On the T's and while we wait for hatch...
In general, eagles start laying later with a new mate and drift earlier. We saw this:
- With Mom and Dad (she was new)
- With Mr. and Mrs. North (he was new)
- With Mr. North and DNF (she was new)
- With Pa (OP) and Ma (she was new)
- With Ma and Pa (NP) (he was new)
There are exceptions to the first year-rule in my records. Mom moved four days later in her second year with DM2. Harsh weather (unusually cold, dry weather coupled with deep snow) can also push eggs later, and intruders can disrupt hormonal cycles as we saw with DNF in 2023. But cold, dry weather did not apply prior to egg laying this year: our other two bald eagle nests moved significantly earlier, as did several of our peregrine nests. We don't know if intruders drove things later, but I would have expected the Ts to float earlier or stay about the same in accordance with what we usually see, and what every other nest was doing. Instead, she laid eight days later this year.
Eagles usually lay the same number of eggs every year after the first year. We saw this:
- With DNF, who laid two eggs every year beginning in 2019, with the exception of 2023 (1)
- With Ma FSV, who laid three eggs every year beginning in 2008, with the exception of 2007 (2, first year nesting), 2010 (2), and 2025 (4)
- With Mom Decorah. However, she did lay two eggs in her first year of nesting (2008)
There are exceptions to number of eggs, and first-year nesting is one of them. However, we see an equally strong correlation between young/new adults and changes in the number of eggs. Mom and Ma FSV were both young/new adults when they started laying. Based on plumage, DNF and Mrs. T were not, and DNF did not change to laying three eggs in subsequent years. Quick note and yes, it still gets argued about: not all birds begin breeding as soon as they reach sexual maturity. We have years of data on it.
So:
- One or both of the two could be new, which would explain why they drifted eight days later and why she laid three eggs.
- Mr and Mrs. T could both be the same eagles as last year. If this is the case, I'm perplexed by how much later they moved, but the switch from two to three eggs wouldn't be that uncommon.
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Topic: Trempealeau Eagles 2025! (Read 5605 times)