1 ecology, behavior, , life history
1.1 diet
1.2 defenses
1.3 predators
ecology, behavior, , life history
the common name marine toad , scientific name rhinella marina suggest link marine life, adult cane toad entirely terrestrial, venturing fresh water breed. however, laboratory experiments suggest tadpoles can tolerate salt concentrations equivalent 15% of seawater (~5.4‰), , recent field observations found living tadpoles , toadlets @ salinities of 27.5‰ on coiba island, panama. cane toad inhabits open grassland , woodland, , has displayed distinct preference areas modified humans, such gardens , drainage ditches. in native habitats, toads can found in subtropical forests, although dense foliage tends limit dispersal.
the cane toad begins life egg, laid part of long strings of jelly in water. female lays 8,000–25,000 eggs @ once , strings can stretch 20 m (66 ft) in length. black eggs covered membrane , diameter 1.7–2.0 mm (0.067–0.079 in). rate @ egg grows tadpole increases temperature. tadpoles typically hatch within 48 hours, period can vary 14 hours week. process involves thousands of tadpoles—which small, black, , have short tails—forming groups. between 12 , 60 days needed tadpoles develop juveniles, 4 weeks being typical. adult counterparts, eggs , tadpoles toxic many animals.
when emerge, toadlets typically 10–11 mm (0.39–0.43 in) in length, , grow rapidly. while rate of growth varies region, time of year, , gender, average initial growth rate of 0.647 mm (0.0255 in) per day seen, followed average rate of 0.373 mm (0.0147 in) per day. growth typically slows once toads reach sexual maturity. rapid growth important survival; in period between metamorphosis , subadulthood, young toads lose toxicity protected them eggs , tadpoles, have yet develop parotoid glands produce bufotoxin. because lack key defence, estimated 0.5% of cane toads reach adulthood.
as rates of growth, point @ toads become sexually mature varies across different regions. in new guinea, sexual maturity reached female toads snout–vent length between 70 , 80 mm (2.8 , 3.1 in), while toads in panama achieve maturity when between 90 , 100 mm (3.5 , 3.9 in) in length. in tropical regions, such native habitats, breeding occurs throughout year, in subtropical areas, breeding occurs during warmer periods coincide onset of wet season.
the cane toad estimated have critical thermal maximum of 40–42 °c (104–108 °f) , minimum of around 10–15 °c (50–59 °f). ranges can change due adaptation local environment. cane toad has high tolerance water loss; can withstand 52.6% loss of body water, allowing them survive outside tropical environments.
diet
most frogs identify prey movement, , vision appears primary method cane toad detects prey; however, cane toad can locate food using sense of smell. eat wide range of material; in addition normal prey of small rodents, reptiles, other amphibians, birds, , bats , range of invertebrates, eat plants, dog food, , household refuse.
specimen el salvador: large parotoid glands visible behind eyes.
defenses
the skin of adult cane toad toxic, enlarged parotoid glands behind eyes, , other glands across backs. when toads threatened, glands secrete milky-white fluid known bufotoxin. components of bufotoxin toxic many animals; human deaths have been recorded due consumption of cane toads.
bufotenin, 1 of chemicals excreted cane toad, classified class-1 drug under australian law, alongside heroin , cannabis. effects of bufotenin thought similar of mild poisoning; stimulation, includes mild hallucinations, lasts less hour. cane toad excretes bufotenin in small amounts, , other toxins in relatively large quantities, toad licking result in serious illness or death.
in addition releasing toxin, cane toad capable of inflating lungs, puffing up, , lifting body off ground appear taller , larger potential predator.
poisonous sausages containing toad meat being trialled in kimberley (western australia) try protect native animals cane toads deadly impact. western australian department of environment , conservation has been working university of sydney develop baits train native animals not eat toads. blending bits of toad nausea-inducing chemical, baits train animals stay away amphibians. researcher david pearson says trials run in laboratories , in remote parts of kimberley region of wa looking promising, although baits not solve cane toad problem altogether.
predators
many species prey on cane toad , tadpoles in native habitat, including broad-snouted caiman (caiman latirostris), banded cat-eyed snake (leptodeira annulata), eels (family anguillidae), various species of killifish, rock flagtail (kuhlia rupestris), species of catfish (order siluriformes), species of ibis (subfamily threskiornithinae), , paraponera clavata (bullet ants). predators outside cane toad s native range include whistling kite (haliastur sphenurus), rakali (hydromys chrysogaster), black rat (rattus rattus) , water monitor (varanus salvator). tawny frogmouth (podargus strigoides) , papuan frogmouth (podargus papuensis) have been reported feeding on cane toads; australian crows (corvus spp.) have learned strategies allowing them feed on cane toads, such using beak flip toads onto back. opossums of didelphis genus can eat cane toads impunity. meat ants unaffected cane toads toxins, , therefore able kill them. cane toad s normal response attack stand still , let toxin kill attacker, allows ants attack , eat toad.
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