Category: Evolution

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Arizona Evolution Safari

Hawk or Buzzard?

Red-tailed Hawk in Tucson, Arizona (left) and Augur Buzzard in Ngorongoro, Tanzania (right)

I dread meeting this bird on safari. I try to distract my clients’ attention:

“Er….Everybody, look at that hartebeest on the left”It’s a beautiful hawk about 2ft tall, who often perches on top of a tree displaying his pure white breast to the morning sun. Try as I will to ignore him, someone always spots him.

“What’s that big hawk on the right, Dave?”

“(sigh)…It’s an Augur Buzzard”.

“A what? An Ogre Bustard?”

“No. A-U-G-U-R as in prophecy. Buzzard as in hawk”

“Oh, so he’s a scavenger then?”

“Noooo!…Let me explain….”

“Hey! Is that a lion?”

“No, it’s a hartebeest.”

“Are we nearly there yet?….”

Back in the day, the Europeans were familiar with large brown hawks sailing on broad wings over hill and farmland, searching for rabbits and rodents. The Romans called them buteo, which morphed through Old French buson or buison to  Anglo-Norman buisart and hence to buzzard. Buzzards were known to be predators who rarely scavenged; the familiar carrion-eaters were black or red kites around the cities, and vultures in southern Europe.

When European naturalists explored Africa, they found their familiar Common Buzzard on winter migration, and met similar native species which they named Mountain Buzzard, Jackal Buzzard, and, ugh, Augur Buzzard. “Why augur?” I would like to ask Herr Ruppell (1836) who named it. It’s not from “auger”, which is a kind of drill, and this is not a boring bird. An Augur in Roman times was a kind of prophet or soothsayer, who interpreted the intentions of the gods from natural signs such as the movement (or entrails) of birds.

The Europeans who settled the New World were more taxonomically confused. They took the ‘buzzard concept’ and applied it to a large black soaring scavenger, a.k.a. Turkey Vulture. The closest relative of the European buzzard was named, quite accurately, Red-tailed Hawk.

So the Red-tailed Hawk which occasionally soars over our saguaros in Arizona is the ecological equivalent of the Augur Buzzard in Ngorongoro and Serengeti. They are virtually the same bird, with brick-red tails and keen dark eyes.

“Just think of it as an African red-tailed hawk”, I tell my confused American tourists.

Redtailed Hawk and Augur Buzzard
Left: Red-tailed Hawk, Buteo jamaicensis, right: Augur Buzzard, Buteo augur

Categories
Evolution Safari

Flamboyant Flamingos

Dense crowd of Lesser Flamingos in lake.
Dense crowd of Lesser Flamingos in Big Momella Lake, Arusha NP

Everyone loves flamingos, those bundles of pink plumes on stilts. People on our safaris always want to find and photograph them. Here in Tanzania, at Arusha National Park near Mt. Meru, there are soda lakes where flamingos cluster. Flamingos are beautiful, yes,  and are also highly evolved to exploit their unique habitats – lakes full of algae and small crustaceans. They feed with beaks upside down, straining this food from greenish looking water. The chlorophyll of the algae contains carotenoids, pink or orange compounds which are deposited in flamingos’ plumage. Lesser flamingos, who feed directly on algae, are pinker than greater flamingos who eat brine shrimps. The quality of their shallow watery ‘pastures’ constantly changes, so they flap from lake to lake in the rift valley seeking the best food. We used to live on a flyway between Lake Eyasi and Lake Manyara, and often at night we’d see and hear their honking V’s passing over. These strange birds do amazing group parades, chorusing while marching, and they build crusty crater-like mud nests in the middle of desolate caustic lakes.

Lake Momella in Tanzania with dense fringe of flamingos
Flamingos fringe one of the Momella Lakes

Here I want to share a  fact about these fascinating birds. Researchers in 20 nations spent four years on a project to sequence the entire genomes of 48 species of birds. One of the results is that flamingos are closer relatives to pigeons and grebes than to look-alikes such as egrets and storks.  Another surprise was that the chicken seems to be way back there in the genome line, closer to the original bird stock than anything except ostriches.  Studies on bird evolution continue to evolve!

 

The Crimson Wing: Mystery of the Flamingos  is a wonderful film produced in 2008 by Disney.  If  you missed the TV presentation maybe your library has it. This link tells you more about the film.

Close-up of Lesser Flamingo head
A Lesser Flamingo’s bill is all dark red, and its plumage is rich pink.

Close-up of Greater Flamingo head.
A Greater Flamingo’s bill is pink with a black tip, and its plumage is paler.

Categories
Evolution

Invasion of the Moa

Feral male jungle fowl
Feral Jungle Fowl, Po’ipu, Kaua’i

This is a fun extension to Safarizona territory – prompted by our November visit to Kaua’i Island in Hawaii. Chickens weren’t on my to-see list but as we drove out of the airport, there they were, freely roaming the roadsides. During the next week, we met handsome, colourful, confident chickens everywhere – from beach to mountaintops, from suburbs to national parks. Why so many? Who owns them? Who eats them? Their story led us into the much bigger picture of island colonization.

The Hawaiian archipelago was born of fire. As the great Pacific tectonic plate drifted northwest over a ‘hot spot’ or convection plume in Earth’s molten magma, successive volcanoes erupted out of the sea and formed a long chain of islands. The oldest ones, up to 60 million years old, have eroded away and mostly disappeared under the sea. The youngest island, Hawai’i, is currently over the hot spot and still has active volcanoes. Further northwest, Kaua’i is 5 million years old.

The cooling volcanoes were colonized by wandering birds and insects, by seeds borne on wind or ocean currents or in birds’ bellies, and by small animals clinging to rafts of floating vegetation. Lush vegetation grew up, but who would eat it? On islands worldwide, this has played out in different ways. In Galapagos and Aldabra tortoises became the herbivores. Mauritius had giant pigeons, the dodo. Madagascar had lemurs, and New Zealand had 11 giant flightless birds called ‘moa‘, a Polynesian word for any fowl.

Two people looking at a sunken cave site on Kauai
Jeannette and docent in Makauwahi sinkhole, Kaua’i

Drawing of 6 extinct and 1 extant goose species from Hawaii.
Moa-nalo; only the nene (far right) survives today. From a drawing displayed at Makauwahi.

The largest herbivores to reach the Hawaiian islands were ducks, 3.6 million years ago. Lacking predators, they evolved into several flightless forms, some as big as domestic geese. Later, ancestors of today’s nene goose joined them. They became abundant, eating ferns and grass and tree seedlings. At Makauwahi archaeological site, which preserves 10,000 years of remains, we learned that in 300-800 CE, the first Polynesians encountered 7 species of these “moa-nalo” (lost fowls).  Unafraid of man, they were soon exterminated. The people brought pigs, which also ate moa-nalo, and chickens, which quickly filled their vacant ecological niche. Moa-nalo were forgotten until archaeologists discovered their bones in the 1980’s.

Enter the chicken! The Asian red jungle fowl, domesticated 8-10,000 years ago, is hardy, tough and eats anything. It is only vulnerable when it nests, on the ground. In all the other Hawaiian islands, sugar farmers introduced mongooses to control the (introduced) rats. But rats are nocturnal, so the diurnal mongooses attacked birds instead, especially ground-nesters; only Kaua’i’s chickens are safe from that threat.

Today the “wild” Kaua’i chickens in parks and reserves are protected. You can harvest chickens that enter your property, but they may be tough. Islanders say: “To cook the moa, boil it in water, with spices and a rock. When the rock is soft, the moa is ready!”