Autumn Olive in Bloom

As I walked the trails at Griggstown Grasslands on Saturday, I became aware of a lot of bees buzzing around one particular shrub. When I looked more closely at what was drawing their attention, I noticed it was an Autumn Olive in full bloom. The small white flowers had a strong fragrance, almost overwhelming at close range. The Honey Bees visiting the shrub made a constant hum of activity, more so than around nearby blooming trees of other species.

Autumn Olive can be recognized by its long, thin leaves that are dark green on one side and silvery on the other. In the fall, these shrubs bear red berries that are very attractive to wildlife and edible for humans as well. The leaf and berry coloration help distinguish it from the very similar Russian Olive, as explained here.

That attractiveness to wildlife is one of the factors that makes this species so invasive since it is easier for a plant to reproduce if it has insects eager to pollinate it and birds ready to spread its seeds. Another factor is that it is able to fix nitrogen with its roots. This allows it to spread readily in poor soils where other plants struggle to survive. Aside from that, they are also drought resistant and difficult to kill by cutting or fire. Autumn Olive may be an example of an introduction succeeding too well. These shrubs were planted widely in Appalachia to revegetate former strip mines and other disturbed areas because of their tolerance for poor soils. Since then the shrub has spread rapidly and become a seemingly permanent fixture of the landscape.

Eastern Tailed-blue at Griggstown Grasslands

While Eastern Tailed-blue is one of the most common species in my area, it can be a frustrating butterfly to photograph. These butterflies are tiny, which necessitates a very close approach, but they are skittish enough that a close approach is likely to make them take flight. When they do sit, the usually keep their wings folded over their backs, so that the light gray undersides are visible instead of the brilliant blue uppersides.

So yesterday, I was very happy to find some cooperative Eastern Tailed-blues at Griggstown Grasslands. Perhaps the cooler weather had something to do with it, as these individuals preferred to bask in the sun with their wings open. Maybe they reacted a little more slowly to my approach due to the morning chill. Whatever the reason, these butterflies were a treat.

Starting the Lower Raritan Bird Survey

New Jersey Audubon has been running citizen science surveys in various parts of the state. Some have focused on particular habitats, like surveys of grassland birds and shorebirds, and others have focused on regions of the state. This spring, the organization initiated a breeding bird survey along the Lower Raritan River and its watershed, along with a pilot project to track bird migration in the same area. The goals of the project are to create a baseline of bird population data for the watershed and to identify important bird habitat for future protection. I signed up as a volunteer and picked a set of ten points in Raritan Center, an industrial complex in southern Edison that includes a sizable amount of wild or semi-wild wetland and old field habitat. I had been curious about this site for some time, as it is difficult to find such large tracts of minimally-developed land in this part of the state.

Yesterday I completed the first of the 2-3 migration surveys I will be doing at the site. All of the assigned points are accessible, though noise and obstructed sightlines make two of the points particularly challenging. All ten points are in the area covered by the image above, at more or less even spacing from each other.

There were a lot of birds around, and I recorded about ten species during each of the five-minute point counts. The dominant songbird species was Red-winged Blackbird, which I recorded at eight of the ten points. Other frequently-recorded songbird species included Song Sparrow, American Robin, and American Goldfinch. I also saw quite a lot of gulls – mostly Herring Gulls – in flight overhead. I heard Field Sparrows at three points (at one, unfortunately, after the five minutes was up). That was probably my most interesting finding of the day. Three points along the riverfront produced a Northern Harrier (seen only before my five-minute point count started), a nesting pair of Ospreys (again, seen after the five minutes was over), a Green-winged Teal, and four Boat-tailed Grackles, which I was surprised to see so far upstream. I am looking forward to seeing what other species pass through over the next few weeks.

Loose Feathers #338

Migrating Smith's Longspur / Photo by Paul Roisen (USFWS)

News about birds and birding

• A study of ten bird species and eighteen on-shore wind farms in the U.K. found no major impact on bird populations from the operation of wind farms, though construction of the wind farms did affect some species. It should be noted that the study did not include the larger raptors that are known to be harmed by collisions with wind turbines.
• The American Bird Conservancy is protesting a regulatory change by the US Fish and Wildlife Service that would extend take permits for wind farms from 5 to 30 years.
• A new study finds that the iron-rich cells in pigeons' beaks are really macrophages and not nerve cells that might detect magnetic fields. This disproves one proposed mechanism for how birds navigate.
• Using geolocators, scientists have tracked four Golden-crowned Sparrows from their wintering grounds at Point Reyes National Seashore to their breeding grounds in coastal Alaska. The data will help inform management decisions.
• There are now over 100 breeding pairs of Bermuda Petrels, which had been considered extinct for several centuries.
• A study of mating patterns among Dunlin over multiple seasons found that female Dunlin enhanced their nesting success by picking a new mate rather than sticking with a mate from the previous year.
• Despite pounding their heads repeatedly against hard objects, woodpeckers do not get concussions because of their skull structure.

Nature blogging

• 10,000 Birds: White-breasted Nuthatch is four species, study says
• Birdchick: Consolidating My Birding Tools On My Bike
• The Birdist: Records Committees and Exotic Birds: Interview with Phil Davis
• Audubon Guides: Variations in Rough-legged Hawks
• Myrmecos: Pison the spider hunter
• Bug Girl: The GOP War on Caterpillars

Environment and biodiversity

• A motion-sensitive camera caught a Canada Lynx using a highway wildlife overpass to cross the Trans-Canada Highway in Banff National Park. Cameras have recorded over 200,000 wildlife crossings on overpasses and underpasses around the highway since 1996.
• The New York Botanical Garden is trying to reintroduce a genetically-modified form of the American Chestnut tree in the Bronx. This variety has a wheat gene to defeat a toxin released by chestnut blight. Meanwhile, another project is attempting to reintroduce blight-resistant hybrids of American Chestnuts in Appalachia.
• An op-ed piece argues for the importance of trees.
• Last month was the warmest March in U.S. history and had the second-most-extreme heat wave of any month in U.S. history. Twenty-five states set their own records, including New Jersey.
• New research bolsters evidence that the white-nose syndrome that is killing North American bats is caused by a fungus that originated in Europe.
• This week the Miami Blue Butterfly was formally listed under the Endangered Species Act. The species is currently confined to a few islands in the Florida Keys.
• The EPA denied a request to ban the herbicide 2,4-D.

Eastern Red Columbine

Eastern Red Columbine (Aquilegia canadensis) is a perennial wildflower native to eastern North America. Normally, the columbines here bloom in May, but this year there are already blooms appearing in mid-April, almost a month ahead of last year's schedule. The long, tubular flowers of columbines are especially attractive to hummingbirds, which play an important role in their pollination.