Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Nesting Behaviors
Name: Sheila
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: N/A

A Robin nested on a window ledge outside a second story window on my house. She laid four eggs and they were there for 2 weeks. Over the last 2 days, all four eggs hatched. We saw all four babies in the nest yesterday. This morning, there are only 2 babies in the nest. The Mom Robin is still taking care of those 2 babies. We (my 3 sons, ages 8, 5, and 2) are wondering what could have happened to the other two babies in a nest on the second story of our home?

A hawk or owl could have gotten them. They also could have fallen out of the nest and been taken as prey by a snake, opposum, or skunk.

Grace Fields

Several senarios could be possible. First, it is common for some of the hatchlings not to survive after hatching. Weaker nest members often do not get enough food. Competiton between nest members is an issue with a large clutch. Of course, disease and general health could have caused their death. In any case, the adults will remove these dead or dying individuals as they do with chick waste.

Keep in mind that Robin adults remove the waste packets and will dump them away from the nest to protect the location of the nest from predators.

Second, predators could be the cause. If all the members end of disappearing, then this is probably the case. However, if the two remaining members survive this is probably not the case for the predators would return for the easy food.

Steve Sample

Click here to return to the Zoology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory