Instruct: Given a question, retrieve passages that answer the question.
Query: Do water rails migrate?
The water rail (Rallus aquaticus) is a bird of the rail family which breeds in well-vegetated wetlands across Europe, Asia and North Africa. Northern and eastern populations are migratory, but this species is a permanent resident in the warmer parts of its breeding range. The adult is 23–28cm (9–11in) long, and, like other rails, has a body that is flattened laterally, allowing it easier passage through the reed beds it inhabits. It has mainly brown upperparts and blue-grey underparts, black barring on the flanks, long toes, a short tail and a long reddish bill. Immature birds are generally similar in appearance to the adults, but the blue-grey in the plumage is replaced by buff. The downy chicks are black, as with all rails. The former subspecies R.indicus, has distinctive markings and a call that is very different from the pig-like squeal of the western races, and is now usually split as a separate species, the brown-cheeked rail.
Breeding species include reed and sedge warbler and water rail. Wintering species include bearded reedling, snipe, redshank and bittern. During the migration periods significant numbers of swallow and sand martin are seen.
This rail is a skulking species, its streaked plumage making it difficult to see in its wetland habitat. Its laterally compressed body allows it to slip though the densest vegetation, and it will "freeze" if surprised in the open.[37] It walks with a high-stepping gait, although it adopts a crouch when it runs for cover. It swims, when necessary, with the jerky motion typical of rails,[26] and it flies short distances low over the reeds with its long legs dangling. Although their flight looks weak, water rails are capable of long sustained flights during their nocturnal migrations,[25] and are sometimes killed in collisions with lighthouses or wires.[37] British-ringed birds have been recovered from as far away as Poland, Czechoslovakia and Sweden.[38]
Deuterium abundance can be useful in tracking migration of various animals. Animals with metabolically inert tissue (e.g. feathers or hair) will have synthesized that tissue using hydrogen from source water and food but ideally not incorporate subsequent water over the course of the migration. Because δD tends to vary geographically, the difference between animal tissue δD and post-migration water δD, after accounting for the biological fractionation of assimilation, can provide information regarding animal movement. In monarch butterflies, for example, wing chitin is metabolically inert after it has been built, so it can reflect the isotopic composition of the environmental water at the time and location of wing growth. This then creates a record of butterfly origin and can be used to determine migration distance. This approach can also be used in bats and birds, using hair and feathers, respectively. Since rainwater becomes depleted as elevation is increased, this method can also track altitudinal migration. However, this is technically difficult to do, and the resolution appears to be too poor to track small altitudinal changes. Deuterium is most useful in tracking movement of species between areas with large continental water variation, because species movement can be complicated by the similarity of local water δD values between different geographic regions. For example, source water from Baja California may have the same δD as water from Maine. Further, a proportion of the hydrogen isotope composition within the tissue can exchange with water and complicate the interpretation of measurements. In order to determine this percentage of isotopic exchange, which varies according to local humidity levels, standards of metabolically inert tissue from the species of interest can be constructed and equilibrated to local conditions. This allows measured δD from different geographic regions to be compared against each other.
Kismayo National Park (KNP) is a national park in Kismayo, Somalia, also known as Haabar Waalid. During the drought previous government had built pawns or mini lakes to avoid migration, some says leapords and other predators and most impalas elephants never migrated do to availability of water all years,the only time most migrated is when country was in war itself.
The most typical family members occupy dense vegetation in damp environments near lakes, swamps, or rivers. Reed beds are a particularly favoured habitat. They are omnivorous, and those that migrate do so at night.
Southern bluefin tunas often migrate vertically through the water column in search of their preferred temperature, and they spend time in cooler waters seeking prey. Some have hypothesized that they take refuge in warmer areas of water fronts and eddies after these foraging periods, but others suggest that these migrations are only associated with the aggregation of prey. Either way, it is clear that southern bluefin tuna have developed complex physiological mechanisms to maintain their body temperature (T) significantly above the ambient water temperature in these changing conditions. In fact, tuna can maintain the temperature of their muscles at above the temperature of surrounding water. Overall, tuna do not have a set body temperature point; rather it maintains its T within a narrow range, with variations of only over time and from individual to individual.
The Patagonian toothfish spawns in deep waters during the austral winter and early spring, between June and September. Discontinuous oogenesis development patterns suggest that Patagonian toothfish do not spawn annually. Individuals migrate to spawn in shallower waters (800-1000 m), although migration patterns can vary widely between different geographic populations. Some data suggest that spawning yields decrease at higher latitudes. 
Broad-winged hawks have a wide range in North America and South America, from southern Canada to southern Brazil. Their breeding range is in the northern and eastern parts of North America, and some migrate in the winter to Florida, southern Mexico, and northern South America. Five subspecies are endemic to the Caribbean and do not migrate. Those subspecies that do migrate fly in flocks of more than 40 up to hundreds of thousands at heights from . They soar using thermals to carry them through their journey of . Fall migration lasts for 70 days as birds migrate about per day from North America, through Central America to South America without crossing salt water. The enormous flocks of soaring broad-winged hawks are termed kettles and are characteristic of many hawk migration spectacles in North America, such as at Hawk Cliff in Ontario, Hawk Ridge in Minnesota, Hawk Mountain in Pennsylvania, and the River of Raptors in Veracruz.
The rails are a bird family comprising nearly 150 species. Although the origins of the group are lost in antiquity, the largest number of species and the most primitive forms are found in the Old World, suggesting that this family originated there. However, the genus Rallus, the group of long-billed reed bed specialists to which the water rail belongs, arose in the New World. Its Old World members, the water, African and Madagascan rails, form a superspecies, and are thought to have evolved from a single invasion from across the Atlantic.[2] Genetic evidence suggests that the water rail is the most closely related of its genus to the Pacific Gallirallus rails,[3] and is basal to that group.[4] The water rail was first described by Linnaeus in his Systema Naturae in 1758 under its current scientific name, Rallus aquaticus.[5] The binomial name is the Latin equivalent of the English "water rail".[6]
Migrations involve the fish moving from one part of a water body to another on a regular basis. Some particular types of migration are anadromous, in which adult fish live in the sea and migrate into fresh water to spawn, and catadromous, in which adult fish live in fresh water and migrate into salt water to spawn.
Sturgeon are an anadromous species that live solitarily or in small groups. They migrate upriver in the spring to spawn. Sturgeons tend to inhabit the shallow waters of coastal shelves, coastal and estuarine areas on soft bottom in the sea, and can live down to a depth of 50 meters. Adults are migratory while at sea and will make long migrations to coastal areas, while juveniles will stay in fresh or brackish water until they are between two and five years of age. However, many larvae and juveniles do start to migrate and disperse small distances from their spawning sites.
Water activity values can also help limit moisture migration within a food product made with different ingredients. If raisins of a higher water activity are packaged with bran flakes of a lower water activity, the water from the raisins migrates to the bran flakes over time, making the raisins hard and the bran flakes soggy. Food formulators use water activity to predict how much moisture migration affects their product.
In addition to resident waterfowl species, Mingo provides for migrating ducks, geese, shorebirds, gulls, terns, loons, grebes, pelicans, cormorants, herons, bitterns, ibises, rails, coots, and swans. Over 95 species of migratory waterfowl have been seen at Mingo. Through year-round management of the water levels on the refuge, the feeding and resting requirements of migrating birds can be met. The refuge provides wintering habitat for over 150,000 ducks and 75,000 geese.
Adults migrate from the ocean to spawn in fresh water. Juveniles migrate to the sea where they feed and become sexually mature before returning to fresh water to overwinter and spawn. Unlike steelhead and Pacific salmon, coastal cutthroat do not make lengthy migrations out to sea. Generally speaking, coastal cutthroat will remain in or near estuarine waters, usually within 5–10 mi (10–15 km) of their natal stream. Some cutthroat, however, have been shown to move as far as 70 mi (110 km) into the open ocean. There are also lacustrine and riverine populations that spend their entire lives in freshwater. One such population is the trout of Lake Crescent in Washington state that was formerly considered to be a separate subspecies called the Lake Crescent cutthroat trout, "Oncorhynchus clarkii crescenti".
A 2016 study by independent environmental consulting group FishBio showed that the artificial spring pulse flows from New Melones Dam do fairly little to support salmon and steelhead out-migration in the Stanislaus River. Rather, the fish take their cues from increased water flow due to rainfall, as they naturally would have before the many dams on the Stanislaus River were built. In the spring of 2016 about 12,500 juvenile salmon migrated downriver to the sea during April and May, but less than 1 percent migrated during the pulse flow. In years of drought when the lake level is low, releasing water during the spring creates consequences later in the year – because there is not enough cold water left for the autumn spawning run.
In salt ponds, "Alexandrium" population growth rates depend on salinity and temperature. (3) However, in areas like the Bay of Fundy, bloom dynamics depend more readily on the mixing of tidal waters in the open region. In salt ponds, "A. fundyense" migrate vertically down at night, but migrate closer to the surface of the pond during the day. (3) However, they do not migrate too close to the surface to be flushed out with the outflowing surface water. (3) The hydro-geographical barrier and the organism's behavior restrict blooms to occur in neighbouring waters, and thus, result in high concentration of toxicity accumulating in shellfish. (3)
In the North Sea, "P. pileus" makes large daily vertical migrations as do its main copepod prey. They spend the night in upper waters, usually just below the thermocline, descending to deep waters between in the early morning, and rising again in late afternoon. These migrations do not take place in the winter and at this period, "P. pileus" remains close to the sediment, often with a cessation of movement of the combs of cilia. This change in behaviour may be due to the scarcity of prey in the water column at this time of year. When on or near the sediment, this comb jelly is preyed upon by crustaceans such as the hermit crab "Pagurus bernhardus", the crab "Carcinus maenas" and the shrimp "Crangon crangon".
Lewin's rail ("Lewinia pectoralis") is a species of bird in the family Rallidae. It is found in Australia, Wallacea, and New Guinea. Lewin's rail is also known as the water rail, Lewin's water rail, Lewin's grind rail, slate-breasted rail, slate-breasted water rail, pectoral rail, pectoral water rail, short-toed rail and short-toed water rail. Its natural habitat is subtropical or tropical moist lowland forests.
Migration may be influenced by water temperature and sun orientation, which explains the seasonal migration pattern. Southern migration may be influenced by solar orientation and Northern migration may be influenced by the change in water temperature.
Water rails are omnivorous, although they mainly feed on animals. These include leeches, worms, gastropods, small crustaceans, spiders, and a wide range of both terrestrial and aquatic insects and their larvae. Small vertebrates such as amphibians, fish, birds and mammals may be killed or eaten as carrion. Vertebrates are impaled with a strike of the bill which breaks the prey's spinal cord. Plant food, which is consumed more in autumn and winter, includes the buds, flowers, shoots and seeds of water plants, berries and fruit.[19] In south Asia, paddy (harvested rice kernels) may sometimes be eaten.[25] The young rails are fed mainly on insects and spiders. Food obtained on land or from mud is normally washed in water before it is eaten.[19] After rain, rails may probe soft ground for earthworms.[21] This species will occasionally feed in the open even when not forced to do so by cold weather; Edmund Meade-Waldo described seven rails feeding in an open meadow.[42] Despite its skulking nature, the water rail appears to thrive in captivity when fed on animal food such as raw meat or earthworms;[43] one individual was taught to jump for worms suspended from a fishing rod.[33]
Nuchequula gerreoides live in coastal waters in a depth of 10 to 30 meters. They are commonly found in estuaries, which is where the tide of the river meets the sea. Nuchequula gerreoides are demersal fish, which means that they normally live close to the floor in seas or lakes. They periodically migrate from salt water to fresh water, this is a process called amphidromous. Generally, fish that do this migrate for breeding purposes, but the cause of their migration is unknown.
Coastal cutthroat trout use a large variety of habitat types, including lower and upper reaches of both large and small river systems, estuaries, sloughs, ponds, lakes, and near shore ocean waters. They spend more time in fresh water environments than other anadromous Pacific salmonids. In fresh water they prefer deeper pool habitat and cover, such as that formed by woody debris. The semi-anadromous forms of coastal cutthroat trout do not overwinter in saltwater and rarely make extended migrations across large bodies of water. Migrations in the marine environment are usually within of land. Semi-anadromous coastal cutthroat typically spend two to five years rearing in fresh water before making their initial migration into saltwater. Generally, semi-anadromous coastal cutthroat trout spend short periods offshore during summer months and return to estuaries and fresh water by fall or winter.
Axle counters are also useful in instances where there are problems with water on the track. Generally, wheel sensors work under water, as long as the wiring is above the water.
Axle counters do not suffer problems with railhead contamination due to rust, grease or compacted leaf residue. Sometimes a train puts down anti-slip sand to aid deceleration while braking, but the sand contaminates the rail and the track circuit stops working. Axle counters are immune to those problems because they do not rely on the contact of wheel with the rail head to provide an electrical circuit.
The function of a vapor barrier is to retard the migration of water vapor. A vapor barrier is not typically intended to retard the migration of air. This is the function of air barriers. Air is mixed with water vapor. When air moves from location to location due to an air pressure difference, the vapor moves with it. This is a type of migration of water vapor. In the strictest sense air barriers are also vapor barriers when they control the transport of moisture-laden air. It must be mentioned that the designated perm ratings do not reflect the diminished permeability of a given vapor retarder medium when affected by temperature differences on opposing sides of the medium. 
A discussion about the differences between vapor barriers and air barriers can be found in Quirouette.