Uninvited nest update.

Yesterday I asked for advice about how to deal with a nest of eggs that presents itself in an inopportune place (a tree slated to meet a gruesome end in a whisper-chipper) at an inopportune time (mere days ahead of when we finally launch our backyard overhaul). The consensus among commenters who professed knowledge of or experience with birds in the wild seems to be that there is no promising way to relocate the nest without scaring the mama bird away and leaving the eggs cold and orphaned. Given that the whole point of moving the nest would be not to throw out the baby birds with the despised tree, this outcome would be sub-optimal.


Some of my commenters homed in on the ethical issue here, rather than the practical issue. In particular, Mouth of the Yellow River wrote:

This is indeed an ethical dilemma and probably will have to be resolved dependent on your personal code of ethics.
If you are of the ID, religious right, environmental protectionists, animal protectionist, dietary vegan, and other related socio-ideologic sects, then you should probably let them hatch and vacate the nest naturally. You can sit back and satisfy that somewhat hypocritical and in the end selfish socio-psycho need to feel good that you have been a protector of innocent life while sacrificing your feelings of urgency to change the landscape over which you have control.
If you are from my old country and Japan and other Asian cultures, you will carefully take the eggs and prepare a nice rice-based dish of only the highest quality, and just before dining, crack each of the eggs carefully, do not disturb the yolk (or the developing embryo), as a topping to the serving. Eat the egg (or embryo) with reverence savoring every taste, and go away feeling good that this life has now been continued as an addition to your body and being.
If you are not in the first or the second category above, but a pure Darwinist, depending on your disposition at the moment, gently or violently destroy the nest and the eggs with it naturally (don’t flush them) so they can contribute to the natural non-human chain of life in your backyard. Go away feeling that you have insured that the genes in the progeny of these parents who were stupid enough to build a nest and lay their eggs in your backyard in such a labile location will not survive and those who did build their nests in a secure location will.

In other words, my decision here is a kind of litmus test of what kind of person I am.
Well, that’s fair enough. It’s true that the desire to save the eggs probably has less to do with a thoroughgoing commitment to protect and enhance the lives of all the wild beasts in the great outdoors (because honestly, you should see what I do to the snails I catch in my garden) than with preferring not to feel bad that a fluke of timing might result in the loss of a clutch of eggs. I don’t know that it’s hypocritical to prefer not to harm the birds if it can be avoided, or even to prefer not to feel bad for harming the birds. (Maybe it would be less hypocritical to embrace my potential for harm and to learn to enjoy it?)
The second option (continuing the life force in my tummy) is rather more vitalist than I am. I suppose I prefer to turn to compost to nourish the vegetables that nourish me. By temperament, I’m more of a cultivator than a hunter-gatherer.
Which, I suppose, brings us to the Darwinian angle: Ought I to be acting as a force of selection here against a bird dumb enough to build a nest and lay a clutch in the most loathed of trees in the yard? (It’s hard for me to call the bird dumb, really, given the glacial pace at which I’ve been pursuing the plan to overhaul the yard. Betting on my sloth is usually a good bet.) The answer might be yes if the thing I valued most were control over the back yard landscape. However, part of why we want the yard improved is so we will spend more time out in it, amongst the flowers and fruit trees and butterflies and birds.
In other words, those birds have the adaptive advantage of appealing to my aesthetic sense and being just the kind of feature I want in my back yard landscape. Pretty sneaky of them.
So, we’re going to try to do every other part of the back yard project before we remove the tree. My better half has tentatively identified the mama bird as a Northern mockingbird. If this identification is correct, we’re looking at 12-13 days for the eggs to incubate and 11-13 days for the chicks to fledge after the eggs have hatched. So, in all probability, that would mean less than four weeks’ delay of the tree removal. We can probably swing that.
I should also point out that one of my commenters who encouraged me to wait for the birds to hatch offered to share the expense this might create in terms of the contractors and their schedules. The theory was, if I tell you you ought to pursue a certain ethical course of action, I ought to be willing to share the burden that pursuing that course of action might impose on you. How cool is that? I’ve said it before and I’ll say it again: my commenters are the best!
Northern mockingbird photo from http://www.mbr-pwrc.usgs.gov/id/framlst/i7030id.html

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Posted in Mailbag, Personal, Research with animals.

16 Comments

  1. Being nice to the hatchlings does not mean you need to be too nice to their parents when they attack your face in a couple of days. These guys can be very aggresive when guarding a nest. My dog was attacked a few times by the jelaously guarding territorial mockingbirds. I was attacked many times as well and their beaks met my fists!

  2. I agree with coturnix, twice a day, every day, for the past two weeks, a mother mockingbird has waited near the end of my street to attack my dog when we walk by. Not just swooping, but actually hitting him and coming away with fur. I had sympathy for the nest until you mentioned that it was a Northern Mockingbird, but I can’t say I’m not biased…

  3. Put eyes in the back of your hat ;-} Actually, if the parent birds know you and you don’t go directly up to the nest, they will probably not molest you–that’s been my experience, at least. Fido or Fluffy get no pass, however. If it’s Mimus polyglottus, the kids will be out of the nest way sooner than you think they oughtta be, all gape and squeak. No tail, no primaries, very unfinished little critters. As to what species, I thought American robin.
    Do you ever just look at what goes on in your yard long enough to get a sense of the rhythms, the denizens? Do you know what birds call it their territory?

  4. Hold it! Taking the inactive position may seem the easy way out at the moment, but has not resolved your ethical dilemma, only complicated and extended it.
    Your strong pro-life, anti-abortion, anti-Darwinian, anti-neo-Kantian stance in leaving this labile nest and brood alone creates the responsibility to actively protect it and a fair shot at survival of the brood in this labile location and situation.
    If you had decided to quickly destroy the nest for any of the discussed reasons, so early in the season these errant parents will be given another chance with another round of female fertility (if I am not mistaken), a chance for selection of a more secure nest location, and maybe even hit the 5 egg limit.
    A great threat in addition to natural elements as wind, rain, debri, etc. other than humans to urban wildlife is wild urban backyard species (possums, raccoons, squirrels, rodents, etc.) that love bird eggs and embryos, particularly in labile locations. However, one of their greatest threats is domestic cats.
    The U.S. Census Bureau has estimated the number of pet cats in the United States at 60 million, not including semi-wild (feral) cats, according to Patricia Thompson, urban biologist with the Washington Department of Fish and Wildlife’s (WDFW) . The combined total of pet cats and feral cats is probably closer to 100 million in this country, she added. A study of urban wildlife in Seattle in 1984 estimated there are more than 20 cats per block, Thompson said.
    Many pet owners don’t believe their cat is capable of killing anything (that includes my vegan all animal protectionist neighbor whose cat decimates the woodpeckers, mockingbirds and other species outside my office window every year). A Wisconsin study estimated that cats kill 39 million birds in that state each year.
    In the old country, such predators including domestic cats were part of the sacred food chain and cycle of life, we also reverently ate them (and I have been tempted to do the same with my neighbor’s two cats).
    There is another active path for you in light of your new responsibility. Take the eggs, incubate them, nurse the young, and teach them to fly yourself. It’s a beautiful thing; I have done it as a child with my parents help. The little fellers place their waste in a neat little membrane bag on the edge of the nest as soon as they are hatched (use tweezers), and they are voracious eaters from liquid in an eyedropper to earthworms and hamburger later. (When they were mature, we ate two and released two).
    Go on with your project, you will have insured the threesome a shot at life, and mom will go out and maybe double this year’s brood!

  5. northern mockingbirds are protected under the migratory species act, which that means that, unless you are gonna act like those arrogant USDA officials in florida and blatantly break laws, well, you are stuck using umbrellas or hardhats to protect yourselves for a little while until the chickies are on their way.
    i still think you should mount a birdcam on the nest.

  6. P.S. Given the extreme immaturity of mocker chicks when they get out of the nest–all gape, legs, and squeak, no tail feathers, no flight feathers–it’s no wonder the parents get so obnoxious with their neighbors about that time. Once the kids are able to get up into the shrubbery out of (most) harm’s way, the adults calm down. Some.

  7. A few things:
    1. Our identification is extremely tentative (and I’d prefer not to involve the feds, if you don’t mind). However, whether we’re talking about a bird that is protected or targeted, one that is nice as pie to dogs, cats, and people or mean as hell, I think we’re still inclined toward co-existence with the birds and toward trying not to mess with the next generation of them.
    2. I fear that raising the birds inside and teaching them how to fly might not work. The hazards in my house may be greater than those outside, even taking into account cats, raccoons, possums, squirrels, birds of prey, and aggressive gastropods (all of which exist in our outdoor environs). Also, I’m not positive that I value any one part of this web of life more than the others — possum’s got to eat. Nonetheless, I choose to watch this struggle rather than be a part of it. (Unless, of course, neighborhood cats are involved. Then it’s garden-hose time.)
    2.5 RE: Giving mama bird a shot at a second brood, we’ve just gone from endless winter (Northern California variety) to summer (with temps in the 80s) overnight. The season (i.e., spring) may have been sufficiently short this year that it’s time for mama bird to move on to summer activities.
    3. I’m not sure it’s fair to characterize someone as having a “strong pro-life, anti-abortion, anti-Darwinian, anti-neo-Kantian stance” unless you know her really well or have more than a couple blog posts upon which to base that judgment. Also, in my experience it’s easier to adjust course on minimally disruptive actions than on big, drastic ones — which is why, in trying to deal with a new situation, we are tending towards a plan that seems relatively inactive.
    4. RE: the birdcam idea, I’m game if someone would like to donate the equipment!

  8. I was attacked many times as well and their beaks met my fists!
    Are you serious? The worst a bird is going to do to you is yank a little hair, if you hit the bird you will probably condemn it to a lingering death from broken bones. A little perspective check is in order, I think. Just put your arms over your head, duck for cover and laugh it off. It’s not like your life is in danger.

  9. Oh, the bird is not harmed, just flies up into the tree and looks at me smugly and does not try me again – the dog is fair game, though. It is too fast and small for a fist to do it any harm, if I even manage to touch it at all LOL. Fists are only good for harming fixed large objects, like people.

  10. I take issue with to the suggestion that there is such a thing as a “Darwinian” ethical stance. To my mind, this is merely replacing God with evolution. One can reasonably argue that God might (hopefully) have one’s best interests at heart, and that one should therefore take God’s advice on matters of ethics. But as a nonsentient natural process, evolution has no moral authority or guidance to offer. However much we might approve of our own existence, there is nothing in evolutionary theory to guarantee that the outcome of natural selection will be desirable from any particular ethical point of view. One might as well ask how one’s attitudes toward gravity should affect one’s ethical decisions.

  11. Trrll: Generally a good point, but both gravity and evolution do affect ethical decisions, as circumstances which must be considered when appropriate!
    For example, antibiotic misuse is, or should be, considered a breach of medical ethics, precisely because we know that the processes of evolution will provide a causal connection between such misuse, and harm to others from resistant bacteria.

  12. I have been amused and amazed by the protectivness of the mocking bird – and at times have helped them protect their nests from predators such as the crow. I have been watching a pair of mockingbirds that are nested nearby and I just happen to be in their “protective circle” They are possibly the most protective parents on Earth – I have more faith in this bird than in mankind. I sit at my picnic table and watch as they protect their nest. I see one of the mockingbirds fly into very low lying shrubbery obviously upset by something that it feels is threatining. After watching the mockingbird repeat a rapid pattern of jumping to the ground and then back into the shrubs I stood up out of curiosity to investigate what the bird was doing. I caught a glimpse of the tail end of a black snake and the mockingbird pecking at it to move it on it’s way. Next come the crows. Such a small bird compared to the crow but determined enough to chase off the persistent predator. When the crows become overwhelming I assist the mockingbirds with a handfull of gravel to chase the predatory ravenous crows away. Next comes the hawk – perched in the half dead pine tree and not seeming interested in mockingbird hatchlings but both mockingbirds are perched near the hawk – not being overly agressive as they are with the crow – but gently trying to urge the hawk on it’s way. Finally the hawk is frustrated enough to continue it’s journey. I notice two crows flying overhead with pink hatchlings trapped in their ravenous beaks. The hatchlings were gone – and so were my friends the mockingbirds.

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