would know if these birds were still in Wisconsin or would be heading their way.
There are so many aspects to the lives and behaviors of Canada geese, as with any other species of birds. Fortunately, these birds have been well studied and we have a fairly good understanding of them which is why we have been so successful in managing Canada geese. I hope this answers your question and hopefully a few others, or at least puts this into context, even if I took the long way around to answering it.
Thanks for your question.
Bill Volkert FdL Co.
On Sat, Dec 22, 2018 at 1:02 PM Sandy Petersen <buboarcto2...> wrote:
> Hi all! > About 1230 pm today, 750+ Canada geese > heading directly south > in many odd V-shapes across the sky > proclaiming something very loudly ... > > Weather predictions all week are about the same as today ... > right around freezing > so what has motivated them to move on??? > > Sandy Petersen, rural Dane co > > > #################### > You received this email because you are subscribed to the Wisconsin > Birding Network (Wisbirdn). > To UNSUBSCRIBE or SUBSCRIBE, use the Wisbirdn web interface at: > http://www.freelists.org/list/wisbirdn > To set DIGEST or VACATION modes, use the Wisbirdn web interface at: > http://www.freelists.org/list/wisbirdn > Visit Wisbirdn ARCHIVES at: http://www.freelists.org/archives/wisbirdn > > >