Tuesday, March 22, 2005

Apple #51: Robins Redux

ROBINS, part II

Since we just had our first official day of Spring the other day, I thought it might be appropriate to re-visit the
robins.


The information in this Apple comes from
Roland Wauer's book, The American Robin


  • Robins are one of the few birds that migrate both day and night. They return to the north at the beginning of Spring to start the breeding process.
  • The majority usually return to an area close to where they were born. Given that most robins live just over a year, most only do this once.
  • With a few known exceptions, robins are monogamous. That exclusivity lasts only through the nesting season, however.
  • Males select the breeding territory, but most often it is the female who is successful in defending it against other robin challengers. She is also the one who chooses the specific nesting location.
  • Robin nests have been found in all sorts of places, including the pocket of a coat left hanging on a tree, on the arm of an active oil well pump, and on a locomotive that traveled back and forth between Sioux City, Iowa and Chicago.
  • Robins have been known to attack even snakes who get too close to the nest. Brown, garter, and ribbon snakes have been killed by protective robins.
  • The female does most of the nest-building, though the male sometimes carries materials. Nests are made of grass and straw on the bottom, a layer of mud, and then softer grasses and moist mud where the eggs will rest. It usually takes about 4 to 6 days for her to build the nest.

  • The female lays usually 3 or 4 eggs, then incubates them for about 2 weeks after the last egg is laid. The male robin stays near the nest and will respond immediately if the female sounds the alarm.
  • After the babies hatch, they grow very quickly. They are fed regurgitated food only for the first four days. By the fifth day, they can eat pieces of earthworm, and soon after that, they can eat whole worms or insects.
  • During the 2 weeks a brood is in the nest, they will eat just over 3 pounds of food. By the last day in the nest, one of the young robins will eat as much as 14 feet of eartworms. To accommodate this demand, both parents are involved in feeding for up to 21 hours a day.
  • If the young birds leave the nest too soon, the parents will continue feeding them on the ground, if they can. Sometimes other species of songbirds will feed fledgling robins on the ground.
  • Once the young birds are out of the nest and moving about, they stay close to the ground at first. This is when the male takes over, showing them how to find worms while watching out for predators. After only a few days of this, the young birds can feed themselves and are fully-fledged. By this time, the second brood has been laid in the nest and is ready to hatch.

Source
Once again, I have used my recently-purchased copy of Roland H. Wauer's The American Robin (Corrie Herring Hooks Series), University of Texas Press, 1999.

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