Search Nature Watch

Showing posts with label fauna. Show all posts
Showing posts with label fauna. Show all posts

Tuesday, May 27, 2025

Roving Ringtails


Raccoon or Ringtail?

The common but elusive Ringtail or Ringtail Cat (Bassariscus astutus) is not a cat at all, but a member of the Procyonidae Family and a close relative of the Northern Raccoon.  The origins of its scientific name comes from bassar or ‘fox’, isc or ‘little’, and astute or ‘cunning’. In Texas, it is found mostly in the Trans-Pecos, the Edwards Plateau, and the Cross Timbers regions.   

An adult Ringtail on our back porch railing.

While ringtails are cat-sized mammals, their face is fox-like with a pointed snout, their body is elongated, and their tail resembles a raccoon.  The ears are large, and their big, dark eyes are each surrounded by a patch of light-colored fur.  The fur on their body is buff to brown-colored above and whitish below, with a spectacularly bushy, ringed tail.  This tail is often longer than their body, and is marked by a series of 14 to 16 alternating black and white rings (black rings incomplete on the underside) with a black tip.  

Close-up of the face of a Ringtail.

Mainly nocturnal but sometimes seen at dawn and dusk (crepuscular), ringtails are roving, solitary mammals that come together only to mate.  Their breeding season starts in late February and continues to mid-April, and females are in heat for only one 24-hour period during this time.  In early May to mid-June 2 to 4 cubs are born fuzzy, white-haired, and with a tail that is not yet colored with the distinctive black and white bands.  The cubs open their eyes at one month, and at four months begin hunting for rodents, insects, lizards, birds, and berries.  Ringtails are quite vocal, especially the young, and will make a variety of sounds including squeaks, chatters, grunts, growls, and hisses, with the typical call being a loud, plaintive bark.  In the wild, ringtails live an average of seven years. 

This Ringtail is eating sunflower seed that has fallen out of our bird feeders.

Ringtails can be found in our oak-juniper woodlands that have rocky areas associated with water, including riparian canyons and caves, limestone cliffs, and sometimes in man-made structures like mine shafts.  They can den in tree hollows, rock crevices, other animals’ abandoned burrows, and even seldom-used spaces in buildings.  They roam frequently, rarely spending more than three straight nights in one den.  Interestingly, the ankle joint of the Ringtail is very flexible and is able to rotate over 180 degrees, which makes them very agile climbers.  By pressing their feet against one wall and their back against the opposite wall, or by pressing both right feet against one wall and both left feet against the opposite wall, they are able to ‘stem’ or ascend/descend narrow passageways and wide cracks in the rock.  Their strong tail can provide balance for negotiating narrow ledges and limbs, and even allows them to reverse direction by performing a cartwheel!       

Getting access to our bird bath is an easy feat for the agile Ringtail!

Ringtails have many other common names, including Miner’s Cat, as they were often kept by miners and settlers as pets, to keep their cabin free of mice.  A hole was cut in a small box that was placed near a stove or fireplace, which acted as a dark, warm place for them to sleep during the day, and they returned the favor at night, hunting mice and keeping them and other rodents at bay.  In the native language of the Nahuatl Indians of Mexico, ringtails were called cacomistle, which is derived from the word tlahcomiztli meaning ‘half mountain lion.’  Whatever you call them, consider yourself lucky should you spot one of these beautiful, timid, and rarely seen nocturnal mammals!  




Monday, September 2, 2024

Migration Isn't Just For The Birds

 

Wandering Glider dragonflies do more than wander...

Most people who are interested in nature know that each spring many species of birds migrate north, and each fall they migrate south.  But birds aren’t the only animals that participate in this amazing natural phenomenon, as even some insects (other than the well-known Monarch butterfly) participate in long-distance migrations as well.  While insects are the most species-rich and abundant group of macroscopic organisms on the planet, understanding many aspects of their annual cycles and behavior drastically trails behind the ability to identify and classify them. 


Migration is defined as the cyclical travel of an animal as it returns to its place of departure.  It can be accomplished in one or multiple generations.  Some animals don’t migrate at all, and others move only short distances south or north.  While the guiding factors for navigation are still being discovered, migration is typically triggered by local climate, food availability, seasonality, or reproduction.


Adult Common Green Darner

Interestingly, about nine dragonfly species are known to migrate, including the Common Green Darner (Anax junius), Wandering Glider (Pantala flavescens), as well as some species in the Skimmer family such as meadowhawks and saddlebags. These dragonflies are known to travel up to 1500 miles over the full cycle of their migration, taking three generations.


Adult Wandering Glider


The secrets of dragonfly migration were discovered and confirmed by biologists measuring the chemical makeup of their wings.  In their immature or nymph stage, dragonflies grow their wings while still developing in local water.  Because the stable hydrogen isotope concentration varies in concentration by latitude, biologists can estimate the geographic region where adult dragonflies developed as nymphs.  


The female Common Green Darner (bottom) is held by
the male (top) after mating, when ovipositing in water.

From February to August the first generation emerges in the south and migrates north.  From June to October the second generation emerges in the north and migrates south.  Both of these generations have the ability to undergo rapid development from egg to adult.  But from November to March the third generation emerges in the south and is non-migratory, focusing mainly on producing another first generation for the cycle to start again.  It is this generation that employs a different strategy, developing slowly in late fall, entering diapause or actively induced dormancy over the winter, and emerging in early spring.


Dragonfly migration was not well understood until very recently.  Research published in 2018 detailed the journeys of Common Green Darners by analyzing 852 wing samples from eight different countries and utilizing 21 years of citizen scientist observations to link each specimen to its place of origin and establish its migration history. However, it is important to note that the timing of migration and the development of nymphs are both highly temperature dependent, so continued climate change could lead to fundamental changes in the migration cycles for dragonflies and other migrating insect species. So as you can see, migration isn’t just for the birds!