Eagles Along I-5

My wife, young daughter, and I just got back from a road trip up to Seattle, WA with a stop in Ashland, OR on the way back. As we drove and drove, we had the good fortune to see eagles on a number of occasions and they were especially spectacular in the behaviors we got to witness.

Our first eagle encounter was just as we drove past Ashland, OR on our way north. My wife spotted two birds that seemed to be struggling, mid-air. They were two Golden Eagles, and as we watched they opened their wings and began to spiral downwards, feet locked together in a talon grapple! The drop was spectacular as they spun around each other and plummeted towards the earth. As we drove closer, they came to the end of the fall and let go of each other. Both huge, adult birds then flew right over our car.

After our visit in Seattle, we decided to hit the road quite early. This meant that I was driving south on I-5 as dawn was spreading her rose-red fingers across the sky. As the day brightened in central western Washington, I got to watch several Bald Eagles fishing in the various waterways we passed over. It was a truly beautiful sight with the morning light just touching the tree tops and these large, dark birds circling over the sky-reflecting water and dropping low to strafe the surface for fish.

Our final eagle encounter was back in the Ashland area. We took a side trip out to the little town of Jacksonville and on our way back stopped at a gas station. As we waited by the pump, a Golden Eagle started circling overhead. It was a very nice look, as the bird was not too high and there were no trees blocking our view. The sight got even better when the eagle climbed in altitude and then began a series of dramatic pendulum flights! Pendulum flights are where the bird flies in a number of roller-coaster-like arching dives, one right after another. At the top of each arch, the eagle would close its wings and dive, picking up speed. At the bottom of the dive, it opened its wings and used its momentum to coast up to the top of the next dive. A wonderful show, indeed!

So, for eagle watching, I would highly recommend the I-5 corridor! We certainly had a great trip!

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Microbeads

There is plastic in your toothpaste! And in body washes and shampoos, as well. Tiny spheres of plastic called microbeads are used to help scrub plaque off the surface of teeth and exfoliate dead layers off the surface of skin, but they have harsh environmental costs.

Microbeads are very small spheres that generally range in size from 0.5 to 500 micrometers and are usually made of polystyrene. They are designed to be small enough that they will wash down the drain of sinks and bathtubs without clogging them. However, this same small size allows them to also slip right past filters and water treatment plants out into the environment. Polystyrene does not biodegrade, so microbeads last for a very long time without breaking down. This means that they accumulate into some pretty significant figures. It has been estimated that 90% of the plastic in Lake Eire, and other lakes in te eastern U.S.A. are microbeads! Once they are out our waterways, they can collect toxic chemicals such as PCBs that bind to their surfaces. They also look like small fish or insect eggs and so are eaten by a wide range of fish. These fish are then eaten by larger fish and the toxins bioaccumulate as they work their way up the food chain eventually to humans.

States are beginning to take a stand to remove microbeads from products. In February, bills were introduced in both New York (by Assemblyman Robert K. Sweeney (D)) and California (by Assemblyman Richard Bloom (D)) that would ban the sale of cosmetic products that contain microbeads. And we, as consumers, can also play a very important part in protecting the environment on this issue by not buying products that contain microbeads, and so voting with our wallets. The environmental group 5 Gyers has produced a free iPhone app called ‘Beat the Microbead’ that allows consumers to scan product bar codes and find out if they contain microbeads. Microbeads also can be found in the ingredient list of cosmetic products; however, they are not listed as microbeads. Instead, watch for polystyrene, polyethylene or polypropylene. If a product contains one of those ingredients, it is likely in the form of microbeads.

Getting rid of microbeads does not mean that tooth paste will no longer clean your teeth or that facial scrubs will no longer clean your face. Nut hulls or fruit pits that are ground into tiny fragments work well as an exfoliant, and some companies, such as Burt’s Bees, already use them instead of plastics.

So, let’s put our money where our mouth is, send a message to cosmetics companies, and stop buying microbeads!

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Biodiversity And How It Is Measured

Biodiversity is the number of species in a given area. The largest measure of biodiversity is the estimated total number of species on the planet (somewhere around 10 million, although estimates of as high as 40 million are not unreasonable). Other scales are often more useful such as how many species occur in a country or mountain range or nature preserve. Ecologists have several measures for comparing diversity in different places.

Species Richness is the number of species found in a particular community. Measures of species richness such as the Shannon Diversity Index are weighted to show that one community if made of many species that all are equally numerous versus another community that has just as many species, but a small number are extremely numerous and the rest are quite rare. Species Richness can also be viewed at different special scales. Alpha Diversity is the number of species in a particular designated area suchas a park or reserve. For example, in the diagram below, Area 1 in Region 1 has an Alpha Diversity of 5. Region 1 has an average Alpha Diversity of 6 ((5+6+7)/3). Gamma Diversity is the number of species in a larger geographic area such as a mountain range or continent. For example, Region 1 has a Gamma Diversity of 7 (ABCDEFG). Beta Diversity is a measure of how species composition changes along an environmental or geographic al gradient such as moving from headwaters to mouth of a river. For example, Region 1 has a Beta Diversity of 1.2 indicating that most of the species that occur at one end of the gradient still occur at the other, in other words, there is low species turnover.

Region 1:     Area 1          Area 2          Area 3               Alpha     Gamma     Beta

Species:          BCDEF        ABCDEF      ABCDEFG              6                7            1.2

Region 2:     Area 1          Area 2          Area 3

Species:           ABC              DEFG            DGHIJ               4               10           2.5

Region 3:     Area 1          Area 2          Area 3

Species:           ABC               DEF                GHI               3                 9            3.0

As can be seen by comparing Region 1, Region 2 and Region 3 to each other, different arrangements of species can be represented with different measures of diversity. For example, while Region 2 has the highest total number of species (Gamma Diversity), Region 1 has the highest number of species per specific location (Alpha Diversity), and Region 3 has the highest turnover of species across the whole region (Beta Diversity).

There are other measures of diversity that are also useful in ecology. Genetic Diversity indicates how much variation exists at the DNA level in a species or population and is often used as a measure of how evolutionarily adaptable that species or population is. Ecological Diversity is a measure of how many different types of communities occur in a given ecosystem.

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Sibley Guide to Birds: Second Edition

It has been 14 years since the first printing of the first edition of David Allen Sibley’s Sibley Guide to Birds. It was a wonderful book and stood out, at least in my mind, as the best guide to come out since Roger Tory Peterson’s guides to eastern and western birds. Now Sibley has produced his second edition, my copy just arrived in the mail yesterday. And this new edition has a lot of changes from he old one.

The first thing that struck me were the colors. This new edition has generally bolder, darker, richer colors than the first edition. This change may serve to highlight plumage characteristics and draw attention to color contrasts, and so may make the guide more user friendly. However, there is always a danger when attempting to improve on reality and the result will be distorting reality. Overall, I really like the richer colors, but I do think that on some of the birds, such as the California Towhee, it may have gone a bit too far.

A second major change is that the families of birds now appear in a very different order. Traditionally, bird guides have been formatted so that they present the groups of birds in an order that follows the evolutionary history of birds. In most guides this has meant that the first groups are the Loons then the Grebes then the Albatross and Petrels. However, with ever more detailed and accurate DNA sequencing abilities, the evolutionary history of birds has been going through several rounds of shake-ups, and Sibley’s second edition reflects the more current understanding of how birds have evolved. Now, the first groups shown are the Ducks and Geese followed by the Gallinacious birds and then the Loons, and the altered order of bird families continues throughout the rest of the book. I really like that the order of bird families has been changed. It means that we all have a better understanding of evolution. I am sure that some people will be annoyed at the new ordering, and may feel a bit disoriented when having to re-learn where to find a particular group of birds, but our knowledge is always changing, and the resources we use should reflect those changes.

A third big change is the addition of 111 rare species. These are species that are generally found on other continents, and that have been recorded a very small number of times in North America. At first, I thought that this would simply clutter up the guide with a bunch of birds that basically no one sees, and that they would distract from the birds that people are generally looking for when they open their bird books. But, on further reflection, I have actually really like having all these new birds. It gives us all a better understanding of, and exposure to, what birds are out there. I think that if we as birders, all have a more global understanding of our favorite taxa, that can lead to nothing but good.

One very minor bone to pick is something that was pointed out to me by the late, great Rich Stallcup. He noticed that the Wrentit had a somewhat worried expression and that this was not really representative of the fierce Wrentit spirit. In the new edition, the Wrentit still looks worried.

So, overall, I really like the new Sibley Guide to Birds a great deal and am looking forward to my next opportunity to use it. If I find a White-crested Elaenia I will now be able to identify it!

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