OK, so it's not tuesday. And I've been grossly negligent in blog upkeep. But I am posting mostly because *drum roll* I have a new pet! Enter "Feynman", a frilled dragon.
Feynman the Frilled Dragon
Chlamydosaurus kingii is an acrodontid agamid, a semi-arboreal lizard found in Australia. They are primarily insectivorous, though they will supplement it with other forms of protein. The frill, for which they are well known, is supported by cartilaginous spines connected to the jawbones, with bright flash colors. Additionally, Chlamydosaurus kingii is facultatively bipedal.
As far as care, Chlamydosaurus kingii cares for very similarly to a bearded dragon. You should aim for 27o C on the cool side of the cage, and 38o C on the hottest part of the basking area. Unlike a bearded dragon, the humidity should be kept somewhat high, spraying the cage occasionally. Moss and substrates like orchid bark or peat moss will help keep the humidity up.
Chlamydosaurus kingii is rated IUCN least concern as of 2009. I'm looking forward to a good long time with my new pet!
Today's Tuesday Tetrapod returns to the land of the fuzzy with Chinchilla lanigera, or the Chilean chinchilla.
C. lanigera. Photo released into the public domain in the Wikimedia commons
Chichilla coats are notable in a couple of ways. Their fur is so dense that you cannot wash them; when their fur gets wet it does not dry, encouraging fungal growth or fur rot. Instead, they naturally take dust baths, which dislodge particulates and absorb oils in their coat. In fact, their incredibly soft and dense coat makes them very sought after in the fur industry, meaning that both variants of the chinchilla are in fact critically endangered, estimated to be losing about 90% of its population every three generations (15 years) due largely to hunting. Chinchillas themselves can release some hair to facilitate in escape from a predator. Due to the density of their coats, chinchillas do not sweat.
Chinchillas are available as pets in the US, partially mitigating their rare status in the wild.
Today's Tuesday Tetrapod is the Lammergeier, or Bearded Vulture, Gypaetus barbatus.
G. barbatus. Photo CC-BY-NC-ND by Flickr user A. Davey.
G. barbatus is a type of Old World vulture (Depending on the phylogeny, this makes them either a Falconiforme or Accipitriforme) with the unusual dietary preference of bone marrow. In part because of this, they lack the customary "bald head" of most vultures. They also have a different flight profile, with narrower wings and a wedge-shaped tail.
G. barbatus eats by reaching a carcass after it has been largely cleaned, then taking bones and dropping them from a height onto rock formations, smashing the bones into pieces small enough to ingest. They occasionally do this with turtles, possibly being the source of the apocryphal tale about the death of Greek playwright Aeschylus.
Image CC-NC-SA by Flickr user fveronesi1
Despite being threatened in its European range, G. barbatus is relatively stable over its very large range in Africa. There is also evidence for minor population decline, but it is not rapid or extreme enough to qualify for a threatened status. It is thus ranked by the IUCN as Least concern as of 2009.
This week's (long overdue) Tuesday Tetrapod is Python molurus bivittatus or the Burmese Python.
P. molurus bivitattus. Photo CC-BY by Flickr user wildxplorer
P. m. bivitattus is one of the six largest species of snake in the world, reaching nearly 6m in length at their maximum. They are standard constrictor snakes (pythonidae), and due to their nice patterning are popular household pets, which are later often released due to their large size.
P. m. bivitattus is actually becoming an increasing problem in the Florida Everglades, as the household escapees are well-adapted to the environment of the Everglades, and compete for the position of top predator along with the American Alligator. They pose overall ecosystem danger, as they eat many of the endangered birds living in the Everglades currently. This led to the famous "exploding snake" incident.
P. m. bivitattus also demonstrates facultative endothermy. During the brooding season, the female python will often wrap around her eggs and increase her metabolic rates (in conjunction with fast muscle twitches similar to shivering) to regulate the temperature of the eggs. This leads the female during this period to approach avian/mammalian levels of food requirements, and overal metabolism.
P. molurus is rated IUCN near threatened, with an update needed/pending.
Now, let's take a turn to the water, and have a Tuesday Tetrapod on Orcinus orca, or the Orca ("Killer Whale").
O. orca. Photo CC-BY-NC-ND by Flickr user SteveWhis.
One of the few common extant animals referred to by its specific name, orcas are the second most widely distributed mammal on the planet, after humans. Specifically:
Orcas CC-BY-ND by Christopher DiNottia
Although killer whales occur worldwide, densities increase by 1-2 orders of magnitude between the tropics and the highest-sampled latitudes in the Arctic and Antarctic (Forney and Wade 2006). Killer whales tend to be more common along continental margins; however, there is some variation in this general pattern that appears linked to ocean productivity. Killer whales appear to be less common in western boundary currents, such as the Gulf Stream or the Kuroshio than in more productive eastern boundary currents, such as the California Current. Known areas of locally higher density often coincide with greater oceanographic productivity (e.g. off Argentina).
O. orca is technically a type of dolphin, a member of delphinidae, and possibly a complex of up to five species (but probably a combination of species, subspecies, and races). Currently, they are grouped as "populations" of transients, residents, and offshore, primarily differentiated by diet and behaviours with minor morphological differences.
Orcas are large, and commonly seen in water shows. They age at a rate similar to humans, with sexual maturity reached around 15 for females, and reaching up to 90 in age.
The orca is IUCN "data deficient", due to possible specific/subspecific splits and that certain populations are experiencing a 30% population drop over 30 years, while others maintain a stable population.
There is a gigantic repository of information on Orcas available — it is a Wikipedia featured article and many other resources are available online.
For last week's Tuesday Tetrapod, we look at Taricha rivularus, or the Red-Bellied newt:
T. rivularis is a plethodontid salamander, which, like other members of the subfamily Pleurodelinae, are sometimes called "newts". They transition to a smooth-skinned morph during their aquatic/breeding stage.
Like many other salamandrids, when stressed they can excrete a whitish neurotoxin on their skin, tetrodotoxin (TTX) which is very potent and can kill an adult human.
T. rivularis is IUCN "Least Concern" and can be found in northern california. The photographed specimen was found in Medecino county.
You can see more photos at CaliforniaHerps.
Covering tetrapods is amusing. I want to try for some sort of balance, but there isn't one — about 55% of my entries should be birds, 20% amphibians, 15% non-avian sauropsids, and 10% mammals. I should keep that in mind as I continue to post, and particularly put up more amphibians. That being said, let's work on that 15%, and bring forth Diomedea exulans, or the Wandering Albatross.
A procellariiform (tube-nose) water bird, like other albatrosses (diomedeidae), they have characteristically stiff wings they use to "dyanimcally soar", utilizing winds close to the surface of the sea. Procellariiformes are almost exclusively pelagic, with an uncharacteristically good sense of smell for avians. D. exulans are among the largest birds in the world, with definitively the longest wingspan. Average wingspans run 2.5-3.5 m, with largest verified reports running to 3.7 m and questionable sources reporting as much as 5.3 m wingspans. Other adaptations include the ability to excrete excess salt from glands in their nasal passage
D. exulans is a distinctive bird with a characteristic beak shape, and mostly white except for black-tipped wings, with some black along the trailing wing feathers as adults.
Like other procellariiformes, D. exulans is long-lived and has a distinctive breeding behaviour. They typically lay only one egg per two years, maintaining a monogamous, lifelong relationship with one other bird. Their breeding population is restricted to three primary sites, with 20% on South Georgia, 40% on Crozet and Kerguelen islands, and 40% on Prince Edwards Islands. This behaviour leaves them particularly vulnerable to cats and rats introduced onto these islands by humans, which cause large problems for eggs and chicks. Particularly on Kerguelen, some breeding colonies have had complete breeding failure due to cats. As a k-selected species, they are sensitive to this sort of predation, with reproduction not occuring until individuals are 11-15 years of age.
During the year, D. exulans is widely distributed, essentially cosmopolitian between 28deg-60deg in the southern oceans. Their wide distribution and their diet of cephalopods, fish, and crustaceans means they are strongly affected by longline fishing used to catch tuna and Chilean Sea Bass. The birds are prone to drowning after becoming ensnareed in the hooks along the lines. A survey in 2007 indicated about half of the chicks on Bird Island have ingested fishing hooks.
They are rated IUCN "vulnerable", with a >30% population decline over the past three generations. Efforts are underway by some fisheries to reduce albatross bycatch.
Well, in this belated TT, let's throw another xenarthran into the fray, with Priodontes maximus, or the Giant Armadillo:
All extant armadillos, including P. maximus, are members of Dasypodidae, which lie on a different branch than the extinct, massive, glyptodonts. P. maximus isn't quite as weird as other armadillos (which, among other things, give birth to four monozygotic young - ie, indentical quadruplets). P. maximus is fairly large, weighing about 30 kg and averaging 89 cm in length. While primarily formicivorous, they will sometimes also eat small rodents.
The armor on dasypodids are keratinized dermal scutes, with varying degrees of flexibility across the clade. Only the genus Tolypeutes has the capacity to actually role into a ball for defense, otherwise just rely on their armor for protection in conjuction with flight.
Native to South America (particularly north-central SA), Priodontes maximus is rated IUCN "Vulnerable" with a decreasing population. Population decline has been estimated at >= 30% in the past 24 years, exacerbating its naturally sparse population.
In an odd aside, IE can't get a break — if you're viewing the IUCN site in IE8, it may not display properly.
And for the second tetrapod this week, I introduce Lophophorus impejanus, or the Himalayan Monal:
Male L. impejanus. Photo by Flickr user poplinre
The Himalayan Monal is a phasianid galliform (my phylogeny of birds is not well resolved in galloanserae [galliformes or anseriformes] — help out if you can!), with a number of the associated trappings (ground nesting, medium size, etc) of pheasants. L. impejanus weighs 1.5-2.5 kg, and is reasonably sized at ~67cm in length. It lives in open coniferous forests in the Himalayan region, 2100-4500 m in elevation.
Female L. impejanus. Note the extreme dimorphism in color. Photo from the Wikimedia Commons.
The males are very evidently highly sexually dimorphic to females, having bright, iridescent feathers with a crest. Their median weight is also about 200g heavier than the females. L. impejanus is the national bird of Nepal, and as such, and due to its habitat, is not threatened. It is rated by the IUCN as least concern, having a large, stable, widespread population.
Time for another double-post! Today's first Tuesday Tetrapod brings us an interesting group of snakes, a member of a group of elapids called the Hydrophiines — sea snakes. Today, we have Hydrophis melanocephalus, or the Slender-Necked Sea Snake
H. melanocephalus. Photo CC-BY-NC-SA by Flickr user Nemo's Great Uncle.
H. melanocephalus, swimming along the seabed. Note the lateral compression along the tail. Photo CC-BY-NC-SA by Flickr user Nemo's Great Uncle.
H. melanocephalus is one of approximately 70 species of elapids to have marine specializations. The bulk of the species are Hydrophiines, with Laticaudines being monogeneric (Laticauda). In Hydrophiinae, this manifests as salt glands around the tounge sheath for osmotic balance, full viviparity, almost nonexistent ventral scales, loss of 1-to-1 association with ventral scales:vertebrae, and enlongate neutral spines and haemopophyses for their tails.
Being fairly elusive, H. melanocephalus has not been evaluated by the IUCN. However, evaluations by other groups suggests it is highly venomous, endemic to the Indian Ocean region (South Chinese Sea, Vietnam, Japan (Ryukyu, Hokkaido, Kochi) Coasts of Taiwan and Guangdong northward to Zhejiang (China) Australia (North Territory?, West Australia), New Guinea Terra typica: Indian Ocean (type series from Indian Ocean and Madras, India) accoring to the catalogue of life). Sadly, the animal has been poorly researched.
Bringing the TT's up to date, for the second Tuesday Tetrapod we look at the largest group of mammals on the planet, as represented by Acerodon jubatus, or the Giant Golden-crowned Flying-fox.
A. jubatus. Image from the Wikimedia commons.
They are part of the only (probably highly paraphyletic) family pteropodidae in so-called "megachiroptera". The common name of the animal is obvious, coming from the long snout and pointed ears highly reminiscent of the red fox. Their diet is primarily composed of figs and other fruits, and act as an important pollinator in the Phillipines.
A. jubatus is the largest known bat, with an average wingspan of 1.5 m and weighing up to 1.2 kg. They are rated by the IUCN as endangered, with a 50% population decline in the past 30 years. The total population is estimated at 10,000 individuals, with the primary threat coming from a 90% reduction of the Phillipine old-growth forest.
As an interesting note, the image from the Wikimedia commons is the only free image available for this species.
After a very full past few weeks, finally I return for a pair of Tuesday Tetrapod updates. In light of my sister's trip to Egypt, the first tetrapod this week is Crocodylus niloticus, or the Nile Crocodile.
C. niloticus. CC-BY-NC by Arno & Louise.
Looking way back at the post on G. gangeticus, there wasn't much specifics back then on the relationships or on the biology of the animals. Well, C. niloticus is a crocodylid, being more closely related to gavialidae than to alligatoridae. Like all extant crocodylomorphs, hatchling sex is TSD (temperature-dependant sex determination). Morphologically, they have a number of adaptations to their aquatic lifestyle, including a well-developed secondary palat with choanae that open behind the secondary palate that can be closed off to facilitate underwater feeding. They also have a "shunt" system that can change their four-chambered heart to functionally three-chambered for increased oxygen saving and submersion time (Franklin & Axelsson 1994 | summary).
C. niloticus is widespread throughout central Africa, and capable of growing to more than 5 meters in length. Additionally, C. niloticus has the strongest measured bite force of any extant animal, reaching 22 kN. In addition to more common fare, they have been observed feeding on giraffes, lions, leopards, and rhinoceroses. As of 1996, they are rated IUCN least concern.
While I suppose my Tuesday Tetrapods should be 12:7:5:1 Aves:Non-avian sauropsids:lissamphibia:theria, where's the fun in that? For the forseeable future, I'll just run with percieved inequities.
Working to reduce one of those inequities, time to address ecosystems! We've painfully neglected the tetrapod return to water, so let's take a look today at Zalophus californianus, or the California Sea Lion:
Sea lions, including Z. californianus, are part of the otariid node (and thus are "eared seals"). Like other pinnipeds, they have finned feet that are highly modified for swimming, with earliest fossils from their lineage originating about 23 million years ago with Puijila darwini.
In particular, Z. californianus is commonly used with humans for entertainment and utilitarian purposes. They are the most common "seals" used in shows (rather than true seals, phocids), and are trained by the navy to retrieve enemy divers. They are rated IUCN Least Concern.
With Christmas just around the corner, it seems now is an appropriate time to put up a Tuesday Tetrapod post on one of the "north pole's" signature animals: Ursus maritimus, or the polar bear.
U. maritimus. Photo CC-BY-NC-ND by Flickr user J.G. in S.F.
U. maritimus is the largest extant land carnivore, and the largest ursid. It is closely related to the brown/grizzly bears, but with a suite of adaptations which optimize its seagoing lifestyle and the cold climate. They are in fact close enough to grizzly bears (Ursus arctos horribilis) that the so-called "Pizzly Bear" has been found both in the wild and captivity.
Despite these genetic similarities, U. maritimus is phenotypically, metabolically, and behaviourally different enough to be classified as a distinct species.
The polar bear is currently rated as "threatened" by the Department of the Interior, a designation that caused a significant amount of political difficulties in 2008 when the IUCN determined that global warming was the primary threat to the species. Due to their habitat, they are difficult to track, though breakup of ice sheets and overal arctic warming has driven polar bear populations further south, interacting more with humans, thus causing an appearance of a population increase. Ursus maritimus is rated IUCN "vulnerable", with an estimated population reduction of >30% by 2050, up to 50%; with complete extirpation within 100 years due to climate change.
About time! Another Tuesday Tetrapod. We've been shirking mammals (though they do have the distinct minority of tet diversity), and have a nasty bias toward eutherians, so here's Macropus rufus, or the Red Kangaroo:
M.rufus. Photo CC-BY-NC-ND by Flickr user wallyg.
Macropus rufus is the largest extant metatherian, and a member of macropodidae, or "large feet". They are diagnostic as diprotodonts by the two large incisors on their mandible, and the characteristic syndactyl morphology of their feet. As with most metatherians, M. rufus is capable of reproductive diapause, where in this context they can delay the birth of any new babies until the current joey has left the pouch.
Red kangaroos can be quite large, with large males running up to 2m in height and 90kg in weight. The unique tendon structure in their feet means that the hopping method of locomotion is highly efficient, recovering most of their energy with each bound. This enables them to comfortably hop at 25kph, with bursts of up to 70kph.
M. rufus is rated IUCN "Least Concern" as of 2008 with a stable population.