Did a tiny bird or an insect lay eggs inside a Pleasanton acorn cap?
DEAR JOAN: I found this acorn in my backyard under an oak tree. Kiana Tenbrink, age 7, Pleasanton  DEAR KIANA: You are very observant  a talent that should serve you well all your life. I showed your picture to a few experts, and they all agreed that the eggs are not from a bird or an insect, and arent really eggs at all. They are a type of fungus that grows on decaying wood, such as the top of an acorn. DEAR JOAN: We have many gray squirrels. Last year when the babies came out, we had one black squirrel. This year there are three black squirrels. Theyre adorable. Madeline Taty, Santa Cruz  DEAR MADELINE: Black squirrels are the product of a genetic glitch  a faulty pigment gene. If a gray squirrel, and less frequently a fox squirrel, is born with two copies of the faulty gene  one from each parent  the squirrel will be black. If it has just one copy of the gene, it will be its usual color. The gene is recessive, but if you have a pair of squirrels that have produced at least one black squirrel, chances are theyll produce others, which could explain your increasing population. DEAR JOAN: I recently built a birdhouse for a pair of black-capped chickadees. They moved in and had a brood of five birds. The chickadees would fly in and out, and I could hear the babies chirping and crying when it was time to eat, and then something strange happened. I came home one day and didnt see any activity around the birdhouse. Two days went by and I didnt see the parents so I decided to get the ladder out, climb up and dismount the box from the tree. When I open the box, I saw five dead baby birds. I was curious as to why all of the sudden the parents stopped coming back and what couldve happened. My daughter was very upset, and I wanted to know if it was too late to build another birdhouse and encourage another set of parents to lay another brood. Todd Mehlbrech, Beaverton, Oregon  DEAR TODD: What a heartbreaking turn of events. Sadly, it happens more than we would like. Birds will abandon their nests and nestlings, but it takes a lot for them to do it. In this case, I think its likely something happened to one, if not both, of the parents. Black-capped chickadees are monogamous, but beyond that, it takes both parents to raise the brood. If something happens to one of them, the other just cant manage on their own, and the nest and babies are abandoned. Related Articles 33 cats, 1 dog found in California home after complaint of smell  East Bay park district to kill cats only as last resort to protect endangered species  East Bay parks district considers if its OK to shoot, kill free-roaming cats on park lands  Critter Corner: How to readjust your dog to pre-pandemic routine  CDC to suspend some dog imports over rabies concern The surviving parent will look to find a new mate and start over again. Black-capped chickadees only have one brood a year, and its getting late in the season for nesting. It wouldnt hurt to put the old box up or a new one to see if you get any takers. At least it will be ready for a new couple next season. To keep from having to climb a ladder or take down the birdhouse, I recommend getting a small mirror on a extension rod (mechanics use them for inspecting under cars) so you can peek in without disturbing anyone. For more wildlife, garden and backyard topics, sign up for our new, free Flora+Fauna newsletter. Use this form to submit questions. Photos should be mailed separately to jmorris@bayareanewsgroup.com.