Internet Naturalist – September 30, 2013

  • Video: Northern Goshawk Flight in Slow Motion | Audubon Magazine Blog 091613
    Alisa Opar: “The northern goshawk is an incredible aerialist. The bird inhabits dense northern forests and maneuvers through impossibly tight spaces in pursuit of prey. A fierce hunter, its quarry includes squirrels, crows, hares, and even other raptors, including merlins and American kestrels (no wonder Attila the Hun’s helmet bore a northern goshawk). See for yourself just how remarkable the accipiter is, in the BBC video below with naturalist Chris Packham.”
  • Blue whale earplug reveals lifetime contaminant exposure and hormone profiles | PNAS 091613
    Lifetime contaminant and hormonal profiles have been reconstructed for an individual male blue whale (Balaenoptera musculus, Linnaeus 1758) using the earplug as a natural aging matrix that is also capable of archiving and preserving lipophilic compounds. These unprecedented lifetime profiles (i.e., birth to death) were reconstructed with a 6-mo resolution for a wide range of analytes including cortisol (stress hormone), testosterone (developmental hormone), organic contaminants (e.g., pesticides and flame retardants), and mercury. Cortisol lifetime profiles revealed a doubling of cortisol levels over baseline. Testosterone profiles suggest this male blue whale reached sexual maturity at approximately 10 y of age, which corresponds well with and improves on previous estimates. Early periods of the reconstructed contaminant profiles for pesticides (such as dichlorodiphenyltrichloroethanes and chlordanes), polychlorinated biphenyls, and polybrominated diphenyl ethers demonstrate significant maternal transfer occurred at 0–12 mo. The total lifetime organic contaminant burden measured between the earplug (sum of contaminants in laminae layers) and blubber samples from the same organism were similar. Total mercury profiles revealed reduced maternal transfer and two distinct pulse events compared with organic contaminants. The use of a whale earplug to reconstruct lifetime chemical profiles will allow for a more comprehensive examination of stress, development, and contaminant exposure, as well as improve the assessment of contaminant use/emission, environmental noise, ship traffic, and climate change on these important marine sentinels.
  • Ear Wax From Whales Keeps Record Of Ocean Contaminants : NPR 091613
    How often do whales clean their ears? Well, never. And so, year after year, their ear wax builds up, layer upon layer. According to a study published Monday, these columns of ear wax contain a record of chemical pollution in the oceans. The study used the ear wax extracted from the carcass of a blue whale that washed ashore on a California beach back in 2007. Scientists at the Santa Barbara Museum of Natural History collected the wax from inside the skull of the dead whale and preserved it. The column of wax was almost a foot long.
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