Some of the helium-3 found in the terrestrial atmosphere is also a relic of atmospheric and underwater nuclear weapons testing, conducted by the three big nuclear powers before 1963.

Some of these mammals would evolve into large forms that would dominate the land, while others would become capable of living in marine, specialized terrestrial, and airborne environments.

Some terrestrial telescopes ( such as the Very Large Telescope ) can reduce atmospheric effects with adaptive optics.

Some salamander species are fully aquatic throughout life, some take to the water intermittently, and some are entirely terrestrial as adults.

Some salamanders that are terrestrial have lungs that are used in respiration, although these are simple and sac-like, unlike the more complex organs found in mammals.

Some particle physics experiments must adjust for terrestrial tides.

Some terrestrial radio relays remained in service for regional connections.

Some orders of heterotardigrades are marine, others are terrestrial, but as for all tardigrades, all are aquatic in the sense that they must be surrounded by at least a film of moisture in order to be active-though they can survive in a dormant state if the habitat dries out.

Some diplurans have the ability to shed their cerci if necessary ( autotomy ); of all terrestrial arthropods, only diplurans have the ability to regenerate these lost appendages over a series of moults.

Some populations of the North American caribou migrate the furthest of any terrestrial mammal, travelling up to a year, and covering.

Some ecosystems, such as many wetlands, do not organize as a strict pyramid, because aquatic plants are not as productive as long-lived terrestrial plants such as trees.

Some of the more familiar and better-known gastropods are terrestrial gastropods ( the land snails and slugs ) and some live in freshwater, but more than two thirds of all named species live in a marine environment.

Some botanists however split Huperzia into two genera, Huperzia in the narrow sense including 10-15 species of terrestrial temperate to Arctic species, and the rest in Phlegmariurus, a primarily tropical to subtropical genus of mainly epiphytic species.

Some terrestrial mammals, especially desert rodents appear to survive without drinking but they do generate water through the metabolism of cereal seeds and they also have mechanisms to conserve water to the maximum degree.

Some terrestrial ecosystems – for example, those of the open deserts and similar arid environments – exist on irregular rainfall and the moisture it delivers to the soil, supplemented by moisture in the air.

Some digital broadcasting systems allow single-frequency network ( SFN ), where all terrestrial transmitters in a region sending the same multiplex of radio programs may use the same frequency channel without self-interference problems, further improving the system spectral efficiency.

Some MATV systems may carry 8-VSB and QAM signals, mostly in apartment buildings and similar facilities that use a combination of terrestrial antennas and cable distribution sources ( such as HITS or " Headend in the Sky ", a unit of Comcast that delivers digital channels by satellite to small cable systems ).

Some exposed outcrops appear to show faint layering, and some researchers also believe that landforms visible in images of the mouth of Ma ' adim Vallis where it enters Gusev resemble landforms seen in some terrestrial river deltas.

Some species are terrestrial and are found under logs, in or on the soil, and on plants in humid areas.

Some structures resembling the mineralized casts of terrestrial bacteria and their appendages ( fibrils ) or by-products ( extracellular polymeric substances ) occur in the rims of carbonate globules and preterrestrial aqueous alteration regions.

Some parts of the world, notably in France and the US, have also offered encrypted analog terrestrial signals, available for subscription.

Some terrestrial species throw a thread of mucus which they use as a rope to climb from one leaf to another.

Some networks use 32 kbit / s ADPCM on the terrestrial side of the network instead of 64 kbit / s PCM and the TRAU converts accordingly.

Some 500 species are found in fresh water ; and another 5, 000 species are the woodlice in the suborder Oniscidea, which are thus by far the most successful group of terrestrial crustaceans.

Some species in the Plethodontidae have a weak zone at the base of the tail and if the salamander is in danger or if the tail is grabbed by a predator, it breaks off, a process known as autotomy.

Some species complete their development inside the egg and hatch directly into small frogs.

Some species are carnivorous at the tadpole stage, eating insects, smaller tadpoles and fish.

Some members of the genera Ambystoma and Dicamptodon have larvae that never fully develop into the adult form but this varies with species and with populations.

Some species of salamander emit a quiet squeak or yelp if attacked.

Some unicellular species rely entirely on external energy sources and have limited or no photosynthetic apparatus.

Some of the species of Allium are important food plants for example onions ( Allium cepa ), chives ( A. schoenoprasum ), garlic ( A. sativum and A. scordoprasum ), and leeks ( A. porrum ).

Some endangered species in British Columbia are: Vancouver Island marmot, Spotted Owl, American White Pelican, and badgers.

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.

Some species, particularly songbirds and parrots, are popular as pets.

Some aspects of brain structure are common to almost the entire range of animals species ; others distinguish " advanced " brains from more primitive ones, or distinguish vertebrates from invertebrates.

Some suggest Neanderthal, Homo erectus, or Homo heidelbergensis to be the creature, but no remains of any of those species have been found in the Americas.

Some species of mold produce alpha-galactosidase, an anti-oligosaccharide enzyme, which humans can take to facilitate digestion of oligosaccharides in the small intestine.

Some species, such as the Lesser Dwarf Lemur, store fat at the hind legs and the base of the tail and hibernate.

Some rare species are viviparous.

Some cosmologists have proposed that Big Bang nucleosynthesis suggests there is a fourth " sterile " species of neutrino.

Some species and genera had a very wide distribution with only minor variations.

Some botanical species are trees having similar foliage to the Lauraceae due to convergent evolution.

Some of the country's most endangered species are the Harpy eagle, the Giant anteater, the Golden toad and the Jaguar.

* Some Dracocephalum, Glechoma and Calamintha species were formerly classified in Nepeta.

* Some crustaceans, such as the coconut crab, though mainly omnivorous, will prey on turtle hatchlings, smaller crabs species, rats, and carrion

Some species form packs or live in small family groups depending on the circumstances, including the type of available food.

Some canid species have also been trapped and hunted for their fur and, especially the gray wolf and the red fox, for sport.