# data[].attributes.body
Many tropical species use subtle changes in day length (photoperiod) to anticipate seasons and use short-term cues, such as rainfall or fruit abundance, to initiate, for example, gonad growth. Spotted Antbirds, for instance, begin growing their gonads during the dry season, roughly six weeks before the rains start, to align with food availability.

# data[].attributes.body
Advantages

allows animals multiple opportunities to rear young, if animals fail to raise offspring one year they can try again the following

allows animals to gain experience

# data[].attributes.body
In polar environments, offspring often rely on their caregivers for warmth, food, and other resources. Emperor Penguins (Aptenodytes forsteri) guard their offspring as eggs and for around 5-6 months after hatching, during that time they protect their chicks from adult aggression, predation and severe weather.

# data[].attributes.body
Can be triggered by rainfall, fruit availability, sunlight, or extreme weather such as storms

# data[].attributes.body
Plants - wind pollination, perennial lifecycle, seed bank persistence, rapid seed production for annuals/biennials, grazing-induced flowering, & photoperiodic regulation.

Animals - seasonal breeding, opportunistic breeding, precocial & large young, burrowing & hiding offspring, & mobility/migration.

# data[].attributes.body
Tropical reptile eggs, such as those of the keelback snake, require specific, high-moisture environments. Females adapt by nesting shortly after monsoonal rains, when soil moisture is optimal for incubation, avoiding waterlogged or too-dry soil.

# data[].attributes.body
advantages

increases chances of offspring development

disadvantages

consumes large amounts of the mothers resources during development

can limit feeding and behaviour of the mother

# data[].attributes.body
In environments with harsh, distinct dry seasons (like seasonally dry tropical forests), some mammals have adapted by delaying embryo implantation to ensure that the birth of their young coincides with the rainy season, when water and food are plentiful.

# data[].attributes.body
The phenology of den building is also negatively impacted by climate change - den building typically occurs in May and June to synchronize with peak prey availability, however due to climate change the phenology of many prey species has changed, meaning they influx in prey does not synchronize with the den building season, impacting the reproductive successes and survival of polar bears.

Furthermore, increased temperatures caused by climate change can make it difficult for female polar bears to create stable dens, leaving the cubs exposed to severe weather and predators.

# data[].attributes.body
Common in corals, many fish, sea urchins, molluscs

Males and females release eggs and sperm directly into the water column

Fertilisation occurs externally

Often synchronised by moon cycles,

temperature, or chemical cues

Advantages

Produces huge numbers of gametes

Increases genetic mixing

No need to find a mate physically

Limiting factors

Very low survival rate

Gametes can be diluted or eaten

Offspring receive no parental care

# data[].attributes.body
The main environmental triggers are temperature, soil moisture, food/nutrient availability, and photoperiod (day length)

# data[].attributes.body
For example fruit-eaters such as primates may time births with peak fruit season. High quality food helps with lactation and weaning takes place while food is abundant. Ring tailed lemurs are more likely to birth twins in especially good seasons.

# data[].attributes.body
Female krill can lay as many as 10,000 eggs at a time. They have been known to give birth several times during the spawning season (Jan-March). Females spawn their eggs near the surface, which then sink in the ocean over a 10-day period before hatching.

Krill make for an easy target for large prey such as baleen whales, which take in an enormous amount of water and filter the krill through its baleen plates. With such high fecundity, Krill numbers can remain stable, even when predation risk is high.

# data[].attributes.body
Some tropical rodents exhibit a strategy where they attempt to breed year-round, but only succeed in producing young during the wet season. During the dry season, females may experience implantation failures or reabsorption of embryos due to food scarcity.

# data[].attributes.headline
Induced Ovulation in Polar Bears (Ursus maritimus)

# data[].attributes.subject
Induced Ovulation in Polar Bears (Ursus maritimus)

# data[].attributes.body
Females often travel alone and may not encounter a male during a specific time frame, induced ovulation ensures eggs are not wasted. This reproductive mechanism increase the chances of successful fertilization in low-density, solitary populations.

# data[].attributes.body
provides the advantage of allowing both parents to care for the egg, allowing th3 mother to feed. whether as with viviparous species when resources are limited the young are not developing inside the mother using energy that would be required for survival. This allows for the survival of parents even if offspring are lost before birth.

increased risks of offspring failing to develop, at risk to the abiotic factors

e.g. penguins

# data[].attributes.body
Such as the frog moving tadpoles to different bromeliads and feeding them, a strategy for dealing with high competition and predation

# data[].attributes.body
Releasing thousands of eggs for external fertislisation

Synchronising mating with lunar or seasonal cues

Some hermaphroditism and sex change to cope with low population density

Some mammals use internal fertilization and long-term parental investment

Migratory breeding for optimal environments

# data[].attributes.body
Extreme temperatures - low winter temperatures are a primary constraint on growth & winter survival. Cold acclimation reduces carbohydrate availability, creating a trade-off that limits the energy available for growth & subsequent reproduction.

Water availability - droughts limit seedling establishment & can cause high mortality of seeds & young plants.

Light limitation - high density of plants can lead to severe competition for light, which restricts the growth & reproductive capacity of smaller, less competitive plants.

# data[].attributes.body
Limiting factors

Heat

Food availability

Water availability

Environmental triggers

Seasons

Rainfall

Humidity

Reproductive strategies

Synchronised reproductive - some species have reproductive cycles that coincide with availability of food and water. Camels demonstrate this strategy

Rapid reproduction - species will have short cycles of reproduction. Kangaroo mice demonstrate this strategy

# data[].attributes.headline
Limiting factor - nutritional stress in Polar bears

# data[].attributes.subject
Limiting factor - nutritional stress in Polar bears

# data[].attributes.body
Inadequate nutrition due to limited food availability can cause a delay in female polar bears reaching sexual maturity. This can impair the polar bear's reproductive physiology, leading to lower ovulation rates and smaller litter sizes.

# data[].attributes.body
In the open ocean, many marine species time their reproduction to environmental cues that boost the survival of their drifting eggs and larvae. Changes in water temperature can trigger spawning by influencing hormonal cycles, while shifts in currents, food availability, and overall ocean conditions help ensure that larvae are released when they have the best chance of finding food and avoiding predators. For example, many open‑ocean fish such as mackerel spawn during seasonal warming, when rising temperatures and plankton blooms create ideal conditions for their pelagic larvae to survive and grow.

# data[].attributes.body
Some insects (for eg. butterflies) use diapause to pause egg production during the dryer season, allowing them to stay active during 'poorer' conditions

# data[].attributes.body
Many species rely on "capital" (stored energy) rather than immediate "income" (food intake) to fuel reproduction, resulting in lower frequency of breeding but higher investment per offspring. This is commonly seen in snakes

# data[].attributes.body
Dioecious refers to species that have distinct single sex individuals, producing either male or female gametes. In animals, sometimes called gonochory. Only the female members of the population produce offspring. It reduces the recessive deleterious mutations by using cross-fertilisation.

# data[].attributes.body
Spontaneous ovulators are mammals that release eggs at regular intervals due to hormonal changes, independent of sexual activity.

Unlike induced ovulators, they do not require mating to trigger ovulation. This process is common in humans, primates, rodents, and most domestic farm animals, allowing for pregnancy to occur at specific times.

# data[].attributes.body
Iteroparity is defined as a reproductive strategy where an individual can reproduce multiple times throughout its life cycle, contrasting with species that reproduce only once (semelparity).

Iteroparity allows animals to reproduce multiple times throughout their lives, leading to more flexible population dynamics and enhancing the survival rate of their offspring.

This strategy is common in stable environments where adult survival rates are high.

Almost all mammals are iteroparous, as well as birds and most reptiles.

A specific example is African Elephants, were females start reproducing around age 10 and have a calf every 4 years.

# data[].attributes.body
Species in which the act of copulation stimulates the release of ova, rather than on a regular, spontaneous cycle. This mechanism ensures that eggs are released only when sperm is present, maximizing breeding efficiency.

In domestic ferrets (Mustela putorius furo) an unmated jill will remain in a prolonged estrus, which can lead to dangerously high estrogen levels.

# data[].attributes.body
The ability of an animal to produce a large number of offspring in a short period of time.

Measured as the number of individual offspring per reproductive event.

E.g. mola mola can release up to 300 million eggs in a single spawning event.

# data[].attributes.body
It is a reproductive strategy in which the development of an embryo is stopped temporarily. This delays implantation until the outside conditions become more safe for the survival of the young.

This method allows animals to coincide the birth of their young with better environmental conditions so they are born having the best chance at survival as it is not worth the adults energy to spend energy growing young for them to not be able to thrive because they cannot find food.

Examples: Bears (Pause pregnancy until winter which allows them to condition themselves to give birth in spring), Marsupials, Roe deer (Implantation occurs in January but they mate in August).

# data[].attributes.body
A reproductive strategy where as organism invests all its available resources into a single, massive, and highly fecund reproductive event - followed by death. Essentially a “big bang” approach, driven by high environmental risk or low adult survival prospects, ensuring maximum reproductive output in one go.

Examples: Pacific salmon, Atlantic eel, Broad-footed marsupial mouse.

# data[].attributes.body
Parental investment to increase the fitness of the offspring. This varies among animals from no parental care to prolonged care. Parental care can include protection, providing food and shelter, and teaching skills to the offspring.

# data[].attributes.body
Biological condition where an organism possesses both male and female reproductive organs, capable of producing both eggs and sperm. Can practice self fertilisation and cross-mating. Common in invertebrates such as snails and worms.

# data[].attributes.body
Sequential hermaphroditism is a reproductive strategy in which an organism changes sex during its lifetime, functioning first as one sex and later as the other. It produces either male or female gametes at different stages, not both at once.

Example:

A classic example is the clownfish. Clownfish live in social groups with one dominant female.

If the female dies, the dominant male changes sex and becomes the new female.

# data[].attributes.body
A reproductive strategy where the sperm stays within the female’s reproductive tract for extended periods of time after copulation. This is common in insects, birds and reptiles to ensure fertilisation success. Females can control sperm usage by storing a selection of sperm from different males, females can then choose which sperm to fertilise their egg/s

# data[].attributes.body
Viviparous species give birth to live young. For example, all mammals. Some reptiles such as the common lizard (Zootoca vivipara) are also viviparous.

# data[].attributes.body
Producing young by the means of eggs which are hatched after being laid by a parent (as in birds)