An online resource based on the award-winning nature guide

Mammals

Virginia Opossums Breeding

2-18-19 opossum 025If you see a Virginia Opossum in your travels, it could well be on the hunt for a mate at this time of year. It’s even possible you may hear one if you are close enough and the timing is right, as male opossums attract females by making clicking sounds with their mouth.

The breeding practices of this marsupial are unusual, to say the least. The male opossum has a bifurcated (two-pronged) penis (see photo inset), and the female has two vaginas. Not only is their reproductive anatomy somewhat unusual, but the behavior of their sperm is as well. During maturation, sperm pair up inside the male reproductive tract and remain paired after entering the female. Just prior to fertilization the sperm pair separate (into two spermatozoa). This phenomenon occurs only in American marsupials, and not Australian. No definitive explanation exists for this, but perhaps paired sperm increase motility in the female reproductive tract.

(NB: Having an opossum on your land is a real asset – according to biologist Richard Ostfeld, one opossum can kill and eat some 5,000 ticks in a single season. Opossums are said to destroy roughly 90 percent of all the ticks they encounter.)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


North American River Otters Foraging For Fish

11-30-18 otter with fish_U1A2403

Whether or not North American River Otters made the original holes evident in Wednesday’s Mystery Photo, they were responsible for keeping them open by frequently poking their heads up through them for some air. Congratulations to Noel K. for being the first to correctly identify their surface holes.  This was a tricky Mystery Photo, as there were none of the usual signs of otter activity (tracks, fish remains, etc.) on the ice surrounding the holes.  This is probably because the ice was too thin to support the weight of an otter.  To find the most humorous response, scroll down on Wednesday’s Mystery Photo comments until you get to Peg Emerson’s.

These semiaquatic members of the weasel family are active year-round and while they are mainly nocturnal and crepuscular during the summer, they are frequently spotted during the day in winter.  If otters encounter open water, they rarely resist the urge to enter it and pursue resident fish.

Thanks to their webbed feet and streamlined body, otters are accomplished swimmers and divers. They are able to reach a depth of around five feet and remain submerged for up to four minutes as they hunt underwater. Top swimming speed is seven miles per hour. (They can achieve a speed of up to 18 miles per hour when running and sliding on snow or ice.)  While fish are their mainstay, these carnivores also consume frogs, snakes, turtles, insects, birds and bird eggs and the occasional mammal (mainly muskrat).  Though called “river” otters, they forage in fresh, salt and brackish waters. (Thanks to Rita and Dave Boynton for photo op.)

Naturally Curious is supported by donations. If you choose to contribute, you may go to https://naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Eastern Gray Squirrel Diet Preferences

11-16-18 gray squirrel_U1A1563

The diet of Eastern Gray Squirrels is extremely varied. Depending on the season, buds, fruit (such as the pictured crabapples being consumed), maple and oak flowers, berries, seeds, fungi, the inner bark of maple and elm, insects, and young birds are eaten. However, nuts are by far the main component, which is reflected in their distribution; the range of Gray Squirrels coincides strikingly with that of oak and hickory forests. Especially during the colder part of the year, nuts, acorns and maple seeds, or samaras, that they have stored for winter consumption are the mainstay of their diet. (Research shows that Gray Squirrels recover 85% of the nuts they store.)

Naturally Curious is supported by donations. If you choose to contribute, you may go to https://naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


White-tailed Deer Giving Birth

deer and fawn alert _H6A8525 copy (002)White-tailed does give birth at the end of May and the beginning of June. A doe giving birth for the first time usually has one fawn; in subsequent years, two or three fawns are common. For the first three or four days after it is born, a fawn is odorless and is well camouflaged thanks to its spotted coat.

During this time the mother leaves her offspring (who remain motionless during her absence) and goes off to feed. (It can be three weeks or so before the fawns follow their mother when she feeds.) The doe stays away as much as possible from her fawns during these first days and weeks to prevent her own body scent from giving away their location. She returns to nurse her young eight to ten times in a twenty-four-hour period.

People discovering what looks to them like an abandoned fawn should know that although the doe may not be in sight, she most likely is within hearing distance and is probably watching them. The fawn has not been abandoned and should not be disturbed. (Thanks to Erin Donahue, who took this photograph.)

Naturally Curious is supported by donations. If you choose to contribute, you may go to https://naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Red Fox Kits Maturing

5-25-18 red fox kit_U1A4366Time is marching on…the blue eyes of Red Fox kits are turning brown, as they do once a kit is around two months old. Their coat is slowly being replaced by the reddish hairs for which they are named. While kits still spend most of their time close to their den, individuals will take short exploratory walks by themselves. Frequently they accompany their parent on forays during which they are instructed on the finer points of being a successful predator.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.

 

 


Black Bear Yearlings Still Nursing

4-6-18 mother black bear with three yearlings nursing in light snow by MHolland 1077

Female Black Bears mate every two years. Their young are born in January or February and  they stay with their mother for the first year and a half of their lives. Although many sources state that cubs are weaned during their first summer, I discovered firsthand that young bears continue to nurse well into their second year (even though they’ve been eating solid food since they were a few months old).

Two different times while I was within a stone’s throw of her, the mother lay down on the ground and her yearlings proceeded to nurse. Soon, in May or June, shortly before she mates, the mother will drive her yearlings away, forcing them to disperse. Life’s lessons have been taught. By their second spring the yearlings have learned the basics from their mother: what to eat and where to find it, how to defend themselves, where to find safety and how to interact and communicate with other black bears. and they should be able to survive on their own.

Naturally Curious is supported by donations. If you choose to contribute, you may go to https://naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Black Bear Yearlings Active

3-30-18 yearling black bears mock fighting 1276

Just like other young mammals, young Black Bears are highly energetic. When they aren’t sleeping, they can be found wrestling, biting, grooming, climbing and playing hard with each other. All of these activities, including the pictured yearlings mock-fighting, equip them with necessary survival skills.

Naturally Curious is supported by donations. If you choose to contribute, you may go to https://naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.