Friday, June 28, 2013

Loose Feathers #398

American Avocet / Photo by Steve Tucker USFWS
Birds and birding
Science and nature blogging
Environment and biodiversity

Monday, June 24, 2013

Photo of the Week: Leatherwing Beetles

National Pollinator Week has ended for this week, but before it did I photographed these beetles mating on Common Milkweed. These are Margined Leatherwing beetles, members of the family Cantharidae, the soldier beetles. Leatherwing beetles are relatively easy to find and recognize, especially compared to other members of their family. While bees are the most efficient pollinators, many beetles, such as the Margined Leatherwing, also pollinate as they feed on the nectar and pollen that flowers provide.

Friday, June 21, 2013

Loose Feathers #397

Arctic Tern / USFWS Photo
Birds and birding
Science and nature blogging
Environment and biodiversity

Monday, June 17, 2013

Photos of the Week

This weekend I participated in the Union County BioBlitz, which covered a cluster of three small suburban parks: Nomahegan, Lenape and Echo Lake Parks. The parks follow the course of the Rahway River and one of its tributaries. The habitats are mostly riparian woodland, with some open fields (both mown and unmown) and freshwater ponds. Saturday was my first time attending this event, but it has been held every year since 2005 and rotates among parks in Union County. A bioblitz is similar to a big day in its duration, but all taxa are eligible and the idea is to make as complete a census as possible of the living things at a particular site. Teams cooperate and share information, and there is usually an educational component.

The bird team came up with 70 species, which is very good for Central Jersey in June. Their sightings included a lingering Magnolia Warbler (which I missed). I came up with a little more than half that, but I was primarily working on insects. I am still sorting through my insect photos to identify and post them. So far I have 27 insect species on my list, with a lot more to identify. I know the total insect list from bioblitz will run into the hundreds.

My weekend included two lepidopteran lifers. One is the Banded Hairstreak shown above; the other is the Eight-spotted Forester shown below. Banded Hairstreak uses oaks, walnuts, and hickories as larval hosts and flies in late spring and summer. Eight-spotted Forester is hosted on vines, particularly grapes and Virginia creeper. While butterflies and moths feed on plants during their larval stages, as adults they drink nectar from flowers, and in the process pollinate many plants, which is necessary for the plants to reproduce. Both of these are fairly common species, so the fact that I had not seen either yet might seem surprising. However, insect lives are very short, and few of them migrate. Many butterflies and moths only fly for a few weeks, so if you are not in the right habitat at the right time, you will probably not see them.

If you would like to learn more about the moth diversity in your area, consider participating in National Moth Week, which is coming up very soon. This year the event runs from July 20-28.  Visit the link to learn more about how to participate.

Friday, June 14, 2013

Loose Feathers #396

Pine Siskin / Photo by Mark Stewart (USFWS)
Birds and birding
Science and nature blogging
Environment and biodiversity

Thursday, June 13, 2013

Book Note: A North Country Life

A new memoir by poet and essayist Sydney Lea describes life in rural New England. A North Country Life: Tales of Woodsmen, Waters, and Wildlife is published by Skyhorse Publishing. This volume consists of a series of short essays, many of which were previously published in literary journals or collections. The chapters are loosely organized by season, though in many of them a seasonal reference is simply a starting point for remembering a person or series of events. A North Country Life records a way of life that is disappearing and preserves the memory of people who have passed away. Some chapters are short and convey the feeling of a particular moment in time. Others expound at greater length on people or ideas. Many are even poignant, describing childhood memories or remembrances of people long gone. While the book is tied to seasons and places, people are always at the center of the narratives.

I must confess that I had some trouble getting into this book, and I picked it up and put it back down a few times. My problem was not with Lea's prose (which is quite readable) but with finding a connection. Some of it may be generational, but I feel it has more to do with the cultural separation between my background (from densely-populated areas) and old-time, rural New England. Not having the background information to put things into context acts as a barrier, at least for me.

A North Country Life is at its best when Lea is describing his own adventures in the woods. My favorite chapter was one in which he describes getting lost ("Turned Around") while tracking deer. Several other chapters provide food for thought, especially when Lea describes changes that have taken place over the past several decades. Birders know well that Ruffed Grouse are becoming harder to find. (I have never seen or heard one myself.) Lea provides evidence from his own experience with the birds — declining numbers of grouse encountered and shot during hunting season. The "daybooks" are also very good, almost poetic at times. The book ends on a strong note with essays on land conservation and memories of parenting. The book is less compelling when Lea is retelling stories told to him by some old-timer, who may have been telling the story second- or third-hand himself. I tended to get bogged down in those essays, especially early on when the people and places named were all unfamiliar.

Sydney Lea's A North Country Life should appeal to anyone with an interest in the culture and history of New England, particularly life in rural New England. How much it will appeal to birders will depend on individual tastes. Most of the writing on birds comes in the context of hunting — for Ruffed Grouse, Wild Turkey, Ring-necked Pheasant, Sharp-tailed Grouse (on a trip to Montana), and Black Duck — though birds do appear in some of the other essays. Lea's observations on these birds are interesting, but as with the other themes in the book, they serve as a starting point for stories about his companions (both human and canine). It may also appeal to those with a general interest in the outdoors.

Monday, June 10, 2013

Photo of the Week: Summer Azure

Birders recognize the transition from Yellow-rumped Warblers to Blackpoll Warblers as a sign that spring migration is reaching its final stages. The situation is more complex than that, as both species are present together for two or more weeks. But if you hear Blackpoll Warblers but not Yellow-rumped Warblers, you are probably in the last week or two of May.

In the same way, one can find seasonal harbingers elsewhere in the natural world. One of them is this species, Summer Azure, which shows up around the same time that Blackpoll Warblers are leaving. Summer Azure is part of a species complex that used to be known as "Spring Azure." Thanks to careful study of phenology, genetics, and microscopic traits, what once was one species is now several species, with a succession of overlapping flight seasons, starting in early spring and continuing through summer. Summer Azure is the last to appear and has two broods. In New Jersey the first emerges in late May or early June, and the second emerges later in the summer.

I photographed this Summer Azure in the Rutgers Ecological Preserve last week.

Friday, June 07, 2013

Loose Feathers #395

Wood Duck / Photo by Tiffany Kersten (USFWS)
Birds and birding
Science and nature blogging
Environment and biodiversity

Wednesday, June 05, 2013

Mercury Poisoning in a Young Saltmarsh Sparrow

Saltmarsh Sparrow / Photo by Wolfgang Wander
Most of us are familiar with the hazards posed by mercury. In the compound known as methylmercury, it becomes a potent neurotoxin, for both humans and wildlife. When infants are exposed in utero, methylmercury causes a variety of developmental problems. Environmental mercury comes primarily from industrial sources, such as waste incineration and the burning of fossil fuels for energy. Burning coal for electricity is a particularly strong contributor. Mercury is aerosolized by these processes and then enters waterways via precipitation. Aquatic invertebrates and fish consume mercury through their diets. It is for this reason that pregnant women are advised to avoid fish, some of which store significant levels of methylmercury in their tissues.

Methylmercury has already been documented in multiple bird species, with particularly high concentrations in Wood Thrushes. Some birds such as raptors and kingfishers have fish as a mainstay of their diets. Songbirds consume mercury by eating invertebrates that spend the early stages of their life in the water (such as mosquitoes, dragonflies, and caddisflies) or by eating spiders that prey on those aquatic invertebrates. Mercury is associated with behavioral changes in songbirds and may skew sex ratios. Like in humans, mercury affects learning and memory in songbirds. It also hampers birds' ability to learn and sing songs.

ResearchBlogging.orgA new study by Sheila Scoville and Oksana Lane adds to the evidence for mercury's harmful effects in songbirds. When a fledgling Saltmarsh Sparrow (Ammodramus caudacutus) was accidentally killed at a study site on Long Island, it was collected and analyzed for mercury poisoning. Feathers were collected and sent to the Biodiversity Research Institute to test for mercury exposure, and the sparrow's brain was analyzed at the Eastern Virginia Medical School. The fledgling showed some exposure to mercury, though not at the levels measured in adults at that study site (which overall were very high).

Based on feather samples taken from adult birds at the study site, it can be inferred that this fledgling's mother had high exposure to mercury at the time that she laid her eggs. This is analogous to in utero exposure in humans. In humans, in utero exposure can lead to brain abnormalities like Minamata Disease. This fledgling Saltmarsh Sparrow showed abnormalities in its cerebellum that would have similar effects on motor control and coordination. Birds with these sorts of defects would have trouble recognizing and escaping danger, thus making them more susceptible to predation and accidental deaths.

While this fledgling Saltmarsh Sparrow is only one data point, the findings have disturbing implications. Since mercury levels among adult birds were so high, many other young Saltmarsh Sparrows are presumably exposed to mercury at the time of egg formation. We cannot know how many of them have brain abnormalities like the one documented in this study, but it seems safe to assume that the problem is widespread.

Even without human interference, Saltmarsh Sparrows lead a precarious existence. At any time during the breeding season, their nests may be flooded by particularly high tides or destroyed by violent storms. Their breeding range is restricted to a narrow strip of saltmarshes along the Atlantic Coast of the United States. Their habitat is constantly under pressure from human encroachment, as more and more coastal areas are developed as beach resorts. Oil and chemical spills further degrade their remaining habitat. There is an additional threat from sea level rise due to climate change and subsidence. For these reasons, BirdLife rates the Saltmarsh Sparrow as a vulnerable species. Now we know that in addition to all these other problems, the species also faces a threat from ingestion of mercury.

The harm caused by mercury is not something conservationists can easily remedy. Shifting away from coal as a source of electricity would at least reduce the amount of mercury entering our waterways. What we can and should do is protect and maintain as much remaining saltmarsh as possible so that the sparrows that survive to adulthood will have enough habitat for breeding.

Thanks to Peter Doherty for alerting me to this study.



Scoville, S., & Lane, O. (2013). Cerebellar Abnormalities Typical of Methylmercury Poisoning in a Fledged Saltmarsh Sparrow, Ammodramus caudacutus Bulletin of Environmental Contamination and Toxicology, 90 (5), 616-620 DOI: 10.1007/s00128-013-0974-y

Monday, June 03, 2013

Photo of the Week: Periodical Cicada

When I lived in Washington, DC, I experienced the first emergence of periodical cicadas that I can remember: the massive emergence of Brood X periodical cicadas in 2004. This was shortly after I started birding. The noise they produced was so loud that at times I had trouble hearing birds. As the emergence ended, dead cicadas littered the streets and were picked up and carried away by the ubiquitous House Sparrows in DC.

This year I am in New Jersey for the emergence of Brood II. So far I have not seen or heard any around Highland Park, but over the weekend, I encountered a fairly large number of them at Fairview Farm Wildlife Preserve in Bedminster, New Jersey. There was a continuous chorus going in some parts of the preserve, though it was not as loud as some I experienced around Washington. The cicadas I examined closely all seemed to be Magicicada septendecim, with an orange spot in front of the wing and broad orange bands on their undersides. You can read more about identifying Magicicada species here.

Periodical cicadas have adopted an unusual life cycle in which adults emerge at 13-year or 17-year intervals to mate and lay eggs. This emergence lasts for only a few weeks, during which the number of adults in any given location may be massive. They spend the rest of their life cycle as nymphs deep underground, feeding on the roots of trees. When they are ready to emerge, the nymphs dig their way to the surface at night and then molt into their adult form. It is thought that the long, prime-numbered life cycle makes it difficult for any predator to specialize in preying on periodical cicadas, though of course birds, wasps, and other predators take advantage of the bounty when an emergence occurs.

If you see any cicadas from Brood II, you can report them at Magicicada.org.

See more of my periodical cicada photos on Flickr.