Saturday, March 28, 2009

Caring for eggs

Hi All, Ron Joseph a wildlife biologist with the U.S. Fish and Wildlife service has contributed this very informative biologist journal about egg care and his experience with Peregrine Falcon recovery efforts. Enjoy!

CARING FOR EGGS AND EGG DEVELOPMENT

Both sexes develop brood patches or temporary featherless areas near the breast to facilitate heat exchange from adults to the eggs. Females perform most of the month-long incubation duties although males will spell females by incubating the clutch about 33% of the time. As a rule, peregrines are relatively quiet during this stage of the nesting season.
Males will occasionally call from a nearby ledge or other perch. And while the male is busy hunting for food (mostly birds) and stashing surplus food in caches, the female sits tightly on the eggs. About once an hour she'll stand up and turn the eggs with her bill to ensure an even distribution of heat in the developing embryos. In the late 1970s, when I began my career as a raptor biologist in Utah and Colorado, there were so few peregrines breeding in the west (none in Maine) we would not allow peregrines to incubate their own eggs. Peregrines back then still produced DDE induced thin-shelled eggs. The normal "wear and tear" of turning thin-shelled eggs by adults was problematic. Cracked eggs translate to dead embryos.
To avoid a potential reproduction loss, we fooled the adults by replacing a clutch of wild eggs with identical looking ceramic dummy eggs. The real eggs were transported in specially designed portable incubators to The Peregrine Fund's captive breeding facility in Fort Collins, Colorado. After the wild eggs hatched in captivity, the two-week old chicks were transported back to their home eyries in places like Dinosaur National Monument. I remember being stunned by the amount of damage to the first set of dummy eggs I collected after a month of incubation. The adults were stunned too in discovering loud, hungry young when minutes earlier an adult was incubating artificial eggs. We dropped many dead bobwhite quail onto ledges near the eyrie to help the adults feed their "surprise" family. Fortunately, peregrine populations today are recovering and the magnificent birds now reoccupy many parts of their former range, including Maine. Peregrine eggshell thickness has improved making it no longer necessary to manipulate the eyries with dummy eggs.

Best,

Ron Joseph
Wildlife Biologist
U.S. Fish & Wildlife Service
1168 Main Street
Old Town, Maine 04468

12 comments:

  1. 03/28 @ 22:40

    How wonderful to receive the information supplied by Ron Joseph. Most of us not only enjoy watching the cams but appreciate the opportunity to be involved in a learning process. Any questions answered tend to increase our thirst for even more knowledge. I believe that the more we understand our natural world, the better we are able to be good stewards. What I learn here I eagerly share with others ... just as I have done in the past with the eagle cam.

    And, so, I will keep watching this beautiful pair with anticipation and hope for their offspring and the continued recovery of peregrines.

    Thanks, again, for the informative and interesting post.

    JAM in IL

    ReplyDelete
  2. 3-29-09 10:44 a.m.
    Mom seems to be "getting" it finally, she's covering all 4 eggs now, when she 'misses" one she quickly gets up and maneuvers the egg around until she has all 4 again under her.

    Judy in Western Maine

    ReplyDelete
  3. I am a bit worried about the legs of the eyas....??I know with doves, pigeons & parrots ..... if the bottom of their nest is slippery...that is ... not with enough traction, that the babies often have ''splayed'' legs. I do hope this does not happen with a wild bird. It would be unable to hunt or perch.

    ReplyDelete
  4. 3/29 5:00PM
    Feel really bad for the parent on the nest. Been very windy and cold rain in Mass, must be worse in Maine. She/He seems to be holding their own against the cold wind. I wish Mother Nature would be more forgiving for this family. Would love to watch some babies grow and fledge like the eagles I watched 3 years ago.

    cathy h in mass

    ReplyDelete
  5. I AM UNABLE TO OPEN THE LIVE CAM. IS THERE A PROBLEM OR IS IT MINE?

    ReplyDelete
  6. Why was the nest platform built with this design? It would be informative to learn from the team why they chose these materials and the shallow bed. Thanks.

    ReplyDelete
  7. was the nest box changed today? its looks very different than yesterday

    ReplyDelete
  8. 4/01 7AM
    I agree! A different nest box. Can one of the biologist comment on how they made the change?

    cathy h in mass

    ReplyDelete
  9. 04/01 @ 8:10

    Wish we had video of the nest box exchange! Also wish the other cam was operating so we could see the "whole" picture. Seems the new box might be on the old? This one looks a little smaller and a lot deeper.

    The four eggs are still there and the falcons are diligently incubating. It seemed to me that, once the full clutch was laid, both falcons seemed more determined to cover them all. Can only hope the eggs are still viable. Time will tell.

    In the meantime, eagle cam2 has an egg ... hopefully more to come. Great anticipation growing at all of the BRI cams. Thanks so much for allowing all of us to share in and learn about the lives of these birds.

    JAM in IL

    ReplyDelete
  10. I am not sure who is responsible for the nest box improvements but thank you by the tons!! Hopefully it isn't too late and the eggs are still viable. More gravel helps to keep eggs under the parent and helps to keep them in place when they roll the eggs and change parent time. GOOD JOB on the new improvements!!

    ReplyDelete
  11. Does anyone know how froona is doing? I found from her profile that she follows this blog, so I am hoping someone knows. Over at the Derby peregrine blog someone posted that she was in the hospital and not well at all, but left no other info.

    ReplyDelete
  12. Decided to blog here today, as I am tired of all the bickering on the eagle cam 2. The baby falcon is growing VERY fast, it's hard to believe he/she could grow so quickly, Mom is having a difficult time keeping him warm, I don't know if the chick cam keep himself warm at night though, so anybody know the answer to this? It's a shame that the other eggs didn't hatch, maybe next year. Have a good evening.

    ReplyDelete