Q: Recently a predator killed my cat -- a healthy 212 -year-old female. My suspicion is that it was a fisher, because the body was almost completely intact when I found the cat (just an opening in her belly and chest, breastbone sticking out). Does this sound correct? Vultures had pulled off her fur and something had eaten her eyes, but otherwise she was not torn apart. (Sorry to be so grisly.) If you have any advice about fishers and other animals that might kill a domestic cat, please let me know. -- Deb, Williamstown

A: The fisher comes to mind, even though there may be more evidence the coyote could well be the culprit. Other predators are known cat killers, including bobcat, fox, great-horned owl. Some say the fisher is among the top predators of house cats and alone is enough justification to keep pets, including cats and small dogs, indoors. A study conducted in north-central Massachusetts showed cat remains in only 2 percent of the fisher scats examined. Fishers are not cats and don't eat fish, but like the other predators mentioned will kill and eat mice, voles, squirrels and even muskrats and ground hogs in addition to fawns, and yes, although rarely, house cats. They also eat apples, and other fruits and berries as well as acorns and nuts.

Q: For years we have had five bluebird houses in our meadow that usually fill up with four tree swallow families and one bluebird family.


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This year, despite much activity, it appears we have only one active tree swallow family in all of the houses, and the bluebirds and the swallows have taken turns feeding the swallow chicks, sometimes one right after the other.

I tried to find out if this is common, but could not. None of our bird books on behavior or research on Google addressed this phenomenon. We certainly haven't seen it before in the many years we have had these houses. Your thoughts? -- David, Stockbridge

A: I have not heard of this particular combination before, but it is common practice among non-cavity nesters to hatch and care for the young of parasitic birds. In North America, the stocky cowbird (too large to get into a bluebird or tree swallow nest box) is such a bird and doesn't make a nest, but puts all her energy into making eggs that she lays in other bird's nests to be hatched and raised. They easily may lay more than a dozen eggs during the summer months, leaving them to foster parents. She is non-descript, being gray all over, compared to the male that is glossy black with a brown head, hence the common name, brown-headed cowbird.

The female cowbird is not fussy where she lays eggs, usually one to a nest. She will toss out an egg to make room for her own, which is most often larger than the host's eggs. And because the cowbird hatchling is usually larger than its nest mates, it gets most of the food at the others' expense. Most birds never notice the odd egg and will try their best to raise it as their own.

There is an account of an unsuccessful egg-laying in a hummingbird nest. To date, about 144 different bird species have been parasitized, including several very rare birds. And, an open mouth is incentive enough to excite breeding birds to feed, regardless of the bird that owns the mouth.

Q: For a couple weeks beginning about mid-June, there was a heavy layer of yellowish pollen covering our house and just about everything else in our yard. We have a large community field on Crane Avenue in Pittsfield with many dandelions among the grasses. It is regularly mowed and treated as a lawn. Could it be those, and would weed killer be the best option?

A: Dandelions are early blooming flower and not one that is a known trouble maker. By mid-June, very few are blossoming especially in a mowed area. It is undoubtedly white pine causing the problem, and weed killer won't help. The other option (removal) would be prohibitive.

Questions and comments for Thom Smith: Email Naturewatch@live.com