My good friend Frank Henzie of Greenfield, Ind., emailed me a picture of a nest containing an obviously larger and different-colored egg among the clutch. Frank simply questioned, “Why is one egg different?”

Frank’s picture was of a nest hijacked by the Brown-headed Cowbird. In a lot of regards, the Brown-headed Cowbird has to be the worst wildlife parent ever. The male and female join up and the female proceeds to lay up to 40 eggs in the various nests of other host birds.

The cowbirds never build nests or raise their own young. They locate nests to parasitize by looking for other birds building nests, walking along the ground, perching quietly in trees or making noisy flights back and forth along foliage to flush out other birds building nests. Once a nest is located, the female cowbird usually lays a single egg per nest.

The female cowbird will wait until the host female begins laying eggs in the nest, and the cowbird will often remove one egg before laying hers. Once the deed is done, the pair of hijacking Brown-headed Cowbirds are off to locate the nest of another unknowing host.

The incubation period on cowbird eggs is short and lasts only 10-12 days, allowing the Cowbird chick to get a head start on the rest of the nestlings. The young Cowbirds grow rapidly and have a huge competitive advantage over the other young birds in the nest. The Cowbird chicks typically leave the nest after 8-13 days, but are dependent on their foster parents until they are about 25-39 days old.

Once fledged and no longer dependent on the host parents, the young Cowbirds will form small flocks with other juveniles.

More than 220 different bird species have been observed with Brown-headed Cowbird eggs in their nests. At least 144 species have successfully raised Brown-headed Cowbirds to the fledging stage, often at the expense and sacrifice of their own young.

The unusual habit of the Brown-headed Cowbird parasitizing nests is thought to have developed because the birds originally followed the buffalo herds on the Great Plains. Eating insects and seeds disturbed by the herd and being constantly on the move, left little or no time to build nests or raise young.

As the forestlands of the East have been cleared for farmland, the range of the Brown-headed Cowbirds greatly expanded.

Occasionally, the host bird detects something is amiss when the nest is parasitized, and abandons the nest and eggs. Such was the case with the nest Frank reported.

C.O. Mollenhour conservation camp is still accepting registrations for boys and girls ages 9-14. The camp for boys runs from July 8-13, and the girls’ camp is July 15-20.

Campers learn about all aspects of Indiana’s natural resources in classes and field situations taught by Indiana conservation officers and other Department of Natural Resources instructors.

Campers are taught and receive a certification in Hunter, Trapper and Boater education, participate in camp challenges and enjoy time fishing and swimming on McClure Lake in Kosciusko County.

The cost is $200 for the week and includes three meals a day and lodging. Registration forms are available online at www.conservationcamp.org

Walk-in registrations will also be accepted on Sunday at the start of camp, from 2:30-4 p.m.

For more information, contact conservation officers at 574-457-8092 or visit online.

The Upper Wabash Interpretive Services is proud to present Dr. Bruce Kingsbury on July 26, from 6-8 p.m. for an Introduction to Herpetology. Kingsbury is a professor of biology and director of the Herpetology Center, Indiana University-Purdue University Fort Wayne.

The workshop will be at the Salamonie Interpretive Center in the Lost Bridge West State Recreation Area off of Highway 105 near Andrews. The evening will present the opportunity to learn about Indiana amphibians and reptiles, see specimens up close and find out more about their lives.

The class is open to ages 10 and older. Attendees younger than 12 years must be accompanied by an adult. There will be a $5 per-family fee and light refreshments will be served.

Registration is requested and can be made by calling the Upper Wabash Interpretive Services at 260-468-2127. The standard entrance fee ($5 per car in-state; $7 for out-of-state license plates) will be waived for pre-registered students.

The views expressed in this column are those of the author and not necessarily those of Farm World. Readers with questions or comments for Jack Spaulding may contact him by writing to him in care of this publication.