Readers’ wildlife photos

May 28, 2014 • 4:25 am

We have a mammal today—and a strange one! The photo is again by Stephen Barnard from Idaho:

Pronghorn Antelope—not really an antelope, not a deer, not a goat—the only surviving member of the family Antilocapridae.

Apparently, at least according to the National Wlidlife Federation, the pronghorn (Antilocapra americana) is the fastest mammal in North America, supposedly able to attain speeds of up to 60 mph (97 kph). I’m dubious about that because it’s hard to measure such speeds.  They are a conservation success: once deemed almost certain to go extinct from habitat loss and hunting, they’re now in good shape, with a population size between 500,000 and a million. This is thanks to many organizations, including the federal government and the Audubon Society, which worked together to protect their land and the crucial migration corridor (see below):

The NWF adds this:

Even more amazing than its speed is the pronghorn’s migration.  Herds of pronghorns migrate 150 miles each way between Wyoming’s Upper Green River Basin and Grand Teton National Park. The only other land animal to travel farther in North America is the caribou.


We also have a bird—a female ruby-throated hummingbird (Archilochus colubris) snapped at the feeder by reader Diana MacPherson:

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29 thoughts on “Readers’ wildlife photos

  1. Pronghorn are known for being endurance champions. I read a study many years ago which claimed they could sustain speeds of 30 mph for an hour (or something like that). When I was studying physiology in grad school years ago, one big question in sports science was which step in oxygen delivery to tissues is limiting.

  2. Irregardless of what speed the American Antilope can run at, why should they be so fast? The Pleistocene fossil record records the American Cheetah in some numbers from Natural Trap Cave in the Big Horn Mountains of Wyoming and Montana. Apparently the pronghorn survived through the Pleistocene extinction event while the American Cheetah (actually more closely related to the Mountain Lion, Felis (or Puma)concolor) didn’t.

    1. Thanks for the tip – the article is:

      R. Barnett, I. Barnes, M.J. Phillips, L.D. Martin, C.R. Harington, J.A. Leonard, A. Cooper
      Evolution of the extinct sabretooths and American cheetah-like cat
      Current Biology, 15 (2005), pp. R589–R590

    2. One of my former colleagues, John Byers from the University of Idaho, developed the idea that modern-day pronghorn speed is indeed an example of a relict behavior, reflecting their past co-existence with cheetahs, long-legged hyenas, and other large predators. He presented it in the 1998 book “American Pronghorn: Social Adaptations and the Ghosts of Predators Past.”

  3. Jim; I can’t even think of an answer to your question because I’m still stuck on the use of “Irregardless”. You know that isn’t a word, right?

    1. What kind of person won’t answer a question because they’re obsessed with being a Word Monitor? Really? Now either apologize, get past the “irregardless” and answer the question, or find another website where you can be a jerk without recrimination.

    2. Irregardless of whether or not “irregardless” is really a word (I live in South Carolina – what do you expect?) the hypothesis of a predator/prey relationship in this case is an interesting one because half of it no longer exists, and so cannot be tested but only surmised. You can find a number of these sorts of relationships when dealing with Pleistocene taxa.

    3. And by the way Lori, look up the definition of “irregardless” on the Merriam-Webster on-line site. The word showed up in the early 20th Century and is listed as an irregular adverb!

  4. There are excellent discussions of pronghorn weirdness in the TetZoo archive.

    Before reading the name of that hummer, my first thought was that there was something very snakey about its face. I guess you don’t have to be a total obsessive to see it.

  5. As I was looking at Diane’s photo of the female ruby-throated hummingbird I glanced over at our feeder and there was a female ruby-throated hummingbird at our feeder. Within a few weeks they will sip at the feeder held in my hand and fly up within inches of my face to study just who I am and what I am. They do recognize faces and are more wary of my wife who does not usually take care of the bird cafeteria on the back porch. I have a feeling that hummingbirds are very intelligent but have found no information on the topic. Like most of our birds there seem to be some from last year’s crowd who arrive and start looking for the feeders when they get here. The Baltimore orioles and rose-breasted grosbeaks are the same. How they locate this place is unknown, but find it they do, year after year.

      1. That looks like a paper which might take a bit more concentration than I can muster in the AM but well worth my while. Thanks for a) compelling me to look up kernicterus (not a dinosaur) and b) a paper that will probably get me thinking more deeply about hummingbird cognition.

    1. The Orioles like to drink nectar too.

      How fun that you get to interact closely with the hummingbirds! Mine are very wary. I have to sit very still outside and I put my camera’s shutter on its quieter setting. Even then, they take quick sips then eye me to make sure I haven’t moved. This is what she was doing when I took her photo.

      The boys have been displaying/scaring the girls. I can never tell which it is (which I think also happens with human :D). They will dive bomb and I can’t tell if it is the wings or their voices that make a strange trill as they fly back and forth in an arc.

      1. Just saw an orchard oriole land on our hummer feeder and sip yesterday. They have to use a slightly different technique for landing! 🙂

  6. After being shot out almost everywhere, pronghorns have been widely reintroduced into their former range. We even have them in southern CA again — even to the edge of the Antelope Valley.

  7. I once had a large male pronghorn jump in front of my car and run down the highway in front of me. I had to slow down a bit, but I clocked it at 50mph.

    The animals are fast, but they aren’t good at jumping fences, which have disrupted their migration routes. There are efforts in Idaho to make fences pronghorn friendly.

    1. Yes, they stot but don’t jump! My son’s seen them go under fences. I gather the pronghorn-safe fences use smooth wire (not barbed) for the lowest strand.

      Very cool photo!

  8. I like the pronghorn. I’ve never seen such a beast and he looks rather African. This one looks like he is shedding and needs someone to scratch his back!

  9. It puzzles me that NWF expresses amazement over a mere 150 mile migration. At a pokey (certainly by antelope standards) 5mph, that is only 30 hours of travel. At ‘half speed’, that is an afternoon’s trek.

    Now, a barred-tail godwit! They migrate 7,000 miles non-stop, over the ocean.

  10. Last year, we drove across the western US twice and saw pronghorns in: South Dakota, Montana, Wyoming. Wonderful sights! They seem more widespread than when I saw them as a kid in the 1970s.

  11. There seems to have been a lot of work done on Antilocapra americana regarding speed and endurance. Here is an excerpt from Byers, J. A. (1997). American pronghorn: Social adaptions & the ghosts of predators past. Chicago [u.a.: Univ. of Chicago Press.

    The running speed of pronghorn approaches 100 kph (Einarsen 1948; Kitchen 1934], and endurance is legendary. Vaughan (1972, p. 246) reported, “On the short grass prairie of north-central Colorado, I observed pronghorns that had run roughly two miles put on a burst of speed and run away from a closely pursuing light plane that was traveling at 72 km. per hour.” Kitchen (1974) measured stride lengths and calculated a resulting speed of 86.5 kph. On a relatively straight road I once had the opportunity to pace an adult male pronghorn than ran on the opposite side of a fence from my vehicle. Over about 2 km, this male negotiated a series of small swales, maintained a speed of about 72 kph, did not appear to be running at top speed, and eventually pulled ahead of me because l was forced to brake for curves in the road. Kitchen (1974) also clocked cruising herds at about 64-72 kph and noted that animals could run for 3 km at these speeds, stop, and not appear exhausted. The specializations that support the running ability of pronghorn include long slender limbs in which distal limb elements are light (slender, with lateral digits lost) and comparatively long, and an ability to transport and use oxygen (Vo2 Max) that greatly exceeds that expected for an ungulate of this size (Lindstedt et al. 1991). The huge Vo2 Max and sustained running ability of pronghorn are consequences of comparatively large heart and lung volumes (McKean and Walker 1974), a comparatively large carotid rete brain cooler (Carlton and McKean 1977), and other, as yet unspecified specializations.

    Also see
    Running Energetics in the Pronghorn Antelope
    Lindstedt, Stan L; Hokanson, James F; et al
    Nature; Oct 24, 1991; 353, 6346; Research Library
    pg. 748

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