Hunting Anacondas in the Venezuelan Llanos – notes and photos for fans of giant snakes

Growing up near the Bronx Zoo, I became fascinated by giant snakes early on, as these magnificent creatures were always featured prominently in my favorite building, the Reptile House.  So it was with great anticipation that, after some years as a reptile keeper for the zoo, I set off for Venezuela to assist in field studies of the green anaconda, arguably the world’s largest snake.

 

Accounts of what I observed and learned during three visits to that country’s central llanos area (seasonally flooded grasslands) would fill several books.  I would like here to just give you some facts and photos – in the future, I will highlight some of my experiences in longer articles.

 

Despite long-standing legends to the contrary, (and, recently, a plethora of internet photos) there is only one reasonably reliable account of a snake measuring over 30 feet in length (I’ll cover the details of this and related stories in the future).  In fact, the Bronx Zoo offered a cash reward, established, as legend has it, by Theodore Roosevelt, for a living snake in excess of 30 feet.  That reward, now withdrawn, stood uncollected for nearly 100 years (I was involved in the last attempt to collect it – please look for details in the future).

 

The snake you see pictured here was the largest that I and my colleagues encountered.  It measured just over 17 feet long and weighed 215 pounds.  As you can see from the close-up of my hand on its head, she (all anacondas Me with 17 ft, 215 lb. green anaconda
of this size are females) put up a quite vigorous battle when captured – indeed, one of her teeth remains imbedded in my wrist till this day as a reminder!  A number of the 500+ green anacondas that were marked during the study were in the 15 to 16 foot range.

 

I was fortunate to come upon quite a few anacondas in the process of feeding upon a wide array of animals, including capybara, caiman, jacanas and other birds, turtles and, most unforgettably, a deer of 60 pounds in weight.  Please look for future articles on the details of these most fascinating encounters.

 

The Venezuelan llanos, especially in the dry season, offers a wildlife-viewing extravaganza that is difficult to put into words.  Encounters with crab-eating foxes, freshwater dolphins, giant anteaters, armadillos, electric eels, caiman, scarlet ibis and countless other creatures large and small are all but guaranteed.  Cougars, jaguars, giant otters, tamandua, tree boas, tegus and a host of others are also a real possibility.  I am planning to write an article for people who might like it explore (and “exploration” it is, in the true sense of the word) this area – please look for it in the future.

 Anaconda Emerging from the water

 

You can learn more about the field research project I described in this article at:

Anaconda Expert Wades Barefoot in Venzuela’s Swamps

The Spotted Salamander, Ambystoma maculatum, – Care in Captivity – Part 1

Welcome to our new blog location!

Please see here for more background information on this animal’s natural history and life cycle in the wild.

 

General

Despite living largely underground in the wild, captive spotted salamanders adjust well to artificial caves and shelters, where they are more easily observed.  Well-adjusted captSpotted Salamanderives quickly lose their secretive, nocturnal ways, and will eagerly accept food offered by plastic feeding tongs.  If attention is paid to their needs, especially as concerns temperature (see below), these stocky, brilliantly marked salamanders make long-lived and hardy pets.

 

Space and Other Physical Requirements

If provided with a deep (6-12 inches) substrate, spotted salamanders will establish burrows that will be defended and used consistently.  Products such as Zoo Med Eco Earth and R-Zilla Fir/Sphagnum Moss Bedding, with a bit of top soil mixed in, work well as substrates.  The surface should be covered with living or dried sheet moss, such as R-Zilla Compressed Frog Moss.  You can spot clean this type of set-up or occasionally remove the top layer of substrate – living plants in the terrarium will aid in absorbing the salamander’s waste products.

 

Another useful tip in maintaining cleanliness is to establish a colony of isopods (sow bugs or pill bugs) in the terrarium.  These small crustaceans can easily be collected below rocks and leaf litter.  They are excellent salamander food and avidly consume feces, dead insects and decaying moss (a bit of fish flake food added occasionally will keep them in top shape and assure that they reproduce). 

 

Land snails are also excellent scavengers, and both they and isopods are fascinating creatures in their own rights.  Snails usually reproduce readily in captivity, and small specimens will be eagerly devoured by spotted salamanders.

 

A single adult spotted salamander requires an enclosure of approximately the size of a 10 gallon aquarium.

 

Spotted salamanders may also be kept in ventilated sweater boxes on sheet moss or paper towels.  Each animal should be provided an individual artificial cave or cork bark shelter.

 

Light, Heat and Humidity

Spotted salamanders favor cool temperatures, retreating far below-ground during the summer months.  They do best at 60-70 F, and are stressed by temperatures over 76 F.  Cool basements make ideal sites for their terrariums, especially during the summer months.  My own basement maintains an air temperature of 50-54 F in the winter, during which time the salamanders continue to feed.  The drop in temperature is good for their health, and helps to maintain normal activity patterns and to spur breeding.

 

Breathing largely through their skin, spotted salamanders require moist conditions – their terrarium should be misted with de-chlorinated (not distilled) water daily.  Free-living adults rarely enter water other than for breeding, but a shallow, easily-exited water bowl will be utilized by captives. 

 

Humidity should not be raised by covering the terrarium with plastic – salamanders require circulating air and should be housed in screen-covered enclosures.  In stagnant air conditions, temperatures rise and fungus often attacks the skin.

 

Spotted salamanders do not require a UVB light source.  If you keep live plants in the terrarium, be sure to use a low output UVB bulb, such as the Reptisun 2.0, as too much UVB can damage the eyes of these and other amphibians.  Check also that the bulb does not cause temperatures to spike.

 

If you keep your salamanders in an unlit basement, it is a good idea to provide a light cycle for them in the form of a weak room light or fluorescent tank light.  They will do fine in complete darkness, but a day/night period is preferable, especially if you plan on breeding your animals.

Check back next Monday for the conclusion of this article. The image above is referenced from the Spotted Salamander entry on Wikipedia.

The Spotted Salamander, Ambystoma maculatum – Part II, Natural History

Spotted Salamander in terrarium

To read the first part of this article, click here.
Natural Diet
Adults consume a wide variety of prey – earthworms, millipedes, crickets, sow bugs, spiders, centipedes, termites and other invertebrates as well as smaller salamanders. The larvae prey upon zooplankton, dragonfly larvae and other aquatic insects, fairy shrimp, tadpoles, red-spotted newt larvae and each other.

Spotted salamanders produce toxic skin secretions but are none-the-less consumed by garter snakes and hog-nosed snakes. Introduced trout, bass, goldfish and other fishes prey upon the larvae and can decimate a population in a single season.

Reproduction
Adults migrate from terrestrial burrows to temporary ponds (vernal pools, swamps, ditches, sluggish streams) in the early spring. The migration is triggered by snow-melt or warm rains, with adults sometimes crossing snow to reach their breeding sites. Males arrive at the ponds 1-6 days before females. I have observed them breeding in Westchester County, NY in mid March, when the water is quite cold. Despite this, I found that food for the larvae, in the form of aquatic insects and fairy shrimp, was abundant.

Large mixed-sex groups form at the pond bottom during courtship. Males deposit a spermatophore (a sperm-filled, jelly-coated capsule) on the pond bottom. The females take this into their cloaca (reproductive opening) and fertilization occurs internally.

The eggs are laid in compact, jelly-covered masses that are attached to twigs, plants or sunken logs. Each mass contains 50-160 eggs. The sight of 20 or more large, brilliantly marked salamanders writhing together in as they vie for breeding rights is really something to see – please write in if you’d like information as to how you might observe this for yourself.

A species of green algae, Oophila amblystomatis, frequently colonizes the egg mass, apparently supplying oxygen to the embryos and utilizing the carbon dioxide that they produce. Larvae from algae-colonized egg masses hatch earlier and exhibit less mortality than do those from algae-free masses.

The adults return to their burrows after breeding. The terrestrial habitat may be 75 – 1,000 feet from the breeding pond.

The larvae hatch in 8-60 days, depending upon water temperature, and have external gills. Transformation to the adult form takes place over a period ranging from 6 weeks to 18 months. In NY, the larvae typically leave the breeding ponds by late July or August, after which the ponds usually dry up.

Miscellaneous
Adult spotted salamanders have lungs but rely largely upon cutaneous respiration (the absorption of oxygen through the skin). The skin must remain moist if this form of respiration is to be effective – they are therefore, limited to damp habitats and rarely appear above ground except after heavy rains. They and other salamanders depend upon protective tree cover, leaf litter and fallen logs to retain soil moisture, and rapidly disappear from degraded habitats.

 

You can read more about spotted salamander natural history and conservation at:
http://www.globalamphibians.org/
Of course, you can also order my salamander book from That Pet Place (see above) – Thanks!

 

The Spotted Salamander, Ambystoma maculatum – Part I, Natural History

Spotted Salamander

Overview
Salamanders are not given nearly the attention they deserve by amphibian enthusiasts and, consequently, we know far less about their habits and care than we do of their more familiar relatives, the frogs. Many species, however, do very well in captivity and make long-lived (to over 50 years!) and responsive pets. A number are brilliantly colored, and all exhibit complex social behaviors and other traits that are easily observed in a properly designed captive habitat. I hope you will check out my book, Newts and Salamanders if you find these creatures as interesting as do I.

In contrast to frogs, salamanders reach their greatest diversity in temperate habitats – more species are found in the eastern USA than anywhere else on earth. Today I would like to take a look at the natural history of the spotted salamander – a large, local beauty that makes both an excellent “first salamander” and a fine addition to advanced collections. Next week I’ll cover their care in captivity.

Physical Description
Varies in length from 4 ¾ to 9 ¾ inches. Stoutly built, with a black or slate- colored body marked by irregular rows of brilliant yellow (occasionally orange) spots. Larvae are usually a uniform olive or brown in color with bushy red external gills.

Range and Habitat
Eastern and central North America – from Nova Scotia and central Ontario, Canada south to Georgia and west to eastern Iowa and eastern Texas. They are absent from southern NJ and the Delmarva Peninsula. Isolated populations are still to be found within NYC, on Staten Island and in Queens and the north Bronx.

Spotted salamanders favor deciduous lowland forests and meadows near forest edges and sometimes inhabit woodland patches within suburban areas. Adults require soil into which they can burrow and the fish-less bodies of water for breeding (the larvae are relatively defenseless against fish). Certain populations breed where fishes are present, but only if dense aquatic plant cover is available.

Spotted salamanders are members of the family Ambystomatidae – the mole salamanders. True to this name, the terrestrial adults spend most of their lives below logs or underground in self-excavated burrows or in those dug by mammals such as moles, shrews and field mice. They have been found at depths of 4 feet below ground, and generally forage on the surface only on damp or rainy nights. Spotted salamanders are sensitive to soil pH and avoid acidic soil.

Status in the Wild
Common in some parts of the range and drastically declining in others due to habitat loss – the removal of trees causes the soil to dry, and results in loss of the protective leaf-litter cover needed by this species. The introduction of trout and other game fish to breeding ponds quickly causes local extinctions.

Spotted salamanders typically breed in vernal (temporary) ponds, which are often small in size and only a few inches deep (these lack fish – see above). Unfortunately, such “puddles” are rarely recognized as worthy of protection, and hence are destroyed at a greater rate than are other habitats.

They are also threatened by acid rain and road-salting, both of which change soil and breeding pond pH, killing the larvae and driving off the adults. Protected by several states but not nationally, and not listed by CITES.

Check back on Friday for conclusion of this article.

Canned Insects and other Invertebrates – An Important New Food for Pet Reptiles and Amphibians

I have long stressed the importance of dietary variety to the health of captive reptiles and amphibians. Most consume anywhere from dozens to hundreds of prey species in the wild, yet are typically fed only crickets, mealworms and a few others in captivity. Collecting insects (Zoo Med’s Bug Napper is a very effective tool) and culturing alternative species such as sow bugs is one option, but few of us find the time to do this regularly.

So it was with great interest that I began experimenting with the whole, canned invertebrates that have recently become available. Animals that normally consume non-living foods, such as box, musk, snapping, painted and spotted turtles, sharp-ribbed and fire-bellied newts and African clawAlbino BullFrogsed frogs, eagerly took most foods offered. I was also able to tong-feed the insects to several species of “live food only” amphibians, including horned frogs, green frogs, leopard frogs (see photo), American bullfrogs (see photo, albino frogs pictured here), gray treefrogs, barking treefrogs, spotted salamanders and fire salamanders (see picture.)

I’m very eager to try these products on several small, insectivorous snake species which do not thrive unless supplied with caterpillars, slugs, and grasshoppers. First among these would be North America’s gorgeous smooth and rough green snakes, Opheodrys vernalis and O. aestivus, followed by the ring-necked and red-bellied snakes, Diadophis punctatus and Storeria occipitomaculata (these last 2 favor slugs, for which snails might be a good substitute).

I was especially happy to see that snails were being offered by several companies. Since childhood, I have longed to successfully keep the striking Malayan snail-eating turtle, Malayemys subtrijuga. I have had moderate success in zoos, but only when large breeding colonies of apple snails were available to feed these beautiful foLeopard Frogod specialists. Supplying enough food is difficult for hobbyists and most zoological parks, and hence this turtle is rarely bred or even kept in captivity, despite being extremely rare in the wild and in need of our help. I look forward to trying again, using canned snails, supplemented with live ones, as a basis of the diet.

I have also written about the use of canned insects in bird diets – please see my article, Feeding Insects to Pet Birds.

I have tried most of the following, and recommend you to experiment as much as possible:

Exo Terra – grasshoppers, silkworms, snails
Zoo Med – grasshoppers, caterpillars, snails
Jurrasidiet – Snails, grasshoppers

 

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