Wide or White?

White Rhino

Recently, one of the last four northern white rhinos in the world died in captivity. Now only three members of this endangered species survive.

The efforts to conserve the Northern White Rhino were initially fruitful, but the resurgence of poaching activity has now brought them to the near extinction. These animals are killed for their horns, which are used to make traditional medicines for many major human diseases and also to make decorative articles.

Actually, the white rhino is not really white. It is grey. There is very little difference in the colour of the black rhino and the white rhino. Then why is it called so? The answer to this lies in the more appropriate name of the white rhino: it is also called the square-lipped rhinoceros.

When Dutch settlers in Africa saw this species of rhinoceros, they realized that these had a wider mouth than the other rhinos. So the Dutch called these rhinos ‘wijd rhinos’. ‘Wijd’ in dutch means ‘wide’. However, the English settlers that followed them mistranslated the word ‘Wijd’ word as ‘White’ – hence the name ‘White Rhino’.  

The White rhinos have a wider squared upper lip, which helps them to bite off short grass. The black rhino on the other hand as a pointed upper lip which helps it to bite off leaves from trees.

Another theory about their name says that the white rhinos, although actually grey, appear white because their backs are often covered with white bird droppings.

One male and two female northern white rhinos left in this world are currently kept captive under high security in a conservatory in Kenya, to protect them from poachers.

 

Black Rhino

 References:

1. http://www.iucnredlist.org/details/4185/0 

2. http://animals.nationalgeographic.com/animals/mammals/white-rhinoceros/ 

3. https://www.savetherhino.org/rhino_info/species_of_rhino/white_rhinos/factfile_white_rhino

The story of the horns

Do you recognize this picture? A devil’s head with horns?

No. In fact it is a close-up picture of a seed. What look like horns are actually hooks.

You might wonder what hooks are doing on a seed! These hooks allow the seed th stick to the fur of an animal. When the animal moves from one place to another, it carries the seed along with it. When the seed falls off the animal to the ground, it has travelled a large distance from the parent plant. Like other modes of seed dispersal, animal dispersal of seeds also helps plants to colonize new habitats.

This is just one mode of seed dispersal. A more common mode of animal dispersal of seeds is through animal droppings. Generally frugivores i.e. fruit eating animals consume the seed of the fruit with their fruit meal. They are unable to digest the seed, which is then thrown out of their body through the droppings, at a new location where the animal has reached. This seed germinates where it falls, giving rise to a new plant.

Some animal dispersed seeds are covered with a slimy substance which helps them to stick to the bodies of birds. The birds fly over large distances and carry the seeds along with them.

References: 

1. http://www.britannica.com/topic/animal-dispersal-in-rainforests-1673040

2, http://theseedsite.co.uk/sdanimal.html

3. http://www.webpages.uidaho.edu/range556/appl_behave/projects/seed_dispersal.html

The Wind Tales

I was walking along a crowded road in the middle of the city. Like many of our roads, this road too was lined with huge old trees. Right there on the footpath, I found something that we were fascinated by as children. Many nature enthusiasts fondly call it the ‘monkey biscuit’, since monkeys nibble at it.

This is the seed of a plant called Angsana or Petrocarpus indicus. What makes it special are the wing like papery structures that surround it, and make it ‘fly’. This is one of the many types of seeds that are dispersed by wind. The wind carries these seeds over large distances. If the seed lands on a surface that is suitable for germination, it can grow into a new plant there. 

Angsana seeds

Plants of the genus Shorea have structures similar to blades of a helicopter attached to their small fruits. These plants disperse their entire fruits with the help of the wind. The seeds, of course, are inside the fruit!

Shorea fruits

The Dandelion seeds have feathery bristles around it which help it to float in air like a parachute.

Dandelion seeds

The structure of seeds of Alsomitra macrocarpa inspired the structure of the first gliders.

Alsomitra macrocarpa seed

Dispersal of seeds in this way helps the propagation of the species to distant places. If the offspring of the same plant grew in close proximity with each other, they would have to compete for food, water and space. Dispersal of seeds to faraway places ensures that this problem is solved.

References:

1. http://theseedsite.co.uk/sdwind.html

2. http://waynesword.palomar.edu/plfeb99.htm