Courtesy of Rochester Falconcam team member Carol Phillips comes this dispatch from Doug, one of Freedom’s “caretakers” at his nest site in Port Colborne, Ontario Canada:

I just thought you would like to know that Freedom & his new mate [Millie] have 2 eggs in the scrape! They were laid on the 7th & 9th as best we can tell. We have our fingers crossed that they will in fact be viable. Mom & Dad are tending nicely to the eggs…..Doug

You may recall that we recently reported the news of a new mate for Freedom. It is unusual, though not impossible, for a first year female to lay viable eggs, so we’ll be eagerly awaiting further news from the Port Colborne nest site.

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Meanwhile, Linda Woods of the Canadian Peregrine Foundation sends this fantastic image of Rhea Mae as she settles down to brood her four eggs.

Thanks to Carol, Linda and Doug for the updates!

-Jess

Brooding appears to be well under way now. Since April 5, Mariah and Kaver have been sitting on the eggs almost full time. Unless Mariah has another “106 hour egg” waiting in the wings it seems that we have another 5-egg clutch. Based on what we’re seeing, we think hatching should take place sometime around Mother’s Day, a most appropriate time!

Last year we talked about incubation, so now is probably a good time to go back and read that article if you’ve forgotten about the process. In that article we mentioned the fact that Mariah and Kaver have to turn the eggs so that they get evenly heated. This is very important for proper development of the growing eyas. The pictures at the left demonstrate how the falcons turn the eggs. It’s a delicate process that Mariah and Kaver approach with a gentleness and dexterity that can be surprising to witness.

Sometimes we hear from viewers who think they’ve seen an egg with a crack in it. The mottled pattern of the eggs, tricks of light in the nest box, and the image quality from the cameras can all contribute to what look like cracked eggs sometimes. Here are a couple of things to keep in mind if you think you see a crack in the egg. First, Mariah and Kaver have never accidentally cracked an egg as far as we know, so while it’s possible, they’re usually pretty good about protecting the eggs as they turn and brood them. Second, hatching begins with a hole being poked in the egg by the emerging eyas. The inside of a falcon’s egg is white, so if you think you see a crack in the egg, look for white behind it. Of course we’ll keep a sharp eye on the eggs and the falcons, and we’ll bring you any news as soon as we learn of it.

-Jess

We suspected that Mariah had laid a fifth egg earlier today, but she and Kaver have been keeping the eggs covered pretty much non-stop, so here’s one of the first views of all five eggs! The last couple of days have seen Mariah and Kaver spending most of their time on the eggs, so it’s reasonable to assume that egg laying may be over and brooding has commenced! Of course, Mariah likes to surprise us so remember to expect the unexpected!

It looks like Mariah laid her fifth egg between 10:53 and 10:55AM. That makes it just a hair over 57 hours since egg#4. In this picture (click for a bigger image) the egg at the left looks darker than the others. That’s usually an indication of a newly laid egg. From looking at the camera images, it appears that she spent a little time rearranging them, then covered them up again without ever giving us a clear look at all five until this afternoon.

-Jess

Rhea Mae, daughter of Mariah and Kaver from 2006, has now laid a total of 3 eggs at her nest site on the Sheraton hotel in downtown Toronto, Ontario Canada. Her third came over the weekend. For more information about Rhea Mae and Tiago, visit the Canadian Peregrine Foundation’s webpage.

UPDATE! (April 8)- Rhea Mae has laid her fourth egg! We received word just this morning from some of our fans who keep an eye on her nest. This is excellent news to be sure. We’re looking forward to following Rhea Mae and her mate Tiago as they raise their first family together this year.

-Jess

It’s hard to tell from the camera views but it looks like Mariah laid her fourth egg in the early hours of April 5, probably around 1:40AM. That’s about 57½ hours since the last egg. Will there be a fifth? Keep watching to find out!

-Jess

Here at the Rochester Falconcam we’re happy to be able to bring you high quality images and up-to-date information about Mariah, Kaver and their families each year. Most of the work that goes into producing the Falconcam is performed by dedicated volunteers, but we still have expenses for internet access, computer storage space, equipment maintenance and more.

We depend on the generosity of our viewers and merchandise sales at The Scrape for nearly all of our funding. You can help to ensure the future of the Rochester Falconcam, and have some fun all at the same time by joining our Pledge an Egg event!

Each year our viewers try to guess how many eggs Mariah will lay. We’ve seen her lay as few as 3 and as many as 6 eggs over the past decade. This year, why not turn the guessing into a fundraising event with “Pledge an Egg”!

How it works:
Pick a pledge amount for each egg. When Mariah has finished laying her eggs, probably around the middle of April, we’ll post the final tally here at Imprints. Multiply your pledge amount by the number of eggs and send in your donation. See how much money you can raise for the Rochester Falconcam! Ask your family, friends, co-workers or classmates to “Pledge an Egg”. Just download one of the handy pledge forms below to get started. On behalf of all of us here at the Rochester Falconcam, thank you for your generosity!

Pledge an Egg sign-up form (Portrait Orientation)

Pledge an Egg sign-up form (Landscape Orientation)

-Jess

It looks like Mariah produced egg #3 right around 4:10PM on the afternoon of April 2. That’s a little less than 56 hours after laying her second egg. She gave us our first clear view of all three eggs a few minutes later, as you can see from the time on the picture above.

Here’s another look courtesy of the Rochester Falconcam’s high-resolution Main camera. This is Mariah’s second year of “unpredictable” egg-laying times. We don’t like to deal in absolutes here at Imprints, but it looks like she may be establishing a new pattern in her golden years.

How many more eggs can we expect? That’s anyone’s guess. Watchers observed mating activity between Mariah and Kaver both in the morning and afternoon today, so we wouldn’t be surprised to see a couple more before the egg laying is done!

-Jess

Here at Imprints we receive a lot of questions from our readers. We’re glad to know there are so many curious people who want to know more about Mariah and Kaver, so keep the questions coming!

Now that Mariah’s in full egg-laying mode, I thought it would be a good time to address some of your questions related to reproduction. We covered some of this territory in last year’s posts on egg laying, and incubation and hatching, but you’re clever enough to have come up with some new questions, so here goes!

We’ve been asked many times about how long Mariah will continue to lay her eggs. After all, she’s been reproducing for 11 years now. So just how long is a Peregrine productive?

Well, that all depends on how long Mariah lives. Unlike human females, Peregrines don’t go through menopause. Once they reach reproductive maturity (typically in their second year), they can begin laying viable eggs, and they’ll continue to do so throughout their lives. Reproduction is one of the falcon’s strongest natural drives, and biologically speaking, it’s one of their primary functions. So, as long as Mariah is with us and has a mate and a suitable territory, we should be able to expect that she’ll continue to lay eggs and raise young.

It is true that as Peregrines age, they may not always lay viable eggs, but eggs can fail for a number of reasons that are not related to age. As we saw in 2006, injury may prevent the eggs from being properly incubated. In 2002, while Mariah was presumably in her reproductive prime, only 2 of her 4 eggs hatched. And last year, one of her five eggs mysteriously disappeared. Still, Peregrines in captivity have continued to lay eggs for as long as fifteen years or more, so we think Mariah still has many good years of motherhood left to her.

Another oft-asked question is: How does Mariah know how many eggs to lay?

Peregrines live a dangerous life. In the wild it takes nearly all of their energy, and a dose of good fortune to make their yearly migrations and return to their home territories to nest. Then they have to deal with availability of food, and external threats like predators and even other falcons who want to muscle in on their territory.

Fortunately, Peregrine females have evolved to take all of this into account during their nesting cycle. The lengthening of the day and warmer temperatures kick-starts their reproductive cycle by stimulating the release of hormones into their bodies. When falcons mate, fertilization of the ovum doesn’t take place right away. Instead, Mariah stores Kaver’s sperm until she’s ready to fertilize her eggs.

To figure out when she’s ready, she determines whether her environment is safe and free from stress, and how much food is available. If prey is plentiful and hunts are successful most of the time, she’s likely to lay more eggs than if food is difficult to come by. She probably doesn’t know the exact number of eggs to lay, but the average for Peregrines is 3-7, with 3 or 4 being typical. Believe it or not, forming the egg shells takes a lot of calcium out of her body, so the lack of calcium may trigger her to stop laying and begin incubating.

Finally, some of you have wondered about the fact that most of Mariah’s offspring have been female.

First a little background… WARNING: Science Alert!

At Harvard Univeristy back in 1973, a biologist named Trivers and a math whiz named Willard had a theory that the ratio of male to female offsping produced by a given pair of animals would tend to favor the sex that gave the best chance of future reproductive success (grandchildren and great-grandchildren) for the least additional investment of resources, that is, food and shelter (Whew– I ran out of breath writing that!). The Trivers/Willard Hypothosis was based on mammals, for which male offspring required more resources to produce. In mammals, healthy males are likely to produce many more offspring than unhealthy ones. So when times were good, mothers produced sons. Females, on the other hand, are likely to produce offspring even if they’re not in prime condition, so when the chips are down, it’s better to produce female offspring. The hypothesis is hard to prove, and many studies are inconclusive, but the theory seems to be generally well-regarded.

In Peregrines and other birds of prey, it is the females who are larger. They require more resources, but healthy female falcons are more likely to reproduce than unhealthy ones. In Australia, a couple of smart people named Penny Olsent and Andrew Cockburn actually studied Peregrines and other raptors using this hypothesis. They proposed a modified version of Trivers/Willard. It says that where prey is plentiful and the mother is healthy, more of her offspring would be females. At the Rochester site, we know that prey is very plentiful, and Mariah’s robustness is unquestioned. Combined with Kaver’s hunting prowess, it stands to reason that Mariah has all the resources she needs to produce the largest, most productive kind of offspring– daughters.

There you have it. A few more details about Peregrine reproduction.

-Jess

We hope you’ll join the Rochester Falconcam’s own June Summers and Jim Pisello as they talk about Mariah and Kaver on the 1370 Connection with host Bob Smith. The show will be broadcast live on WXXI AM 1370 radio at 12:30PM on Tuesday, April 1. And if you live outside of the Rochester area, not to worry! Listen to the simulcast on the Internet.

-Jess

Egg-citement reigns here at the Falconcam! At about 8:30 this morning, 106½ hours after laying her first egg, Mariah came through with number two. You can see the newest egg between her feet in the picture above, captured only a few minutes after it was laid.

Here’s another look at the two eggs. Mariah’s normal egg-laying interval of about 54 hours stretched last year to an average of over 70 hours, thanks to a long 106 hour period between eggs 2 & 3. Today’s longer interval equals the longest one she had last year. This may be due to her age, or it may be influenced by other factors.

Here’s a close-up of the eggs courtesy of the Rochester Falconcam’s zooming Camera 1. Peregrines normally lay an egg every 2-3 days, with the time between eggs getting longer as the falcon ages. We think Mariah’s at least 12 years old, so her advancing years could certainly explain these longer times. They might also have something to do with the recent battle for control of the nest box territory in which she and Kaver drove off an invading falcon. It’s impossible to say for sure, so we’ll just have to keep watching to see when her next egg will arrive!

-Jess