Boshonto Family

This thread is for the wonders of natures we see in different species other than us.
My sis actually gets me into it time to time... as she is studying biology (specifically human biology)

enjoy the wonders

Whiptail Lizards
Cnemidophorus species

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What Kind of an Animal is It?

Lizards are vertebrate animals (with backbones). They belong to the class of Reptiles, animals with a number of advanced features:

A scaly waterproof skin
4 legs (they are tetrapods)
Well-developed lungs
Internal fertilization
Most lay special amniotic eggs which conserve water; an adaption for life on land
The whiptail lizards are in the family Cnemidophorus, and are noted for a long slender tail. There are 45 different species within this family.

What is its Lifestyle?
Several of these features help reptiles adapt to dry environments with little water. The whiptails live in the deserts of the southwestern US and Mexico. They run around under mesquite and yucca bushes and catch spiders, insects and scorpions for food.

Whiptail Lizards and Parthenogenesis (Virgin Birth)
In 15 of the Cnemidophorus species there are no males. They reproduce without fertilization, a process known as parthenogenesis of "virgin birth". Parthenogenesis is well known in lower animals, such as aphids,bees, and Daphnia but is rare in vertebrates. The offspring of parthenogenic lizards are clones, identical to the mother.

There are some advantages to a parthenogenic lifestyle:

All members of your species can lay eggs and reproduction is more efficient
Good mutations are passed on more efficiently in clones than in sexual species
You don't waste a lot of time and energy searching for a mate (this might not be true in this species, since the females do pair up)
One of the surprising things about unisexual whiptail reproduction is that a courtship ritual is still required even though there is only one sex. Unisexual whiptails pair up. In the courtship ritual one female takes the part of a male, while the other takes the role of a female. Later the 2 lizards switch roles. The switch is caused by hormones: estrogen promotes female behavior; progesterone stimulates male behavior. The mating ritual is required for survival of the species: without it few eggs are released (ovulation).

Some Things to Think About

Are there any advantages to having 2 sexes? Will males in our species someday also disappear like those of the whiptail?
Why is nature still experimenting with so many types of reproductive strategy?
How are the hormonal rhythms regulated so that one of each pair has high progesterone (male role) at the same time that the other has high estrogen (female role)?

interesting  to...
but appi...
technical terms gula ektu kom dile hoi na???
porte gele chokhe betha pai.

ashole eta to collection .. amar lekha na
technical naam shoriye kono naam deyar moto gaan-je amar nai
tobe next time cheshta korbo

Hummingbird

Sobai niscoi Hummingbird ar nam shuneshen.......... well I'm really interested in them....... akhon porjonto hummingbird kasa kasi dekhini......... i would love to see them and touch them........ i raelly want to see how tiny they r!!!!!!! anyway here goes some info anf pics abt hummingbird.

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Hummingbirds are the tiniest and most fascinating birds that will visit your backyard. The early Spanish explorers to the new world called them Joyas Volardores or flying jewels.

Here are some interesting facts about them:

>Hummingbirds are built for power and dazzle, hummingbirds are little more than flight muscles covered with feathers. 30% of a hummingbird's weight consists of flight muscles.

>Hummingbirds require lots of energy. They have the fastest wing beats of any bird and their hearts beat up to 1,260 beats per minute

>In their non stop quest for fuel, Hummingbirds may visit 1,000 flower per day. For protein, hummingbirds eat spiders and strain gnats from mid-air. They will pull insects out of spiderwebs including the spider itself.

>Hummers have a fast breathing rate, a fast heartbeat, and a high body temperature. They must feed every 10 minutes or so all day, and they may consume 2/3 of their body weight in a single day.

>The hummingbird's tiny brain, 4.2% of its body weight, is proportionately the largest in the bird kingdom.

>Hummingbirds can live a decade or more in the wild.

>Hummingbirds do not make good songbirds. Most of them manage no more than a few mouse-like chirps, squeaks and twitters, though they deliver them dramatically with quick turns of the head. Hummingbirds do
make distinctive "zinging" noises with their wings.

>The Spanish names for Hummingbirds are very descriptive of their behavior:
Chupaflor - which means flower-******
Picaflor - which means flower nibbler
As well as the more romantic Portuguese Beija-flor or Flower-kisser.

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look how tiny it is!