HYPOTHESIS :ABSTRACTViviparity has evolved many times within squamate reptiles, mostly in cool climates, but the selective advantages of uterine retention of eggs remain obscure. Previous analyses have assumed that intrauterine incubation enhances offspring survival because of early hatching or protection of the young in utero. I suggest instead that prolonged uterine retention directly enhances hatchling viability, because eggs incubated at maternal body temperatures produce ''better'' hatchlings than do eggs incubated at normal nest temperatures. To test this idea, I incubated eggs of two species of montane scincid lizards from southeastern Australia (Bassiana duperreyi and Nannoscincus maccoyi) under thermal regimes designed to simulate temperatures in nests and maternal oviducts. Hatchling phenotypes were substantially affected by incubation temperatures. The variables affected by incubation at maternal Versus nest thermal regimes include the hatchling's morphology (body size, relative tail length), running speed in a laboratory raceway, and behavior (activity levels, frequency of basking, antipredator tactics). The running speeds of hatchling B. duperreyi were also influenced by brief retention at ''maternal'' temperatures after the usual time of laying (a presumed intermediate stage for the evolution of viviparity) and by body temperatures of females prior to oviposition. Hence, a direct effect of uterine retention on offspring viability offers a plausible selective advantage for the evolution of viviparity in squamate reptiles and possibly in other Vertebrates and invertebrates also. More generally, the expression of phenotypic plasticity may play an integral role in the adaptive modification of life-history phenomena.

Objectives :

LARA: the Lancashire Amphibian and Reptile Atlas Project.Our main objective is to produce the first amphibian and reptile atlas for the vice counties of South and West Lancashire, an area now covered by Lancashire, Greater Manchester and Merseyside.The aims of LARA:

To support and encourage the recording of amphibians and reptiles in Lancashire, Greater Manchester and Merseyside.To promote recording in areas that are currently under-recorded, such as north and east Lancashire.To provide a resource to support the conservation of amphibians and reptiles in Lancashire, Greater Manchester and Merseyside.To actively collect data that is otherwise unavailable for conservation purposes (for example records that remains in surveyors notebooks).To bring together existing data to enable a better understanding of species distribution in the vice counties of South and West 

.Importance :

Ecological roles of reptilesReptiles are important components of the food webs in most ecosystems. They fill a critical role both as predator and prey species. Herbivorous species can also be important seed dispersers, particularly on island habitats. They are also known to act as pollinators, and the blue-tailed day gecko (Phelsuma cepediana) is now the only pollinator for the rare plant Trochetia blackburniana on the island of Mauritius, since the disappearance of the plant’s key-pollinator, the olive white-eye. 

Removal of any species from its ecosystem can drastically alter the populations of other organisms, but those that have a particularly influential role within an ecosystem are known as keystone species. Top predators, such as the crocodile, are often keystone species, though they also contribute to the food chain as prey whilst they are still young. Some species are considered critical for the way they modify their habitat. American alligators (Alligator mississippiensis) living in the everglades dig “gator holes”, which are often the only aquatic habitat left during the dry season, providing important refuge for many species of fish, turtle and other aquatic species, as well as a source of water for birds, terrestrial animals and plants. 

Reptile species can also have a useful anthropogenic role in ecosystems. In some areas, they help control the numbers of serious agricultural pests by consuming rodent and insect pests. 

Reptiles and humans

Reptiles have been hunted and traded by humans throughout history, particularly as food. Still today, reptiles can provide an important protein source for many people, or may be sold as a luxury food. Some reptiles are even used in traditional medicines. The skin of crocodiles and snakes are used in the creation of shoes, handbags and belts, and tortoiseshell has become a popular material for jewellery and decoration. Reptiles also make popular pets, with about 3% of households in USA having at least one pet reptile. 

Many people are afraid of certain reptiles, such as snakes and crocodilians, and as such certain species have been persecuted by humans. 

Reptiles have been popularly used in symbology and myth. Worldwide, snakes have been used as a symbol of power and sometimes evil, though they are also used in symbols for medicine. Turtles on the other hand usually represent longevity and stability, and are also often associated with creation stories. 

Material and Method :

Experimental Design This technique is a quick survey method requiring few restrictions on the approach. Three points need to be considered: (1) collecting should be done away from forest Time-Constrained Searches edges; (2) aquatic habitats, such as breeding ponds or creeks should be avoidedthese are covered by a separate protocol (Bury and Corn, in press); and (3) collecting should cover as much of the stand as possible. There are two ways to accomplish this last point. One is to devote enough time to the search to be able to collect across the entire study area. The second is to restrict the search to a fairly small area (for example, a circle with a radius of 25 m) and restrict the amount of time spent collecting. The number of smaller areas that can be searched in each study area depends on the amount of time devoted to the TCS. We found that 6 or 8 staff hours of collecting were sufficient; few additional species were detected by collecting for longer than that. If 1 hour is spent in each of the subsamples, then six to eight areas can be searched in each study area. Surveys of Coarse Woody Debris This technique is somewhat more complicated than TCS in that it involves systematicaily searching a predetermined number of logs in each study area. Several questions must be addressed when a study is designed, including how many logs to sample, how to apportion the sample among the different decay states of downed wood, and how to select the logs sampled. in 1985 in the Oregon Coast Ranges, we conducted

CWD surveys in 18 study areas. Each survey included 30 logs greater than 10 cm in diameter. We selected 10 logs in decay classes 1 and 2, 10 in decay class 3, and 10 in decay classes 4 and 5 (see Franklin and others [1981] or Maser and Trappe [1985] for methods of classifying CWD). The three decay categories that we used reflected natural divisions of the five-class scale. Class 1 and 2 logs are intact with more or less complete bark cover. Class 3 logs have decaying sapwood, and the bark is beginning to slough off. Class 4 and 5 logs are thoroughly decayed, have little bark, and are disintegrating. We recommend sampling equal numbers of logs in each of these decay categories. We searched each log for a maximum of 20 staff minutes. 7 Pitfall Trapping We found salamanders in only 37 percent of the logs (198 of 536) that we examined, so a sample size of 30 logs per stand should probably be considered the minimum. if few logs are sampled and salamanders occupy a small percentage of these, then the estimates of salamander density will be based on minimal information. Logs to be sampled are best selected by a systematic sampling scheme (Mendenhaii and others 1971). If the study area has not been mapped and the locations of ail logs determined, it will not be possible to draw a random sample. A systematic sample involves selecting logs in a specified order as they are encountered while the crew moves through the stand. Planning pitfall trapping mainly involves selecting the appropriate trap design. We used two different pitfall designs in our old-growth studies (fig. 3). in 1983, we used arrays of pitfall traps with aluminum drift fences (Bury and Corn 1987). in 1984 and 1985, we used grids of single pitfall traps without fences. There were quantitative and qualitative differences in the yield of each technique that must be considered in planning a project. PITFALL ARRAY DETAIL OF ONE ARM: Fr t Sm I 3m -I 6 X 6 GRID OF PITFALL TRAPS COLUMN ABCOEF lx x xx x x 2x x x x x x ROW 3 x x x x x x 4x x xxx x 5x x xx x x I 15m 6x x XX x x llSm Place traps within 2 m of flagged station: use natural fenws (logs) where available Figure 3-Designs for arrangements of pitfall traps either with or without drift fences. PT = pitfall trap, FT = funnel trap. Trap rates for salamanders are similar for both arrays and grids, but arrays caught considerably more frogs and reptiles than grids did (table 2). The differences were due, in part, to the absence of drift fences in pitfall grids and the season when trapping was done. Pitfall arrays were open continuously for 180 days in 1983, from May to November. Grids were open for 30-50 days, beginning in October 1984. The grids were operated too late in the year to capture reptiles and large numbers of postmetamorphic juvenile frogs, which disperse from breeding sites in late summer or early fall. These frogs composed the majority of frogs caught by the arrays.

Description : Snakes

Snakes range in size from small (the size of a worm) to many feet in length. The skin of snakes is made up of

scales that may be smooth or ridged. The scales on the belly (called scutes) are thicker than those on the sides

and back of a snake to provide protection as it moves.

Snakes have some clear differences from other reptiles. They have no limbs, no moveable eyelids, and no ear

openings. Most nonvenomous snakes have teeth that include 2 rows on top and 1 row on the bottom. The teeth

are curved backwards to help keep struggling prey from escaping. Venomous snakes have grooved or hollow

fangs that they use to inject venom into their prey. The bones in the lower jaw of snakes are long and flexible,

which helps enable the snake to swallow large prey.

Anatomy of a snake

Internally, snakes have many sets of ribs to support their length. These ribs are also somewhat flexible to allow

the prey to move through the snake's body. In addition, the organs inside a snake are long and narrow to allow

them to fit inside the body cavity. There are several different ways in which snakes can move, including the

familiar undulating crawl (slithering), side-winding, and the accordion-like movement used to climb trees.

Snakes rely primarily on their senses of smell and touch. Their forked tongues assist in bringing small air

particles into the mouth, where an organ on the roof of the mouth is used to identify smells. While snakes do not

have external ears, they do have an ear bone that is used to detect vibrations of sound waves that move through

the ground.

Lizards

There are more than 4,000 species of lizards, ranging in size from a few inches to the Komodo dragon, the

largest lizard, which can reach up to 10 feet in length. Lizards that are commonly kept as pets include geckos,

anoles, iguanas, skinks, chameleons, and agamids (including bearded dragons).

Anatomy of a lizard

Most lizards have dry skin made up of scales. The scales of lizards vary from the smoother scales of skinks to

rough scales or even spikes. In many species, the tail is fragile and can break easily. It can regenerate;

however, the new growth may look different.

Lizards are adapted to many different environments. Some are good swimmers, while others spend most of their

time in trees. Many have clawed feet that help them climb and cling.

Like snakes, lizards use their tongues to help them smell. The tongue captures particles of air and brings them

into the mouth, where a specialized organ can detect various smells. Lizards do have external ears and appear

to be able to hear better than snakes. Most lizards have eyelids that clean and protect their eyes when they

blink. A few, however, have fixed eyecaps like snakes.

Some lizards have developed special features to help them survive. Chameleons and some other species such

as anoles can change the color of their scales to blend in with their surroundings. The males of some species

have a loose flap of skin called the dewlap that can be extended to either intimidate a predator or to help attract

a mate. And, as mentioned above, a lizard's tail can break off, which can help it escape from predators.

Turtles and Tortoises

Turtles and tortoises belong to a group of reptiles known as chelonians. They are easily distinguished by their

hard protective shells that protect their upper and lower bodies. The upper covering is known as the carapace,

while the bottom portion is called the plastron. The words “turtle” and “tortoise” are often used interchangeably

by people, and in different parts of the world they can mean different things. In general, however, a turtle spends

most or a large portion of its time in water (including sea turtles and those found in ponds or rivers), whereas a

tortoise generally lives on land.

Anatomy of a turtle

Chelonians range in size from small (shells 3 to 4 inches in length) to very large (shell length of up to 8 feet).

Many chelonians can be quite long-lived. Some species of tortoises have been known to survive in captivity for

up to 150 years, and some aquatic turtles may live for 70 years.

The shells of turtles and tortoises are made up of a large number of bones that are covered by large scales

called scutes. The shell is permanently attached at the spine and rib cage. Some turtles can tuck their head,

legs, and tails inside their shells, but others cannot. The shell enlarges as the turtle grows, either by replacing

old scutes (during shedding) with larger ones or by enlarging the diameter of existing scutes. In some cases, this

can help determine the age of the animal.

Observation :

Report Non-native Watersnakes Seen in California

If you find an aquatic snake in California that you think is a Watersnake (Nerodia - similar to those shown below or here, and here), please send pictures of it to the California Nerodia Site, which is tracking the distribution of this

potential threat to native fish and wildlife.

  

Result :

Many reptiles appear nervous and insecure in captivity. This can be reduced by providing appropriate cage “furniture” and hiding spaces. Arboreal species (those that live in trees) should be provided with horizontal and vertical tree branches or other appropriate climbing material. Terrestrial species (those that live on the ground) usually require more horizontal space. Many terrestrial species, as well as those that like to dig or burrow, require hiding places such as boxes, tree trunks, rocks, or other objects. For some species, a solid black border painted on the glass wall 8 inches (20 centimeters) from the cage bottom provides added security.

Some species of reptiles are solitary and prefer to be housed alone. Housing animals of the same species together may sometimes be possible; however, groups should not include more than 1 male, as males of the same species may become aggressive toward each other. For experienced reptile owners, it may be possible to create an enclosure suitable for housing several compatible species together. Community housing of highly social species that are active during the day often requires placing several stations for basking, eating, and drinking that are all out of the view of dominant animals from the same species and any human observers. Overcrowding must be avoided to reduce stress and competition for food, water, basking sites, and mates. Aggressive species may have to be separated during feeding to prevent injury to cage mates. Fighting can be reduced significantly by housing only compatible species together.

The floor of the enclosure should be covered with a material that is disposable, inexpensive, nontoxic, and nonabrasive. The best ground coverings, or substrates, are those that provide the least amount of area for microbial growth and help make cage cleaning easy. Newspaper, sand, peat moss, potting soil, wood shavings, cypress mulch, corncob bedding, walnut bedding, gravel, alfalfa pellets, and artificial turf have all been used successfully for snakes. Cedar shavings should be avoided as the strong odors and vapors may cause breathing problems as well as potential neurologic problems. Snakes less than 18 inches (45 centimeters) long should

not be fed while on “loose” substrates such as shavings, corncob or walnut bedding, or small gravel because these substrates accumulate around the mouth (possibly causing inflammation of the mouth) and may be swallowed (possibly causing a blockage in the intestine). One solution is to remove the snake from its normal cage and feed it in a separate cage on newspaper. This results in conditioned behavior that is thought by some to decrease feeding frenzy activity in large snakes when approached in their normal, nonfeeding cage.

Bibliography reference :

Bibliography on the Biology of Amphibians and Reptiles. .

 

 

 

Contents: AMPHIBIANS, CHILDREN'S BOOKS, FIELD GUIDES, GENERAL HERPETOLOGY, GOOD READING!,MAGAZINES FOR CHILDREN, PERIODICALS, REPTILES, SOCIETIES, WEB SITES

Over the past two decades, amphibians and reptiles have become increasing popular as pets, creating a multimillion dollar industry in equipment, supplies, and publications. This popularity has both positive and negative aspects. Awareness and interest in these animals has increased the public’s attention to the need for their survival and conservation, locally and internationally. Popularity has stimulated the study of amphibians and reptiles in the wild and in captivity and has produced a wealth of information and a steady flow of herpetological publications. The unfortunate byproduct of popularity is that many books and articles are published that simply capitalize on the public curiosity and are inaccurate and/or shallow in content. The following list represents the better and more informative of the books (general, but not necessarily nontechnical) which are available and can be obtained from local public or university libraries and bookstores. The publications listed are not available from the Smithsonian library, education department, or research departments.  A guide to recommended web sites follows the book-list sections.