1. Australian Seahorse
Australian Seahorse, scientifically known as Ariidae, is a species of fish that lives in the sea or brackish waters. They are commonly found in warm temperate and tropical waters. This fish typically breeds in September each year. Each breeding cycle, the female seahorse lays 20-65 eggs.
The male Australian Seahorse carries the eggs laid by the female in its mouth to protect them until they hatch. Naturally, it cannot eat anything during this time. The incubation period for the eggs of this fish is usually around 30 days. After the eggs hatch, the male continues to guard the young fish for another 2-4 weeks until they are strong enough. The male closely follows the school of young fish and swiftly sucks them into its mouth to protect them when danger approaches. These fathers also typically refrain from eating during this period for fear of accidentally ingesting the young fish. Thus, the male Australian Seahorse goes without food for nearly two months, demonstrating a remarkable sacrifice.

2. Stickleback Fish
Stickleback Fish, commonly found in freshwater habitats worldwide, is scientifically known as Gasterosteus Aculeatus. Its distinctive feature is the three sharp spines on its back.
The breeding season for Stickleback Fish typically occurs in late April each year. During the breeding season, male fish build nests using aquatic plants. These nests usually have multiple chambers to accommodate eggs from different females. Each nest can contain approximately 40-300 eggs.
After the female fish deposits eggs into the nest, the male fertilizes them and then guards the nest entrance to protect the eggs. Moreover, the male tirelessly pumps water into the nest to supply oxygen to the eggs by fanning its pelvic fins located on both sides. After about 7-8 days, the fish eggs hatch, and the devoted father continues to care for the young until they are strong enough to fend for themselves. The Stickleback father diligently watches over the offspring and herds them into the nest when danger is detected.

3. Darwin's Frog
Darwin's Frog, scientifically known as Rhinoderma Darwinii, is named after the renowned scientist Charles Darwin, who first discovered it. Darwin's Frog inhabits the riverine areas of Chile and Argentina.
During reproduction, the female frog typically lays around 40 eggs onto the moist leaf litter of the forest floor. The male frog stands guard until the embryos develop, which takes about 3-4 weeks. It then ingests these embryos into a special pouch located in its throat. After three days, tadpoles emerge. The male frog continues to hold the tadpoles in the pouch until they are fully developed, becoming healthy froglets. During their time in the pouch, the tadpoles are nourished by nutrients secreted by the pouch lining. Once the froglets are ready to fend for themselves, the father frog 'vomits' them out through its mouth.

4. Emperor Penguin
Emperor Penguins, scientifically known as Aptenodytes Forsteri, inhabit the seas of the Antarctic and are the largest species of penguin. They breed during the winter months of the Southern Hemisphere, typically from March to April each year. They are monogamous birds, forming lifelong pairs.
After pairing, the female penguin lays a single egg, which is then transferred to the male for incubation. The female sets off to sea to forage for food shortly after laying the egg. Due to the considerable distance between the nesting site and the feeding grounds, the female may take up to two months for the round trip. The male penguin incubates the egg on its feet, balancing it carefully while standing on the ice. This process requires meticulous care, as any contact with the icy surface could be fatal for the developing chick inside the egg. The incubation period for Emperor Penguin eggs is approximately 64 days. If the female has not returned by the time the chick hatches, the male penguin secretes a nutrient-rich substance from its esophagus to nourish the chick.
During the prolonged waiting period of two months, the male penguins huddle together to conserve warmth and shield themselves from the harsh winds. It is estimated that each male penguin may lose up to 20 kilograms in weight due to hunger and exposure to temperatures as low as -40 degrees Celsius and winds reaching speeds of up to 200 kilometers per hour. Upon the female's return, the male transfers the chick to her care, and they take turns caring for the chick and foraging for food.

5. Giant Water Bug
Giant Water Bugs, scientifically known as Indentatus Abedius, are the largest species of bugs living in freshwater environments. They can grow up to 12cm in size, making them one of the largest bugs in the world.
During the breeding season, to protect the eggs, females lay them onto the back of males, with each female laying around 30-100 eggs. The male carries these eggs until they hatch, which usually takes 1-3 weeks. During this time, the Giant Water Bug males face many dangers as they are unable to fly and are vulnerable to attacks from other species.
Despite carrying such a burden, the water bug fathers do not abandon their offspring. Scientists have observed nurturing behaviors in male water bugs, such as cleaning the eggs, sunning them for drying, and removing parasites from them. After all the eggs have hatched, these fathers discard the remaining eggshells, find a mate, and begin a new reproductive cycle.

6. Wattled Jacana
Wattled Jacana, scientifically known as Irediparra Gallinacea, is a species of water bird. It is also known as the 'Jesus bird' due to its ability to walk on water. More precisely, this bird can walk on the surface of aquatic plants like lilies or reeds thanks to its long legs and toes that help distribute weight. The Wattled Jacana primarily inhabits tropical regions.
Similar to the Grebe bird, male Jacanas are responsible for nest building, egg incubation, and chick care. However, male Jacanas are somewhat luckier than their Grebe counterparts because Jacana mothers take on the responsibility of nest guarding instead of abandoning them like Grebe sisters. Male Jacanas also have a special skill of hiding chicks under their wings when they detect danger (you can observe this behavior in the accompanying video). It can be said that in the Jacana water bird species, the roles of males and females have been swapped.

7. Horned Owl
Horned Owls are large owls native to Africa, later introduced to North America and now thriving in Asia as well. The scientific name of this owl species is Bubo Virginianus. Horned Owls typically breed from October to December each year. They are also monogamous birds, mating for life.
During the breeding season, the male owl will build a nest in tree hollows or utilize nests abandoned by other bird species. The female owl will choose a mate based on these nests. After pairing, the female owl will lay eggs and remain in the nest to incubate them. Each female owl can lay an average of 2 eggs, and the incubation period is around 28-37 days. During this time, as the female owl does not leave the nest, the male owl takes on the responsibility of hunting for both of them.
Because female owls are typically larger, male horned owls must hunt 1.5 times more prey than usual. It's truly a demanding job.

8. Phalarope Bird
Phalarope Bird, scientifically known as Phalaropes, is a waterbird species inhabiting the polar regions. The average body size of phalaropes is 18 - 19 cm, with a wingspan of 31 - 34 cm. They have black, pointed bills and black legs with webbed feet. This characteristic enables them to swim exceptionally well in aquatic environments. In this species, females are typically larger and brighter in color than males.
During the breeding season, the male phalarope builds nests on grassy bushes near rivers or lakes. After laying eggs, the female leaves to find another mate while the male takes on the responsibility of incubating the eggs and caring for the hatchlings. The incubation period for this bird species is about 20 days, and each female can lay up to a maximum of 4 eggs.

9. Seahorse
Seahorses, scientifically known as Hippocampus, inhabit shallow seas and are widely distributed across the world. They are perhaps the most unique creature on this list because it's the males that bear the burden of pregnancy, not the females.
Male seahorses have a pouch, similar to a uterus, on their abdomen that functions just like a womb, providing oxygen and nutrients to the developing offspring. During the breeding season, after pairing up, female seahorses deposit their eggs into this pouch. The eggs are fertilized and nurtured until the seahorse offspring fully develop, which takes about 10-30 days. After this period, the male seahorse 'gives birth' by contracting its abdominal muscles. Each pouch can hold anywhere from 10-300 offspring depending on the seahorse species. Truly, they are remarkable fathers.

10. Lumpfish
The Lumpsucker fish is scientifically known as Cyclopterus Lumpus. It's a fish species with an adorable appearance. They have a small suction cup under their belly to cling to rocks or coral reefs on the seabed. This fish species thrives in cold waters of the Arctic, North Atlantic, and North Pacific. They typically breed from June to December each year.
During the breeding season, male lumpfish seek shallow waters to prepare nests. Lumpfish nests are usually situated amidst narrow rock crevices. Once the nests are ready, females come to choose their preferred nest to deposit eggs. Each female can lay from 100,000 to 350,000 eggs. This is a 'quantity over quality' strategy, where more eggs increase the chances of offspring survival.
After laying eggs, female fish leave the nest. As for the male lumpfish dads, their task is to guard the nest until the eggs hatch. They use the suction cup under their belly to anchor themselves next to the nest and keep watch. Besides protection, these dads also have to continuously supply oxygen to the eggs by fanning water into the nest using their fins. It's indeed a challenging job, but these fish dads must feel immensely happy when they see their offspring hatching healthy.

11. Namaqua Sandgrouse
The Namaqua Sandgrouse scientifically known as Pterocles Namaqua, inhabits the arid lands located in southwestern Africa. Despite being called sandgrouse, the Namaqua's appearance resembles that of a bird more than a chicken, and it's also capable of flying quite well. A distinctive feature of the Namaqua sandgrouse is the white ring of feathers around its neck. Namaqua sandgrouse is a highly social species, enjoying congregating in flocks and frolicking in waterholes.
The breeding season of Namaqua sandgrouse depends on rainfall as they require water to nurture their offspring. During the breeding season, male sandgrouse build nests with dry leaves or grass in burrows. Each female lays 2-3 eggs. The incubation period is about 22 days. Female sandgrouse incubate the eggs during the day, and at night, it's the male's turn. After the chicks hatch, the pair of sandgrouse jointly nurture them.
The male Namaqua sandgrouse also plays a crucial role. It provides water for its mate and offspring. Every day, the Namaqua dad flies to find waterholes, immerses itself in them to soak water into its special chest feathers, and brings water back for its chicks. Because water is scarce in arid areas, sometimes, the male sandgrouse has to fly up to 80km a day to find water.

12. South American Rhea
South American Rheas, scientifically known as Rhea, are mainly distributed in countries within the South American region. They are medium-sized birds, not as large as African ostriches, nor as small as Australian emus.
In this species of rhea, each male usually has from two to twelve wives, jokingly referred to as a polygamous lifestyle. During the breeding season, males gather dry grass and leaves to build nests. Nests of South American rheas are quite large, capable of holding from 10 to 60 eggs. The reason males build such large nests is that all of their wives will lay eggs in the same nest. After the female rheas lay eggs, these rhea dads will chase the wives away and then proceed to incubate the eggs and care for the hatchlings themselves. Eggs typically hatch after about three days of incubation. Thus, for the South American rhea species, the male has taken on all the roles of nurturing the future generation.

