Dolphins

I have spent many, many hours watching dolphins with my aunt, both from the beach and from a boat. Seeing them up close or from afar brings a sense of joy. I never asked her why she loved them, I just accepted that she did and joined her in that love. Whenever I see a dolphin, my first thought is always of her.

Perhaps she loved dolphins because they are intelligent creatures. Not only do they have excellent problem-solving skills, they’ve been known to use tools. In addition, different pods have created innovative ways to hunt, showing both intelligence and incredible teamwork. They also have a sophisticated communication system that includes a variety of squeaks, clicks, and whistles. Dolphins use this language for communicating with one another, and like bats they use the sounds for hunting. This tells the dolphins the size, shape, and location of their prey.

Dolphins also like to have fun. While jumping out of the water is sometimes to get a better view of their surroundings, it’s oftentimes because of their playful nature. They will surf in the wake of a boat too, leaping and diving in the waves. Some dolphins even know certain boat schedules and sounds, and will appear when the boat takes off. Dolphins also like to play with objects. Because of their social and curious nature, they will even play with people.

But maybe my aunt loved dolphins because play, work, travel, and explore widely…and they do it together.

Bat Appreciation

April 17 is International Bat Appreciation day. Why take a day to appreciate bats? Because bats are often baselessly feared and vilified. Yet armed with a little knowledge, I think everyone can come to appreciate them.

Juvenile Mariana Fruit Bat, Photo Credit: Anne Brooke USFWS

Bats are Earth’s only flying mammals and there are over 1,400 different species, with 40 species in the United States. They can live to be 100 years old. Many species can fly at over 60 miles per hour; the Brazilian free-tailed bat was clocked at over 100 mph! As you probably know, they use echolocation to find their food.

But here’s where the appreciation should really kick in. Bats eat pest insects. A lot of them. Some species will eat 1,200 mosquitoes in an hour throughout the night. For farmers, bats are especially important. According to Merlin Tuttle’s Bat Conservation, “Insect-eating bats save farmers approximately $23 billion in annual agricultural losses in the United States alone.” In addition, bats are important pollinators and seed dispersers for 70% of tropical fruits. Their guano is also a rich fertilizer.

The fear of bats has been sensationalized using misinformation. But the truth is, if people leave bats alone, which they should, bats will leave people alone. Armed with the facts, we should not fear bats, but instead respect and appreciate them.

The Wonder of Eggs

Hummingbird Eggs – Photo Credit – Renee Grayson

Bird eggs are one of nature’s many masterpieces both in appearance and function. They come in a wide variety of shapes and sizes. Shape-wise, it’s easy to stereotype eggs as all looking like chicken eggs. But hummingbirds, for example, lay eggs the shape of Tic-Tacs. Many owls lay eggs that look like golf balls. And other birds lay eggs at are pear-shaped. Scientists are still unraveling the mystery behind why different birds have different shaped eggs. The latest research suggests that birds that spend more time flying have more elongated eggs, while those that don’t lay rounder eggs. There are, of course, exceptions to this because king penguins lay eggs that are somewhat pear-shaped, but they don’t fly at all. They’re still researching.

The largest eggs are laid by ostriches – they are about 6 inches long and can weigh up to four pounds! It is no surprise that the smallest eggs are laid by hummingbirds; these eggs only weigh as much as a paperclip and are roughly a half inch long (but there are also many species of hummingbirds, some larger than others, so egg size also varies). Egg shells also vary in thickness. The award for the thickest egg goes to the cassowary of New Guinea and Australia, which are about ¼ inch thick!

Eggs also have different colors and patterns. The red-winged tinamou of South America, for example, lays monochromatic glossy eggs that vary from purple to yellowish green. Robins lay beautiful blue eggs. Other eggs have spots or speckles or streaks or lines like an abstract work of art, like that of the great bowerbird. In some cases, these markings work as camouflage to deter predators. Shore birds, for example, lay speckled eggs that blend in with pebbles or sand.

All bird eggs are made of calcium carbonate. Interestingly, but not surprisingly, this is the same material mollusks build their shells from! Bird eggs are also porous. This leads to a question that had never occurred to me until investigating eggs: how does a developing chick breathe? As it turns out, there is a small pocket of air in the egg. The chicks breathe this air and exhale carbon dioxide, which can then escape from those pores! The pores also allow moisture in. This protects the baby bird and the inside of the egg from drying out. If you think about it, eggs are kind of brilliant. They offer the developing chick shelter, food, air, moisture – everything it needs!

Great Blue Heron

There’s always something magical about spotting a heron at the water’s edge (at least for me). They are elegant and graceful, poised and stately. They stand like statues watching for prey. Then, when they’re ready to strike, it’s lighting fast. It’s as if their necks are spring loaded. As it turns out, they kind of are.

Photo Credit – Kozarluha

Herons have special neck vertebrae that allow them to curl their necks into an S-shape. They do this when flying, but also when hunting. The curled neck allows them to strike quickly from a distance with incredible force. The unsuspecting fish or frog or small mammal never knows what hit ‘em. Sometimes herons will grab their prey in their beaks. Other times they simply impale them. Stealth and powerful, herons can also hunt both day and night thanks to special photoreceptors in their eyes that give them night vision.

These stately birds are also fastidious about keeping clean. But they don’t just splash around in the water to do this. They have specialized downy chest feathers that grow continually and fray. To wash, herons crumble these feathers into dust and then use that “powder down” like a washcloth. They comb it over their bodies using a claw on their middle toes which helps absorb and remove silt, oils, and fish slime on their feathers as they preen.

Interestingly herons nest in colonies that can number 500 birds. I find this interesting because I’ve only ever seen them one at a time! However, a little bit of Googling has revealed that there’s a “heronry” (new word!) near me. And, nesting season is here!