Did cool spell outside Yosemite confuse nesting house sparrows?
DEAR JOAN >> In the spring, I had sparrows that built a nest on my door wreath and subsequently raised four baby birds. Now in July, I have another pair intent on building another nest in the same place!
Is nest building common in July or could it be the uncommon shift in the weather?
I live in the Yosemite foothills, where we experienced a week of temperatures in the 80s that is very uncommon for this area, where the normal summer temperatures run 90 degrees into triple digits.
— Marcia Miles,
Coarsegold
DEAR MARCIA >> Climate change has all of us discombobulated, but the activity you're seeing now is not unusual.
House sparrows can have up to four broods a year, spring through summer. This very well could be the same nesting pair you hosted in the spring, or it could be a new couple looking for a new nesting spot.
As long as you don't mind the inconvenience of having a maternity ward and nursery on your front door, there's no harm in it, and you can expect them to return season after season.
Not everyone likes house sparrows, however. They compete with native birds for nesting spots and nesting boxes and have caused concerns about driving out some bird populations.
House sparrows were imported from Europe in 1851, when flocks were released in Brooklyn as a means of controlling Linden moth caterpillar populations that were threatening the city's basswood trees. No one realized, or possibly cared, that the birds would not remain in Brooklyn or even the state of New York. Within 50 years, the plucky little birds were winging over the entire continental U.S.
Their numbers have declined in more recent years, dropping from a high of 150 million in the 1940s to around 7 million now. No one is quite sure why we've seen a 95% decline, but it's suspected that the transition from farms to industrial use and urban development is the central cause.
DEAR JOAN >> OK, we all hate it when rats race down our fences at night, but here's my question: Do I discourage my dog from going after a night opossum on the same fence?
Opossums are famous for destroying rat nests. Those opossums are nasty, snarling, fearless beasts, but I'm starting to like them. Dog disagrees.
DEAR MARK >> My dog would agree with your dog, but having seen my dog make some questionable choices, I'm skeptical of some of his opinions. Although he was right about the Kardashians.
Yes, please have a talk with your dog about leaving the opossum in peace. Of all the wild creatures that visit our yards, the opossum is the least likely to cause problems and the most likely to be a benefit, the rat evictions being just one.
Opposums eat cockroaches, rats, mice, snails, slugs and beetles. As a bonus, they'll also happily glean overripe fruit and berries, but leave the good stuff for us.
Opossums have a certain amount of resistance to the venom of rattlesnakes, so they'll help keep your yard snakefree. They also eat around 5,000 ticks a year. What's not to like?