When do animals mate

Infant mortality rates shoot up when a drought or other environmental factors deprive the species of the seasonal foods they planned on having for their offspring, says Emery Thompson. And big primates like great apes and humans are, well, big.

Raising these babies takes a lot more energy for a prolonged period — like breast-feeding for years at a time. In these cases, it's too hard to stick to just one of the typical approaches to rearing offspring.

Humans — and fellow large primates — are more likely to tie pregnancy to our personal ability to support a child, as well as the abundance of available resources. Research with hunter-gatherer communities has found that births swell in times of high food availability. But the rhythms have more to do with when mothers can nurture their infants best — rather than an innate drive to reproduce at that time.

Additionally, humans live all around the world in a huge range of climates and nourish themselves with a wide variety of foods. But decoding what internal biological processes set us up for child rearing is challenging to figure out. On the whole, human reproductive systems are very sensitive to change. Both obesity and being underweight can tamper with fertility , and intense exercise can inhibit periods or ovulation , too.

Beyond that, we generally struggle to get pregnant compared with other primates. For those species, it might take two to three menstrual cycles for conception — in humans, the average is six, Emery Thompson says. Our societal structures let us have kids in succession faster than our other relatives.

Energy-dense foods, like those with lots of oils and fats, give us the calories we need to produce breast milk all in a few bites.

Most women of childbearing age ovulate regularly and menstruate to shed the uterine lining if an egg is not fertilized, and do not require physiological processes to prompt sexual activity. However, people still share some of the same behaviors seen in other primates — even if we don't recognize the vestigial cues. The similarities in courtship patterns between humans and nonhuman primates stems from our shared social behavior ancestry, says Dr.

Jacqueline Prime, founder of the environmental nonprofit Prime Earth and a wild gibbon researcher. Touch and vocal communications help us solidify our bonds as individuals who get along with each other.

Humans aren't really different from any other non-human primate on this, we just have different styles and ways of doing things. Even with plenty of evidence to the contrary, the concept of a mating season may still be in play for humans, although few people would recognize it as such.

Among the nomadic Turkana in northwest Kenya, more than half of all births occur in spring, from March to June. It's a phenomenon experts attribute to the harsh environment, when an influx of food leads results in high conception rates.

In addition to nutritional peaks, humans' hidden mating seasons may also be influenced by factors as varied as environmental and social factors. According to a study published in the Journal of Reproductive Rhythms, when the sun shines for about 12 hours a day and the temperature stays between 50 and 70 degrees Fahrenheit 10 and 21 degrees Celsius , women are more likely to ovulate, and men tend to produce more sperm.

And findings published in the Journal of Human Reproduction showed that married, educated women aged 25 to 34 in the Czech Republic have strong seasonal ties to reproduction, with most giving birth in the spring.

Meanwhile, women in the study who were younger than 19 or older than 35, unmarried and with low education levels, were more likely to give birth at no particular time of year. The Diversity of Behavior. How Does Social Behavior Evolve? An Introduction to Animal Communication. Animal Behavior Introduction. Mating Systems in Sexual Animals. Measuring Animal Preferences and Choice Behavior. Perceptual Worlds and Sensory Ecology. An Introduction to Eusociality. The Ecology of Avian Brood Parasitism.

Social Parasitism in Ants. Causes and Consequences of Biodiversity Declines. Disease Ecology. Animal Migration. Sexual Selection. Territoriality and Aggression. The Development of Birdsong. Krasnec, Chelsea N. Citation: Krasnec, M. Nature Education Knowledge 3 10 One of the most fascinating aspects of human life is how we choose our mates. Animals also choose their mates, sometimes with a great deal of care. Mating systems are important to understand because they reflect the result of natural selection on mate choice, and ultimately on strategies for maximizing individual reproductive success.

Aa Aa Aa. Social monogamy is the behavioral pairing of a single male with a single female. It is most common in birds and rare in other animals Figure 4. Theoretically, individuals in monogamous pairs will both contribute to the defense and parental care of offspring.

Choosing an inappropriate mate could have a high fitness cost see the sections above for more on mate choice. Because the costs of poor mate choice in monogamous species can be so high, in some instances organisms engage in strategies of either serial monogamy or extra-pair copulations. Extra-pair copulations are very common in birds Petrie et al. Monogamy reduces the potential for genetic variation among a female's offspring. By mating with more than one male over the course of her lifetime, a female gains higher genetic variation among her offspring.

The benefits of monogamy, which are shared parental care and territorial resources, are maintained by having only one mate at a time, or by concealing extra-pair partnerships. Polygyny is the association of one male with multiple females. This mating system is found in a few birds and insects, but is most common in mammals. Polygyny is a strategy used by males to increase their reproductive fitness.

Resource Defense Polygyny. In resource defense polygyny , groups of females are attracted to a resource — males then compete for territorial possession of the resource, and, by extension, mating priority with females at the resource Beletsky Thus, individual males form territories centered on resources needed for successful mating McCracken Another common type of polygyny is membership in a harem , a defended group of females associated with one male.

Females may initially associate in a harem for group defense, or they may be herded together by a male. Males compete for control of the groups. Harems typically exhibit a dominance hierarchy among the females in the group.

A lek is an aggregation of males that are each seeking to attract a mate. Within a lek, males typically perform sexual displays. Unlike most other mating systems, leks are not associated with resources. Aggregations of males may be near particularly attractive females or in areas where females are likely to travel Lank et al. It is thought that males form leks because they attract more females than do isolated males. Attracting more females is a strategy used by males to help increase their reproductive success.

Polyandry is a group with one female and many males. Polyandry is a reproductive strategy that helps a female ensure reproductive success by providing her with multiple mating options. Resource Defense Polyandry.

In the Spotted Sandpiper, females control resources, which in turn controls male mating associations Oring et al. Cooperative Polyandry. The Galapagos hawk exhibits cooperative polyandry. In this case all males in the group copulate with the female and all participate in brood provisioning Fabborg et al.

Some mating systems have looser male-female bonds within groups. In polygynandrous groups, multiple females and males mate with each other, and males may care for the broods of several females.

Chimpanzees and bonobos rely on this strategy — it allows groups of males and females to live together and spend less time being concerned with mate competition. Polygynandry may be advantageous from the female's perspective because it causes paternity confusion, which decreases infanticide and allows her to have multiple males care for her brood Hrdy , In promiscuity there are no pair bonds, and males and females, although sometimes choosy, often seem to mate randomly.

As it is typically more advantageous for one or both sexes to pick their mate, promiscuity may occur in species for which the environment is unpredictable Birkhead , Burton Sperm Competition. Conclusions To transfer their genes to the next generation successfully, animals need to choose a suitable mate.

Failure to do so leads to low or no reproductive success — that is, poor fitness. But reproductive success can also hinge on the number of mates, and on social interactions that extend beyond mating. By classifying social interactions, scientists have been able to identify different types of mating systems, such as monogamy and polygyny.

The mating systems described in this article represent a variety of strategies to achieve reproductive success. The diversity of mating systems in animals is a fascinating example of the incredible variety of solutions that a complex evolutionary problem can yield.

References and Recommended Reading Aspbury, A. Behavioral Ecology and Sociobiology 36, Fisher, H. The Woman That Never Evolved. Lank, D. Genetic polymorphism for alternative mating-behavior in lekking male ruff Philomachus pugnax.