Can you guess who laid these eggs?

Hope you’re all having a happy Easter break! I thought this week’s post could be something a bit different and hopefully fun!

Below are 10 unlabelled pictures of animal eggs. But can you guess their mothers?

Some are more difficult than others, but quite frankly they’re all pretty difficult, haha! When you’ve guessed them all, scroll down for the answers and some interesting facts about the species responsible!

Hint: they’re not all birds 🙂 .

THE EGGS:

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10.

THE ANSWERS:

1. Crocodile

Crocodiles lay 10 to 60 eggs at a time. The hatchlings will stay in their eggs for 55 to 110 days. Crocodile embryos do not have sex chromosomes, and so their sex is not determined by genetics. Instead, sex is determined by temperature, where at 30 °C (86 °F) or less most hatchlings are females and at 31 °C (88 °F), offspring are of both sexes. A temperature of 32 to 33 °C (90 to 91 °F) gives mostly males. Above 33 °C (91 °F), some species continue to give males, but other species result in females, which are hence called high-temperature females.

2. Emu

The Emu is native to Australia and is the second largest bird in the world after the Ostrich. The eggs turn a turn shade of green (pictured above) over the eight weeks that they are incubated. It is the male Emu that does the incubating. During this time he doesn’t eat, drink or defecate, and will lose a third of his body weight. He only moves to turn the eggs around 10 times a day.

3. Port Jackson Shark

Juvenile Port Jackson Sharks, called pups, are about 25 cm long when they hatch. The egg case is soft when laid by the female. She uses her mouth to wedge the egg case into a rock crevice where it then hardens. Then the pup emerges after ten to twelve months! Sharks can be oviparous ( laying eggs like the Port Jackson Shark), viviparous (giving birth to live young such as the Blue Shark), or ovovivaparous (producing eggs which stay and hatch inside the female with no placental connection), such as the Grey Nurse Shark.

4. American Robin

The blue colour in American Robin eggs is due to a pigment called biliverdin. There is some evidence that higher biliverdin levels indicate a healthier female, and therefore brighter coloured eggs. Eggs that are a brighter shade of blue encourage males provide higher quality care for their young.

5. Atlantic Salmon

Most Atlantic salmon are anadromous, meaning they feed and grow in salt water for most of their lives, but then return to spawn in freshwater streams. Adult female salmon can deposit from 600 – 800 eggs per ~500g body weight. The eggs are usually a pale orange colour, and measure about 5 – 7 mm in diameter.

6. Kiwi

The Kiwi lays the biggest egg in comparison to body size. Ostrich eggs are just 2% of their body weight. Whereas the kiwi egg takes up about 20% of the mother’s body. To put that into perspective, a human’s baby is only about 5% of it’s mothers body size. Ouch.

But by laying such a large egg, the Kiwi’s egg has 65% yolk (most birds are 35%) . This means the chicks that hatch are fully feathered and independent, and can provide for themselves. Meaning Kiwi parents rarely have to feed their chicks [1].

7. Great Crested Newt

Great Crested Newts are the biggest newt species in the UK and have been around for approximately 40 million years! They have light coloured eggs which are surrounded by a jelly capsule around 4.5-6 mm across. Adult newts emerge from their overwintering sites in spring and head to a pond to breed. At the pond, the males perform an elaborate courtship dance before the eggs are laid. Females lay individual eggs on aquatic plant leaves and carefully wrap them up to protect them.

8. Bee Hummingbird

The smallest bird in the world. With the smallest eggs in the world. Bee Hummingbirds take their name from their teeny tiny bee-sized bodies. Their nests are also tiny, with a diameter of <2.5 cm ! Females will lay 1 or 2 eggs per year.

9. Duckbill Platypus

The only mammal on the list and the only egg laying mammal in the world, of course, I couldn’t not include it! Male Platypus take no part in rearing the young. Females build nursery burrows, in which they will lay two small leathery eggs. Gestation lasts 2-4 weeks, and incubation of the eggs takes another 6 to 10 days. Once hatched, the young suck milk from special mammary hairs and stay inside the burrow where they are protected. After 3 to 4 months they become independent.

10. Swan

Pairing for life, both the male female swan take care of their cygnets. The average number of eggs produced by a pair of Mute Swans is about six. The clutch size also varies depending on how late in the season the eggs are laid. Once the cygnets hatch, they live with their parents for 6-9 months.

Did you guess any correctly? If you did, I’ll be very impressed! Let me know in the comments section below!