July 4th ducklings

The west nest hen started incubating 10 eggs on about the 4th so they should hatch sometime around Independence Day. I think the eggs are mostly or even all hers because we didn’t notice any other ducks dumping eggs in that nest and 8 to 14 is a normal number for one hen. We do still see adult ducks in the creek and the yard but their nest-seeking activity has nearly disappeared as it always does this time of year.

(I was wearing gloves because I was doing garden work, but that and/or washing afterwards is a good thing to do.)

However a duck has been in the east nest box for a half hour on some days in the past week and has now laid two eggs there. She wasn’t there at all today but it’s possible she’ll be there tomorrow and there’s still a chance that this nest will also have another round of ducklings – or she might not finish. The next few days will provide the answer.

These hens might simply be late in getting started, but also if a wood duck loses her brood she may try again in the same spring season. Reasons she might lose them include a raccoon getting into the nest and eating all of the eggs or ducky-disasters such as the nest tree falling, a flood carrying all of the ducklings away, or heavy predation that takes all of the ducklings.

Fortunately those are rare, but wood duck duckling mortality averages nearly 50% during the first 6 weeks. That is one reason they have evolved to have such large broods.

West nest, round 2

It’s now very likely that the West nest box will have another batch of ducklings five or six weeks from now. There are now 6 eggs and a hen has been sitting in the box for several hours each morning.

Also a hen has already visited the recently vacant and beautifully redecorated (new wood chips) East nest box. She was in there for about 10 minutes this morning trying it out, sitting this way, then that way, then another way, all the while moving the furniture (the wood chips again) around. This is typical pre-inspection nesting behavior. So maybe there too? It has happened before that both nest boxes were used twice in one season.

The hen that is laying eggs in the West nest posed nicely for a photo this morning.

The six eggs this morning. It’s kind of silly to keep posting duck pictures that look like many others and egg pictures that look like dozens (because that’s how you count eggs) of others. I do it anyway.

18 Ducklings – Video

Eighteen new ducklings left the east nest this morning at 8:15. There was one unhatched egg. The new low-level camera worked well but the one inside the nest box was kind of grainy when color was turned on – I’ll take it out and test it – but it worked well enough.

I have once again edited a video, partly for those of you who could not watch live, and partly because that’s just what I do on jump day, I guess. I had my regular camera set up on a tripod in the house so the video has three camera angles: telephoto from the side, the usual camera inside the nest, and the one near the ground outside the nest box. Enjoy!

Leaving Soon

Right now, 7:15am, the hen is out for breakfast. The ducklings will leave sometime this morning.

What to expect:
Out to breakfast: in the early morning the hen often leaves for 10 minutes or a half hour, to go out for a last breakfast without all of the kids.
Watching for danger: When she thinks it might be time to go she’ll jump up and sit in the nest box doorway and watch. She’ll sit there for 2 minutes … or 15, and after that she may decide not to go and d settle into the nest again for while. Repeat. Sometimes repeat and repeat.
Time to leave: When she’s ready and thinks it’s safe, she’ll drop down below the nest box and call using a special and fairly soft pulsing sound. The ducklings respond by peeping loudly, jumping around kind of like popcorn, and climbing up to leap from the doorway. 
On their way: From when she starts until the nest box is empty is only a few minutes typically (two weeks ago it was an exception: 11 minutes). When the ducklings are all out (she keeps calling as long as she hears their loud peeping sounds) then she leads them away into the creek and they never return.

When: The earliest they’ve left is a bit before 7:00 and the latest was a few minutes after noon. Those are both unusual. Typically it’s sometime between 8 and 10am.  These ducklings hatched mostly last night so they are perhaps more ready-to-go than usual so she might go early. If you watch it’s often lots of waiting, then 5 minutes of action.
I hope you enjoy watching!

Jump day: Saturday

I checked the East nest this morning while the duck was out and all of the eggs on the top layer were pipped. Thus I expect hatching will occur starting tonight or early tomorrow and that would make their jump day Saturday.

Also a surprise: there are now 3 eggs in the West nest. There were none just two days ago after two weeks of brief visits, so that led me to predict in the previous post that there would not be a round two for the West nest box. I should know better. Whenever I predict something (for a good example, see the paragraph just above and the headline of this posting) the ducks like to fool me. I should just stop doing that and instead always write “we’ll see” instead.

The last stages of hatching occur when the duckling uses its “egg tooth” to break through the egg membrane into an air pocket that forms in the egg between the membrane and the shell. At this time the egg white has been fully absorbed and the yolk is becoming internalized in the duckling, so there’s no free moisture inside. The duckling breathes in this air pocket and there is some air exchange through the shell, which is porous.

A while later the duckling adds to the air exchange by pecking at the egg shell in one spot (wherever its little beak is), which is called pipping the egg shell. That lets in more air.

Since the duckling is breathing it can make sound and I’ve heard faint peeping when holding a pipped egg. I think this stimulates the hen to be even more active than usual in turning the eggs. Hours later, about a day or so after pipping, the duckling has developed enough to use its legs to push and to very slowly rotate inside the egg as it pecks with its egg tooth. It takes many hours to break the egg all the way around and to finally emerge. The egg tooth is a sharp spur at the end of the ducklings bill. You can see it as a white spot after they hatch:

East nest – still waiting

I just now (4:30 CDT) checked 10 of the 19 eggs (I didn’t dig through all of them) and none of them were pipped. The ducklings will “pip” the eggs – crack them slightly in one spot – about 24 hours before they hatch. Some sites say 24 to 48. So I’d estimate the earliest hatching day at this point as Thursday and jump day no sooner than Friday. It could be into the weekend.

Estimating the start of incubation is something of a guess: is she actually incubating (heating) the eggs, or just resting in the nest box? Then the incubation time also varies: it’s nominally 30 days but that’s plus or minus two or three. The east nest is apparently going to the plus side.

The ducks have stopped visiting the west nest box and there aren’t any eggs in there. One year we had two batches in both nest boxes: 70+ ducklings! But it looks like this year it will be one hatching for each.