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Current profile will feature people, animals, or topics related to panthers & their habitat.   
Highliting some of those teachers and creatures that provide us with inspiration & knowledge. 

  Panthers are Cursorial Predators  
   the power they are able to exert over short distances should never be underestimated..

  

 Evolution of the Cursory Predator 

Author: Joseph Lankalis.

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Puma Concolor Stanleyana

 

When the mammals came to the helm 65MY ago, they were fairly uniform in appearance because they were narrowly diversified and restricted to primarily one niche. That was as an understory insectivore. They were believed to be shrew like in appearance. Probably, opossum like is a better idea. Being carnivorous has more proclivities to specialization than being omnivorous. Omnivory are more open to divergence than carnivory. Some omnivores leaned toward herbivory; others carnivory. Thus began predation when the carnivores began eating the herbivores.

 

The primitive mammals were four legged with five toes on each foot. The opossums are the most primitive prototherian mammals. The shrews are the most primitive eutherians. Neither is adapted for running -- the cursorial habit. As herbivores adapted to evade being eaten, thus began the foot race. The race not only involved speed, but also development of the appendages. To understand the latter, let's define the primitive appendages. The leg is composed of three parts: the proximal segment, distal segment, and the foot. The bones in the proximal segments are the humerus in the fore limb, and femur in the hind limb. The bones in the distal segments are the radius and ulna in the fore limbs, and the tibia and fibula in the hind limbs. The feet contain metapodals and phalanges. The primitive leg had the first two segments about the same length. The second segments had well developed pairs of bones. The feet were five-toed with short metapodals (the long bones in your hands and feet), and the critters walked on plantigrade feet. Bears, raccoons, and man are plantigrade. They walk on the whole foot, rather than on their toes. 

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Opossum Hand

 

This foot race between herbivores and carnivores involved adaptations to increase speed. The carnivores were always playing catch-up to the herbivores. Whenever the herbivores developed an advantageous structure, the carnivores had to follow suit. The herbivores were evading the carnivores by being ahead in development.

 

Adaptations for increasing speed occurred in all three parts of the leg. In the proximal segments, the humeri and femurs became shortened. The function of these segments is to move the whole leg from rear to front and back again as quickly as possible. Longer segments require more torque to move the legs forward. Although long legs do produce more speed, the longer femur lengths induce a cumbersome mode. The application of length to increase speed occurs in the second segment. The bending of the joint between the two segments reduces the amount of torque required to move the legs forward. When the legs are bent and shortened, the forward motion is less cumbersome. The legs are extended just before the feet touch the ground to gain the advantage of leg length. The purpose of the double bones in the distal segment is to allow rotation of the foot. This is not necessary and gets lost in advanced development of the cursory mode. First, the medial bone can no longer cross over the lateral which ends the ability to rotate the foot, then the medial bone becomes reduced, and then lost. This is seen in deer.

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White tail deer & fawn

 

To understand how structure plays in locomotion speed, let's analyze a simple situation. Dogs, bears, and cats run twice as fast as humans because they have twice as many legs. This statement, although appears true, is absurd. Quadrupeds run faster because they have much longer strides. Ostriches are bipeds and can run much faster than man, and as fast as, in not even faster than dogs, bears, and cats. Why? It has to do with proportions of leg segments. In comparing man to an ostrich, the lengths of the femurs and tibias are roughly 50:50 in man. This is primitive. In ostriches, the proportions of the femurs, tibias, and metapodals are 18%, 42%, and 40% respectively. The shorter femurs move the legs back and forth more quickly. The tibias and metapodals increase the strides. Since man is a plantigrade animal, his metapodals are not used to increase stride. The ostrich is definitely digitigrade because it walks on the distal ends of its metapodals at all times. Man lands on his heel the lifts off on the ball of his foot. His metapodals are very short and not used as much to increase stride. 

 

Another feature seen in cursory animals is the loss of the clavicle.  The clavicle or collar bone is either completely lost or is vestigial, therefore, the pectoral girdle is unattached to the spinal column.  Whether or not this is an adaptation to the cursory habit, it does allow the free-floating front legs to extend stride.  Any stridal extension increases speed.

 

Carnivores and ungulates are in a foot race for survival. The ungulates must run faster than the carnivores to survive, and the carnivores must catch ungulates to survive. Previously, the adaptations in the legs were described. Adaptations in the feet were not mentioned. The development of the cursorial foot involves increasing the stride. When plantigrade animals became digitigrade, certain modifications in the feet had to occur. The most cursorial mammals are the ungulates. The most cursorial carnivores are the wolves.

 

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Hybrid Wolf

 

The primitive feet of mammals are 5-toed with short metapodals. The metapodals (the long bones in your hands and feet) are called metacarpals in the front feet, and are called metatarsals in the hind feet. The primitive feet were used mainly for walking and climbing. In primates, grasping was another function. Modification for grasping is seen as zygodactylism, where the hands and feet fold length wise.  That is why our hands have opposable thumbs.  Apes have zygodactyl feet as well.  Zygodactyls are suited for the arboreal mode. When man came down from the trees, his feet became orthodactyl where the toes point straight ahead. Orthodactylism is an adaptation towards the ambulatory and cursorial modes.
 
The first trends to the cursorial mode in the foot were plantigrade to digitigrade. That was followed by the lengthening of the metapodals. And that was followed by reduction of the number of digits. The original primitive number is five. Equines have the least number which is one. They walk and run on the tips of one toe.
 
Plantigrade animals travel on the ends of the second leg segments or heels. Digitigrade animals travel on the ends of their metapodals. Man does this on the balls of his feet. This adjustment lengthens the stride for more speed. The herbivores made this adjustment first. The carnivores had to follow in order to keep up with the herbivores. The herbivores advanced further by traveling on the tips of their digits, thus further increasing their strides. The claws received more stress and become modified into hoofs. The carnivores have yet to evolve to this stage. But, in given time, this may eventually happen.
 
Secondary modifications towards the cursorial habit involve the reduction of number of toes, claws becoming hoofs, and loss of ability to rotate the paws at the wrists and ankles. In ungulates, the radii and fibulae bones are lost in recent species.  The musculature of the second segments is reduced. There is not much to eat off the shins, and the metapodals are just skin and bone. Prehistoric horses were 5-toed. Today, they are one-toed.
 
The secondary modification forms a dichotomy in specialization. Some ungulates place primary stress on the central toe. These later evolved into the odd-toes ungulates. The primitive species are the rhinos that travel on three toes. The central toe is very large with two small lateral toes.  The most recent arrivals travel on one single toe. These are the horses and asses -- the equines.  The rest of the ungulates place primary stress on two central toes. These evolved into the even toed ungulates. They have the cleft hoofs with two vestigial toes out of use. Deer, goats, sheep, cattle, buffalo, and bison comprise the even-toed ungulates. A digit has three phalangial bones. That number is retained in the hoofed animals.
 
Now that l have explained locomotion and evolution in terrestrial mammals, you can now understand the differences in dogs, bears, and cats. Which of these are the most cursorial?  Which are the least?  What is the nature of their modifications?
 
Bears, or ursids, are the least cursorial because they manifest the least specialization towards that habit. First of all, they are plantigrade walkers. They walk on the distal ends of their second leg segments. They are able to rotate their wrists, but not their ankles. Rotation involves the ability to cross the radius bone over the ulna. The radius is well developed in bears. The feet of bears have five digits, all of which are functional. The metapodals are short. The plantar (heel) pads are large and the toe pads are small. The overall structures are designed for walking, the ambulatory mode. Their feet have some arboreal ability with the front ones even having raptorial qualities. Bears frequently capture fawns and buffalo calves. How is it that an ambulatory predator can capture these cursory items of prey? The bear has an advantage with size. He can make longer strides. But when the calves and fawns become larger, the bear's success diminishes.
   

en.wikipedia.org
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Black Bear Paw

 
Dogs, or canids, are the most cursorial of the carnivores. They manifest this by being digitigrade to lengthen stride. The second leg segments lose the ability to rotate. They don't have to worry about twisting an ankle while running. The radii and fibulae are reduced and nonfunctional in that they are fixed and immovable. The toes are reduced in number from five to four. If the fifth exists, it is the vestigial dew claw. The plantar pads are small with large toe pads. Domestic dogs like beagles are least cursorial with their round feet with splayed toes. Greyhounds are bred for running. Their feet are oval with orthodactyl toes. Since they place most stress on their two central toes, these toes are slightly larger than the lateral toes. This is so in wolves and coyotes.  Eventually, their feet will evolve into the feet seen in deer. But that is several million years into the future. The most primitive canids are the gray fox and coon dog. These animals have round footprints with splayed toes. These animals are also capable of climbing trees. Keep in mind that it is not the feet that define a canid. It is their dental formula.

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Wolf Paw

 

Cats are cursory predators, but not as cursory as canids, but more so than bears.  And among the family felidae there are differences. Wolves would best be described as being active cursory because they give long chases to capture prey. Cats, on the other hand, are passive cursory predators, or ambush predators. They do not expel large amounts of energy to make a capture.  They lie in wait, or stalk as closely as possible, then make a mad short rush and make a capture.  Because they practiced this energy saving procedure for a long time in their existence, they became predators of low stamina. If you don't use it, you lose it. The most primitive cats are arboreal and retain the ability to rotate their hind legs allowing them to descend trees head first.

 

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Panther Paw

 

The cats have more adaptations to the cursory mode than bears, but not as many as the canids.  Cats have developed the digitigrade feet with a reduction of toe number, but they retain the rotating wrists. (Cats and dogs walk on four toes. Their front legs do have vestigial fifth toes.)  They have a larger plantar pad with small toe pads. Their front paws are not purely cursory like in wolves. Their front paws are both raptorial and arboreal, therefore, cats can grasp with their front paws. When canids walk, they apply the main stress equally on the two medial toes. In cats, the main stress is applied slightly more on the inner medial toe. The result is that the dog track is symmetrical bilaterally. The cat track is asymmetrical with a lead toe.

 

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Panther Pads

 

The most cursory cat is the cheetah. lt is able to outrun ungulates even though it has not developed the digital extensions with hoofs. Instead, it acquired a development in a different direction to gain its speed advantage. That is the flexible spine which contracts and extends propelling the cat forward increasing the stride. Their feet are basically the same shape as in other cats, but lack retractable claws. Their claws function as spikes in track shoes. The cursory felid does not run the same way as a cursory canid. The canids run in a straight line, whereas cats are designed to run in zigzags. To do this, they need a longer tail than dogs. The long tail of the cheetah helps to keep its center of gravity above its feet during turns; otherwise, the cat would fall over.

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