Friday, October 31, 2014

Pacific Forktail

On 21 July 2014 our family visited the Hand’s On Children’s Museum in Olympia, Washington. Who knew that I would need my telephoto lens? In the middle of the water lilies in a small, decorative pond flitted a Pacific Forktail, a new damselfly for my list. (Generally we were disappointed in the relatively low numbers of dragonflies observed during our western trip, and this was the last one we saw.)

I had to make do with my short lens, focusing through a glass window, and greatly enlarging the photo—never excellent strategies for producing stunning wildlife photos. At least I had a sunny day! Especially if you enlarge this image on your computer screen, you can see this species’ salient field marks. At least four pale blue spots grace the top of the thorax. No other forktail in the Pacific Northwest sports such spots (Paulson (2009). The urban habitat also fits well. Paulson writes, “in the Northwest, more likely to colonize backyard ponds than other damselflies.”

Thursday, October 30, 2014

Rough-skinned Newt

The McLane Creek Nature Trail, near Olympia, was developed by the Washington Department of Natural Resources. Although only a mile long, the trail winds through forest and wetlands and is a great place for birding. We walked the trail on 20 July 2014.

A new creature for us, however, was not a bird, but this Rough-skinned Newt. This amphibian is common throughout western Washington and along the West Coast. This species is likely to be found out in the day, perhaps because its skin is highly toxic and is avoided by predators. The toxin is the same that is found in pufferfish and can induce paralysis and death. Only the Common Garter Snake can survive eating a Rough-skinned Newt (Washington DNR). The DNR warns that these newts "can be handled safely but care should be taken with small children prone to putting things in their mouths. After handling any amphibian, one should avoid touching the mucus membranes of the eyes, nose and mouth until hands have been washed.” People usually just suffer skin irritation, although one person, on a dare, is reported to have swallowed a Rough-skinned Newt—he died (Wikipedia).

Rough-skinned Newts are usually terrestrial, and move to ponds to breed. A few populations remain in ponds through the summer but migrate back to land in the fall. Others remain in ponds all year. Reproduction is aquatic. Adults breed when they are about five years old, and may breed every other year. Males arrive at ponds, transform into their aquatic phase, and wait for the females. When a female enters the water, males rush to grab her. The successful male hugs her from the back until she is ready to have her eggs fertilized. The male then deposits a sperm sac and she picks it up with her cloaca.  The eggs, which are also toxic, are deposited on submerged plants.  The eggs hatch into larvae, which become terrestrial after about a month, or they may overwinter and transform the next summer (Californaiherps.com).

Wednesday, October 29, 2014

Hooded Merganser

This young Hooded Merganser rested at the McLane Creek Nature Trail, near Olympia, Washington, on 20 July 2014. Unlike the nearby Wood Ducks (see last post), Hooded Mergansers are single brooded. Males abandon the nest cavities when the females begin incubating. Females are on their nest for about a month. The hatchlings leave the nest within a day of hatching, in response to the females' calling to them. The ducklings feed themselves, even on their first day out. They are capable of diving, but often feed with just their heads underwater. They eat aquatic invertebrates. The young fledge after about 70 days. Banding studies show that some young fly up to 700 km north in the fall before moving south in the winter (Dugger et al. 2009).

Tuesday, October 28, 2014

Wood Duck

Wood Ducks breed in nest boxes and in tree cavities. They are among the few North American ducks that nest twice in the same season. Often, but not always, this second brood is laid by older females. The second brood is usually smaller than the first. The number of eggs laid by females depends not on her age, but on her weight.

Wood Ducks often lay their eggs in other Wood Ducks’ nests. Hooded Mergansers will also lay their eggs in Wood Duck nests. Rates of this nest parasitism vary, but have been reported in some populations as high has 85% for nests with other Wood Duck eggs and 39% with Hooded Merganser eggs. The rate of parasitism is apparently correlated with how easy it is to see the nest cavity. The average number of eggs in non-parasitized nests is 9 to 12; parasitized nests can host up to an average of 22 (Hepp and Bellrose 2013).

Erika and I photographed this male Wood Duck as it warily eyed us during a stroll in the McLane Creek Nature Trail, near Olympia, Washington, on 20 July 2014.

Sunday, October 26, 2014

River Otter

Writing this post, I was surprised to learn that River Otters are found throughout North America. I only knew them from the Boundary Waters Canoe Area of northern Minnesota. They are, however, rare in some parts of their range, as they are sensitive to pollution, over-trapping, urbanization, and wetland destruction. Reintroductions have been successful in other areas where they have disappeared.

On 19 July 2014, Erika and I visited the Nisqually National Wildlife Refuge near Olympia, Washington. Otters burrow near water and can submerge under water for almost eight minutes. This habit makes them somewhat difficult to photograph. Otters eat small fish and various amphibians, crayfish and even turtles (National Geographic).

Saturday, October 25, 2014

Review: Beetles of Eastern North America


J. S. B. Haldane, the famous British geneticist, is reputed to have been asked by a theologian about what conclusions the study of evolution might have on the nature of God. Haldane replied, assuming the Lord spent most of his time creating the creatures He liked best, and there being so many beetles on the planet, then the Creator must have “an inordinate fondness for beetles.” Beetles make up to one-fifth of all plant and animal species found in eastern North America.

The Beetles of Eastern North America is written by Arthur V. Evans and published by Princeton University Press in 2014. Naturalists will enjoy this stunning guide. Most of the 560 pages are illustrated with up to four, large, color photographs of various beetles—1500 photographs in the whole book. Each photograph is accompanied by a short paragraph describing the species and a bit about identification, habitat and range. You can take a peek at some of the pages by clicking on the link at the top of this review.

An illustrated key to the most common of the 115 beetle families found in eastern North America begins the accounts. 1409 species are included in this book. The problem is that this total is fewer than 10% of the beetles of the region. Thus this book is more of an introduction to beetles of the East, rather than a field guide. Furthermore, only experts with hand lenses can separate many beetle species. In fact, many beetles lack common names.

Those wishing to learn more about beetles will enjoy this book's introduction. Anatomy, behavior and natural history, and where to find beetles are all covered. Subsequent sections talk about observing, photographing, and collecting beetles—and, if you are really taken by studying beetles, how to keep and rear them in captivity.

Friday, October 24, 2014

American Bullfrog

Bullfrogs are native to eastern North America but have been introduced across the country and around the world. These introductions have been accidental or on purpose—they are considered a delicacy and escape from farms, they have been used as biological control agents, or they may be escaped pets.

Where established outside of eastern North America, they are invasive species. Female Bullfrogs lay up to 25,000 eggs, and, after about two years, hop out of their ponds onto land (MN DNR). The concern is that Bullfrogs may out-compete, native amphibians and unbalance local ecosystems. Bullfrogs are voracious, opportunistic, ambush predators that capture any small animal they can overpower—rodents, small reptiles, amphibians, crayfish, birds, and bats have all been found in Bullfrog stomachs (Wikipedia).

On the other hand, Bullfrogs provide nutrition to their predators, including herons, otters, large fish and snakes. Bullfrogs may be resistant to copperhead and cottonmouth venom—an interesting hypothesis for study if one were looking for a thesis topic.

This bullfrog and many others hunted under the algae-covered pond at the Nisqually National Wildlife Refuge near Olympia, Washington. I confirmed my identification with a refuge ranger, who made an unhappy face and said, “I wish they weren’t there."

Thursday, October 23, 2014

Caspian Tern

This Caspian Tern flew by us at Nisqually National Wildlife Refuge on 19 July 2004. The tern is flying in a typical posture, with its bill pointed downward. When a fish is spotted, the bird hovers and then plunges, often completely going under water. Fish are the Caspian Tern’s main staple.

I have blogged about these terns before; indeed, this observation is my second for the year—the first being on the Texas coast in February. This tern occurs on all continents except Antarctica. In North America, they breed both coastally and in the interior. American Caspian Terns winter south to Colombia and Venezuela. Our populations are increasing, unlike those in Europe and Africa, where they are often rare or extinct (Cuthbert and Wires 1999),

Tuesday, October 21, 2014

Barn Swallow

The Nisqually National Wildlife Refuge near Olympia, Washington, has a long boardwalk across the mudflats at the south end of Puget Sound. On 19 July 2014, Erika and I discovered this Barn Swallow family under the eaves of a covered bench along the walkway. Pandaemonium broke out every time an adult flew up to the nest, but the adult always flew in and out before I could snap a photograph.

Barn Swallows tolerate extra adults at their nests. These extras may help at the nest for an entire breeding season and are not necessarily related to the nesting pair. This situation sometimes leads to polygyny. Other helpers may replace a deceased pair member. The extra adults do not help much in feeding the young, but do assist in building the nest, incubation, and brooding. A nest with helpers is often “owned” by an older female, and the hypothesis is that male attendants are trying to secure high-quaility mates. Juveniles from first broods also help at the nest. In this case, the helpers do supply substantial amounts of food. Occasionally unrelated juveniles serve as helpers.

Sometimes extra adults are chased off. Curiously, reproductive success is not affected by the presence of adult helpers. The extra adults are most often found when swallow populations have a skewed sex ratio, and not all individuals can find a mate or a nesting site. Related juvenile helpers benefit from the experience of “baby sitting,” and assuring the survival of their parents’ genes. Why unrelated juveniles would be tolerated is less clear (Brown and Brown 1999).

Monday, October 20, 2014

Savannah Sparrow

Like the Least Sandpiper I wrote about in my last post, the abundant Savannah Sparrow has a wide range across North America. Also like the sandpiper, the sparrow usually returns to its nesting area. This behavior often results in reproductive isolation and genetic differentiation among breeding populations. Unlike the monotypic sandpiper, 17 subspecies of Savannah Sparrows have been described by ornithologists. To see some of this variation, look at my posts of birds from Minnesota and Florida. This sparrow was first named by Alexander Wilson, when he collected the first specimen near Savannah, Georgia (Wheelwright and Rising 2008).