Western Bluebirds

WESTERN BLUEBIRDS

from Bob Franz
5121 Hamer Lane, Placentia 92870
(714) 528-5082
bluebirds.bob@gmail.com

DESCRIPTION
   There are three species of bluebirds but only two are native to California - the Western Bluebird (Sialia mexicana), hereafter identified as WEBL, and the Mountain Bluebird (Sialia currucoides), hereafter identified as MOBL. The third member is the Eastern Bluebird (Sialia sialia), and it can be seen from the Midwest to the East Coast. Bluebirds are members of the thrush family that also includes robins. Since WEBLs are the most prevalent bluebird in southern California, the following information pertains mostly to them.
   WEBLs are smaller than the most-often seen blue bird in our neighborhoods, the Scrub Jay, and the bluebird's feathers appear more iridescent than the Scrub Jay's. The WEBL adult male’s head, throat, back and wings are bright blue; the breast is a rusty orange; and the belly is white. Female WEBLs are similarly colored but all colors are duller. The MOBL is slightly larger, with lighter blue upper parts and a lighter blue breast. The bluebird’s call is a rather faint and brief few few fawee.
   All bluebirds are in a group called cavity-nesters in that they require a protected hollow area in a tree, stump, post, or man-made nestbox, in which to build a nest and raise their young. Thus no cavity, no nest, no eggs, no nestlings, no fledglings.

BRIEF HISTORY OF BLUEBIRDS
   About 30 years ago, ornithologists in the Midwest noted that the number of bluebirds was decreasing at an alarming rate due to the shrinking of their habitat and natural nesting sites. A few of these bird lovers formed the North American Bluebird Society (NABS) in Maryland under the leadership of Dr. Lawrence Zeleny, a former Minnesotan. In the same year Vi and Dick Peterson of Brooklyn, Minnesota initiated the Bluebird Recovery Program (BBRP) of Minnesota. They soon discovered that, as cavity-nesters, bluebirds welcomed man-made nestboxes and the number of bluebirds in these areas has been increasing ever since.
This effort has grown since then and there are now NABS volunteer organizations in 25 states and 4 Canadian Provinces. California has a NABS affiliate organization called the California Bluebird Recovery Program (CBRP) that is based in Walnut Creek.
For about 15 years, a relatively small but increasing army of volunteers in Orange County has been dedicated to helping WEBLs. They installed nestboxes in Orange, Los Angeles, Riverside and San Bernardino counties and monitor them throughout the nesting season. Because of their efforts, the number of WEBLs has increased dramatically every year.
In early 2007, a few of the veteran bluebirders formed the Southern California Bluebird Club (SCBC) to increase local interest in WEBLs. I invite you to visit our website at www.socalbluebirds.org.

HABITAT
WEBLs thrive in and near fairly large open grassy areas where their food is most plentiful. MOBLs are found in higher eleva-tions.

FOOD
WEBLs eat mostly worms, insects and larva, found in grassy areas and some seeds and berries. Mealworms, available commercial-ly, are a delicacy for them.

NESTING SEASON
   The nesting season varies from year to year but it may start as early as mid-March and end in early August. Unusual weather in terms of cold or wetness sometimes increases or decreases these spans.

NESTBOX LOCATIONS
   Most advantageous locations for nestboxes are determined by the topography and habitat. Nestboxes are usually placed in or near large grassy areas such as golf courses, parks, schoolyards, cemeteries and residential green belts. Almost all nestboxes in southern California incorporate a hook at the top for hanging them in trees to avoid sprinklers and vandalism.

NESTING ACTIVITY
   Once a pair of WEBLs selects a nestbox, it usually takes the female a week to complete the nest. Upon completion, the female lays eggs, light blue in color, at a rate of one per day, usually in the morning. Although the number of eggs laid varies, five is the average although there can be as many as seven or even eight.
   Incubation of the eggs takes from 12 to 14 days after the last egg is laid. Once fledglings appear, both adults feed them every 5 minutes or so. Nestlings leave the nest - fledge - when they reach 16 to 21 days of age. It is important that the nestbox not be opened after nestlings reach 14 days of age to prevent premature flight. This is why it is recommended all activity be recorded, including the date, in order to determine the age of nestlings - see Recording below.
   Typically, they will build a second nest and fledge a second brood and sometimes build a third nest but this is rare.

MONITORING
Monitoring involves opening the nestbox and recording the existence of activity such as presence of a nest and/or number of eggs, nestlings and fledglings. Although some bluebirds appear to become quite agitated when their nestbox is taken down, they normally calm down after it is replaced and the monitor leaves.
Each nestbox is opened once per week, but no less often than once every two weeks. After the last fledgling has left, all nesting material and nest residue is removed and the nestbox reinstalled. Toward the first of August the nesting season is over and nestboxes are cleaned out.

RECORDING
There is no one unique type of form on which to record findings but whatever is used should indicate dates for each nesting action including the number of eggs, nestlings and fledglings. It is rare to see nestlings as they make their first flight, so the total number of fledglings usually equals the last record of the number of nestlings.

REPORTING YEARLY TOTALS
   After the last fledgling has left and the nestbox is clean, the year’s activity in terms of the number of nests, eggs, nest-lings and fledglings is summarized. Monitors send their totals to the CBRP/SCBC via an on-line program or they report them to another monitor.

WOULD YOU LIKE TO PARTICIPATE?
   We are always looking for volunteers; if you would like to participate, or know someone who might be interested in partic- ipating, please contact me – see the top of page 1. Bluebirding is strictly a volunteer effort and one can monitor as many or as few nestboxes as he/she wants. It takes only a few minutes to unhook a nestbox, look inside, record the observations and reinstall it, and the rewards are heartwarming.

PRESENTATIONS
I am available to give presentations on WEBLs most anywhere in Orange County – free of charge. The presentation takes about 30 minutes and besides talking about WEBLs, their habitat and nesting activities, I have a nestbox, real nests and real eggs for attendees to view.