The Dark Female (Ginger/Lima) spend another night on the nest this evening.  Around 7:40 p.m. she circled the area of the hawk bench and then landed on the nest. 

My original hypothesis about this year’s nesting seems to be holding true.  I thought that the Dark Female, who was hanging around with a young hawk who she stole food from, didn’t yet have the hormones to bond properly with Pale Male in January. 

This allowed the Pale Female (Pale Beauty) to come in and try to bond with Pale Male later in the season.  But I think she was too young to lay eggs yet, so things didn’t work out.  She never seemed interested in the nest.  I believe this allowed the Dark Female, who was now more motivated to mate since the days were much longer, to move in and displace her.

Even though it was late in the season, I wasn’t concerned.  Triggers other than longer days must play a part in getting a female to ovulate.  This must include copulation, nest building, constant displays of food by the male, etc.  With help from other hawk watchers, we estimated that it would take three to four weeks for the Dark Female to ovulate from the date of her return.  It’s been sixteen days since the Dark Female returned, and now our timing estimates look like they might be correct.  I certainly hope so!

As the Dark Female begins to settle in, Pale Male has been introducing her to his full territory which includes the Beresford Apartments at 81st and Central Park West.  Pale Male eat and gave leftover to his new mate on the south tower of the building on Saturday.

As I came into the park, there was a wonderful rainbow over the east side.  Later, I followed the the dark female fron the “Woody” building to the Beresford Apartments.  In Lola’s favorite spot, it was like seeing a ghost. 

Sunday at Fifth Avenue seemed to be just like the last few days.  The only surprise was Pale Male’s roosting location, north of the Met!  He was on the Jackie O building before roosting.

On Friday, I posted a request for information about what triggers ovulation in a female hawk and what the logical time frame would be for the Dark Female to lay eggs.

Katherine Herzog and Pamela Langford offered some excellent insights.

Katherine reminded me that Pale Male and Lola usually started courting behavior around mid-February and nested in early-March, so they had about a four week window.

Pamela asked a biologist for my question.  The answer was that scientists don’t know all of the variables.  Certainly, time of year/daylight and food supply play a large part, but scientists also know other factors such as behavior play a part.  (Even less is known about what triggers a second clutch, when things go wrong!)

So, given all of what I know so far, I only think I can say that we shouldn’t be concerned if this new female takes up to four weeks to lay eggs or somewhere around April 22nd.  I could however be much shorter.  Bets anyone?

Saturday was typical of what has become the normal pattern at the nest.  Copulation, a shared late afternoon meal, chasing an intruder Red-tailed Hawk (whose identity is a mystery), and lots of nest visits primarily at this point by Pale Male.

The dark female and Pale Male continue to cement their relationship, as the photos below show. 

In the surprise that partners had switched yet again last week, I assumed that this new female was the Dec./Jan. mate based on my memory of how she looked.  I went back to old photographs tonight and video, and the hawks from the two periods are a close match.  But a perfect match?   I can’t say for sure.