Leg Modification in birds. By. Dr. Vidhin Kamble

                     

Leg / Feet Modifications in birds 

The birds are creatures, that adopted for true aerial flight.  In birds, the forelimbs are modified into the wing and hind limbs are for bipedal movement.  In the case of birds, there are several kinds of feet/leg modifications are according to the habits and habitat which are as follows.

1.   Perching feet

2.   Raptorial feet

3.   Scratching feet

4.   Climbing feet

5.   Climbing feet

6.   Clinging feet

7.   Wading feet

8.   Swimming feet

9.   Cursorial feet.

10. Thermoregulatory feet

1.     Perching feet. sparrow, crow, pigeon      

  

These modifications are observed in the majority of birds. The toes are slender and weak. In these birds, 4 toes are present. 1^st toe directed posterior/backward and three toes directed forward. The toes are opposable. Because of this, when birds seat on the branch, their body weight falls on toes, due to this, toes turn backward automatically because of tendons attached to it. This modification helps to perch the twig or branch very firmly.

2.     Raptorial feet:- Ex. Vulture, kites, owls, eagle.

In this type of feet modification, the legs are very strong used for grasping and holding the prey.  The toes are four in number. The toes are strong and powerful with sharply pointed claws.  A lower surface of the toe is rough due to the presence of a horny spine. Such type of feet is found in carnivorous birds. These toes are modified for firm grip around captured prey during flight.

3.     Scratching feet: ex. Fowl and peafowl

In this type, the feet are long and slender.  There is the presence of four toes. 1^st toe directed backward and 2^nd, 3^rd, and 4^th toes directed forward. The toes are long and slender with sharp claws. These types of feet are modified to scratch the ground to expose food grains, grubs, and tiny food particles. In the male there is the presence of sward like a tarsal spur, used for fighting. Hence, it is also called a fighting spur.  Spur is a sexually dimorphic character in these birds.

4.     Climbing feet : Ex. Parrots, woodpecker 

The feet modifications are adapted for climbing on the vertical surface. In parrot 4 toes are present. 1^st  and 4^th toes directed backward. Whereas, 2^nd and 3^rd toes directed forward.  In woodpeckers 1^st and2nd  toes directed backward and 3^rd and 4^th toes directed forward. Such type of feet modifications is called as heteroductylous or zygoductylous feet. The toes are with sharply pointed claws. Such type of feet are used to climb on the stiff vertical surface of the tree trunk or barks.

5.     Clinging feet – Ex. Swift, swallow

In these feet, toes are slender. All the four toes are directed forward. Such type of modifications are called homoductylous feet. Such type of feet is used to cling with vertical walls and ceiling.

6.     Wadding feet:- Heron, jackana, lapwing

Walking of aquatic vegetation is called wading. In this type the legs are long and slender. The toes are free, elongated and slender adopted for walking over aquatic vegetation.

7.     Swimming feet:-  e.g. Duck, Cormorants, Coot.

Swimming type of feet is found in waterside birds, adapted for swimming and floating. In these types of feet, the membranous skin fold is stretched between the toes forming a web. The web acts as a paddle for swimming. In the case of duck, the web is present between front toes. In the case of cormorant,  all the toes are included in the toes while in the coot web is lobe like.

8.     Running or Cursorial Feet: eg. Rhea, ostrich, bustard, etc.

In running birds, the feet are strong and powerful. In these birds, the number of toes is reduced. Poster toe is greatly reduced or absent. In the case of Rhea, Emu, bustards, etc. the toes are short and only forwardly directed 3 toes are present. in the case of ostrich, only two toes are present i.e. 3rd and 4th toes. All the toes terminated with the nail plate. These feet modification is used for fast running on the open ground.

Thermoregulatory feet.

Such type of feet is found in ptarmigan in the Antarctic region. In this bird, there are only forwardly directed three toes are present.  the toes are covered with soft feathers, which at as insulators to prevent loss of heat from the body. Hence, such type of feet is called thermoregulatory feet.

S. Y. B. Sc. Zoology Practical Syllabus - II

Practical Course in Zoology for B.Sc.II As per Solapur University.

 Practical – II

I. Taxonomy-

Classification with morphological peculiarities of the following up to orders:

i) Reptiles – Turtle, Tortoise, Chamaeleon, Garden lizard, Crocodile

ii) Aves – Duck, Kite, Woodpecker, Sparrow, Sunbird, Vulture, Kingfisher Fowl.

iii) Mammals - Platypus, Bat, Scaly ant eater, Loris, Rabbit

(Models/Photographs/Sketches)

II. Study of Rat : Anatomical observation and detailed explanation of the following system with CD/Model/Chart of

i) Digestive system

ii) Respiratory system

iii) Arterial system

iv) Venous system

v) Excretory system

vi) Reproductive systems (Male and Female)

III. Anatomical observation and detailed explanation of brain of bird with

CD/Model/Chart-

IV. Observation and detail explanation of following with CD/Slide/Model/Charti)

Blood of mammal ii) Pecten of bird iii) Sclerotic plate of bird

iv) Collumela of bird v) Hyoid apparatus of bird

V. Study of Mesozoic reptiles (using chart/models/CD)

VI. Identification of the following poisonous and non poisonous snakes using laboratory specimens

i) Cobra ii) Russel’s Viper iii) Indian little Viper (Phoorsa) iv) Krait v) Sea snake

vi) Rat snake vii) Sand boa

VII. Study of Beak and leg modification in birds using laboratory specimens

i) Parrot ii) Woodpecker iii) Heron iv) Duck v) Sparrow/Pigeon vi) Hawk/Kite

viii) Owl ix) Vulture

VIII. Study of dentition in mammals using laboratory materials/models/CD of:

Sheep, Rat, Rabbit, Dog, Man

IX. Study of histological structure (T.S./V.S.) of the following mammalian organs using spermanens, slides:

i) Tooth ii) Salivary gland iii) Oesophagus iv) Stomach v) IIeum vi) Rectum vii)Liver viii) Pancreas ix) Kidney x) Testis xi) Ovary xii) Uterus xiii) Pituitary gland xiv) Spinal cord

X. Study of Rat sperm and vaginal smear using CD/Chart/Permanent slides

XI. Study of following abnormal urine constituents: Glucose, Bile, Blood and Albumin

XII. Study of ABO blood group system and blood group antigens

XIII. Study of following contraceptives: Oral contraceptives (pills), Intra-uterine device, Condom using chart/photographs.

Excursion Tour : Six days tour is recommended

As a part of practical, visit to sea-shore/any suitable place of Zoological interest (Visit to sea-shore, Fishery Centers, National Parks, Wildlife Sanctuaries, National Research Institutes, Central Research Institutes, Zoological Survey of India, Fresh Water Ecosystem etc. to study animal diversity and economic Zoology. A report is to be submitted at the time of Practical examination.

S. Y. B. Sc. Zoology Practical Syllabus - I

Practical Course in Zoology for B.Sc.II As per Solapur University.

 Practical – I

I. Taxonomy-

Classification with morphological peculiarities of the following up to classes.

a) Arthropoda- Apus, Balanus, Prawn, Lobster, King-crab, Grasshopper, Butterfly

Moth, Millepeds, Centipede, Scorpion, Spider, Peripatus

b) Mollusca – Chiton, Dentalium, Patella, Aplysia, Snail, Slug, Mytilus, Pearl Oyster,

Sepia, Octopus

c) Echinodermata – Sea-star, Brittle star, Sea-lilly, sea urchin, sea cucumber

d) Hemichordata – Balanoglossus

II. Study of Cockroacha)

External characters and sexual dimorphism (CD/Model/Chart)

b Anatomical observation and detailed explanation of systems using CD/Model/Chart

of

i) Digestive system

ii) Nervous system

iii) Male reproductive system

iv) Female Reproductive system

c) Anatomical observation and detail explanation of systems using CD/Model/Chart of

i) Walking leg

ii) Mouth parts

iii) Thoracic spiracles

iv) Salivary apparatus

v) Gizzard

vi) Cornea

vii) Trachea

III. Study of Pila-

A) External character- Shell, Pallial complex (CD/Model/Chart)

B) Anatomical observation and detailed explanation of systems using

CD/Model/Chart of

i) Digestive system

ii) Nervous system

C) Observation and detail explanation using CD/Slide/Model/Chart of

i) Osphradium

ii) Radula

iii) Statocyst

IV. Study of mouth parts of : Honey bee, Mosquito, Butterfly, Housefly using

permanent slides/CD/Model/Chart

V. Mosquito as disease vector : Whole mounts of Anopheles, Culex, Aedis using

permanent slides/CD/Model/Chart

VI. Study of foot in mollusca with reference to Chiton, Pila, Mytilus, Unio,

Sepia/Octopus using museum specimens/CD/Model/Chart

VII. Study of mitosis using onion root tip

VIII. Differential count of WBCs.

IX. Examples in genetics (at least 10 examples):  Examples based on Crossing over, Linkage and interaction of genes

X. Detection of Carbohydrates(Gulcose, Fructose, Maltose/Lactose, Starch), Proteins

and Lipids.

XI. Colorimetric estimation of protein by biuret method

XII. Colorimetric estimation of glucose by suitable method

XIII. Study of Glass aquarium fishes using laboratory specimens/photographs/CD/videos

(Any five fishes)

XIV. Study of Apiculture – Kinds and castes of Bees, Honeycomb, Honey, Bee wax

using laboratory specimens/material

XV. Study of Sericulture – Study of silk moth, silk cocoons, and silk using laboratory

specimens/material

XVI Study of Dairy Science – Study of Milk and Milk products using available material

XVII. Study of Poultry Science- Different kinds of Poultry birds, Eggs and Poultry manure using available laboratory specimens/material