A Little Bit More
Altricial (all-TRISH-al) birds are those birds whose young remain in the nest and are fed by parents for an extended period. These birds rely on their parents as their sole source of food. A variety of stimuli causes the feeding response from nestlings. In some cases, the vibrations of a parent landing on the nest are enough to trigger the young to gape. In other species, special vocalizations by the parents cause an eager begging response. The brightly colored fleshy folds of skin at the base of the bill on many nestlings are very sensitive. When these folds are touched by the parents, the young react automatically with an instant begging response. The food begging of the young in turn reinforces the parents' feeding behavior. The begging usually takes the form of strident cries along with head bobbing and wing fluttering. Most altricial young have brightly colored mouth linings providing distinct "targets" for the parents to use in feeding.
The urge for parents to feed their young is a strong one, but it is occasionally misdirected. Birds have been observed feeding neighboring nestlings of the same or even different species! One Northern Cardinal was totally preoccupied with feeding goldfish! Each tine the insect-laden bird approached its nest near a goldfish pond, the fish's eager, open-mouthed begging redirected the parent to feed them instead of its own young.
It's unwise to attempt to raise so-called abandonded nestlings. Taking on the responsibility of raising baby birds can be a laborious, frustrating experience. One initial problem to be solved is how to elicit the food begging response. Many attempts may have to be made before one succeeds in eliciting a gape. Once a particular method works, the young can be counted on to demand a steady stream of food and should be fed approximately every 30 minutes all day long. A quality diet, as well as, quantity is important. A bird raised on an inappropriate diet is likely to be stunted, perhaps even doomed to slow death by well-intentioned malnutrition. Remember too that possession of most wild birds is illegal and the appropriate local authorities should be notified if you are planning to raise a baby bird.
A fledgling is a young bird that has left the nest, is feathered, yet still depends on its parents for food. These are the very birds that are so often found and thought to have been abandoned. In fact, the fledglings are simply waiting for their parents to bring food and at the same time are quickly learning to become independent — do them a favor and leave these birds alone.
Activities
Eye Blink
Objectives: See a reflex in action
Materials: Just a partner
A reflex is an involuntary (not under your control) or automatic action of the nervous system to some kind of stimulation. The baby birds in the poster have a swallowing reflex to food in their mouths but that reflex doesn't work twice in quick succession. Humans have different kinds of reflexes too and they're very important to our survival. If you*ve ever touched something hot and immediately jerked your hand away, you've experienced a reflex action. You didn't have to think about whether or not your hand was touching something that was too hot, you simply moved your hand away without thinking. After you responded, then you thought, "oh, that was hot, wasn't it!" Reflexes shorten the time necessary for a reaction to take place and are therefore an important adaptation for survival.
Humans experience different kinds of reflexes daily. Here's a reflex you can try with a friend. Have your friend stand near you in a relaxed position. Assure your partner that you won't touch them with this experiment. Now raise your hand near their face and quickly snap your fingers. If they aren't expecting you to do this, their reflex action should be to blink - an involuntary reflex action. After you've done this one or two times, they'll want to try doing it without blinking, and this can be done. One can "override" the reflex action but only with effort. Your partner will have to concentrate a bit but should be able to avoid blinking as long as you don't touch them. It should be quite easy to see how this reflex provides a margin of safety for your eyes. By not thinking about this action, your eye shuts even more quickly than would otherwise be possible.
Key Concepts
Behavior and Regulation, Growth and Development, Life Cycles
Questions
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Posted by Sharon Gilbert on May 29, 2006 at 02:49 PM
Q: Last year I had a family of barn swallows nesting on an eve under my carport. When the babies fledged, they weren't able to fly. They just hit the ground and fluttered around flapping their wings without getting airborne. None of them survived (killed by a cat, car, etc.).
Is that normal, for them not to fly immediately after leaving the nest?
I'm concerned because this year they are nesting in the same place again and there are 5 new babies.
Is here anything I can do to help the fledglings survive? It was so sad to see them struggling in vain last year!
Thanks,
Sharon
A: I have a guess as to what happened last year. I'm guessing the the babies were close to fledging, not quite ready, but something frightened them and they left the nest early. This year, keep things as quiet as possible around the nest and see if this won't help. I realize you may be using the garage for your car but what if you didn't park it there once you realized the young were almost ready to leave? The babies should have been able to fly from their nest although they wouldn't yet be very good at it. A day or two after the babies fledge, if all goes well, they should leave the garage altogether and you'll have your space back. Barn Swallows are really beautiful birds and certainly deserve our best to keep their populations healthy. Thanks for asking and I hope this helps.
Posted by Kathy on July 06, 2003 at 02:14 PM
Q: a baby bird has been abandoned by the mother bird in my yard what should I do with it and how can it be fed until I know what to do with it...please reply a.s.a.p. thank you
A: This is a very common misconception. Baby birds that are old enough to leave the nest and fly a bit still need to be fed by their parents and are called fledglings. Although it may appear that your fledgling is abandoned, if you watch from a disant (hidden) location, I think you'll find the parents are regularly returning with food. Don't disturb the fledgling and over time it will become more adept at flying and finding food and become totally independent.
Posted by ailz on March 12, 2003 at 02:45 AM
Q: reflex action of human and how it protect the body?
A: Reflexes are very important in protecting our bodies. Just imagine touching something really hot on the stove. Before you're even aware that it is hot, your hand jerks away from the stove. The message that says, "THIS IS HOT" goes only to your spinal cord, not all the way to your brain, and quickly back to your hand to pull it away - this is a reflexive action. Now imagine what it would be like if you didn't have reflexes. If you touched a hot object on the stove, nerves would send a message beyond the spinal chord to your brain telling you "THIS IS HOT" and you would feel the pain and know it was hot, then decide to pull your hand away. Granted, this doesn't really take much time to occur, but it is longer than a reflexive response. Another good example of reflexes is our eyes' ability to blink reflexively when something approches our face - you don't have to think about it, you just blink automatically. So...the bottom line here is that reflexes accomplish various protective actions much more quickly than would otherwise be possible. I hope this helps.