Pair and extra-pair copulation of Asian openbill storks: Abstract: The copulatory behaviour of Asian openbill stork was observed in the heronry for two years. Atotal of 282 pair copulation attempts (PCAs) and 41 extra-pair copulation attempts (EPCAs) (14.53% of all copulation attempts) were observed among 30 focal pairs. 85% of PCAs and 50% of EPCAs resulted in cloacal contact. Thirteen males (43%) and 21 (70 %) females were involved in EPCAs. There was a correlation between the time that female spent alone on the nest and the occurrence of EPCAs during the presumed fertile period of the female. The incidence of EPCAs observed at Bhitarkanika heronry was greater than reported for the species in other localities, and could be explained by more opportunities for promiscuous behaviour at high densities. Data provided by this study support the conclusion that mate guarding and PC frequency are mechanisms of paternity defense under the sperm competition hypothesis. Introduction: In most bird species considered socially monogamous, extra-pair copulations (EPCs) have been observed, suggesting that among males, EPCs are part of a mixed reproductive strategy (Trivers 1972, Birkhead & M011er 1992). EPCs have been reported for many colonial birds (Gladstone 1979, Fujioka & Yamagishi 1981, Werschkul1982, McKinney et al. 1984, Ramo & Busto 1985, Frederick 1987, Aguilera & Alvarez 1989, McKilligan 1990, but see Tortosa & Redondo 1992). High copulation rates and mate guarding among these birds have been interpreted as paternity defense (sperm competition hypothesis, Birkhead et al. 1987). The aim of this paper is to test two questions of the sperm competition hypothesis under different breeding densities in the Asian openbill storks... ... middle of paper ... ...quency of trips to collect nest materials by males and the number of EPCAs suffered by his mate, neither during preincubation (n = 6, rs= -0.25,P >0.05), nor during erratic incubation (n =12, rs = 0.073, P > 0.05). Conclusion: Our data support the hypothesis of a Mixed Reproductive Strategy (Trivers 1972, Birkhead & Moller 1992) in the Asian openbill stork, since the occurrence of EPCs at Bhitarkanika heronry seems to be a common phenomenon, most of the individuals involved in EPCs were paired, and most of the EPCs occurred during the presumed fertile period of the female. Mate guarding and frequent pair copulation is the main behavioural adaptations to paternity guards. They are an efficient way for males to increase certainty of paternity, although their effectiveness should be assessed by DNA fingerprinting or some similar technique (Birkhead & Moller 1992).
...ed, J. M., Walters, J. R., Emigh, T. E., and Seaman, D. E. 1993. Effective population size in Red-cockaded Woodpeckers: population and model differences. Conservation Biology. 7(2):302-308.
Abstract: The house cricket, Acheta domesticus, was used to test whether food and potential mates drive aggressive behavior. Male crickets were randomly selected in pairs and place into a cage to observe aggressive behaviors in the presence of no food, food, and female. The cage provided a confine area for the crickets to fight one another while the variables of food and female were used in attempts of increasing aggressive interactions between the male crickets. There was no significance found through this experiment due to a lack of data. It was discovered that the experiment would have to be done at a larger scale to be able to see any significance in the two variables.
The Northern White-tailed deer have a polygynous mating system (fcps.edu, nd). Most white tails mate in their second year but it is possible for females to become sexually active after only seven months. The male species are polygamous but may develop an attachment to a doe for several days or weeks. The female species come into heat in November for only twenty-four hours. If the female is not mated she will have a second heat...
Fruteau C, Range F, Noe R. 2009 Infanticide risk and infant defence in multi-male free-ranging sooty mangabeys, Cercocebus atys. Behavioral Processes 83, 113-118
The experiment was conducted to test three different variables. These variables are an assessment of female aggressiveness, food deprivation, and staged male to female interactions. When testing the female aggressiveness, virgin females were run through a latency of attack assay to determine their aggressiveness. The spiders were given 30 seconds and a cricket was dropped in and a measurement was taken of how long interaction occurred between the cricket and the spider. When testing food deprivation, the number of days that female spiders went without food varied and was paired in groups of 1, 3, and 5 days for routine feeding. It was predicted that the longer female spiders went without food, the hungrier they would be. When testing staged male and female interactions, the males were placed in female containers with open lids as an escape route. Each pair interacted for six hours and all pairs resulted in successful copulation, sexual cannibalism, or the male abandons the female’s web. All instances of cannibalism were precopula and occurred shortly after males initiated their courtship sequence. After interaction, the remaining males were taken out the female web and females that cannibalized a male were given 24 hours to feed on the male before being given another male. A female never cannibalized two males consecutively. It was concluded that females that attacked prey more rapidly were more likely to cannibalize their first male mate. There is no detection of an association between cannibalism or food deprivation and female’s body mass. There is a positive association between the mass of egg cases and the number of offspring in females. The study proved that two factor are important in sexual cannibalism, female hunger state and female aggressiveness. There is also a source of fitness benefit for the female.
The female reproductive system in birds is reduced in most species to a left ovary and oviduct. This unilateral reduction of the female reproductive system is thought to bear two benefits: it reduces the female’s body and it prevent the potential problem of simultaneously carrying two large fragile eggs within the abdominal cavity. It also balances the body with the liver on the right side adjacent to the left ovary.
The courting ritual begins with the males circling females in an offshore mating ground and then the males approach and bite a female’s neck and if she accepts, they mate; if she does not accept, she swims to the bottom of the mating grounds (Deurmit L 2007). Males have long claws to use during mating because other males try to remove the mating male in order to mate with the female (Deurmit L 2007). Caretta caretta are polygynandrous and breed seasonally in the early summer (Deurmit L 2007). With mating, the females have the ability to store sperm throughout the reproductive season (Sakaoka K et al.). This characteristic developed with “changes in the sperm storage tubules (SSTs) in the oviduct” and allows the females to reproduce more (Sakaoka K et al.). This storage helps to combat climate change because Caretta caretta, as a species, only breed during certain temperatures (Sakaoka K et al.). Female loggerhead turtles have developed sperm storage abilities within mating to combat climate
Deborah L. Duffy, Yuying Hsu, James A. Serpell ,Applied Animal Behavior Science - 1 December 2008 (Vol. 114, Issue 3, Pages 441-460, DOI: 10.1016/j.applanim.2008.04.006)
...to 300 individuals, the newborn seahorses are independent of parental care and the male is free to fertilize and accept more eggs(Lourie 11). The offspring bearing roles displayed by Hippocampus spp. is an extreme shift in relation to many other species of kingdom Animalia, of which the bearing of young is predominantly carried out by females. According to Foster, growth rates throughout the life cycle and the duration of the life cycle of seahorses in the wild varies between species and cannot be determined due to insufficient research data(foster 22). Once sexual maturity is reached, often determined by the presence of a brood pouch in males, adults are able to reproduce. During reproduction, the overwhelming majority of Hippocampus species display monogamous behaviors, usually mating with the same partner for the duration of the mating cycle(lourie 10-11).
In order to understand the present lifestyles relating to different approaches and tactics applied by humans in mate choice preferences, there is the need to refer to Darwin (1859, 1871) evolutionary perspectives. Darwin (1871) sexual selection is the driving force for males and females reproductive quest for their genes survival. These driving forces have been classified into two categories as intra-sexual and intersexual mate selection.Intersexual selection is male sexual selection process whereby males compete with other males and the females choose the strongest as their ideal partner. Intra-sexual selection occurs when the male species fight among themselves and the strongest gain access to females for
The female red Oophaga pumilios prefers to only mate with red males which leads to speciation. According to GrrlScientist, 4 researchers conducted an 18-month mark-recapture study on this. These researchers captured 677 wild Oophaga pumilios (312 males, 274 females, and 91 juveniles) (GrrlScientist, “Choosy Females Speed Speciation of Poison Dart Frogs.”). When the researchers analyzed the data, they found that 91% of the females mated with red males. With the yellow females, there was no clear pattern on how they mated leaving out that most of the frogs were red. That leaves the frogs that were yellow not being able to breed down. If this was to continue, then the frogs would separate and become different species of different
1These two populations are different species because they have different capabilities of performing in nature. For example there is behavioral isolation. My evidence for that is that in the data, it states that the average time spent in courtship display for the St. Kitts rodent is 12.6 seconds. While the courtship display for the Nevis Rodent is 21.3. You can see that there is a major difference in the way that they behave. Also there is another type of isolation which is gametic isolation. There is gametic isolation because the average gestation time for St. Kitts rodent is 29.3 days. The average gestation for the Nevis rodent is 42.7 days. Therefore a sperm from St. Kitts rodent wouldn’t survive in the reproductive tract of the Nevis rodent. It wouldn’t survive because it wouldn’t develop properly and is not accustomed to its environment. There is also another type of isolation happening with the rodents of St. Kitts. This type of isolation is called temporal isolation. There is temporal isolation because the article states, “the reproductive seasons are being delayed by up to one year.” This is talking about that the rodents are having a hard time finding mates therefore, their reproductive season is being delayed. Also in the article it states, “In the 240 attempts to bring a Nevis animal into the St. Kitts population, you are unable to observe a single successful reproductive event.” The rodents are mechanically isolated, because if you can’t have a reproductive event, there reproductive organs might not be matching with one another. Their appearance might look identical but they are genetically different.
The finch hybrids before the El Niño of 1983, two different species did not mate each other but during the child, a scandens mated with a fortis and produced four fledgings.
del Hoyo, Josep, Andrew Elliott and Jordi Sargatal. Handbook of the Birds of the World. Vol 1, Ostrich to Ducks. Barcelona: Lynx Edicions, 1992.
When the colony becomes well established, the queen begins to lay some eggs that develop into queens and males. It takes a few years before a colony becomes large enough to send out winged males and young queens to start new colonies. The cycle will now begin all over again. Nests come in all shapes and sizes. One tropical species built a nest that extended forty feet below the surface of the ground.