Black Caiman

                Black Caiman (Melanosuchus niger)

           Order: Crocodylia

                   Family: Alligatoridae

Description: This crocodilian is one of the largest reptiles, and adults are at least 4 meters in length.  Black caimans are dark in coloration, and can look similar to spectacled caimans.  The distinguishing difference between the two is that the spectacled caiman has a light colored jaw, while the black caiman’s jaw has three black spots on it.  As in other caiman, it has a bony ridge from the eyes down to the snout.  The black caiman is also distinguishable by its eyes, which are bigger than other caimans.

Distribution and habitat:  The black caiman is found in several countries in South America, such as Brazil, Bolivia, Colombia, and Ecuador.  It lives in freshwater habitats, such as streams and lakes.

Distribution of black caiman

Diet:  Black caiman eat fish, including piranhas, as well as aquatic vertebrates.  They are also known to eat capybaras, which are large rodents that are about a meter long.  Due to their good sight and hearing, black caimans are also good terrestrial hunters at night.



Eating a piranha



Reproduction: Black caimans make a nest during the dry season, and the female will lay 30 to 65 eggs. Females stay with the nest until the eggs hatch, which is thought to be between 42 and 90 days after they are laid.  The female also helps her offspring to hatch.  Hatching occurs the beginning of the wet season, the mother shows parental care by protecting her offspring from predators.



Conservation status:  As with many crocodilian species, black caiman were at one point heavily hunted for their skin, which was used to make a black leather.  Hunting black caiman became popular in the 1950s, and eventually they were nearly driven to extinction.  However, conservation programs were created to protect them, such as captive breeding and reintroduction in Bolivia in the 1990s.  Today the species has recovered, and their wild population is estimated to be about 1,000,000.

Personal interaction:  In July 2010, I got the chance to go to the Pantanal in Brazil, where black caimans live.  After visiting there, it feels as if saying their population has recovered is an understatement—they were everywhere.  It was really cool to see hundreds of them in one place.  They also had a much more passive character than I expected.  One night while I was out walking, I almost tripped over one.  Luckily, it didn’t seem to care, and the caimans seemed not to pay attention to others when they crawled all over them.  Since they didn’t mind humans being so close, I was able to get some good photos, so the pictures on here of black caimans are ones that I took.

More Sources:

http://crocodilian.com/cnhc/csp_mnig.htm

http://www.arkive.org/black-caiman/melanosuchus-niger/

Examining the common misconception that toads can give you warts.

"Why would you ever want a frog or toad as a pet? All they will do is give you warts on your hands," was always the response I received from my mother when I was a young child and asked to get a toad or frog every time she dared to take a child into a pet store. In time I came to understand that this was not true but I still wonder if she believed this or was she just saying this because she simply did not want me to have one?

For a long time now toads have been given a bad reputation for the way they look. Appearance wise they are not that much different looking than the always accepted frogs, besides the bumps and warts but so what? Humans and other animals can develop warts and we do not think poorly of them or avoid touching them. Whether we believe it or not, everyone has heard the common herpetological myth that toads can pass warts to people. The origin of this common misconception is not really known. It could be just the fact that toads have warts and some people assume that "like causes like" or that possibly there have been cases of people who have had allergic reactions to some of the secretions from a toad's parotoid glands which may have caused bumps. 

Image shows a picture of the cane toad (Bufo marinus)
secreting it's poison from one of it's parotoid glands.

The American toad (Bufo americanus) shows numerous warts on it's back.

Even though to anyone who has learned anything about herpetology this myth seems ridiculous and very unbelievable, this common misperception still persists. This could be due to numerous things such as it is something commonly said to children to prevent them from touching something a parent finds repulsive or to prevent them from wanting a frog or toad as a pet. In my opinion and from doing research on this, I believe the reason why the myth has been around so long and is so commonly heard is because people simply do not know. It just could be that people have heard the myth so frequently and over time that they may blindly believe it and pass it on.

It is a fact that toads do not pass warts to people. There have been numerous articles written about the subject and numerous research in the world of dermatology has given physicians a very in-depth understanding of what causes warts in humans. According to dermatologist Dr. Natasha Cook, "Basically warts are a virus that human skin can pick up. And wart viruses are ubiquitous, that means it's everywhere in the community … it's the Human Papilloma Virus, which we basically call HPV." Warts are caused by a virus that enters any surface of our skin and causes cells to rapidly multiply. In a study done by National Geographic, dermatologist Jerry Litt was interviewed about this topic in which he said, "warts are caused by a human virus, not carried by frogs or toads." While researching this topic, I was able to find many examples of dermatologists and other experts who said toads do not cause warts in humans, but I was not able to find a single source that claimed that toads did. A simple search on any internet search engine or a quick read of a herpetological book will show anyone interested that there is overwelming support from experts that prove that toads do not carry the human virus that causes people to get warts and that the myth about toads is completely false. 

 Today resources for looking information up are readily available and should be taken advantage of, especially by the people who continue to perpetuate this myth without any background knowledge. This myth only spreads nonsense, and going back to the example of the parent who says it in order to have their child avoid contact with or wanting a toad, telling a child something false does not help with anything. Simply tell them no or to stay away, that right there is not spreading false information and not continuing a common misconception. Hopefully one day this common misconception can be eliminated and people will have a somewhat better understanding about toads and even the causes of warts. Something that could help is those who have been informed, such as students of herpetology class, should make an effort to correct people when we hear it. Though it is not too important for someone to know the truth about this myth, having a little more knowledge never hurt anyone. From everything we know about warts, they can appear anywhere on our bodies and are spread to us from viruses found all over. It is not certain how one's body will react when the virus is contracted, they may grow warts or their immune system might fight the virus away but one thing's for sure - you will never, ever get a wart from a toad. 

Now that all of the readers of this post are educated and know the truth behind this common herpetological myth....

Green Iguana (Iguana iguana) Natural History

Green Iguana

                Order: Squamata

                Family: Iguanidae

                Scientific Name: Iguana iguana

Description: The green iguana is a large (5-7ft) lizard that can weigh up to 18lbs.  Its body is covered with soft leathery scales, and has a dorsal crest of spines that descend in size from their starting point, at the base of the head, to their ending point, the tip of the tail. They typically start life as a bright green color, but it fades to a more grayish-green with age.  However, the green iguana is capable of slightly altering their color due to their moods, social interactions, or environmental conditions, so the colors will vary.  The green iguana is typically an arboreal lizard so it has characteristically short legs with feet that have five very long toes with sharp claws.  It also has a long, whip-like tail, which helps with balance when climbing and allows for easy swimming; the tail is also used as a weapon or can be broken when as a "get-away" strategy.  The green iguana can be distinguished from other iguanas based on the hanging dewlap found under their throat, the dorsal crest down the middle of their back, large scales on each side of the head, variably ringed-tails, and a membrane-covered tympanum. 

Habitat and Distribution: Green iguanas are naturally distributed from south Mexico to the northern parts of South America, including the Lesser Antilles islands.  They have also been introduced to Florida and Hawaii due exotic pet trade.

The green iguana is commonly found in tropical rainforest trees, as high as 1,000 meters.  Although mostly arboreal, they are also terrestrial.  They typically avoid the deep forests, so as to have plenty of sunlight for exothermic processes and for egg incubation on the ground.  Though it is possible to find them in open areas where there are plenty of resources, they are most commonly found where the tree-line meets water, as they are known to swim, like the one I spotted in Key Largo.  Although s/he swam away before I could snap a picture, s/he looked something like this in the water:

Diet:  The green iguana is an herbivore.  They prefer to eat leaves, flowers, fruits, and other plant material, but bird nestlings and eggs are also known to be eaten.  While green iguanas are young, they require a lot of protein for growth, so they will eat mostly insects, but they too will eat other animal matter, such as adult iguana droppings.   

Reproduction: Typically correlated with rainfall, the reproductive season occurs in the first part of the dry season in fall.  The males will perform color and behavioral displays, which can include dewlap extensions, head-bobbing, and pushups.  The females will choose the males with impressive displays.  During the mating process, the male will bite the female to line up their cloacas so he can use his hemipenis deposit his sperm within the female.  The female will then carry the eggs for about 2 months.  The eggs are laid toward the end of the dry season, in clutch sizes from 12 to 40.  The eggs hatch into one foot, bright green, juvenile iguanas after about 90 days, which is during the wet season, and they will mature after about 3 years.

Longevity and Conservation status:  In the wild, green iguanas typically live about 8 years, but in captivity they can live up to 20 years.  Although the green iguana is not considered a threatened, CITES lists them so as to maintain the natural populations.  Green iguanas are known in their natural habitats as “the chicken of the trees” due to their tasty meat.  As a result, their main predator is humans, who overharvest the iguanas for their tasty meat, as well as, for their skin to make leather products, and their eggs for pet trade.

Personal Experience:  I encountered my first green iguana in the gravel driveway of my hotel in Key Largo.  S/he was at the base of a tree line basking in the sun.  The moment I took a slight step in its direction, it was gone.  The second time I spotted a green iguana was also in Key Largo, on a hot day.  I know it was hot because the iguana was sitting on a patch of seaweed and algae in the Bay’s brackish water near a patch of pushes, as shown and stated above.  S/he sat there for a long time until some people came up behind me making a lot of noise, which caused it to swim down in water.

For more information:

http://www.dpi.qld.gov.au/documents/Biosecurity_EnvironmentalPests/IPA-Green-Iguana-Risk-Assessment.pdf

http://animaldiversity.ummz.umich.edu/site/accounts/information/Iguana_iguana.html

http://www.greenigsociety.org/inthewild.htm

http://www.sms.si.edu/irlspec/iguana_iguana.htm

Spring Peeper (Pseudacris crucifer) Natural History

Description: The spring peeper is a small (1.9- 3.2 cm), generally tan or brown-colored tree frog with its defining trait being a dark X on its back. It has terminal discs characteristic of tree frogs that assist with climbing. Males are typically smaller and have dark throats. Additionally, males have a vocal sac that allows them to make the easily recognizable "peep" used to attract mates (http://www.youtube.com/watch?v=uhBsNqF7Hkk).

Distribution and Habitat: Spring peepers are distributed throughout the eastern United States and eastern and central Canada. 

                                                                                                                                         (http://wwknapp.home.mindspring.com/docs/spring.peeper.html)

P. crucifer generally inhabit swamps or moist woodlands near ephemeral wetlands. It is found near the ground among underbrush and detritus. Personal observation occurred on the forest edge near wetlands in Lorain County, Ohio. Some key predators of adult frogs include snakes, skunks and other (larger) frogs.

Reproduction: Spring peepers are among the earliest amphibians to emerge from hibernation and begin calling in February and March. Males call on the edge of moist habitats including small wooded ponds, larger swamps, vernal pools, flooded ditches, and wet meadows. Reproduction is aquatic and occurs between March and June depending on location. Each clutch includes 700-1000 eggs that are hidden at the water base beneath vegetation and debris. Tadpoles hatch in 1-2 weeks and metamorphose in approximately 3 months based on environmental conditions. Great diving beetle larvae are important predators of tadpoles.


Feeding/Diet: Whereas tadpoles are herbivores that suspension feed on organic and inorganic material on submerged surfaces, adults are carnivores that hunt invertebrates in low vegetation. 


Overwintering: Spring peepers hibernate beneath tree bark or under logs and have demonstrated some freeze tolerance. It increases glucose levels in order to help survive freezing.


Longevity and conservation status: The average life span of this species in the wild is 3 years and it reaches reproductive maturity the first year after hatching. Spring peepers are listed as a species of least concern according to IUCN. However, many habitats are becoming unsuitable or disappearing altogether and this species is listed as threatened in Iowa and Kansas.


Personal interaction: I first encountered spring peepers while working for Lorain County Metro Parks  (northeast Ohio) in the early summer of 2009.  The two individuals that I had physical contact with seemed to have no problems being the in presence of humans. An interesting place to look for this species was at the base of leaves invasive teasel plants where water would pool. These frogs were frequently heard calling near wetlands bordered by forest and tall grass fields. 

                                         

Above: Found on the seat of a Gator work vehicle along the forest edge on a rainy day in the summer 2009. 

Middle: Spring peeper caught and crawling on my arm. As you can see from the cattails in the background, this individual was not far from water when captured. He was released unharmed.

Bottom: Stock photo of a spring peeper (http://upload.wikimedia.org/wikipedia/commons/a/ad/H_crucifer_USGS.jpg )