When animals jump, they use an explosive burst of power to cover a larger vertical and horizontal distance than they can cover in a single walking or running stride. A hedgehog’s roly-poly appearance does not give credence to their ability to jump, but can they jump if forced to do so?
Hedgehogs can jump. They use a proprioceptive mechanism to control the direction and height of the jump, while skeletal muscle contraction is used to power the jump. Hedgehogs use jumping as a defensive measure and when navigating environmental obstacles which are blocking their path.
An animal who spends half its life curled up into a prickly ball and the other half happily snuffling along the undergrowth hardly fits the idea of what a superstar jumper looks like! However, just because an animal won’t break world records in jumping doesn’t mean they can’t jump.
The Ins and Outs of Hedgehog Jumping Locomotion
Locomotion is the ability of animals to move from one point to another. Locomotion is divided into three categories based on the medium through which the animal is traveling:
- Terrestrial locomotion: moving across the land
- Aquatic locomotion: moving through water
- Aerial locomotion: traveling through the air
Hedgehogs, like many other creatures, primarily rely on terrestrial locomotion. When moving across the ground, animals have recourse to four movement strategies: slithering (e.g., snakes), walking, running, and jumping.
Researchers studying the mechanism of vertebrate and invertebrate jumping have classified jumping according to the strategies used and jumping style.
What Jumping Strategies Are Used By Hedgehogs
Jumping is one of the common movement strategies animals employ. Humans jump, dogs jump, frogs jump; basically, every creature can jump in some form or another.
Jumping requires animals:
- To maintain their balance while jumping
- Accurately judge the distance of a jump
- Generate, conserve and manage the energy needed to perform a jump
How Do Hedgehogs Stay Balanced When Jumping?
Jumping is a dynamic movement with periods of static instability, i.e., the motion will continue regardless of whether the hedgehog wishes to terminate the jump.
Thus, to maintain control over a jump, the hedgehog must precisely control its take-off and landing while maintaining postural stability when airborne.
A hedgehog maintains control of its jump through dynamic balance mechanisms.
There are two components to maintaining dynamic balance:
- Proprioception refers to the ability of the hedgehog to receive feedback via the nervous system and, in so doing, orient themselves in space.
- Body adjustment refers to the hedgehog’s ability to use its musculoskeletal system to alter its body position in response to the proprioceptive feedback.
Hedgehogs with inner ear infections will have impaired proprioception and cannot effectively perform a jump; in fact, most of these hedgehogs will fall upon landing.
The inner ear contains the proprioceptive elements of the vestibular system, which is vital for maintaining balance. The vestibular system provides critical information on the position of the hedgehog’s head relative to the rest of its body.
The decline in neural function results in progressive loss of muscle control, culminating in total paralysis. Hedgehogs with WHS cannot respond to proprioceptive feedback and, as such, develop ataxia that prohibits the execution of a successful jump.
How Do Hedgehogs Judge The Distance of a Jump?
Depth perception is the ability to perceive the 3D nature of objects and accurately judge the distance between objects.
Depth perception is most precise amongst animals with forward-situated eyes, e.g., humans, cats, and chimpanzees.
When viewing an object, the light will hit the two eyes at different times. By calculating the difference between the two eyes’ perceptions of the same light source, the animal can accurately judge the object’s distance.
Animals with eyes positioned on the sides of their head cannot employ this depth perception strategy.
During hedgehog evolution, more emphasis was placed on the hedgehog’s ability to spot and avoid predators than their ability to accurately judge distance. A hedgehog’s panoramic field of vision came at the cost of their depth perception.
A hedgehog’s poor depth perception explains why hedgehogs will occasionally misjudge the jump and end up as a prickly heap of disgruntled hedgehogs after a failed jump attempt.
How Do Hedgehogs Generate the Energy to Jump?
Animals primarily use two mechanisms to generate and conserve energy before and during a jump:
- Muscle power
- Specialized elastic structures
When jumping, most vertebrate animals employ skeletal muscle power to jump. Before the jump, the flexor muscles contract causing the joints of the front legs, hind legs, and spine to contract.
The antagonistic extensor muscles then rapidly contract, causing the joints to extend (i.e., straighten), thus propelling the animal forward in a jump.
The initial flexion of critical anatomical structures allows potential energy to be stored in the joints and muscles of the animal. The subsequent rapid extension results in an explosive power release as potential energy is converted into kinetic energy.
Vertebrate animals who are known for their superior jumping abilities tend to have hyperflexible skeletons and large, well-developed hind legs.
Invertebrate animals (e.g., crickets) do not have the skeletal muscle power necessary to perform successful jumps. Instead, these animals feature specialized elastic structures within their joints.
These elastic structures are gradually loaded with elastic energy. The explosive conversion of elastic energy to kinetic energy allows these animals to perform jumps many times longer than their body length.
While hedgehogs lack the necessary features to be world record-breaking jumping superstars, they can jump if forced. Their hind legs and skeletal muscles are strong enough to support modest jumping attempts.
How High Can Hedgehogs Jump?
Hedgehogs can jump a maximum of:
- 12″ to 15″ vertically (high)
- 20″ horizontally (long)
What Jumping Styles Are Employed By Hedgehogs?
The two most common styles of jumping are:
- Continuous jumping
- Intermittent jumping
With continuous jumping, the animal uses postural adjustments to maximize energy conservation, i.e., these animals use the kinetic energy of the previous jump to fuel the next jump in the sequence.
Intermittent jumping is more common than continuous jumping. With intermittent jumping styles, animals must pause between jumps as they prepare for the next jump.
Hedgehogs are intermittent jumpers who cannot perform continuous successive jumps without a recovery period between jumps.
Why Do Hedgehogs Jump?
Hedgehogs will use jumping as a defensive manoeuvrer to avoid predators. This video shows a hedgehog’s characteristic defensive jump.
If a hedgehog cannot dig under, go around, or climb over an obstacle, they will jump it.
Can a Hedgehog Jump out of Its Enclosure?
A hedgehog can jump out of its enclosure if the sides are lower than 20″. However, most hedgehogs prefer to climb out when making an escape attempt.
Using an enclosure with a roof will ensure your hedgehog remains safely in its cage; both climbing and jumping escape attempts are foiled in cages with roofs.
Hedgehogs can jump, although they are not proficient jumpers. These prickly creatures will only jump if forced to defend themselves or navigate challenging obstacles they cannot climb, go around, or dig under.