Why Do Venomous Animals Live In Warm Climates? - As a Canadian-Australian, I have always wondered why it is that Australia has so many venomous animals that can kill you while Canada has virtually none. But it's not just Australia - it seems like all beautiful, warm places are cursed with venomous native species. So I set out to find the truth: why have all these venomous species evolved in the world's best holiday destinations?
I asked chemists, visited the zoo, interviewed entomologists and snake experts. The answer I found was complicated:
1. The majority of venomous species are ectotherms, cold-blooded creatures whose internal temperatures are governed by their surroundings.
2. This means they have limited periods of activity - mainly while it's warm out, and can only exert short bursts of energy, so they are generally "sit and wait" predators. This may explain why they, more than mammals or birds, evolved venom.
3. It also explains why there are more of these species in warm climates. There are more of all species in warm climates, but this trend is especially pronounced for ectotherms.
4. So there are a greater number of venomous species in warm places, simply because there are more species in warm places. Cold climates still have venomous creatures, like the rattlesnakes of Canada and European vipers.
5. But history also has a role to play. In Australia, there were no snakes until 20 million years ago when a venomous sea snake from Asia encountered the land, sending venomous species to all corners of the continent. Later non-venomous arrivals have done well in the tropics but not as well in Australia's colder climates, so venomous types still dominate there. Hawaii has no venomous land snakes and nor does Jamaica.
6. The recent ice age also would have driven ectotherms from the northern parts of the Northern Hemisphere. This is why there are no snakes in Ireland, for example.
Mysteries of vernacular: Earwig - Jessica Oreck and Rachael Teel - An earwig is neither an ear nor a wig; it is an insect. Jessica Oreck and Rachael Teel explain how folklore gave this bug its name, combining entomology with etymology.
Read these documents: http://bit.ly/AntDoc1 http://bit.ly/AntDoc2
Tweet this: http://bit.ly/UC05L0 Post to Facebook: http://on.fb.me/XWr8v3
Subscribe for more.
Outro song: "Trilobyte" by A Shell in the Pit Here: http://ashellinthepit.bandcamp.com/tr...
Tweet ideas to me @SmarterYouTube
Instead of saving for my kids' college, I make videos using the money I would have saved.
The thought is it will help educate the world as a whole, and one day generate enough revenue to pay for their education. Until then if you appreciate what you've learned in this video and the effort that went in to it, please SHARE THE VIDEO!
If you REALLY liked it, feel free to pitch a few dollars towards their college fund by clicking here:
First video released of new spider that builds decoys of other spiders!
Read more about the spider here: http://bit.ly/NewSpider
Tweet this video: http://bit.ly/Us5ali Post to FB: http://on.fb.me/V4EI16
Discovery made here: 13°08′04″S 69°36′38″W
Download the song "Trilobyte" by A Shell in the Pit Here: http://ashellinthepit.bandcamp.com/track/trilobyte
Please share this with your friends! Media outlets please do not post this video on your media forms without proper permission/licensing. I still have not recouped what I spent to travel and make this video, so obviously I'm trying to do that. Feel free to contact me about licensing.
Why Aren't There Giant Insects? - Hank and physiologist Jon Harrison discuss the question of insect size and major theories that attempt to explain why there is a limit to how large insects can get with current conditions on Earth.
Fire ants use their claws to grip diverse surfaces, including each other. As a result of their mutual adhesion and large numbers, ant colonies flow like inanimate fluids. This film shows how ants behave similarly to the spreading of drops, the capillary rise of menisci, and gravity-driven flow down a wall. By emulating the flow of fluids, ant colonies can remain united under stressful conditions.
In this remarkable BBC footage, Sir David Attenborough reveals the world
of insects such as ants, stick insects, beetles and digger bees. Visit http://www.bbcearth.com
for all the latest animal news and wildlife videos and watch more high
quality videos on the new BBC Earth YouTube channel here: http://www.youtube.com/bbcearth
Sir David Attenborough hosts this amazing video from BBC wildlife show 'Life in the Undergrowth' investigating the weird and wonderful mating ritual of the leopard slug. Trust us - this is one free animal video that has to be seen to be believed!!
Bugs, Arthropod, Hemiptera
Insects and other creepy crawlers.
Birds (class Aves) are feathered, winged, bipedal, endothermic (warm-blooded), egg-laying, vertebrate animals. Around 10,000 living species makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from the 5 cm (2 in) Bee Hummingbird to the 2.75 m (9 ft) Ostrich. The fossil record indicates birds evolved from theropod dinosaurs during the Jurassic period, around 160 million years (Ma) ago. Paleontologists regard birds as the only clade of dinosaurs to have survived the Cretaceous–Paleogene extinction event 65.5 Ma ago.
Modern birds are characterised by feathers, a beak with no teeth, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton. All living species of birds have wings—the now extinct flightless Moa of New Zealand was the only exception. Wings are evolved forelimbs, and most bird species can fly, with some exceptions, including ratites, penguins, and a number of diverse endemic island species. Birds also have unique digestive and respiratory systems that are highly adapted for flight. Some birds, especially corvids and parrots, are among the most intelligent animal species; a number of bird species have been observed manufacturing and using tools, and many social species exhibit cultural transmission of knowledge across generations.
Many species undertake long distance annual migrations, and many more perform shorter irregular movements. Birds are social; they communicate using visual signals and through calls and songs, and participate in social behaviours, including cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of bird species are socially monogamous, usually for one breeding season at a time, sometimes for years, but rarely for life. Other species have polygynous ("many females") or, rarely, polyandrous ("many males") breeding systems. Eggs are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching.
Many species are of economic importance, mostly as sources of food acquired through hunting or farming. Some species, particularly songbirds and parrots, are popular as pets. Other uses include the harvesting of guano (droppings) for use as a fertiliser. Birds figure prominently in all aspects of human culture from religion to poetry to popular music. About 120–130 species have become extinct as a result of human activity since the 17th century, and hundreds more before then. Currently about 1,200 species of birds are threatened with extinction by human activities, though efforts are underway to protect them.
Amphibians (class Amphibia, from Amphi- meaning "on both sides" and -bios meaning "life"), are a class of vertebrate animals including animals such as frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic (or cold-blooded) tetrapods. Most Amphibians undergo metamorphosis from a juvenile water-breathing form to an adult air-breathing form, but some are paedomorphs that retain the juvenile water-breathing form throughout life. Mudpuppies, for example, retain juvenile gills in adulthood. The three modern orders of amphibians are Anura (frogs and toads), Caudata (salamanders and newts), and Gymnophiona (caecilians, limbless amphibians that resemble snakes), and in total they number approximately 6,500 species. Many amphibians lay their eggs in water. Amphibians are superficially similar to reptiles, but reptiles are amniotes, along with mammals and birds. The study of amphibians is called batrachology.
Amphibians are ecological indicators, and in recent decades there has been a dramatic decline in amphibian populations around the globe. Many species are now threatened or extinct.
Amphibians evolved in the Devonian Period and were top predators in the Carboniferous and Permian Periods, but many lineages were wiped out during the Permian–Triassic extinction. One group, the metoposaurs, remained important predators during the Triassic, but as the world became drier during the Early Jurassic they died out, leaving a handful of relict temnospondyls like Koolasuchus and the modern orders of Lissamphibia.