Tortoises

Beez Neez now Chy Whella
Big Bear and Pepe Millard
Sun 7 Apr 2013 22:27
The Tortoise Sanctuary on San Cristobal
 
 
 
 
 
 
BB Torts and Day Out 071  BB Torts and Day Out 072  BB Torts and Day Out 073
 
We arrived at the sanctuary, Pedro gave us a brief talk and then we wandered along the paths and boardwalks in search of the tenth biggest reptile in the world. Bear got straight into whispering to the babies to see if he still has his great skill with these fast moving creatures. Number fifty six was a feisty critter and bit everyone who came near, those that didn’t he went after and bit, legs, shells and anything in reach. I had to step in and shout at the bad boy.
 
 

The Galápagos tortoise (Chelonoidis nigra) is the largest living species of tortoise and tenth heaviest living reptile, reaching weights of over eight hundred and eighty pounds and lengths of over five feet nine inches. With life spans in the wild of over one hundred years, it is one of the longest-lived vertebrates. A captive individual has lived at least one hundred and seventy years.

The tortoise is native to seven of the Galápagos Islands, named them after the Spanish galápago, meaning tortoise.

Shell size and shape vary between populations. On islands with humid highlands, the tortoises are larger, with domed shells and short necks - on islands with dry lowlands, the tortoises are smaller, with "saddleback" shells and long necks. Charles Darwin's observations of these differences on the second voyage of the Beagle in 1835, contributed to the development of his theory of evolution.

Tortoise numbers declined from over a quarter of a million in the 16th century to a low of around three thousand in the 1970’s. This decline was caused by exploitation of the species for meat and oil, habitat clearance for agriculture and introduction of non-native animals to the islands, such as rats, goats and pigs. Ten subspecies of the original fifteen survive in the wild; an eleventh subspecies (Chelonoids nigra abingdoni) had only a single known living individual, kept in captivity and nicknamed Lonesome George until his death in June 2012. Conservation efforts, beginning in the twentieth century, have resulted in thousands of captive-bred juveniles being released onto their ancestral home islands, and it is estimated that the total number of the species exceeded nineteen thousand at the start of the twenty-first century. Despite this rebound, the species as a whole is classified as "vulnerable" by the International Union for Conservation of Nature (IUCN).

The Galápagos giant tortoise is now strictly protected and is listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora.

 
 
BB Torts and Day Out 075  BB Torts and Day Out 076  BB Torts and Day Out 077
 
BB Torts and Day Out 078  BB Torts and Day Out 079
 
So tiny and the indignity of being weighed
 
 

Egg-laying: Females journey up to several kilometres in July to November to reach nesting areas of dry, sandy coast. Nest digging is a tiring and elaborate task which may take the female several hours a day over many days to complete. It is carried out blindly using only the hind legs to dig a foot deep cylindrical hole, in which the tortoise then lays up to sixteen spherical, hard-shelled eggs ranging from nearly three to five and a half ounces in mass, and the size of a billiard ball. Some observations suggest that the average clutch size for domed populations (nine point six per clutch for porteri on Santa Cruz) is larger than that of saddlebacks (four point six per clutch for duncanensis on Pinzón). The female makes a muddy plug for the nest hole out of soil mixed with urine, seals the nest by pressing down firmly with her plastron, and leaves them to be incubated by the sun. Females may lay one to four clutches per season. Temperature plays a role in the sex of the hatchlings, with lower temperature nests producing more males and higher temperature nests producing more females. This is related closely to incubation time, since clutches laid early will incubate during the cool season and have longer incubation periods (producing more males), while eggs that are laid later incubate for a shorter period in the hot season (producing more females).

 
 

BB Torts and Day Out 047  BB Torts and Day Out 048

The slightly older ones were comical to watch, especially when sugar cane is so much bigger than you are.

 

BB Torts and Day Out 049  BB Torts and Day Out 060  BB Torts and Day Out 055 

BF Torts and Blues 064

BB Torts and Day Out 062  BB Torts and Day Out 069

 

We were introduced to Genesis, the first baby born when this centre opened in 2001, he actually came racing over. And smiled beautifully. To think he will outlive us and our great, great, great, great, great grandchildren.

 

Early life and maturation: Young animals emerge from the nest after four to eight months and may weigh only one point eight ounces and measure two and a half inches. When the young tortoises emerge from their shells, they must dig their way to the surface, which can take several weeks, though their yolk sac can sustain them for up to seven months. In particularly dry conditions, the hatchlings may die underground if they are encased by hardened soil, while flooding of the nest area can drown them. Subspecies are initially indistinguishable as they all have domed carapaces. The young stay in warmer lowland areas for their first ten to fifteen years. They encounter hazards such as falling into cracks, being crushed by falling rocks, or excessive heat stress. The Galápagos Hawk was formerly the sole native predator of the tortoise hatchlings; Darwin wrote: "The young tortoises, as soon as they are hatched, fall prey in great numbers to the buzzard". The hawk is now much rarer, but introduced feral pigs, dogs, cats and black rats have become predators of eggs and young tortoises. The adult tortoises have no natural predators apart from humans; Darwin noted: "The old ones seem generally to die from accidents, as from falling down precipices. At least several of the inhabitants told me, they had never found one dead without some such apparent cause".

 

Sex can be determined only when the tortoise is about fifteen years old, and sexual maturity is reached between twenty to twenty five years in captivity, possibly forty years in the wild (when they reach their full size). Harriet, a specimen kept in an Australia Zoo, was the oldest known Galápagos tortoise, having reached an estimated age of more than one hundred and seventy years before her death in 2006.

 

 

BF Torts and Blues 077

Next we went to see the older chaps, this one was quite affronted as Bear came into view for some perspective.

 

BB Torts and Day Out 091  BB Torts and Day Out 092  BB Torts and Day Out 094

A policeman tried his hand at tortoise whispering but had to step aside for the master. The chap on the right was clearly number fifty sixes dad as he was a nasty piece of work nipping at anything near as we met up with the elder statesmen.

 

BB Torts and Day Out 095  BF Torts and Blues 082 

My what a big tail you have. An odd resting pose.

 

 BF Torts and Blues 094

Soundo. 

 
BF Torts and Blues 087  BF Torts and Blues 092  BF Torts and Blues 093
 
BF Torts and Blues 041  BF Torts and Blues 075
 
Everything about them looks so prehistoric
 
 
BB Torts and Day Out 099
 
BF Torts and Blues 096
 
 
........our parting words “Be gone thou tourist, I want to sleep.”
 
 
BF Torts and Blues 101
 
 
 
 
 
 
 
 
 
ALL IN ALL WHAT BIG BOYS AND GIRLS