Species of the Month

This month’s species of the month is the largest critter to ever roam the planet. Even bigger than the biggest dinosaur, the blue whale is wide-spread but seldom seen. Hunter to near extinction, they now number just a few thousand. Hopefully these gentle giants will fully recover.

Blue whale (NPS)

Scientific name: Balaenoptera musculus

Kingdom: Animalia (animals)

Class:   Mammalia (mammals)

Order: Cetacea (dolphins and whales)

Range: Atlantic, Indian, and Pacific Oceans from the near-polar regions to the equator

Habitat: Open ocean

Lifespan: Estimated to be 80 to 90 years

Diet: Krill, small fish, small crustaceans, copepods

Predators: Humans, sharks and killer whales prey on calves

Conservation Status: Listed as endangered by IUCN and under ESA.

Blue whale spouting (NPS)

Other Information: Blue whales were hunted for oil and blubber. They have been protected since 1966. Blue whales are baleen whales, those that do not have teeth but instead have bristle-like filters. An adult can eat up to four tons of krill in a day. Not much is known about their reproduction. Males and females mature at about five years old, and females give birth every other or every third year. Gestation is about a year. Most blue whales are migratory, spending winters in the tropics and summers in the high latitudes. Dives can last 10-20 minutes between breaths. Blue whales are vocal, but their songs are too low for humans to hear. Like other whales, blues fluke (tail emerges from the water), breach (entire body emerges), spyhop (head is exposed), and spout (back and blowhole exposed, the whale exhales).

Blue whale fluking (NPS)

This week’s information comes from the University of Michigan’s Animal Diversity Web.

Winter Adaptations

As I deal with a pair of winter storms over the course of writing this blog, I am sitting cozy and warm inside my house. How do animals, who don’t live in houses with central heating or furnaces make it through the winter? Some migrate to warmer areas, but those that stay behind have special adaptations that help them cope with the cold and snowy weather.

Many animals go into mega energy conservation mode during the winter because not only do they lack heating systems for their homes, they also lack supermarkets that carry a reliable food source. For herbivores, their plant-based food supply is either dormant (and not producing the nutritious shoots they crave), or buried under snow and ice. Whether warm-blooded or cold-blooded, both need to keep warm to survive. Cold-blooded critters rely on the sun’s radiant heat to stay warm, and this is a challenge when it’s cold outside and the sun isn’t reliable. Warm-blooded critters metabolize food to stay warm- they eat much more than cold-blooded ones. One option to keep up metabolism is to spend energy to search for scarce food. But there are other ways to get by.

Hibernation is probably the first coping mechanism you think of, and it’s quite common in the mammal world. Bears do it, bats do it. What is it, compared to normal sleep? When you go to sleep your body slows down. Breathing and heart rate go down and metabolism slows, and your body temperature cools a bit. Hibernation is an extreme version of this. But to be asleep for weeks or months on end requires quite a bit of sustaining energy, even if bodily functions slow to the point of nearly stopping. That’s why bears go on a feed frenzy each fall, gorging themselves on spawning salmon or high-energy moths if they live in the right place.

NPS graphic of a hibernating bear

For those that don’t hibernate, finding food is a priority. Arctic foxes and snowshoe hares both grow a white coat for snow camouflage. The fox uses its camo to hunt; the hare uses its to avoid being eaten. The bison uses its large head as a snowplow to uncover buried vegetation. Ever wonder what that large hump at its shoulder is? Extra muscles to support all that head.

Snowshoe hare (Montana Fish, Wildlife, and Parks)

Bison plowing for food (NPS)

Preserving body heat is a great way to maximize caloric efficiency. The thick fur coat of a muskox traps body heat. Blubber insulates whales, seals, and walruses. Polar bears have black skin that absorbs heat, and their fur traps heat, including body heat that they radiate.

Walruses (US Fish and Wildlife Service)

Ease of mobility is also an efficiency adaptation. Lynxes and caribou both have large feet that act as snowshoes, making it easier to get around so they burn fewer calories doing so.

Check out the foot on that lynx! (Natural Resources Research Institute)

These are just a few of the many adaptations that make survival possible for warm-blooded mammals. There are others, and there are also adaptations for cold-blooded animals (like a frog with antifreeze in its blood) and plants too! Enjoy your heater for the rest of the winter! 

Endangered Species

This week Nature Minute will take a look at something most have never seen before- endangered species. You may have seen one or two because there are so many species that are endangered, but most likely not because there are so few of each species. They come in all shapes and sizes, from lichens to flowers to trees and from insects to corals to snails to whales.

In legal terms, an endangered species is defined by the Endangered Species Act (ESA) as being in danger of becoming extinct. A companion term in ESA is a threatened species, which is under threat of becoming endangered. ESA requires protection for endangered and threatened species as well as their habitat, because how can a species survive without having a place to live?

While ESA is an American law, it also extends global protection to species listed as threatened or endangered wherever they may be found. For example, the cheetah is listed as a foreign endangered species. While US laws regarding the conservation of cheetahs and their habitat can’t be enforced in Africa, the extent of the law here at home prohibits trafficking in them and other foreign endangered species.

Currently there are close to 2000 threatened and endangered species just in the US. When a species is listed, the appropriate state and federal agencies must develop a recovery plan. The recovery plan outlines how to increase the species population and preserve habitat and specifies a target population to be considered sustainable so the species can be delisted. Lead federal agencies that oversee ESA listing and recovery plans are the US Fish and Wildlife Service for terrestrial species and National Marine Fisheries Service works with oceanic critters. Both partner with state fish and wildlife agencies, local and tribal governments, private organizations.

My time in the field gave me the opportunity to work on conservation projects aimed at species recovery. I was even lucky enough to see some of the species I was trying to help.

In the US, four of the five Pacific salmon species (pinks are excluded) are listed as threatened or endangered. I volunteered with the Nisqually Land Trust, an organization that works to preserve and enhance salmon habitat. Although the salmon is a fish, salmon habitat begins with healthy forests that keep the rivers cool and clean.

Chinook salmon returning to spawn

I also volunteered with the Center for Natural Lands Management on two prairie preserves. I removed invasive blackberries and Scotch broom from the Glacial Heritage Natural Area and also collected wildflower seeds from there and the Mima Mounds Natural Area. The work I did was to open space for native plants to grow and collect seeds for propagation at other sites. The prairies are home to the endangered Taylor’s checkerspot butterfly, Mazama pocket gopher, and golden paintbrush, a flower. 

Golden paintbrush

Mazama pocket gopher (US Fish and Wildlife)

Taylor's checkerspot (US Fish and Wildlife)

My list of endangered species that I’ve seen in their natural habitat is short, but probably longer than most other people’s. I’ve seen the beluga whale (Alaska), golden paintbrush (Washington), Chinook salmon (Washington), black-footed ferret (South Dakota), and West Indian manatee (Florida).

Black-footed ferret (National Park Service)

West Indian manatee

I am glad that we have ESA to protect endangered species. Several, such as the bald eagle and the alligator, are considered recovered and have been delisted. The road to recovery takes a long time, and sadly the list gets longer as new species are added before the existing species recover. 

Bald eagle

American alligator (National Park Service)

My only regret about ESA is that it takes a reactive approach to protecting species with critically low populations, rather than a proactive approach that prevents them from needing to be listed in the first place. For more information on the Endangered Species Act visit the US Fish and Wildlife website here.

Sea Lions and Whales

Summer weather is hear for most of us (off and on here in the Northwest- off as I write this) so let’s take another trip to the beach in search of marine mammals. Actually, this a recap of a trip to the beach I took in December 2014. I went to Florence, Oregon to check out the local pinnipeds and cetaceans. What are those you ask?

Cetaceans are whales and pinnipeds are critters such as seals and walruses. Pinniped means fin footed, and the feet of these critters are modified into swimming flippers. Maybe you’re wondering why I went to the beach in December. I actually stopped by the Sea Lion Cave in August, but the sea lions weren’t home. Sea Lion Cave is the largest sea cave in the world, home to a Stellar sea lion rookery. During the summer the sea lions are out to sea, and I got so see some swimming at a distance. Because they weren’t home, I got a rain check to return any time within a year and chose December because they would be roosting and migrating gray whales would be passing by.

For those of you outside of the Northwest, this was a big gamble, picking out a weekend to get a hotel months in advance. The weather is notoriously wet in this corner of the world, especially during the winter months. On the coast, winds can reach hurricane force during a good storm. And I was betting that I’d have good enough visibility to see a whale out there somewhere.

I was either lucky or a genius. Saturday’s drive to Oregon and Sunday at the cave were great for driving and whale watching. Inside the cave smelled of sea lion, but the fresh sea breeze kept the smell from becoming overwhelming. It’s a noisy place, alive with the sounds of crashing waves and the grunts and groans of half-ton beasts. No flash photography, and humans are in a cage to keep us and the sea lions safe from each other.

 

Lion's den, devoid of sea lions (summer 2014)

Incoming wave at the sea-facing opening of the lion's den (summer 2014)

 Outside, squadrons of gulls and guillemots patrolled the skies above. Heceta Head Lighthouse kept watch to the north, southward were the city of Florence and the towering Oregon Dunes. The back side of the Sea Lion Cave gift shop (at the top of the elevator down to the “lion’s den”) is a picnic area and observation deck on a bluff over a hundred feet above the Pacific Ocean. All around were sea bird rookeries. It’s a huge area to scan, hoping to see a whale drift by. What are the odds that one would surface right where I was looking? I didn’t see any whales that day but I did see the spouts of a few. This was exciting for me, since I’d never seen a whale before, other than Shamu and friends in Orlando.

Pigeon guillemot (from Audubon Society)

Gray whale (from NOAA)

Stellar sea lion (from NOAA)

Rain and fog settled in north of Salem as I headed back home after a successful day of new wildlife encounters. Since then I’ve encountered harbor seals just offshore from Tacoma and I would love to do a whale watching cruise in the San Juan Islands. What do you watch for when you hit the beach?

Ocean-going sea lions (summer 2014)

Shore bird rookery #1

Rookery #2

Whale jaw bone at Umpqua Lighthouse in Oregon

Sea lion (NOAA) http://www.noaanews.noaa.gov/stories2010/20100806_sealion.html

Gray whale (NOAA) http://www.fisheries.noaa.gov/pr/species/mammals/whales/gray-whale.html

Pigeon guillemot (Audubon) http://www.audubon.org/field-guide/bird/pigeon-guillemot

Animal Attraction

In a previous episode of Nature Minute we talked about porcupine love. With Valentine’s Day right around the corner it’s time to revisit the subject.

In the human world, success is usually measured in money and power. In the natural world, success is measured by passing on genes to a new generation. Darwin proposed evolution as natural selection by survival of the fittest. Those best equipped to survive their environment will have the most offspring, in theory.

There are two ways in nature to ensure that your offspring will survive to produce offspring of their, furthering your own genes. The first is a high reproductive rate (fecundity) with little to no parental care. The second is lower fecundity with a high rate of parental care.

Some examples of high fecundity animals are insects, which lay thousands of eggs, and mice, which may have multiple litters of a dozen or more in a single year. Surviving mouselings reach sexual maturity at a very early age and have babies that are older than their aunts and uncles. Many plants fall into this category also. Think of how many wishes you’ve made with dandelion seeds. Or if you are like me, think of how many mornings you woke up to a yard full of dandelions that weren’t there the night before.

Lower fecundity breeders are typically larger than high fecundity breeders (this is a general rule, but there are exceptions of course). We fall into this category, along with whales and elephants. We all have a relatively long gestation period (40 weeks for people, 20 months for elephants) and births are commonly single. Sexual maturity takes years to reach and mothers do an excellent job of caring for their young.

Just as there are two ways of breeding, there are also two ways of breeding- monogamy and promiscuity. Monogamy is what we think of in human relationships, a pair mating for life. Bald eagles and barn owls are monogamous.

Promiscuity can be either male or female. Male promiscuity is very common in the natural world (and humans too). A successful male has many offspring, but why should he limit himself to a single female? In these situations, frequently a dominant male will have a harem of females to mate with. Elk and bison are great examples. Going back to a previous Nature Minute on the elk rut, we learned that young males will challenge the older dominant male for the right to mate.

Elk rut, photo by Tom Bartel

Female promiscuity is way to confuse males. In some species, a male will kill any young that are not his own. He wants his own genes, and not someone else’s, to be passed on in perpetuity. To counter infanticide, in some species the female will take multiple mates. Since no one is really sure who the father is, all males assume fatherhood and are unlikely to kill any young since it very well could be their own. It is even possible for all of them to be the father. Bees, hedge sparrows, and garter snake females will all take multiple mates.

In the human world, typically a boy will ask a girl out on a date. Females hold all the power. The same is true in the animal world in many cases. Males will put on a courtship display or perform a courtship ritual, hoping to catch the attention of a lucky lady. Prairie chickens have a lek, which is similar to a middle school dance, but the stakes are higher. Boys on one side, girls on the other. The males strut their stuff and the females pick out their favorites. After it’s over, they all go back to their home territories. Usually there is some desirable trait that females are looking for that demonstrates the male’s fitness (as is “survival of the fittest”, not like a fitness test in gym class). It can be brightly colored feathers, awesome dance moves, the loudest croaking, huge antlers, or any number of other things. The male with the best traits gets to pass those on to the next generation through his genes.

Greater prairie chicken lek, photo by Adrian Binns

So what did we learn today? When it comes to love, people are still pretty much animals. It’s ladies’ choice, and the guys really don’t care as long as she says yes.