Rodents biology and classification

Dr/ Walaa Samir Ahmed Nasser

Rodents research department

Research institute of medical entomology

Scientific classification

Scientific classification

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Superorder: Euarchontoglires

Order: Rodentia

Suborders

SciuromorphaCastorimorphaMyomorphaAnomaluromorphaHystricomorpha

Introduction

The mammals of Rodentia are called rodents’

They are found in vast numbers on all continents other than Antarctica.

Common rodents are

Mice

rats

Squirrels

Porcupines

and guinea pigs, etc.

feeding behavior

Rodents use their sharp incisors to cut wood, and bite predators.

Most rodents eat seeds or plants, cutting wood, Nearly all rodents feed on plants, seeds in particular, but a number of species eat insects .

Range of orders

Rodents make up the largest order of mammals. With about 2,277 species ofrodents,

over 40% of mammalian species belong to the order.

Their success is probably due to their small size, short breeding cycle, and ability tocut and eat a wide variety of foods.

Rodents are found in vast numbers on all continents except Antarctica, mostislands, and in all habitats except oceans. They are the only placental order.

All rodents have a single pair of upper and a single pair of lower incisors whichgrows constantly , followed by a gap , and then one or more molars or premolars,

Their anterior and lateral surfaces are covered with enamel, but the posteriorsurface is exposed dentine. Rodents lack canines, and have a gap between theirincisors and premolars.

Beavers

* Their homes are called lodges

* Two species: Eurasian Beaver

North American Beaver

How beavers build their homes?

dormouse

* What do they eat?Fruits, berries, flowers,

nuts and insects.

* Main characteristic:

Hibernation

Squirrels

Can fly squirrels?

* They use their skin flats to

glide some distance.

porcupine

Characteristics:- Herbivorous

- Sharp spines over its body

- 60 to 90 cm

2 groups:

- New world porcupines

- Old world porcupines

Prairie dog

Characteristics:

- Herbivorous

- 30 to 40 cm

- Diet:

Insects, roots, seeds, fruits and

buds

Guinea pig

Characteristics:

• Cavies, cobayo, cobaya, acure, curí, cuilo cuis

• 22 cm

• South America

• Diet:

• Grass,(alfalfa) and some

leaves

Which is the smallest rodent?

African pygmy mouse (Mus minutoides)

10 Cm

7 g

Which is the biggest rodent?

1.25 m

66 kg

the capybara, (Hydrochoerus hydrochaeris)

Commensal rodents

The three commensal rodents include:

the Brown or Norway rat ( Rattus norvegicus )

the Black or Roof rat ( Rattus rattus )

the House mouse ( Mus musculus )

Classificationالتصنيف

The Brown or Norway rat الفأر البنى أو النيرويجى

The Black or Roof rat الفأر االسود أو المتسلق

The House mouse الفأر المنزلى

Common name Brown rat Black rat House mouse

Scientific name Rattus norvegicus Rattus rattus Mus musculus

Sexual maturity Attained in 2-3

months

2-3 months 1.5 months

Gestation period Averages 23 days Averages 22 days Averages 19 days

No. of young Averages 6-12 per

litter

Averages 6-8 per Averages 5-6 per litter

No. of litters Averages 4-7 per Averages 4-6 per year As many as 8 per year

Weight 250-500 grams 225 grams 15-25 grams

Common name Brown rat Black rat House mouse

Total length (nose to tip of tail)

45 cm

(nose to tip of tail) 35-45

cm

(nose to tip of tail) 15-

19 cm

Head and body Blunt muzzle, heavy

thick body

Pointed muzzle, slender

body, 16-20 cm

Small, 6-9 cm

Tail Shorter than head

plus body

Longer than head plus

body,

Equal to or a little

longer than head plus

body,

Ears Small large large for size of animal

Fur Coarse, generally

brown to gray-brown

Black to slate grey; tawny

above, gray-white below;

or tawny above, white to

lemon belly

Silky, dusky gray

Brown rats are natural burrowers and will burrow near their food and water supply in areas that provide harborage, such as vegetation and piles of clutter.

Black rats are excellent climbers and will nest in higher places rather than burrowing; hence requiring warmer climates than Brown rats.

House mice are ubiquitous and exist in all climates and are routinely found both indoors and out. Their constant gnawing, urinating, and defecating causes extensive damage

Rodents are nearly blind, using their sense of touch for guidance. Their long hairs, or "guard" hairs, are used for guidance as they move along walls and other objects.

Rodents have sensory pads on their feet which are very sensitive.

Rodents are excellent swimmers. Brown rats can swim in a 30 mph current without drowning.

Detecting Rodents

Thank you