Environmental mating strategy employed by various organisms
Flexible or opportunistic breeders mate whenever the conditions of their environment become favorable. Their ability and motivation to mate are primarily independent of day-length (photoperiod) and instead rely on cues from short-term changes in local conditions like rainfall, food abundance and temperature. Another factor is the presence of suitable breeding sites, which may only form with heavy rain or other environmental changes.[1]
Thus, they are distinct from seasonal breeders that rely on changes in day length to induce entry into estrus and to cue mating, and continuous breeders like humans that can mate year-round. Other categories of breeders that perhaps can be subdivided under the heading "opportunistic" have been used to describe many species, such as many that are anurans like frogs. These include sporadic wet and sporadic dry, describing animals that breed sporadically not always under favorable conditions of rain or lack thereof.[1]
Many opportunistic breeders are non-mammals. Those that are mammals tend to be small rodents.[2]
Since changes in season can coincide with favorable changes in environment, the distinction between seasonal breeder and opportunistic can be muddled. In equatorial climes, the change in seasons is not always perceptible and thus, changes in day length not remarkable. Thus, the tree kangaroo (Dendrolagus) previously categorized as a seasonal breeder is now suspected to be an opportunistic breeder.[3]
Additionally, opportunists can have qualities of seasonal breeders. The red crossbill exhibits a preference (not a requirement) for long-day seasonality, but requires other factors, especially food abundance and social interactions, in order to breed.[4][5] Conversely, food availability by itself incompletely promotes reproductive development.
^ abWE Duellman, L Trueb. Biology of amphibians. The Johns Hopkins University Press, 1994, p. 20
^Malpoux B. The Neuroendocrine Control of Seasonal Rhythms. In: Conn PM, Freeman ME, ed., Neuroendocrinology in physiology and medicine. Humana Press, 1999, p. 437
^Martin R, Johnson P. Bennett's Tree-kangaroo. In: R. Straham, ed., Mammals of Australia, Washington, DC: Smithsonian Institution Press, 1995, pp. 307-8, PMID 16026787
^H.B. Tordoff; W.R. Dawson (1965). "The influence of daylength on reproductive timing in the red crossbill". The Condor. 67 (5): 416–22. doi:10.2307/1365634. JSTOR 1365634.
^T.P. Hahn (1995). "Integration of photoperiodic and food cues to time changes in reproductive physiology by an opportunistic breeder, the red crossbill, Loxia curvirostra (Aves: Carduelinae)". J. Exp. Zool. 272 (3): 213–26. doi:10.1002/jez.1402720306.
and 24 Related for: Opportunistic breeder information
Flexible or opportunisticbreeders mate whenever the conditions of their environment become favorable. Their ability and motivation to mate are primarily...
distinct from opportunisticbreeders, that mate whenever the conditions of their environment become favorable, and continuous breeders that mate year-round...
non-human primates via swelling and redness of the genitalia. Opportunisticbreeder Seasonal breeder Goodbody, I. (1961). "Continuous breeding in three species...
the snowy owl's foods. It is R-selected, meaning that it is an opportunisticbreeder capable of taking advantage of increases in prey numbers and diversity...
between August and January in the south, although budgerigars are opportunisticbreeders and respond to rains when grass seeds become most abundant. Budgerigars...
sea water, which is very rare in mammals. Acomys russatus is an opportunisticbreeder that reaches sexual maturity at approximately 58 days of age. There...
breeding nest is always guarded. The Australian zebra finch is an opportunisticbreeder, initiating reproductive behaviour about one to three months after...
the nest about 35 days after hatching. These parakeets are truly opportunisticbreeders, with pairs choosing to nest when food is plentiful. They nest in...
scuttle backward rapidly instead. The eastern swamp crayfish is an opportunisticbreeder, breeding whenever the vernal pools they inhabit are flooded, usually...
to form new territories whereas females generally stay and are opportunisticbreeders rather than seasonal. The visual apparatus of mice is basically...
call types. Compared to the red crossbill call types, which are opportunisticbreeders throughout most of the year, the Cassia crossbill will consistently...
woodlands, grasslands, open savanna, and agricultural fields. It is an opportunisticbreeder utilizing small, temporary pools, and apparently, streams. The tadpole...
they try to grab at their opponent. African openbill storks are opportunisticbreeders. The species forms monogamous pairs and breeding colonies usually...
Rather than having one set breeding season, cape spiny mice are opportunisticbreeders, only reproducing when they have sufficient food sources. They produce...
is a large bird with black plumage and a red bill. It is a monogamous breeder, with both partners sharing incubation and cygnet-rearing duties. The black...
young emerge completely naked, without any down. Toucans are resident breeders and do not migrate. Toucans are usually found in pairs or small flocks...
and lymphocytopenia before six weeks of age, may be susceptible to opportunistic infection and may die of infection by agents that would not usually...
winter, many journeying as far as South Africa. The common buzzard is an opportunistic predator that can take a wide variety of prey, but it feeds mostly on...
can range in size from 12 to 40 eggs. Desert rain frogs are terrestrial breeders meaning that the eggs develop in a borrow and one of the adult frogs remains...
solitary and do not usually live with other animals. Leopard geckos are opportunistic predators that eat a variety of prey items. Invertebrates are presumed...
food supply and old-growth trees for nesting. The bald eagle is an opportunistic feeder which subsists mainly on fish, which it swoops down upon and...
America in the southern winter; they are the only bird family endemic as breeders to the Antarctic region. They are also the only Antarctic birds without...
the central nervous system is affected. Cryptococcosis is a common opportunistic infection for AIDS, and is particularly common among people living with...
gulls are ground-nesting carnivores which take live food or scavenge opportunistically, particularly the Larus species. Live food often includes crustaceans...