Snowy Palms: An Omen of Death

Recently, parts of Southern California experienced some surprisingly cold weather, as falling snow graced the tops of the palm trees around Christmas time.  A White Christmas is nothing terribly surprising for folks like myself, born and raised in Colorado, but for California natives it was definitely more of a surprise.  People had pulled over on the side of the highway for an opportunity to play in the snow, throwing snowballs and taking selfies all over the place.

Wind turbines in the foreground, and snow capped mountains in the background in the middle of the desert just outside of Palm Desert in California.

A family stopped along Interstate-15 in Temecula, California to play in the snow, a scene that could easily have been lifted out of Colorado, if not for the trees adorned with green leaves, and especially the palm tree in the background.

A snow selfie on the side of the Interstate-15 in Temecula, California.

Although the winter freeze was very exciting for many of the residents, for the native residents of Southern California's deserts, the freeze would be much less welcome.  Over millions of years, the animals that call these seemingly barren slopes home have evolved to cope with extreme environmental stress typical of those experienced in the desert.  Aridity and extreme heat of course play major roles in any desert ecosystem, and many of the adaptations of desert animals are in response to these climatic factors.

The bobcat (Lynx rufus), one of the residents of the Southern California deserts.  This particular individual was at The Living Desert in Palm Desert.

A captive desert bighorn sheep (Ovis canadensis nelsoni) at The Living Desert.  This subspecies is native to the southern United States and Mexico.

A western diamondback rattlesnake (Crotalus atrox), also native to the southern United States and northern Mexico.

A wild greater roadrunner (Geococcyx californianus) that I chased through a Target parking lot.  

A wild California ground squirrel (Spermophilus beecheyi) that we saw foraging around at The Living Desert.

A hummingbird, possibly an Anna's hummingbird (Calypte anna).  Hummingbirds in Colorado will fly south for the winter, in order to avoid harsh weather like that seen in Southern California last week,

Of course, environmental conditions that fall well outside the norm are arguably equally important for animals native to a specific biome or region.  Even if a population of animals thrives in the harsh, arid landscape of Southern California, if all it takes is a single night of snow to wipe out the population, unusual weather (such as that seen in the area last week) can be extremely troublesome.  Extreme weather can also help control populations, and can be what keeps other animals from colonizing an area.  For example, if a population of desert rodent attempts to colonize the mountains around Palm Desert, but is unable to cope with the occasional snow storm, then that type of rodent would be much less likely to survive and thrive there.

Part of the mountains west of La Quinta and Rancho Mirage, prior to the snowstorm.

The same mountains, following the snowstorm.

Works Cited:

Hummingbirds found in California, USA. (n.d.). Retrieved January 4, 2015, from http://beautyofbirds.com/hummingbirdscalifornia.html

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Flickers on a Rainy Day

Rain makes lots of animals behave differently than they normally do. Many birds either take shelter or, like the American robin, head out to forage for drowning worms. The other day (and by other day, I mean several months ago, because I kept forgetting to post this post) during a rainstorm, I was walking with my friend Mona when we noticed a flicker stabbing repeatedly at the ground.

Here is a picture of the end result of what we were witnessing!

According to one source, the Puget Sound Backyard Birds, ants compose about 80% of a flickers diet, and foraging for this tasty insect snack is probably what the flicker was doing as it continually stabbed its beak into the ground! Even if it wasn't looking for ants, most of the flickers diet is insects. During the winter, when insects can become scarce, the flicker consumes berries and seeds. Certainly an unusual diet and foraging behavior for a woodpecker!

Below is a video uploaded by Deepa Mohan of a flicker foraging for food.  As you can see in the video, this flicker is foraging when the weather outside is not so frightful.  I assume that perhaps the flicker we saw was active while it was raining both because the insects would be scurrying around trying to find safe ground, and also probably because the ground was softer than usual.  

Like other woodpeckers, the flicker will nest in holes of trees, but will sometimes nest in the abandoned burrows of birds such as the belted kingfisher or the bank swallow, whose nests are located in holes within the earth.  Below is a picture of a pair of belted kingfishers flying into their nest:

Flickers are pretty common where I live, and they seem to be pretty common throughout the United States!  If you have any great flicker stories or pictures, make sure to send them in or comment below!

Works Cited:

Flocks of Robins and Winter Territoriality

Where I live in Colorado, and in fact across much of North America, the American robin (Turdus migratorius) is a common sight, especially during the spring and summer.  You can often find this bird hopping across the ground, rooting around in the ground for worms.  However, this morning, on my walk across campus, I noticed a flock of about thirty or so robins in a random tree, and couldn't remember a time when I had seen so many robins in one place, not even close.  What was going on?

Just like for a robin, a little digging proved fruitful....or should I say wormful?  "The Great Backyard Bird Count" (GBBC) revealed that during the winter, the territoriality of the American robin decreases dramatically.  Two graphs on the website, which I have included below, help us to understand what is going on.  The first graph, titled "Percent Submissions With Positive Sightings," charts the number of people who see robins.  As you can see, the peak months for robin sightings are between the months of April and July, with a peak in July.  March, as well as August through October, are also pretty good times to see robins, but during the winter months between November and February, robins are not seen as often.

The second graph, titled "Average Number of Birds for Positive Sightings" charts how many robins people typically see together: i.e., if they report a robin sighting, they also report how many robins there were together.  As you can see, April through September are definitely the worst months to see multiple robins together, with October through February being the best time, and a large peak in November.

Graphs are tough: what does this all mean in English?  Essentially, during the breeding season (spring and summer), robins maintain strict territories, which causes them to spread out, with a more even distribution.  This means that you would be more likely to see a robin on a walk through the park, but not several robins in the same place.  During the winter, presumably because their breeding territories are simply too small for them to get enough food, and since it is no longer the breeding season, they abandon their territories, allowing different robins to go wherever they wish.  For whatever reason, probably something to do with mutual protection, they also form flocks.  The forming of flocks also causes the number of individuals per sighting to increase.

Another study conducted by the GBBC (read the full write-up HERE) pertained to snow depth and frequency of robin sightings.  As you can see in the graph below, the likelihood of spotting an American robin with even just a little bit of snow drops quite dramatically.  Similar results were reported for the red-winged blackbird, while birds such as the white-throated sparrow and northern flicker responded to increased snow depth as well, but not quite as dramatically.

For the robin, a bird that typically feeds on the ground, even just a little bit of snow cover might prove to be an issue.  However, other ground-feeding birds, such as the dark-eyed junco, didn't seem to mind the snow anywhere near as much as the robin.  GBBC suggested that other factors must affect the distribution of these birds, such as "weather, diet, and the species' normal range and altitudinal limits."

A subspecies of the dark-eyed junco called the gray-headed junco.  I took this picture of the stuffed animal when we were in Ouray over the summer.

A picture of a dark-eyed junco that I took in my backyard.

The GBBC devotes a paragraph to acknowledge the uncertainties in these results, a humility that I find refreshing and, sadly, not too common on many Internet sources these days.  GBBC looks at the graph below, plotting the snow depth against the likelihood of seeing a house finch, and notes the steady decline, as opposed to the sharp drop seen in the robin graph, or the lack of real pattern seen in the junco graph.  GBBC reports that this would be a pattern not expected if it was access to the ground (or lack thereof) that was causing these birds to move.  Instead, one would expect the sharp decline of the robin graph.  Other factors, such as temperature, could be what is causing birds like the house finch or the house sparrow to move.

A male house sparrow.

A female house finch, silhouetted against the backdrop of the evening sky.

Works Cited:

"Snow Depth Survey." The Great Backyard Bird Count. http://www.birdsource.org/gbbcX/science-stories/past-stories/snow-depth-survey (accessed January 23, 2014).

Stokes, Donald, and Lillian Stokes. The Stokes Field Guide to the Birds of North America. New York: Little, Brown and Company, 2010. (accessed January 23, 2014).

"Winter Robins." The Great Backyard Bird Count. http://www.birdsource.org/gbbcX/science-stories/past-stories/is-that-winter-flock-of-robins-in-your-yard-unusual/ (accessed January 23, 2014).

Chiidax the Northern Fur Seal and the Evolution of the Otariids

Late last year, the New England Aquarium in Boston, Massachusetts received Chiidax, an orphaned northern fur seal (Callorhinus ursinus).  However, it was last July that Alaska SeaLife Center first took in Chiidax, after he was left outside the Alaska Department of Fish and Game offices.  A note which was included on the outside of the box that the pup came in said that the pup's mother had died while she was giving birth.  Notice how in the first two pictures of Chiidax below, the pup is covered in an all black coat, a mark of his young age.

After the pups are weaned at around four months old, they molt into their next coat, the cream and brown color of the young juvenile northern fur seal.  Look for those in these next four pictures, taken sometime last fall.  The post on ZooBorns (read that HERE) doesn't say exactly when the pictures were taken, but given that the post was published late last November, these last photos were presumably taken around then.  

When the first post on Chiidax was written on November 23rd of 2013, he weighed 18 pounds, but when he's full grown, he will definitely be a bit bigger: the males, or bulls, of the species can weigh nearly 600 pounds, which is several times more than the females weigh!  The males have to be so large because they create harems of thirty to forty females, and defend them from other males.  The seals are native to the Pacific Coast of the United States, as well as the coast of the Bering Sea in Canada, Alaska, and Russia.  

The last report on Chiidax was in late December, on the 29th.  Below are several pictures that were shared then.  You can see how smooth he looks, and how perfectly adapted for a life beneath the waves this creature is!  

The northern fur seal is the sole extant member of the genus Callorhinus, but there is also a fossil species of Callorhinus.  C. gilmorei is known from the Pliocene Epoch of southern California and Mexico, as you can see in this paper HERE.  Other sources cite another paper, linked HERE, as stating that this genus is also known from Japan, but I was unwilling to pay the fee to read the paper, so that fact remains unconfirmed.  If you have a subscription to this online journal, let me know what you find!

According to the first paper, the eared seals, or the members of the family Otariidae, can be traced back at least to the Mid to Late Miocene Epoch, approximately 11-12 MYA in California, in the form of Pithanotaria starri.  Another taxon, Thalassoleon mexicanus, is known from Mexico during the Late Miocene, approximately 5-8 MYA.  The authors of the paper suggest that between 5 MYA and today, between our time and the time of Thalassoleon, was when fur seal diversification took off, resulting in the eight extant species of Arctocephalus and the extant Callorhinus ursinus, which includes little Chiidax!  The genus Arctocephalus, along with the genus Callorhinus, comprise the extant members of the eared fur seals.  The writers of the paper also suspect that it is during this 5 million year period that the sea lions developed as well.

Things have probably changed a lot in this area of paleontology since this paper was published in 1986, but unfortunately I can't seem to access most of these papers.  Callorhinus gilmorei still seems to be a valid taxon, however, as do Thalassoleon and Pithanotaria.  Hopefully, new fossils will yield more interesting results regarding these creatures very soon!  

Unless otherwise noted, the photo credit for all of these pictures in the post go to ZooBorns, either this post HERE or HERE.  

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Works Cited:

The Shark-Like Edestus: An Interview With Wayne Itano

We've heard from Wayne Itano before, when he told us about the Kremmling Cretaceous Ammonite Locality in Colorado. (To read the post, click HERE.) A physicist at NIST (National Institute of Standards and Technology) in Boulder, Colorado, Wayne also has a hobby interest in paleontology, and is a curator adjoint at the Natural History Museum of the University of Colorado. He has also been doing some very interesting work with a shark-like animal called Edestus, and he graciously agreed to answer a few questions for me regarding this creature! So please join me in welcoming Wayne Itano, as he tell us about this fascinating prehistoric creature!

Scissor-tooth model for Edestus.  Credit Ray Troll, www.trollart.com

The Natural World:  You've been doing some work with an ancient shark-like creature called Edestus. What can you tell us about it?

Wayne Itano:  Edestus is my candidate for the strangest shark of all time. In my opinion, it is even stranger than the better-known spiral-toothed Helicoprion, since it is harder to imagine how the teeth might have been used.  (Read more about Helicoprion HERE.)  Almost the only fossil remains of Edestus are its symphyseal (midline) tooth whorls, which consist of triangular, serrated teeth, joined together at the bases (roots).

Edestus had one tooth whorl in the upper jaw and one in the lower jaw. Since the whorls are bilaterally symmetric (same on the left side as on the right side), they must have been located in the middle of the jaws.

This is a photograph of a specimen of a species called Edestus mirus. It was found in Pennsylvanian-aged deposits (about 300 million years old) of Iowa.

Smithsonian Institution Specimen USNM V 7255. Scale in cm.  To see a better resolution of the picture, click HERE.  Photo Credit: http://collections.si.edu/search/results.htm?view=&dsort=&date.slider=&q=Edestus+mirus+holotype&tag.cstype=all

This is a rare specimen, since it shows both the upper and lower tooth whorls.

The curvature of the tooth whorls makes it difficult to understand how they could have been used.

According to the conventional reconstruction, the two tooth whorls were used as scissors, to cut prey between the two whorls, as in this drawing by Ray Troll.

Scissor-tooth model for Edestus.  Credit Ray Troll, www.trollart.com

To me, this model seems unlikely, given the curvature of the tooth whorls. It seems that the outer teeth are nonfunctional, since they can’t come together, so there would be no reason to retain them.

It seems to me that the teeth would be more efficiently used if the entire head was moved up and down, with jaws fixed, to slash large prey. This is a radically new idea. I have submitted an article for publication elaborating on this idea, but I expect that it may be some time before it gets into print.

New vertical-slashing model for Edestus. Drawing by Gary Raham, www.biostration.com, reproduced with permission of Wayne Itano

My new reconstruction of Edestus, showing the pair of symphyseal tooth whorls, in front, used for slashing prey, and flat teeth in the rear for crushing prey. Drawing by Gary Raham, www.biostration.com, reproduced with permission of Wayne Itano.

TNW: I noticed that you referred to Edestus as being a candidate for the "strangest shark of all time." Is Edestus truly a shark? If not, how do you classify it?

WI: I was using "shark" in an informal sense, as the term is not well-defined for many extinct fish. Edestus certainly falls within the class Chondrichthyes, which today comprises 2 subclasses - Elasmobranchii (sharks, including rays) and Holocephali (ratfish). There is some evidence that Edestus (and also Helicoprion) belong to an extinct line that is closer to the Holocephali than to the Elasmobranchii, but this is a matter of debate. It is safe to call Edestus a chondrichthyan, and I try to avoid the word "shark" when I write a technical paper, or maybe keep it in quotes.

TNW:  Tell us a little bit about your research.

WI:  I am interested in many aspects of paleontology, but for the last 22 years I have focused on fossil sharks, particularly ones from the Paleozoic (older than about 250 million years ago). My interest in Paleozoic sharks dates from 1991, when I found a finspine of a Pennsylvanian-aged shark called Ctenacanthus in a roadcut near the town of McCoy, in Eagle County, Colorado. I wrote an article about this find for the newsletter of the Western Interior Paleontological Society (WIPS) in 1992, which you can read by clicking HERE.

Ctenacanthus finspine found near McCoy, Colorado. Scale in cm.  Photo Credit: Wayne Itano

In trying to identify this finspine, I read everything I could find about Paleozoic sharks. Knowing of my interest in the topic, Professor Martin Lockley of the University of Colorado at Denver loaned me a large collection of shark teeth and finspines from McCoy that he and Karen Houck, also of CU Denver, had found in the 1980s. His paleontological interests had by then switched entirely to ichnology (footprints and other fossil traces), and he gave me the opportunity to write up the fossil shark specimens. I published an article on the finspines in 2003 with Houck and Lockley, which you can read HERE, but I haven’t finished with the teeth yet.

My interest in Edestus started when an amateur fossil collector showed me an unusual shark tooth that he had found at McCoy. After a bit of study, I realized that it was a tooth of Edestus, the first known from the entire Rocky Mountain region. This eventually led to my publishing a rather long paper on Edestus in 2012, again with Houck and Lockley, which you can read HERE.

Recently, I have also published three short papers related to Edestus: one on an Edestus tooth from England, one on an Edestus tooth with abnormal serrations, and one on a tooth from China that had mistakenly been identified as Edestus, but which actually belonged to a more “normal” shark called Carcharopsis.

TNW:  Do you have any future expeditions or research papers in the works?

WI:  Lately most of my “field work” has been in museum collections. In the last few years I have been able to view specimens in the collections of the Yale Peabody Museum, the Natural History Museum (London), the British Geological Society, the American Museum of Natural History (New York), and the New Mexico Museum of Natural History and Science. I have several publications in the works, largely based on fossil shark specimens I have seen in those collections.

One area is the taxonomy (classification) of Edestus species. About 15 species of Edestus have been named, but I think that many of these are synonymous. For example, people have named new species based on unusually small or large teeth, but I think they are just teeth of the same species of Edestus but of different ages. There may be as few as 3 valid species of Edestus.

I have another project where I am examining microscopic scratches on Edestus teeth. I am hoping that I can find feeding-related scratches and that their orientation will provide some clues as to whether the scissors-model or the up-down-slashing model is correct.

-Thank you so much, Wayne, for answering some of my questions!  I look forward to hearing more about Edestus in the future!  Thanks again!-

Damu the Greater Angle-Winged Katydid!

A few months ago, I looked up at the dorm room wall and there was a katydid perched there!  I captured him and put him in a container for a week!  I learned a little bit about katydids, so put your listening ears on!

Damu in his container.  "Damu" means "blood" in Swahili, and for good reason.  This little insect was a bloodthirsty demon, I tell you what.  Which is a joke because it eats leaves.  Ha.

I figured out that Damu was probably a greater angle-winged katydid (Microcentrum rhombifolium), native to the southwestern and eastern United States.  The adults are only around from between July and October, except in Florida, where the higher year round temperatures allow the species to live year round.

The greater angle-wing is pretty large as insects go (especially here in Colorado), and looks quite cool!  As you can probably tell from the picture below, the katydid has evolved to superbly mimic its surroundings: i.e., the leaves of trees!  This makes the katydid one of my Top Ten Favorite Camouflagers, one of four insects to make the cut!

Top Ten Favorite Camouflagers
By Zack Neher

1.  Octopus
2.  Walking Leaves
3.  Leafy Sea Dragon
4.  Katydid
5.  Ghost Mantis
6.  Harry Potter Under the Invisiblity Cloak
7.  Arctic Fox
8.  Walking Stick
9.  Optimus Prime
10.  Ptarmigan
11.  Leaf-Tailed Gecko


If you live in much of the United States (refer to the map below), you can probably see the greater angle-winged katydid!  Or, at least, hear it!  I know for me personally, once I knew what I was listening to, I heard them ALL the time!  Click the link to hear a sound clip of the male making its distinctive clicking sound!  (Damu made these sounds, which is why I am almost positive of him being a male).

Male Katydid Clicking Sounds

Damu is sadly no longer with us: I kept him for about a week, and decided to let him go.  He spent a lot of time making his clicking sounds (which are surprisingly loud for a critter of his size), especially at night when we were trying to sleep.  It got quite annoying, and I wanted him to be free, so I released him from his prison.  Plus he pooped WAY more than an insect of his size should.

I caught another katydid later on, this time a female.  You could tell that Damu Mbili (Damu II in Swahili) was a female because she never clicked and had an ovipositor, an organ possessed by some animals to aid in egg laying.  She died in the middle of October, right around when you would expect these katydids to pass away, though I did hear male katydids clicking away intermittently through the 27th of October.  Here are a few pictures.

Check back soon for our next post, where we look at some insects that I saw at my recent visit to the San Diego Zoo, many of which are expert camouflagers!

Works Referenced:

A Family of Red-Shouldered Hawks by Wes Deyton, Guest Blogger

A month or so ago, I came across a documentary on YouTube about a family of Red-Shouldered Hawks made by a man named Wes Deyton.  I also saw a number of really cool pictures that he took of the birds, and thought it might be interesting to see if he'd be willing to do a guest post!  Kindly, he was happy to oblige!  First, a bit about Mr. Deyton:

My name is Wes Deyton and I recently graduated from Western Carolina University with a Bachelors Degree in Communications and Broadcasting.  I live in Fuquay Varina North Carolina, which is near Raleigh.  I enjoy taking pictures and making videos of wildlife as well as scenic nature.

Anyways, let's all give Mr. Deyton a warm welcome!  I hope you enjoy these pictures and the video, all of which were taken by Mr. Deyton, as much as I did!

The Red Shouldered Hawks in the video (below) were filmed in the woods behind my house. I have been following them for about the whole Summer.  I did not get any footage of the hawks in the nest when they were really young, because I was still at WCU. I have not been able to find them lately because I think the young Hawks have gone on to find their own territory.

The Red Shouldered Hawk is a medium sized hawk, it primarily lives in woodland areas and it can be found all over the eastern woodlands as well as California and Northern Mexico. These birds generally live in woodland and swamp areas and build their nests high up in trees, close to sources of water such as lakes, streams and swamps.  The nesting period of these birds is about 45-60 days.  

The female hawk spends most of her time getting food to bring back to the nest for her young.  The diet of these birds consist mostly of small mammals, reptiles (including snakes), and amphibians.  There is no sharing in a hawks nest when it comes to food: when the mother brings food to the nest, the chicks have to fight for food.  Sometimes, the female hawk will feed the smaller hawk to make sure it gets enough nourishment to grow and develop healthily.  

Hawks get bored in the nest and dream about life on the outside. They dream about flying high like their parents. This is very evident by seeing them jump back and forth and flap their wings in the nest before they are fully developed to fly. The young hawks climb from branch to branch to develop their balance and then fly short distances until they build up their confidence to fly away from the nest.

The hawk is at the top of the food chain and strikes fear in smaller birds when they are around.

Aren't those pictures brilliant!  Thank you very much Mr. Deyton for sharing these pictures and the video with us, we hope to hear more from you again in the future!  Thanks again!  -Zack Neher

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