Saturday, August 5, 2017

Temporary Role Reversals in Canada Geese and the Magical, "11-Weeks" Number

Two of the four Boat Lake goslings. Friendly little chaps.
Last photo of the Reservoir family just prior to them departing on the predicted August 2nd date.
Boat Lake goslings as one of the dads hovers in background.
Boat Lake goose families as one of the mothers is relegated to "sentry duty" on perimeter.

One doesn't need a calendar if a close observer of Canada geese.

When the Central Park Reservoir goslings hatched on May 8, I predicted to other park goers and goose admirers that they would be flying out of the Reservoir with their parents on the first or second day of August -- the precise time the goslings would turn 11-weeks-old.

Sure enough (as if the parents were themselves marking off a calendar), the family was long gone when I arrived to the Reservoir this past Wednesday on August 2nd.

As always, they did not bother to bid a fond, "Good-bye," or thank me for supporting them over the past 11 weeks. Nor did they tell me where they were going! (They like to keep such secrets close to the vest.)

The reason I knew the family would depart on week eleven, is because that is precisely what the parents have done for the past three years when raising healthy goslings. Eleven weeks also appears to be the magical number for other goose families observed over the years, though there has been one notable exception to that rule -- the Boat Lake geese. (More about them later.)

As in the past, I never witnessed the parents actually teaching their goslings to fly, nor did I see the goslings attempting to fly on their own.  However, in recent weeks I had noticed Hansel, the gander, hovering close to and spending far more personal time with the goslings (especially the one male) as his mate, Greta took on the more (usually male) vigilant role of chasing off other geese. (Greta was quite aggressive about it, too. Don't mess with Mother goose, as the saying goes!)

Apparently, as goslings grow, the male ganders ("Dads") have far greater input into their raising and training than initially thought. When small, it is the mother goose who is particularly close with her goslings, covering them with her wings and staying close to them at all times as her mate keeps vigilant watch, protects and wards off intruders. But as the goslings grow close to the age of flight, the parent geese appear to reverse roles, with Dad taking over training, flying lessons and discipline while Mom takes on duties of vigilance and protection.

This particular observation has not just been true for Hansel and Greta, but also the two Canada goose families currently at the Boat Lake in Central Park. Over the past couple of weeks, the two father ganders are usually seen close to and hovering over the goslings as the two moms skirt perimeters and keep watch for any possible threats. I have even seen one of the dads actually running off one of the mother geese as if to remind her of her "new duties."  

As previously noted, there are many "rules," regimens and protocols in the goose world and none are taken lightly. This, along with organization and family structure are the primary reasons Canada geese have such high survival rates.

As the four goslings (from two sets of parents) at the Boat Lake all hatched during the first couple of days in June, they are not due to turn eleven weeks until the last week of this month (August). 

However, I am not as confident in predicting the two families will take flight at that time as the parents of the two mothers (Man and Lady) tended to linger at the Boat Lake with their babies long after usual "departing" times.  I am speculating that because grass is plentiful at the Boat Lake and it is generally a safe environment for the geese, they could reasonably stay there until winter. Another reason for the uncertainty is because both female geese are "new mothers" with their first offspring, so there is no past history and timetable to go on. The two families may fly out later this month -- or they could linger until ice covers the lake in January. We shall see.

Meanwhile, all the geese who molted at the Reservoir this past June and July departed on schedule as soon as they grew in new flight feathers by mid July.  And Stumpy and Stanley also left Turtle Pond earlier this week. Geese are usually eager to take to the air once again as soon as they are able to.

It is now bittersweet going to the Reservoir and not seeing "my" goose family. They will likely not be seen again until next March when the family returns as a solid unit and a few weeks later, Dad runs the then-young adult goslings off to again nest with his mate.

All is ritual and baked into thousands of years of evolution.  

But, I would be greatly curious to learn when exactly the geese "figured out" that reversing sex roles during the goslings' early upbringing was the best way to ensure survival and assimilation of rules?

Did a daddy gander announce to his sweetheart one day, "Move over, honey. I'm taking over the raising and flying lessons for now!"

Nothing surprises about our marvelous and supremely intelligent and adaptable Canada geese!  -- PCA


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