An Introduction to Insectivores

To understand the Insectivores, we primarily need to know the insectivore definition which goes as; Insectivores are carnivore animals that consist of 450 species of moles, desman, hedgehogs, moonrats, and gymnures, etc. Insectivores are species that prey on insects. They are dependent on the insect as their source of food. They first catch and then feed on them. Insectivore is a taxonomic order. Insectivore is filled with 10 percent of mammals and another percent with small animals like mice. 


Most of the predators of insectivores are amphibians or ground dwellers. They feed mainly on invertebrates and small invertebrates. They are terrestrial mammals, either living on or under the ground. Some are also aquatic. They have an acute sense of sight and smell which help to locate their prey easily and accurately.  Insectivore has less developed skills of intelligence and manipulation compared to placental mammals. Insectivore as long, flexible proboscis with sensory whiskers which is used to probe and locate the prey. Insectivores are secretive and active mammals. 

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Insectivore Examples and All About Them

Insectivores are carnivore animals who choose to depend on the insect as their main source of food. Amphibians were the first invertebrates. Some insectivore examples are echidnas, frogs, lizards, bats, anteaters, etc.


Few plants are also insectivores that trap insects like the pitcher plant, Venus flytrap, etc. They have few insectivores that feed upon flying insects which are known as aeroplankton. Aeroplankton consists of the small size of bats, dragonflies, swallows, etc. The insectivore that feeds on aeroplankton is a quick and maneuverable flyer. They are mostly visual predators who feed insects just by sight. But in darkness, they use echolocation to locate their prey. 


Other types of insectivores are gleaners who search and dig surfaces to locate insects to eat. Gleaners carefully examine the plant leaves, trunk, and branches of the tree to locate their prey. Warblers are the type of birds who exploit the forest’s canopy in search of insects.


Few other species of insectivores search their prey inside wood such as woodpeckers who make cavities in the tree in search of food and also bears while searching for beetle grubs and carpenter ants. Many insectivores live in the soil. While some small mammals dig and feed on insects. Haitian solenodon, also known as Solenodon paradoxus uses their toxic saliva and paralyzes their insect prey to feed on them. Others just graze and search in their zone for their prey. 


Even in ponds, lakes, and wetlands, there are numerous numbers of insects that are eaten by insectivores. They walk underwater in search of insects to feed. We know all insectivores are animals but there are few plants as well who feed on insects by trapping, digesting, and killing insects. 


Few insectivores have some odd reproductive as well as parental habits. The tenrec female release odour when there is the arrival of mating season

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Physical Characteristics of Insectivores

The third largest of mammals are Insectivora after the bats and rodents. The size of insectivorous animals ranges from a mouse to a large house cat. Moonrat (Echinosorex gymnure) is the largest insectivore which weighs 2kg with a body of 40 cm and a tail of 20 cm. Moonrat is mainly found in Sumatra, Malay Peninsula, and Borneo. They release foul odour to feed on their prey.  Many insectivores have few of the same characteristics such as short legs, long, flat, and small skulls. Also few have incomplete cheekbone, etc. Most of the insectivores have tiny eyes and have poor eyesight. The almost blind insectivores are moles and desmans and in other eyes are covered with their fur and few insectivores have small ears while moles do not have external ears. They have whiskers known as Vibrissae which are sensory hairs that help them to locate their prey. 

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Variations of dental formulae are found in insectivores but the most common formula of dental is Intine is 3/3, Canine is 1/1, Premolar is 4/4, Molar is 3-4/3-4 by multiplying by 2 it makes 44,46 or 48. Deciduous type of teeth is the first set which developed in mammals. The tail length and texture of insectivores vary with different types of insectivores.


The Behaviour of Insectivora 

Insectivores are notorious as well as shy in their behaviour. They are active mammals. Their eyesight is not highly developed so they mainly depend on their other sensory senses like touch, smell, and hearing. Though few of them use echolocation. Echolocation is the use of sound to locate their prey. They have different ways to protect themselves. Most of the insectivores hide in deep forests, tunnels, and holes that are deserted by animals or under branches of leaves or roots of plants. 

They have various ways to communicate from intraspecific which is communication between two different species to intraspecific which is communication between the same species. Few insectivores mark their area by using body secretions. Scent glands are used as a way of communication between golden moles. Most of them are nocturnal. Insectivores keep moving to maintain their body temperature so they dig non-stop. They keep their body warm by their involuntary muscle called twitches while sleeping.


Distribution of Insectivores

Insectivores are found everywhere but mainly in Australia, Antarctica, and South America. Shrews are such insectivores that cover almost the planet except for the poles. Shrews are mainly found in Australia and the greater part of South America. While shrew mice and moles are only insectivore families which are located in North America and few of them are located in the northern side of Northern America. While gymnures and hedgehogs are located in New Zealand, Africa, Eurasia, Borneo, and Southeast Asia. 


Solenodons are endangered now so they are found only in Cuba and Haiti. Earlier they were also found in Hispaniola and Puerto Rico. The Shrews of West Indies are believed to be present in the West Indies till Spaniards settled and existed there in the 16th century. It is still hoped that they exist but no further evidence is there to prove their existence. In Africa, moles are not found while tenrecs are inhabited by Madagascar and lesser extent to the Comoro Islands and in the western part of central Africa. In the southern half of Africa golden moles exist. 


Reproduction of Insectivore

Very little is known about the reproductive biology of an insectivore. The short life span insectivores are the shrews' majority who produce after several litters a year and the long life span insectivore like tenrecs does it mating only once in a year. They make as few as many offspring per litter but the tenrecs can have as many as they wanted in 32 young years at one time. Two weeks to two months is the gestation period of insectivores. Two to 24 is the number of teats. Their location is dependent on the species. Male has tests present in the abdominal cavity which is near to the opening of the perineum. Only tenrecs and moles have a penis bone known as a baculum. 


Few mating practices like polygamy are also observed. But they are short and last for a few seconds in some species while in some species it lies for hours. Young tenrecs are born with hair that helps them to run immediately after birth and they are independent in a few weeks. While the moles are naked when they are born, they are born with few vibrissae and guard hairs to protect them. Moles stay dependent on their mother for a few months. Few insectivores have some odd reproductive as well as parental habits. The tenrec female releases odour when there is the arrival of the mating season while the male secretes milky white substances.


Habitat of Insectivore

Insectivore is mainly terrestrial animals. They either live under or on the ground. They are fossil as well as few are aquatic. Insectivore also inhabits them in altitudes of sea level up to 14760 ft which is 4500m. An approx. of 30 species of Talpidae are burrow diggers. Many tenrecs, Soricidae, and Chrysochloridae are fossorial. The golden moles dig burrowers; they dig sandy areas, farmed lands, and forests. Gymnures live under brush piles, tree roots, deserted burrows, etc.  


While solenodons live in rocky as well as in forest areas but tenrecs prefer brushlands and forest. The shrews prefer to live in different altitudes and habitat that ranges from high snowy to dry hot desert. Many of the shrews like to live in moist habitats. They live to live inside shallow runaways where they dig or live inside the holes made by animals. Some live under twigs or decomposed lives. Solenodons mate by making the nest. The shrews who are short tails make a large mating nest for mating consisting of two different types of grass and leaves inside tunnels. 


The aquatic species of insectivores like to live in streams, rivers, and springs. The Eurasian water shrews dig tunnels that open into water bodies. The mouse-sized animals of insectivore make the tunnel according to their size so that they can easily squeeze out the water using their fur to exit water bodies. Many arboreal species live in trees when they are attacked. The shows who are short-tailed are climbers.

FAQs (Frequently Asked Questions)

1. Write a Short Note on Insectivores.

Ans: Insectivores is a carnivore animal who locate and feed on their prey. They depend upon insects and their source of food. They are a group of mammals that consist of moonrats, shrews, hedgehogs, and moles. Insectivores prey both on invertebrates and small invertebrates. Around 450 species are them out of the 365 are alive. The most common characteristics of insectivores are small eyes, ears, and long snout. 


Few of them don’t have external ears. They also have clawed toes on every foot and their teeth are primitive in number and pattern. Hedgehogs and moonrats have a long body. They depend on their sense of hearing, touching, and smell compared to vision. Some of the species use echolocation to locate their prey. 


Insectivores are terrestrially habituated. Some species are also present in an aquatic environment. The diet of insectivores is not limited to just invertebrates it also includes a various variety of plants and animals. Most of the insectivores use their sense of smell to navigate their prey. While some of them use their tentacles to navigate and capture their prey.

2. What are the Feeding Habits and Diet of Insectivores?

Ans: Insects are the main source of food for insectivores. While hedge dogs, solenodons, tenrecs, and some shrew have an animal-based diet that consists of reptiles, worms, snails, and also ground-nesting bird eggs. Plant matter like fruits, vegetables, nuts, etc. is also the source of nutrition for insectivorous animals. 


Most of the moles and shrews have a high rate of metabolism. Ground dweller's insectivores feed by searching under leaves, dirt, branches, etc. The aquatic desmans, moles, and shrews are insectivores who are good swimmers who can easily catch small fishes and invertebrate in water. Otter shrews like a freshwater crab to eat. The lifespan of insectivorous animals is short and ranges from one year to 11 years depending upon the different species of an insectivore. The shrew with long-tail eats all day long.

3. What is the Reproductive Biology of Insectivores?

Ans: Not much is known about the reproductive biology of an insectivore. The short life span insectivore is the shrews' majority who produce after several litters a year and the long life span insectivore like tenrecs does it mating only once in a year. They make as few as many offspring per litter but the tenrecs can have as many as they wanted in 32 young years at one time. Two weeks to two months is the gestation period of insectivores. Two to 24 is the number of teats. Their location is dependent on the species. 


Male has tests present in the abdominal cavity which is near to the opening of the perineum. Only tenrecs and moles have a penis bone known as a baculum. Few mating practices like polygamy are also observed. But they are short and last for a few seconds in some species while in some species it lies for hours. Young tenrecs are born with hair that helps them to run immediately after birth and they are independent in a few weeks. While the moles are naked when they are born, they are born with few vibrissae and guard hairs to protect them. Moles stay dependent on their mother for a few months.