Thursday, November 29, 2012

Which Jackrabbit?

White-sided Jackrabbit (Lepus callotis) photo from wickimedia commons. Note the black on the inside of the ears.
A couple of years ago Charlie O'Brien and I were traveling through the San Rafael Valley close to the tiny town Lochiel at the Mexican border when suddenly two hares came racing across the undulating grassy hills. They were chasing each other the way courting hares do, flinging themselves high into the air and thus overtaking each other in the vertical rather than the horizontal plane. Even from a distance of several hundred feet we could see that they each had a large white area on their flanks. A year later I was returning with Eric Eaton from a bug-party in Sierra Vista, so it must have been in late August. We took the long way home, around the Chiricahua Mountains and, at dusk, were just turning north again in the Canelo Hills. Landscape-wise the area is the northern extension of the San Rafael Grasslands. We may have even been talking about my earlier observation. At any rate, we saw another Jackrabbit with white flanks. Eric got out of the truck and followed it for a while to get some photos. I had only my 50mm macro lense, so I didn't even try. I never saw the result of this pursuit, but I think it was already too dark to shoot a moving target.

I was reasonably sure then that the hares we saw on both occasions were white-sided jackrabbits (Lepus callotis) also known as the Mexican hares. Literature gives Northern to Central Mexico and Hidalgo County in SW New Mexico as the distribution range of this threatened species. But occurance in Arizona is assumed possible but has not been clearly recorded. So did we actually see L. callotis?

The two other possible species are Black-tailed  and Antelope Jackrabbit, and both are widespread and common in Arizona.

 Watercolor of Black-tail Jackrabbit under Creosote bush with dry Cheat Grass. by Margarethe Brummermann  
On our property in Picture Rocks, Arizona, we regularly see the Black-tailed Jackrabbits (Lepus californicus). Especially the youngsters that congregate to drink at our bird bath are literally 'all ears'. They can use these huge appendices for heat dissipation, and when it's hot, a bright pink glow from expanded blood vessels makes the ears look even more impressive. They feed on anything here. They clipp creosote branches, graze on cheat grass, love cactus fruit whose seeds they distribute undigested in their pellets. When a barrel cactus falls over and exposes its thornless underside, a Black-tailed Jackrabbit can hollow it out in a single night. Only a huge pile of pellets will stay behind.


Like the White-sided Jackrabbits, they have black areas on the tips of the ears, but on the outside, and black tails. But their flanks are tan colored like the rest of the upper side of the body. This JR has a wide distribution range, including all of the Southwestern US, east to Missouri, north to Nebraska and Washington and south into Mexico. 


Antelope Jackrabbit (Lepus alleni)  Photo by Eirini Pajak
The other Arizona species is the Antelope Jackrabbit (Lepus alleni). I can't say that I have actually consciously seen them - I only became aware of their field marks while preparing this article. The antelope jackrabbit is one of the largest hares in North America, weighing 9 to 10 pounds (4.5 kg). This jackrabbit’s huge ears are edged in white. The large eyes are placed high and towards the back of its slightly flattened head, allowing it to see nearly 360 degrees as it watches for predators. The antelope jackrabbit is so named because it has a patch of white fur on its flanks that it can flash on one side or the other as it zigs and zags, running from a predator, much as the pronghorn antelope does. (Arizona-Sonora Desert Museum-http://www.desertmuseum.org/books/nhsd_rabbits.php)

Antelope Jackrabbit photo by Rick Wright
According to literature, its prefered habitat is even dryer than that of the Black-tailed JR, which seems nearly impossible considering that we have Black-tails on our creosote flats. But its main distribution is more southern (Sonoran Desert in AZ and the western states of Mexico)  and it can reportedly deal better with extreme heat (Best and Henry, 1993).  It also prefers lower elevations than the Black-tailed, and  grassland to brush.

Antelope Jackrabbit flashing its white side. photo by A. Schmierer
So which jackrabbit flashed its white flanks? During my internet search for an image of the White-sided, I repeatedly found a misidentified Antelope JR, with white flanks, but clearly lacking the black on the inside of the ear tips. The San Rafael Valley is still rich in endigenous grasses that L. callotis likes, but the Canelo Hills location may be to high in elevation for the species. The photo by A. Schmierer, above, cleraly shows an Antelope JR, and it was taken in the Patagonia area which isn't far from the Canelo Hills. The White-sided JR is crepuscular to night-active. We saw the pair during the bright afternoon (but mating activity may disturb the pattern?) and the single one at dusk. We did see the flashing white flanks, but I paid no attention to the ears. So if Eric doesn't find his photos and they clearly show black ear tips, I think we will never know whether those were Antelope or White-sided Jackrabbits, but I now assume they were the former.


Old Jack.  watercolor M.Brummermann

Anyway, I think they are all amazing desert creatures, adapted to some of the most inhospitable habitats and chased and hunted by everyone from Golden Eagles and other raptors to felines, canines and humans, but still jumping, cavorting and playing.

All Ears. watercolor M. Brummermann

I found this in the AZ Star this morning and just couldn't help it, it just had to go on this blog:


When not able to find shelter, Lepus alleni can tolerate heat stress at high levels better and for a longer time than Lepus californicus. (Best and Henry, 1993; David S. Hinds, 1977; Mearns, 1890; Vorhies and Taylor, 1933)
When not able to find shelter, Lepus alleni can tolerate heat stress at high levels better and for a longer time than Lepus californicus. (Best and Henry, 1993; David S. Hinds, 1977; Mearns, 1890; Vorhies and Taylor, 1933)


 
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10 comments:

  1. So, I've already learned something new, today. Clearly the 1st rabbit you showed is different from ours (ours = black-tailed jackrabbit) 'cause I immediately STARED at the black mark inside the ear and could not stop.

    And I love the white ear border in the antelope rabbit. SO glad to know those field marks, so THANK YOU!! =) I'll stay alert as I drive to Big Bend NP this February--maybe I'll see a new (to me) species. =)

    Your watercolors are AMAZING! Wow. SO realistic, jeepers. Skillz!

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  2. Great post. I've not seen jackrabbits in the San Raphael Valley myself, but I have seen the White-sided in the S end of Gray Ranch in New Mexico twice – and both times at night. I had a sighting of probable White-sided Jackrabbits in far southern Tamaulipas, Mexico, east of Ciudad Mante – where there are supposedly no jackrabbits of any kind. White-sided is mapped sort of close to there at the http://www.natureserve.org/infonatura/ website.

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  3. I really like the "Old Jack" painting -- do you plan to "turn it into" a greeting card or a print of some sort?

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    1. Rich, you saw them at or close to areas where they are recorded - there are several distribution maps for Mexico that vary from each other.

      Robyn, I am just working on prints and cards - there was a lot of interest i that picture at the show last weekend.

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  4. OK, I might like to purchase one as a companion for the Bobcat!

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  5. Great! Any time, the prints are ready and turned out well.

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  6. Always enjoy your posts. Takes me back to parts of the Arizona desert I love.

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  7. Oh, Margarethe, you are a naturalist in the fullest sense of the word! Your curiosity has led you to all sorts of fascinating discoveries! I had no idea there was a different species of jack in Mexico, and though I'd heard the terms "antelope" and "black-tailed", I just assumed they were two common names for the same species. So next time I see one I'll look for field marks! Your paintings of the old jack and "all ears" are fabulous!

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  8. Your painting of a jackrabbit under a creosote is beautiful too!

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  9. I just found your blog at Networkedblogs, and it's just so specially and beautiful, I'll certainly follow it from now on.
    I wish you a great new year ! Elisabeth

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