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"Mom! Any old mom, I'm hungry!
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Linda Bower sent me a note along with a link to a You tube video she posted.
"A cowbird parasitized a phoebe nest that is located by my front porch. Phoebe parents are rearing a cowbird instead of their own babies. I'm disappointed and it is hard to watch the insects from my yard and tiny pond (dragonfly larvae) getting eaten, but this cowbird chick is as cute as it can be."
First, I would encourage you to
watch her video with the perfect musical pairing of Mozart's Eine Kleina Nachtmusik.
The highlights for me were the recognizable insects and the size
of them that the cowbird chick managed to stuff down. In one late sequence,
the chick, which we named Mozart, has a big wad of butterfly apparently stuck while the phoebe
tries to ram an additional insect into its craw.
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Serving seconds |
In
addition to seeing the diversity of insects the phoebe collects, you
will get a close look at the nest sanitation habits of the bird. Mozart extrudes the fecal sac when fed or sometimes even before.
Frequently it backs up over the edge of the nest to drop it down and
other times the phoebe collects it as it comes out. In case you missed
the recent fecal sac description, I repeated it below.*
Until now I
have never found anything to love about
brown-headed cowbirds aside from their
melodic liquid call, a
musical gargle. They are brood parasites, leaving
their eggs in other birds' nests where the new mother doesn't recognize
them and raises the cowbird as her own. Since the cowbird egg can hatch
earlier and the baby is larger, it hogs the adoptive mothers attention. The cowbird chick may even attack the nest mother's own
eggs.
This parasitic strategy was important when cowbirds
followed bison on the prairie, harvesting insects, and were on the
move daily without time to build a nest. Many prairie bird species
recognized their eggs and tossed them out. Now that they are no longer
migratory, cowbirds have moved into our urban
areas where there are close cropped grasses, cropped by lawnmowers
rather than bison. Here they find nests of bird species that weren't
prairie
species. These naive birds aren't familiar with the dastardly habits of
the cowbird and frequently lose their nestlings to the parasitic cowbird
young that they don't recognize.
I dare you to go back and view the last of
the video again. Linda's timing of Mozart's "final movement" at 5:32 is absolutely brilliant!
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* "A
fecal sac (also spelled
faecal sac) is a mucous membrane, generally white or clear with a dark end, that surrounds the feces of some species of nestling birds.
It allows parent birds to more easily remove fecal material from the nest.
The nestling usually produces a fecal sac within seconds of being fed;
if not, a waiting adult may prod around the youngster's cloaca to stimulate excretion."
Wikipedia
Linda referred me to
this article
if you are tempted, like I have been, to remove cowbird eggs or
chicks. In addition to being illegal, Audubon offers a rational
argument for letting nature take its course.
Now for extra credit, see if you can identify the insects. I edited a version of her video at
this link showing just the food deliveries. The challenge is to
identify all twelve in order. When you are through, compare it to the answer list below, but NO Cheating!
1. Moth
2. Hackberry Emperor butterfly
3. Dragonfly larva
4. Grasshopper
5. Dragonfly larva
6. Green Dragonfly larva
7. Damselfly
8. Dragonfly larva
9. Orange Sulphur butterfly
10. Dragonfly larva
11. Caterpillar, small, maybe a sawfly larva
12. Green caterpillar
Other opinions will be cheerfully considered.