Friday, February 26, 2016

Wood Frog

A Wood Frog with its typical dark, raccoon-like bandit's mask.

     Wood Frogs (Lithobates sylvaticus) are not the typical frogs that come to mind when people think of frogs. For one, they are the most cold tolerant of all North American frogs, being the only American species found north of the Arctic Circle. They can tolerate having substantial parts of their bodies frozen with out harm and are usually the first frogs to breed every year. Wood Frogs can do this due to the production of high levels of glucose in their blood and other adaptations. This allows these amphibians to come out despite the fickle weather conditions of early spring and survive not only very low temperatures, but sudden decreases that would kill most other amphibians. Indeed, I've seen them when their ponds still have ice on them and seen them hopping through the snow after a sudden temperature drop has caught them away from shelter.
     As their common name suggests, Wood Frogs live in woodlands, under leaves and in other animals' burrows, but need to return in the early spring to lay their eggs in vernal pools. Breeding starts after the first sustained, warm rains of spring, normally in late February or early March around the DC region. They are among the first vernal pool species to come out of their winter torpor (called brumation) look for their natal pools. 
     Vernal pools are for the most part temporary, drying up in the heat of the summer. This means they cannot support fish and some other pond species. Because wood frogs tadpoles do not compete well with fish (or even other tadpoles), they rarely lay their eggs in waters containing fish, which consume their young readily. Instead, like other vernal pool species, they gamble on being able to go through metamorphosis before the pools dry up. Some years many do, other years none. Luckily, they are explosive breeders, and so, as long as the habitat remains suitable, they usually have enough good years to make up for the bad ones they always suffer. Their habitat though has to contain both established woods along with temporary pools.


Multiple Wood Frog egg masses laid communally in a vernal pond.

     Female Wood Frogs are larger than the males to allow them to carry more eggs, up to 3,000 at a time. These are are often laid communally. They can take some cold and perhaps gain some protection from being mostly laid close together. Because they also often have certain unicellular algae that grow on them, they can be well camouflaged. The algae is also suspected of providing oxygen to the developing embryos.  Depending on water temperature, tadpoles can emerge very quickly. I've had them born with 3 days of being laid in warm room conditions. Upon first emerging from their jelly-like egg mass, they are very dark. This perhaps helps them retain heat better. They change to a lighter color as they mature. 


A late stage Wood Frog tadpole.

     The tadpoles mostly feed on algae and detritus, but have been known to scavenge and even feed on toad tadpoles. The warmer the water and more food that is available, the faster they mature. They can metamorphose into froglets in under 2 months. They can also speed up their metamorphosis if the pool starts to dry up, though the smaller froglets that emerge are at a competitive disadvantage. Siblings from the same egg mass seem to recognize each other and stick together. Though distasteful to some predators, fish gobble them up. Under ideal conditions, they can be quite numerous, as this short video shows:

                            https://www.youtube.com/watch?v=a7cwRBAqAYk 

     They look really neat underwater: https://www.youtube.com/watch?v=vw2y9TlrlKA

     These frogs are various shades of brown, normally 2-3" and sport a dark bandit's mask. They are good jumpers and also good at concealing themselves in the forest duff. Indeed, they're rarely seen outside the breeding season at their vernal pools. Adult Wood Frogs can alter their body color somewhat. They get very dark when they first arrive to their ponds and when they're cold. If they're lucky, they can live 4-7 years, with the larger females living longer and needing an extra year (or 2 at higher elevations) to mature. 

A mating pair of Wood Frogs in amplexus, the smaller male on top.

     These are one of the first signs of spring for many naturalists, the males giving their duck-like "craw-awk" calls during any wet, warm spell in early spring. They can gather in huge numbers, but just as quickly disappear as soon as the weather changes or they're done breeding. To me, they signal that many more spring signs are on the way, but these cold-hardy amphibians are among the first to brave the worst weather. Being around on a "big night" (as herpetologists sometimes call when conditions are just right) and when they are migrating in large numbers is a truly wonderful experience. This is well worth braving the cold rain that usually accompanies them. Here's a video of a chorus of Wood Frogs from the Capital Naturalist YouTube Channel for your enjoyment:

                                 https://www.youtube.com/watch?v=eCo_J1__Qxo 


A pond full of the eye-shine of Wood Frogs on a "big night"
     We have had luck building vernal pools and restocking wood frogs where they had disappeared. It's quite enjoyable to know that you were partially responsible for bring animals back into places they once haunted. So I leave you with this last video of a 
successful restocking effort: https://www.youtube.com/watch?v=aaQxe35yuDQ


Wednesday, February 17, 2016

Rosebay Rhododendron - Great Laurel


     Rhododendron maximum goes by a variety of names: Rosebay, White Rosebay, Rosebay Rhododendron, Great Rhododendron, Great Laurel, and Mountain Laurel (though this last name is more closely associated with another native shrub Kalmia latifolia) to name a few. It is an evergreen shrub with twisted trunks. The maximum part of its name can refer to the big 4-10 inch leaves, large white to light pink flowers, and/or may be due it being one of the largest of our native rhododendrons.
     Rosebay prefers moist woods with light shade where, because it layers or roots where it touches the ground, it can form over time fairly formidable thickets. Indeed, some parts of the country such as the Smokies are known for their "laurel hells" or "laurel slicks" which can seem almost impenetrable. In June or so when they bloom however, they look like anything but hell. The large blooms are on the tips of the branches and really standout in the shady woods.
     Each large evergreen leaf can last up to 8 years before falling off, and is very resistant to decomposing even once it hits the ground. The dry seed capsules that form from pollinated flowers also are long lasting, often standing through the winter. Although each capsule might contain 400 seeds, the shrub tends to form colonies, albeit slowly, from the clones spreading from the parent plant rather than from germinated seeds.
     Though beautiful, the flowers can produce poisonous honey if visited by honeybees. Sometimes called "mad honey" or simply honey intoxication, it can cause all sorts of issues due to the presence of toxins referred to as grayanotoxins. Luckily, this is rarely fatal. The main natural native pollinators, in my experience, seem to be bumblebees who do not appear to be affected by these toxins.

Bumblebees seem to be the main pollinators, sometimes not even waiting for the blooms to open completely.

     The plant protects itself from being eaten by utilizing these and other toxins. Even though it is evergreen and so might be one of the few green things available to eat, most herbivores do not feed on it unless few other food sources are available. Having said that, this Genus of plants is known to host 51 caterpillar species that feed on various parts of these shrubs.
     Despite their toxic traits, people have used Rosebay in various ways. The Cherokee for instance made a liniment from it for pains and a poultice for headaches. It was used by them to treat everything from scratches to heart problems. A concoction from the leaves was used for rheumatism and the wood was used for spoons. Clumps of leaves were even thrown into fires in the belief that this would bring about cold weather.
     Confederate doctor Francis Porcher, ordered to find wild plant substitutes for goods and medicines no longer available during the Civil War due to Union blockades, listed several uses for Great Laurel. He recorded that it could be used to treat chronic rheumatism, gout, glandular enlargements, and even to induce sneezing. He did acknowledge that it had to be used cautiously though due its toxic nature.
     These days, Rosebay Rhododendron is used mostly as a landscape plant. Its beautiful blooms (now available in several colors), large evergreen leaves, few garden pests, and relatively compact size (10-40' tall at most) allows it to fit into many garden settings. The name Rhododendron actually means "rose-tree" and refers to the large and beautiful blooms these plants have. Rosbeay however does not like salt, compact soils, or drought and is very slow growing, so is not for every garden situation.

A Great Rhododendron bloom up close.

     Being evergreen has its own set of problems however. Besides having to have substances in the leaves to act as antifreeze and having distasteful properties to deter herbivores, there's the problem with water. Deciduous trees partially lose their leaves in winter to conserve water. Water, often frozen, cannot be transported effectively if it is lost through the leaves. Evergreen plants like Rhododendron often have a thick waxy covering to help prevent that loss.
     Rosebay Rhododendron is one of the few evergreens on the East coast that can survive repeated freezing and thawing cycles. This may be partially due to one of its interesting leaf traits. This plant's leaves are thermotropic, responding to temperatures and exposure. The leaves both droop and curl in response to cold and exposed conditions. This was often thought to be a response to help prevent desiccation and to keep snow from damaging them from accumulation, but others think there's a lot more to it than that.

Rosebay leaves drooping and curling on a very cold day.

     For instance, some people claim that they can tell how cold it is depending on how much the leaves droop and curl. If they are extremely cold, they point almost straight down and almost close. But if they're completely covered in snow, then the leaves may not curl, perhaps due to the insulating effects of the snow. In extreme drought and very bright sun, the leaves also curl. If it's bright due to the canopy having lost its leaves and cold, the leaves can also curl and droop. So the temperature, light exposure, and water availability may all play a role in how much or whether the leaves droop and curl. It's always interesting to note the angle and position of the leaves when I'm out on a walk. 
         So Great Rhododendron, the "rose-tree maximum," is a unique and interesting shrub. It's beauty and evergreen nature make it worthy of being the West Virginia state flower and a favored landscape plant. I certainly enjoy the one I have in my own yard, both for its beautiful blooms in June and for the promise the giant buds and evergreen leaves hold for beauty in winter. 

The large flower buds on the Rosebay at my house promise many blooms this June.


Tuesday, February 16, 2016

Resident Geese

A group of resident Canada Geese sleeps along a trail. Note all the droppings in the background.

     Just about everyone is familiar with Canada Geese, emblematic symbol of migration in long V-shaped flocks. Indeed, the Algonquian-speaking native peoples of the East even had one of their 5 seasons named for the "co-honk" sound signaled by arriving geese. But these days, the Canada Geese we see are not normally the migratory creatures of the past. They are instead permanent residents of parks, golf courses, and lakes who's presence can cause many issues.

A resident goose sits on a paved path, unafraid of human presence. Note the droppings in front of it.

     While we have 7 (some argue up to 11) subspecies of Canada Geese with differing ranges and sizes, our resident geese are the largest. They are larger than the migratory Atlantic Canada Geese (Branta canadensis canadensis) that fly through here and overwinter along our coast. Originally called the Giant Canada Goose, Branta candensis maxima, it once was in trouble of extinction and had a limited range. That it now is so common and often reaches pest status makes for an interesting story.
     The now-resident Giant Canada Goose (Branta canadensis maxima) averages 13 pounds in weight and can reach 20 pounds. They can stand 45" tall, with the males (ganders) being larger than the females. They are the largest geese in the world. Giant Canada Geese are not thought to breed with other Canada Geese subspecies in the wild, though they will mingle together when feeding. Originally they ranged from Manitoba through Kentucky, but were considered extinct in the wild by the early 1900's. 
     Flocks however were being kept by some collectors and hunting groups. They were popular live decoys due to their larger size and thus visibility, being used to lure in wild flocks of other Canada Geese. Some were also released outside their natural range for hunting and decorative purposes. By 1935, the use of live bird decoys was outlawed and many hunters released their pets rather than destroy them. Some 21,000 were estimated to have been released, many adopted by local parks. 
     In the 1960's, a truly wild flock of Giant Canadas was discovered in Minnesota. A push for conservation and reintroduction of these geese reached nation-wide efforts and was extremely successful. Every park wanted to have some of these large birds and assist in their conservation. This, along with the protection of the released captive live decoys, made for the establishment of colonies throughout the USA. The Giant Canada Goose was not only saved, it expanded its range and reached huge populations.
     Migration in geese though is a learned behavior. Since generations of these geese had never migrated (despite their human assisted movement throughout the USA), they did not know how to do so. Some people may be familiar with the movie Fly Away Home and how geese were taught to migrate following an ultralight airplane. What some people do not know is that this is based on a true story, first with the experiments with local migration by Bill Lishman, and then based on experiments done by Dr. William Sladen at the Airlie Center in Warrenton, Virginia. The purpose was to see if Endangered Whooping Cranes could be taught to migrate, but first by using the more expendable geese. This was finally accomplished in 1993 with 18 geese that were taught to migrate 400 miles from Lishman's property in Ontario to Warrenton Virginia. 
     So our resident Giant Canada Geese have never learned to migrate and are with us all year round. This permanent residency and their growing numbers (estimated at 3-5 million these days) can lead to multiple issues. That these wild geese can live an average of 12 years old (though the oldest wild one was 30 years and the oldest domestic one 80) and can have 4-8 young yearly, means they can form very large flocks quickly. 

Goose goslings are cute.

     Though it is well known that they mate for life, this merely means that if the old mate dies, a new one is found until death does them part again. Both geese care for the young and are devoted parents who can act very aggressively in their defense. This can not only lead to complaints from people who get too close to the goslings, but means that these large birds are fairly successful at rearing their young. Many predators think twice before messing with an adult giant resident goose pair.

Resident goose droppings litter a boardwalk and the water underneath.

     Large numbers of geese lead to large numbers of droppings. A goose can poop every 20 minutes or so if it finds enough food. They are mostly herbivores, capable of grazing on grass and any other plants they find. They can defecate a pound of 3-inch long droppings a day. Multiply that by the number of geese, and you can see that "Lawn Carp" as they are sometimes referred to, can make quite a mess.

There are many reasons not to feed wildlife.

     This is why they are not welcome in many public areas, and why most places also ban feeding them. This attracts and accustoms them to those locations, while usually not being very healthy for the individual birds anyways. Goose dropping are not only a nuisance and unattractive, fouling lawns and swimming areas, but can also be unhealthy and affect water quality. 
     Because of their appetites and sedentary nature, they can have a very significant negative effect on the habitat as well. They not only compete with other waterfowl and wildlife for food, but also can destroy the habitat they all depend upon. Already in our region, areas that are replanted with SAV's (Submerged Aquatic Vegetation) often need to be fenced off to simply give the plants a chance to establish themselves. This imperils restoration and conservation efforts that affect all sorts of other wildlife and flora. A flock of geese can overgraze an area very quickly, and unlike their migratory kin, do so everyday so that the habitat can never recover. 

A resident Canada Goose grazes on the short grass it prefers.

     Large geese flocks can also have some tragic consequences in the wrong locations. Huge amounts of funds are spent yearly to prevent geese and other birds from being around airports. These still result in approximately 240 plane-bird collisions a year. Luckily, these are not often to the extent of US Airways Flight 1549 and the Miracle on the Hudson, but do cause concern.
     There are of course many methods attempted to prevent resident geese from causing these issues. Some tactics include pyrotechnics, hazing, chemical repellents, alteration of habitat (geese dislike long grass or brush where predators can sneak up on them), and even dogs trained to chase them. But in reality this just moves the problem to another area, and perhaps to places who cannot afford these tactics themselves. They do nothing to deal with the issue that these animals are overpopulated, will grow their numbers each year, and will continue to cause environmental and aesthetic harm. 
     So there are logically also attempts to control their numbers. These are sometimes complicated by the fact that Canada Geese are protected under the US Migratory Bird Treaty Act, despite not being migratory anymore. This means that depredation permits and/or other legal methods need to be obtained in order to control them. One of the methods that is sometimes approved are round-ups while the geese have young and are temporarily flightless. Often the meat is donated to the homeless and these can be very effective since the geese cannot fly away, but is often dealt with misinformed public outcry and poor portrayals by the media. While this may make people feel good about their actions towards the geese, they do not alter the damage these geese cause and ignore the plight of the habitat and those other animals/plants that are then critically affected.
     Another way to control the increase in resident goose numbers involves addling the eggs. This means using some method such as shaking the eggs or coating them in oil so that they can no longer hatch. If the eggs are simply removed, altered visibly, or destroyed, the parents will simply re-nest. Addling tricks the parents into wasting their time incubating dead eggs until it is too late for them to nest again. This is very effective in keeping numbers from growing, though it does nothing to quickly lower any overpopulated numbers that may already exist in these long-lived birds. 
     Another method that is used is extended hunting seasons and liberal game bag limits. By timing the season both before the migratory geese start migrating and reach our region, or starting them after they've left (in areas where migratory geese do not overwinter), their numbers can be harvested. While this can be effective, hunting of course is not always possible in all locations and so would not work in all locations. 

Resident geese are quite comfortable living side by side with people.

     Canada Geese are very adaptable waterfowl and have learned to benefit from close association with man. These giants may not have learned to migrate, but have learned to live along side people and survive in even very urban environments. In numbers that the habitat can support and that do not damage the habitat, these birds are to be admired for their ability to survive. But people need to understand the effects these huge birds can have day after day in the same locations and that they need to be managed for the health of the habitat and all its occupants, whether animal, plant and/or human. 
     
A gaggle of Canada Geese.
     
     More on resident Canada Geese in this short video from the Capital Naturalist YouTube Channel:
                             https://www.youtube.com/watch?v=G4ypmJwGhU4 

Wednesday, February 3, 2016

Red Foxes


     Vulpes vulpes, the Red Fox, is the most widespread carnivorous mammal on earth, with 45 subspecies being found throughout. Our local subspecies is Vulpes vulpes fulva. It is found naturally or has been introduced to many parts of the world, being invasive in some places it was introduced into, such as Australia and some islands. Our version has its own interesting history, not being originally native to the mid-Atlantic, but now being among our most common predators. 
     There are a couple of leading theories as to why we have them around here now. Some believe them to be a combination of the introduced English Red Fox and North American Red Foxes that colonized this part of the country after it was altered by farming to make it more suitable for them. Others think they moved in when the land was changed for agriculture and that the introduced English foxes were lost in the mix, not playing a significant role in establishing what we now consider our red fox. 
     Fox hunting has always had an important place in our region and most specially in the Commonwealth of Virginia, as it has in quite a few former British colonies. Many of our forefathers were quite fond of chasing foxes. In fact, our own Father of the Country, George Washington, is considered the father of the American Foxhound as well, a breed he helped develop. The American Foxhound is the Virginia State Dog, and Washington experimented with improvements in breeding this dog due to his great love for the chase. Mount Vernon was the site for regular hunts both before and after the revolution.
     Apparently our own native Grey Fox, due to its preference for deeper woods and its tendency to quickly climb a tree to escape trouble, was considered not as suitable for fox chases. English Red Foxes were introduced instead, and when the habitat changed enough for the red foxes from other parts of North America to colonize, our own red fox was born. Some people think that the red fox's success has come at the expense of our native Grey Fox, but habitat changes are probably the biggest reason for its decline locally. 
     Red foxes are very adaptable, being able to feed not only on the rodents they prefer, but just as easily feeding on fruits, insects, many other small animals, carrion, and sometimes finding other clever ways to obtain food. The ones around suburban neighborhoods and restaurants for example often know when trash day is and know the trash pick up routes. They regularly check out what is being discarded and check to see if any rats or mice are around at the same time. 
     Red foxes generally do not use burrows or dens outside of the breeding season, rather preferring to sleep above ground. Their thick fur coats provide ample warmth and the tails function as blankets and scarves for cold noses. They will readily dive into groundhog holes or other cover to escape predators or bad weather however. Reds also make use of blown down trees, brush piles, and other natural shelters. If nothing happens to them, they can live to 15 years or so, but less than 5 is more usual in the wild.
     Foxes very rarely (if ever) endanger pets, since adult cats or dogs are too dangerous to mess with. During the breeding season however, I often get a call about an amorous fox courting a small dog, much to its frustration. I also get reports of foxes who escort pets when they walk by their dens, keeping an eye on them and hoping to intimidate what they see as a potential predator from getting too close to their young. This is all bluster however, foxes not really willing to confront dogs and cats.


An active fox den, the leaves cleared out from the front.

     In late winter or very early spring, foxes start looking for den sites to raise young. They often search for hill sides that will provide good drainage. They also look for natural features such as large rocks or the stumps of trees to provide extra shelter. Since groundhogs often use similar sites, old groundhog holes are often used. These require much less work to expand and customize for fox use. Dens are rarely used in successive years, as that helps cut down on parasites such as ticks, lice, and mites. Both male (confusingly called "dogs" or "dog-foxes") and female (referred to as "vixens") help raise the young. 


Two red fox kits outside their den in an Arlington, VA park.

     Antics of young fox kits outside their dens are something I hear about every summer. People find them adorable, like little puppies playing and goofing around. We had one family that lived under our nature center. The young used to regularly play tug-of-war with a road-killed (and very flat) squirrel. I must admit it was hard to get as much work done as we were distracted by them day and night. A fox den is often only calm when they think danger is outside. 
     Here's a short video of a fox den with kits in Arlington, VA: 
                            https://www.youtube.com/watch?v=mvTbwH7p_5o 
     Foxes are very susceptible to sarcoptic mange, the mites causing loss of fur and being a primary control on their numbers around here. This sometimes results in my receiving reports of unusual animal sightings, such as of coyotes and even chupacabras, when infected foxes surprise someone on an evening stroll. They can look very different once their fur starts to fall off and especially if they start to bite at their infected parts.
     Although foxes are considered a rabies vector species in Virginia due to their common nature and frequent encounters with other wildlife, rabies is still rare in foxes. People often report what they consider dangerous animals when they see one out during the day. This is really not that strange for them. Though nocturnal, they will hunt during the day, specially when they have extra pup mouths to feed. Reds also love to sun themselves on cold winter days, making themselves quite visible. Since they may also use our own trails and paths to get around, particularly after deep snows, encounters with foxes are very common place. Only if the animal is acting lethargic, stumbling, or aggressive should we report a fox as being sick or worry about them. Foxes are just trying to survive the best they can, and that sometimes means bumping into us. But we really have little to worry about from any healthy fox. I've had numerous encounters with foxes and have never been worried about any threat from them. 


Fox tracks in the snow. Notice they are in a single file, not side by side.

     The presence of foxes can often be told by the signs they leave behind. Tracks may look like a dogs, but among other things, foxes prints are laid out in a single trail. They direct register their footprints, much like cats, with the the back feet usually landing where the front feet have already stepped. This means you don't get many tracks side by side. Fox scat is also a good clue, often having both animal hair and seeds present. Foxes also seem to like to advertise their presence, so their droppings are often left on top of rocks, logs, or bridges. The scat is also pinched off and pointy on the ends, unlike say the cut-off blunt ends of the otherwise similar raccoon. 
     Red foxes are very inquisitive creatures, investigating anything new in their neighborhoods and using their superb senses of hearing and smell to find food even when it is buried under snow. The one in the first photo was checking out my deer hunting set-up when I snapped these pictures. I took advantage of it stopping to smell the the fake doe scent I had placed on the tree trunks, allowing me the time to get my camera and snap some quick shots before the sound alarmed him enough to run away. Its distinctive black legs and feet are visible, but not the white-tip on the tail that they are also known for, regardless of the various color forms they can be. 
     I once had a red fox that got extremely close. I was working at a park when I heard a flock of gobblers calling in the spring. Having my turkey call handy, I proceeded to try and call them. When they suddenly stopped calling, I thought I had hit a sour note. But that's when I noticed a red fox trying to sneak up on what he thought was a turkey. Foxes will try and catch a turkey, though usually the smaller hen. I hid behind a stump and proceeded to call him. He got so close, maybe 6-7' that I could see he only had one good eye. The chickadees were also mobbing and bombarding him. He kept trying to circle me, not knowing what to make of the situation. I finally decided he had gotten close enough and stood up. You should have seen the look on that fox's face, jumping and running away from what I'm sure he thought must have been the biggest, ugliest turkey it had ever seen. 
     I've also seen foxes actually follow turtles who are trying to lay eggs. They follow the turtle, who they would have a hard time eating due to the hard shell, and wait for her to lay her eggs. Turtle egg laying is often preceded by the mother urinating on the spot she intends to dig up, perhaps to soften the soil. The fox waits until she lays her eggs in the hole and then gobbles them up. Foxes often find nests by sniffing out the places turtles urinate as well, though some species of turtle make fake nests and urinate in random spots to throw predators like foxes and coons off.
     So you can see that red foxes are remarkable, adaptable creatures. Their numbers and range have actually expanded when many other animals have declined. Their varied diets and sly skills allow them to survive in less than wild settings. Whether visiting the local restaurant after hours for leftovers or rodents, to raiding pet dishes left outdoors, to following turtles to get fresh eggs, foxes are true survivors. So we needn't be worried about them around our residences and parks. Rather, we should consider ourselves lucky to be able to see them as our neighbors, day or night. So, what does the fox say? I suspect it's just leave me alone to act like a fox...