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.
Opportunistic breeders are typically capable of breeding at any time or becoming fertile within a short period of time. An example is the golden spiny mouse where changes in dietary salt in its desert habitat due to rainfall appear to cue reproductive function.[6] Increased levels of salinity in drying vegetation cause females to experience a reproductive hiatus.
While reproduction is generally independent of photoperiod, animals can still experience reduced fertility with changes in day-length.
^ 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
^ abMartin 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.
^ abU. Shanas; A. Haim (2004). "Diet salinity and vasopressin as reproduction modulators in the desert-dwelling golden spiny mouse (Acomys russatus)". Physiology and Behavior. 81 (4): 645–50. doi:10.1016/j.physbeh.2004.03.002. PMID 15178158. S2CID 8150833.
^Hugh Tyndale-Biscoe (22 April 2005). Life of Marsupials. Csiro Publishing. pp. 342–. ISBN978-0-643-09921-0.
^Wayne NL, Rissman EF (1990). "Environmental regulation of reproduction in an opportunistic breeder: the musk shrew (Insectivora: Suncus murinus)". Prog. Clin. Biol. Res. 342: 668–72. PMID 2381955.
^Fleming, P. A., and S. W. Nicolson. "Opportunistic breeding in the Cape spiny mouse (Acomys subspinosus)." African Zoology 37.1 (2002): 101-105.
December 07, 2023
opportunistic, breeder, flexible, opportunistic, breeders, mate, whenever, conditions, their, environment, become, favorable, their, ability, motivation, mate, primarily, independent, length, photoperiod, instead, rely, cues, from, short, term, changes, local,. 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 Contents 1 Physiology 2 Partial list of opportunistic breeders 2 1 Mammals 2 2 Birds 2 3 Amphibians 3 See also 4 ReferencesPhysiology editOpportunistic breeders are typically capable of breeding at any time or becoming fertile within a short period of time An example is the golden spiny mouse where changes in dietary salt in its desert habitat due to rainfall appear to cue reproductive function 6 Increased levels of salinity in drying vegetation cause females to experience a reproductive hiatus While reproduction is generally independent of photoperiod animals can still experience reduced fertility with changes in day length Partial list of opportunistic breeders editMammals edit Golden spiny mouse 6 Red kangaroo 7 Tree kangaroo 3 Musk shrew 8 Cape spiny mouse 9 Birds edit Zebra finch Crossbill Budgerigar Princess parrot Blue footed boobyAmphibians edit Frogs and toads including Long thumbed frog Southern spadefoot toad Scaphiopus African clawed frog Fowler s toadSee also editopportunistic feeder opportunistic infectionReferences edit a b WE 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 a b 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 a b U Shanas A Haim 2004 Diet salinity and vasopressin as reproduction modulators in the desert dwelling golden spiny mouse Acomys russatus Physiology and Behavior 81 4 645 50 doi 10 1016 j physbeh 2004 03 002 PMID 15178158 S2CID 8150833 Hugh Tyndale Biscoe 22 April 2005 Life of Marsupials Csiro Publishing pp 342 ISBN 978 0 643 09921 0 Wayne NL Rissman EF 1990 Environmental regulation of reproduction in an opportunistic breeder the musk shrew Insectivora Suncus murinus Prog Clin Biol Res 342 668 72 PMID 2381955 Fleming P A and S W Nicolson Opportunistic breeding in the Cape spiny mouse Acomys subspinosus African Zoology 37 1 2002 101 105 Retrieved from https en wikipedia org w index php title Opportunistic breeder amp oldid 1170882279, wikipedia, wiki, book, books, library,
