Having noted the higher number of nestling losses in boxes of late season nesters (June-July) versus early season nesters (March-May), I have begun providing water and/or Elderberry berries to the adults. A video and photos showing the techniques and results follow.

The video shows an adult Bluebird repeatedly picking berries from small branches taken from an Elderberry bush, and piled on box's roof. The adult then fed the berries to a nestling inside the nest box.

The first photo below shows a hanging water dispenser on the left, and a hanging Bluebird nest box on the right. The nest box has branches containing Elderberry berries piled its roof. Subsequent photos show the male Bluebird repeatedly picking a berry which he then fed to the nestlings inside the nest box.

Too often, I have found two plus week old nestling dead in the box with no apparent cause. This is a demanding time for the adults who must feed both themselves, and their brood which is approaching adult size. Late season nesters experience higher daytime temperatures which, in Santa Clara County, can exceed 100 degrees Fahrenheit for days and sometimes weeks. The food base also decreases as the grasses become dry.

This season (2009), I provided water and/or Elderberry berries to ten of my more remote nest boxes, and all broods, but one successfully fledged. The brood that did not fledge was Violet-green Swallows, which did not consume the berries.

The hanging water dispenser is made from a recycled plastic fruit juice container.