Good News, Bad News, Good News, Bad News: A Follow Up On The 2015 Nesting Season

L7/8-11 had moved away from their nest when we arrived but were keeping a close eye on it & moved back when a coot swam near.
Phillip, Sara, and Carrie enter the field to go collect the eggs with Gabe close behind documenting everything.
Carrie and Phillip use brooms to safely keep birds away from the nest while the eggs are collected.
L7 & 8-11's 2015 nest with 2 eggs.
Each egg is placed in a ziploc bag and then put in a foam egg bed inside a cooler to keep them protected while being transported
Dimensions of the nest are collected along with water depths and type and amount of vegetation in the vicinity.
L1 & 6-11's flooded nest in the White Lake marsh.  GPS coordinates and photos are taken.
Remaining intact egg found on L1 & 6-11's flooded nest.
Bottom of the egg was stained from sitting partially in water and on wet nest material.

Good news – The pair, L7 & 8-11, that we last reported were incubating 2 eggs continued sitting and sat full term which is ~30 days.  In fact they sat beyond full term which brings us to the Bad news – after 30+ days had come and gone it was clear the eggs weren’t going to hatch.  Although we were pretty confident on the timing of when the eggs had been laid (and therefore when they should have hatched) thanks to observations reported to us by the farmer and landowner, we were cautious and let them sit several days beyond when the second egg could possibly have hatched.  Then on day 40 we went in to collect the eggs as we did last year.  We did this because there is no point in the birds continuing to sit on eggs that aren’t going to hatch and because we can collect valuable information from those eggs and also collect information on the nest and the surrounding habitat at the same time.  Eggs that don’t hatch are either infertile, as the four eggs from this pair were last year, or they can be fertile but no longer viable, meaning at some point in development the embryo died.  Examination of these eggs determined that they were infertile, which is a bit disappointing but not something to be overly concerned about since the birds are still young.  In fact, one of my favorite pairs from the eastern migratory reintroduced population produced infertile eggs the first four years they nested, and then in their fifth year they hatched a chick from their very own fertile egg!  Apparently, it just takes longer for some birds!  Last year L7 & 8-11 renested and there is still time for that to happen this year so we’ll just have to wait and see and keep trying to be patient.

Good news – A new pair, L1 & 6-11 nested for the first time in the marsh at White Lake in early April.  We suspected the pair might have a nest based on continuous overlapping data points we received from the GPS transmitter on the male.  Unfortunately, once we were able to confirm this good news we also confirmed the Bad news.  From April 10th-14th the White Lake marsh received ~10 inches of rain.  Cranes will try to build their nest up to protect the eggs from rising water but they couldn’t keep up with that much rain in such a short amount of time and the nest flooded.  On the 16th we found the flooded nest with one intact egg still sitting on top.  There was also a piece of eggshell on the nest indicating there had been a second egg.  We collected the egg and shell fragment as well as some measurements of the nest and water depths. 

Back at the office I used a flashlight to candle the egg to try and determine if it was fertile or not.  As an embryo develops in a fertile egg light will easily shine through the air cell at the large end of the egg and that area will appear light while the rest of the egg appears dark due to the developing embryo.  That distinct line between the light air cell and the dark rest of the egg is what indicates the egg is fertile.  If light shines all the way through the egg there is no developing embryo and the egg is infertile.  Good news – the egg was fertile.  Bad news – it likely wasn’t viable since it had been sitting on a wet, flooded nest and hadn’t been incubated for at least one, but probably several days.  However, just to be cautious I made arrangements to transfer the egg to ACRES, the whooping crane breeding center in New Orleans, where they have incubators and staff who could monitor the egg for further development.  Unfortunately, as I suspected the egg was no longer viable but the good news is that this new pair built a nest and laid two eggs, and at least one of them was fertile!  There’s still plenty of time for them to renest if they decide to try again and we’ll just hope the weather cooperates this time, and if not, there’s always next year!

Thanks to Richard Dunn and additional staff from ACRES for meeting me to transfer the egg and for additional care and examination of the egg.

Check back soon, we plan to post some video from the day L7 & 8-11’s eggs were collected.

Update written by Sara Zimorski

Photos by S. Zimorski, C. Salyers, G. Giffin, and S. Dartez - LDWF and T. Zimorski

Captions for photos from upper left to upper right then bottom left to bottom right.

1) L7/8-11 had moved away from their nest when we arrived but were keeping a close eye on it & moved back when a coot swam near.

2) Phillip, Sara, and Carrie enter the field to go collect the eggs with Gabe close behind documenting everything.

3) Carrie and Phillip use brooms to safely keep birds away from the nest while the eggs are collected.

4) L7 & 8-11's 2015 nest with 2 eggs.

5) Each egg is placed in a ziploc bag and then put in a foam egg bed inside a cooler to keep them protected while being transported.

6) Dimensions of the nest are collected along with water depths and type and amount of vegetation in the vicinity.

7) L1 & 6-11's flooded nest in the White Lake marsh.  GPS coordinates and photos are taken.

8) Remaining intact egg found on L1 & 6-11's flooded nest.

9) Bottom of the egg was stained from sitting partially in water and on wet nest material.