As noted a few days ago, we were up to 7 eggs in the Eastern Phoebe nest at
work after a Brown-headed Cowbird added two eggs to the nest. Weirdly, on Friday there were suddenly only 6 eggs in the nest.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEisNnJhn7CP0impesfR9wXcvPGMdiAyoeCnWLPjtyge_Ekh9Dfi7v2Qgqv1Im447FDNATMSHFbD1WPf2JZJziWcallOQEwhsBaugcQ955fKSbXHZrsvamPcJe_sXkLGn2NeqUZjJk4z280/s400/mn-warner.jpg)
Eastern Phoebes are not known to remove cowbird eggs so this seemed strange. I took a look on the big monitor we have in our lab downstairs. The lab feed is a direct live video feed of the nest and the image is larger than the stills we can pull from
the feed we send to Cornell. I could clearly see that the two cowbird eggs were still in the nest. It was a phoebe egg that was missing. I next looked out the window near the nest and sure enough I could see a broken smashed egg on the ground under the nest. On Saturday, I taught a group of girl scouts and at the end of class we stopped by the monitor so I could tell them about the nest monitoring project and how they can take part. How's this for weird, there's another egg missing from the nest. I could see on Saturday that there were only 5 eggs in the nest. The cowbird eggs are still there but there are only 3 phoebe eggs now.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKpby3a2fY7pzG7zTZ-8MwHKeaifNzkFiY63HvV7TileqiJrYT0c0YM13MgmjnkCkDjKfpzQBrqN_xmDcEx7i3_gV8hsTOuhVpMskp4YazVrqo_78m-1MTE-bWuoOx4zEHHXa4_jhP43I/s400/mn-warner-1.jpg)
Did she knock them out on purpose? Was it an accident? Did the cowbird return and destroy some of her eggs for some reason? To try to find out I turned to the
time lapse videos of the nest on YouTube. On Saturday evening, all six eggs are there at 5:57:19.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSCpwhXQy4VjdhRO0do2yQVrpEqsHOaUcnsj3W6_jqgxmM2XRQ2mk26lBd-3w5ehco8r1z4674YuKIxiidhcMt9F6Tx1_ssAA24n3CL9hq7cWFhGDv5QD8toXBDjQI3L8p1szszG9v00Q/s400/Picture+4.png)
She returns at 6:03. She moves around a bit and has her head down by the eggs. There is no sign of a cowbird visiting the nest. When she leaves again at 6:11, just 8 minutes later, the sixth egg is gone and there are only 5 in the nest. The one in the upper left, which was closest to her head, is gone.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhdMKKVRh-A2kIkRTYTKeh2VYypRjGQRLkV3CQJF-VsSFd1vO2Jn9l6RUyN8OlOdkc_FcIM8gIrfXI9OACbYFlU2UIaHcmP50QZ62i5HPxSfIoOLtTr_mtakAlT11on2i54T305xXK64jg/s400/Picture+3.png)
Did she eject the egg on purpose then because she thought the nest was too crowded? One clue may be this image from the same evening at 5:44. Is that an egg she's pushing up toward the edge? Maybe she tried to push it out earlier and was unsuccessful but got it right half and hour later.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKbolL7lKyRfT501_7fiVH7nIRM5gWN4tm8CcSiBTat3xF2DhLyoQ4YkbxuJOL4-IbrVkpThyY5klJLNtDLGtPsk6ExHhU45IQXD2C0lNLf-plUdo-u2qfrwoQPPtY8ap3eRfEnZte7WA/s400/Picture+1.png)
If I get time I may try to figure out when the first egg went missing and see if anything shows up on the images.
~Kirk
1 comments:
Might not be happening in this case, but I've heard of predators taking one or two eggs at a time. However, I've only heard about that with species with larger eggs, like waterfowl...hard to imagine a single phoebe egg making much of a meal!
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