Source of calcium, the one thing that martins are missing in their diet of flying insects. Martins collect calcium in form of shells and bones and feed to their young. They also feed grit, to help grind up insect exoskeletons - so it's not unusual to find small pieces of stone, glass, or metal, in nests and in droppings.
Here's a little more info about offering calcium & grit to martins. Females benefit from calcium at egg-laying time.
Martin Colony History: I have been exposed to purple martin sounds in utero when my mother went out to get my father away from his martin colony. I played around the martin colony every summer and watched as my father maintained his colony. In the late 50's until the 70's he did not notice European Starlings in south Texas. When old enough, I helped maintain his colony. My primary task was eliminating English House Sparrows with a 1956 Benjamin 317 .177 air rifle. When I settled into my own home, I started my first colony with an original Trio Castle and Trio Grandpa. When I moved again, I did not put up any martin houses. Frustration with European Starlings in the Southeast US was overwhelming. Found PMCA Forum and learned about modern enlarged compartments and SREHs. Inherited my father's last martin house, a Trio Grandma, modified it to modern specifications and have had good results since then.
Is it still believed that washing the eggshells in water to remove any remnants of egg albumin prior to drying/sterilizing the eggshells necessary?
Mark.
Mark.
Firm believer in HOSP/EUST Control, Enlarged Compartments, SREHs, Pole Predator Guards, Owl/Hawk Guards, Mite/Parasite Control, Housing Insulation, and Vents for Compartment Cooling.
PMCA Member.
Martin Colony History: The 1972 St. Agnes flood wiped out all the Martins in my area. One day, in 1997-98, 5 or 6 Martins landed on the power wires crossing my back yard. I had no house for them. They kept coming back day after day. We got a martin house a few weeks later & they have been coming back every year since. I average 12-15 pair per year.
Is it still believed that washing the eggshells in water to remove any remnants of egg albumin prior to drying/sterilizing the eggshells necessary?
Mark.
Mark:
I rinse the egg shells, then soak them in water for a few hours before peeling the membrane out. Then I set them on paper towels to dry. I then crush them & put them in a ziploc bag. My colony ate a good 3-4 cups of egg shells last year. They also feed them to their chicks.
