Okay, I sort of knew about this in an offhand, heard it somewhere or another kind of way, but this would be my first, first hand experience with it, and with that, came a mess of knew knowledge!
My wife likes to have hanging flowers on our front porch, for one, because they're pretty, but two, because she enjoys watching birds make nests, and raise their young through the window. So about ten days ago, a new set of hanging flowers were hung, and in no time there was a finch nest with eggs, and all was right with the universe.
Then a few days ago,when she was waters her flowers and being generally nosy, she noticed an odd egg in the nest. The finch eggs were smallish with an ever so faint blue tint, the odd egg is clearly larger, but more prominent, is, is heavily speckled.
Knowing there's a species of bird that will not make a nest of it's own, but will instead lay its egg in another birds nest, allowing the host bird to raise it's young, I did some quick research to see if that was, in fact,what we had here. Yep, it's a cowbird egg.
Now my first instinct was to evict the interloper, but, further research said this was a bad idea for a multitude of reasons, not the least of which, it's illegal! But that wasn't all. Removing the egg could cause the adoptive parents to abandon the nest completely if an egg were to come up missing. Seems birds aren't all that aesthetically aware, but they can count. So even though the odd egg is so distinctly different to you and I, as far as the bird is concerned, and egg is an egg.
But even worse things than that can happen. Apparently, despite having little interest in raising their young, a cowbird mother will keep something of an eye on the nests they've deposited their eggs in, and if it's been removed, they may come back and destroy the nest and it's contents.
So, given the options, we'll be watching a pair of adoptive parents raise their young,and a cowbird baby too.
