Orca

 Orcas are a type of marine animal. They are sometimes misidentified as whales because of their ‘killer whale’ name. But did you know that orcas are actually classified as dolphins? They are, in fact, the largest members of the dolphin family! In ancient times, mariners reported seeing orcas hunting larger whales and called them “killer whales” as a result.

Orcas may be found in every ocean on the planet. You’ll find them in the Arabian Sea to the Gulf of Mexico, from Japan’s coastal waters to the Atlantic Ocean, and from the Arctic seas to Antarctica. Because of their extraordinarily broad range across the world and erratic migrations, determining the precise global population is challenging. It is estimated that there are more than 50,000 orcas.

The average orca lifespan is between 30-50 years in the wild. In captivity, their lifespan has been averaged between 10-45 years. Orcas kept in captivity are thought to live shorter lives than those in the wild; however, this is open to scientific debate.

In orcas, life expectancy differs between sexes. Wild female orcas live an average of 50 to 80 years. Wild males live an average of 29 years, with a maximum lifespan of roughly 60 years.

Some researchers claim that females have lived even longer than most estimates. Orca Granny (J2) was considered by some experts to have been as old as 105 years old at the time of her death, despite a biopsy sample indicating her age to be 65 to 80 years. 

The Average Orca Life Cycle 

The orca life cycle is unique in many regards. Let’s explore each stage in more detail to better understand how these magnificent creatures reproduce.

Gestation Period 

Pregnancies of killer whales last 18 months, making it one of the longest gestations of any mammal. Babies are born all year, and there is no statistical evidence supporting birth seasons.

Unfortunately, orcas have a high risk of miscarriage and newborn death which is why many of their pregnancies don’t result in birth. 

Newborn Calf 

Newborn baby orcas are called calves. Calves are around 8 feet long and weigh about 400 pounds when they are born. Each orca female gives birth to only one calf at a time. The calf’s dorsal fin and tail flukes are soft and malleable in the first few days after birth. They stiffen over time as the orcas grow. Most calves grow around 64 cm (25 in.) during their first year and acquire roughly 400 kg (882 lbs.). They grow to be around 53 cm (21 in.) during their second year.

Adolescence 

As the young orcas grow, the adults teach them the skills necessary for hunting and interacting with other orcas. They advise them on the ideal eating and breeding sites, as well as the optimal migration routes. Orca culture varies widely among groups, and knowledge is passed down from generation to generation. Even when they reach adults, orcas remain with their mothers.

Adult Orca

Female orcas reach sexual maturity between the ages of 6 and 10 and begin mating around the age of 14. Males acquire sexual maturity between the ages of 10 and 13 years.

Orcas are extremely sociable creatures with intricate social structures. As they age, they continue to live in pods of up to 50 members. However, this varies according to their specific group. Males, females, and calves of varying ages make up a pod. They frequently stick together in pods, share prey, and don’t leave the group for more than a few hours at a time.

What Factors Threaten The Orca’s Lifespan

Orcas are apex predators, which means they have no natural predators. However, they are still susceptible to threats from other sources. 

Orcas are threatened by: 

Getting trapped in fishing nets by accident: Orcas are extremely vulnerable to being caught in fishing gear. Whales that become entangled may drag and swim for long distances with connected gear or become fixed in a spot and become unable to swim. These kinds of incidents cause exhaustion, impaired feeding capacity, or serious injuries, which can lead to death.

Oil spills: The 1989 Alaska Exxon Valdez oil disaster directly caused the deaths of individual killer whales. On the other hand, oil spills reduce the variety of prey species available to killer whales, which can have an indirect effect on the animals. In addition, they have been observed to accumulate some pollutants in oil, such as polychlorinated biphenyls (PCBs), especially because they are known to migrate in various waters.

Food scarcity: Overfishing and habitat destruction have reduced the availability of prey for some orcas. Killer whales may have lower reproduction rates and higher death rates if there is insufficient prey.

ORANGE-BREASTED BUNTING

 The orange-breasted bunting is a species of passerine bird in the family Cardinalidae. It is endemic to Mexico, where its natural habitats are subtropical or tropical dry forests and subtropical or tropical dry shrubland. With its wide range and large total population, the International Union for Conservation of Nature considers it as being of “least concern”.

Violet-green Swallows

 These aerial insectivores perform acrobatic stunts over lakes and streams high in the sky in search of flying insects. Violet-green Swallows can look dark at first, but their true colors come to life when sunlight illuminates their metallic green backs and iridescent purple rumps. They are a common sight in the West in spring and summer, but they vanish to Mexico and Central America for the winter. They can be distinguished from other swallows by the white patches on the sides of their rump and their white cheeks.

Find This Bird

One of the best places to look for Violet-green Swallows is to head out to a river, pond, or lake early in the morning and keep your eyes to the sky. Watch for birds swooping and twittering over the water snatching up insects. They tend to be in groups from 10 to over 100 and they often hang out with other swifts and swallows. To pick one out of the crowd look for the white saddlebags on the sides of the rump and a clean white belly. It can be difficult to get a good look at flying Violet-green Swallows, but you might have an easier time following one with your binoculars if you spot one a little bit further away. That way the swallow won’t zip out of your field of view as soon as it enters. They often perch on power lines and dead trees, so you’ll be able to get a better look at perched birds in those spots.

Cool Facts

• Violet-green Swallows have been recorded flying at 28 miles per hour—a pretty respectable speed considering that the Peregrine Falcon, the fastest bird of prey, averages about 25–35 miles per hour in traveling flight.
• Sometimes late hatching young are at a disadvantage, but female Violet-green Swallows invest more antimicrobial proteins in the eggs laid later within a clutch possibly reducing infection for late hatching young and giving them a leg up.
• The Violet-green Swallow is very similar to the Tree Swallow, both in appearance and habits, but it is more closely related to two other swallows found in the Caribbean: the Golden Swallow and Bahama Swallow.
• A pair of Violet-green Swallows was observed assisting a pair of Western Bluebirds in raising young. The swallows guarded the nest and tended the bluebird nestlings, and after the bluebirds fledged, the swallows used the nest site for their own young.
• The oldest recorded Violet-green Swallow was a male, and at least 9 years, 1 month old, when he was recaptured and rereleased during banding operations in California in 1993. He had been banded in the same state in 1985.
• The scientific name for Violet-green Swallow is Tachycineta thalassina. Tachycineta means fast moving and thalassina means of the sea referring to the sea-green color of their backs.