Otterly awesome.

Sea otter awareness week

Did you know that this week is sea otter awareness week? You can watch them ...
otter cam here

Description (Taken from FWS fact Sheet, 2005)

Sea otters are a member of the weasel family (Mustelidae) and live in the near-shore waters along the North Pacificocean. Sea otters are the smallest marine mammal and are most closely related to river otters. Sea otters are suited to their marine environment by adaptations of dentition, skeletal structure, and pelage. Sea otter dentition is adapted for crushing hard- shelled invertebrates such as clams, urchins, and crabs. The skeletal structure of the sea otter is loosely articulated and lacks a clavicle which allows for increased flexibility in swimming and grooming. The forelimbs are used primarily for grooming and foraging rather than swimming. The hind feet are flattened and flipper-like with an extension of the fifth digit which enables the animal to more efficiently swim on it’s back on the surface of the water. Sea otters do not have a blubber layer as other marine mammals do, instead they depend upon a dense, water-resistant fur to provide insulation against cold. Sea otter fur is very dense and has a greater number of hair follicles per inch than any other mammal. 

Adult sea otters can reach lengths of up to 6 feet (1.8 m) but average about 4.5 feet (1.4 m). Adult male otters weigh from 70 - 90 pounds (32-41 kg) with some males reaching up to 100 pounds (46 kg). Adult female otters average 40 – 60 pounds (18-27 kg).

Life History

Sea otters’ average life span is approximately 15 - 20 years. Female sea otters do not begin to breed until age 2 - 5 years and may breed annually up until age 20. Males become sexually mature at ages 4- 6 years but may not hold breeding territories until several years later. Mating occurs at all times of the year, and young may be born in any season. In Alaska, most pups are born in late spring. Sea otters generally have a single pup during each breeding cycle and the gestation period can be highly variable due to delayed implantation of the fertilized egg. A pup will weigh from 3 to 5 pounds (1.4 - 2.3 kg) at birth and stay with its mother from 3 - 6 months.

Range and Population Levels

Historically, sea otters occurred in near shore waters around the North Pacific rim from Hokkaido, Japan through the marine coastal areas of the Russian Far East and the Pacific coastal areas in the United States as far south as Baja California. The world-wide sea otter population was drastically reduced to just a few hundred animals between 1742 - 1911, due to commercial harvest by the Russian and Russian/American fur trades. Three population stocks of sea otters exist in Alaska today. The statewide population is believed to number around 70,000 animals.

The latest conservation efforts for sea otters in Alaska have now been made available. You can read the full report here. Fish and Wildlife sea otter recovery plan

 

References:

FWS (Fish and Wildlife), 2005, 2013. http://www.fws.gov/alaska/fisheries/mmm/seaotters/pdf/biologue.pdf

http://www.fws.gov/alaska/fisheries/mmm/seaotters/recovery.htm

image:  http://en.wikipedia.org/wiki/File:Sea_otter_cropped.jpg
 

Don’t rain on my parade!

Weather modification: fact or fiction?

image copyright Patrick Owsley

Is weather modification a real thing or just something made up in cartoons, like  

SIMON BAR SINISTER 's rainmaker machine from the classic Underdog cartoon?

Weather modification is fact. It has been a pretty standardized practice since around 1950, more commonly known as cloud seeding. In Nevada, scientists are trying to increase the snow pack that feeds Nevada's water supply by 5- 15%.  With drought conditions, those numbers would make a significant impact.

What exactly is cloud seeding? It is a process where aerosolized silver iodide (invented in 1946 but Bernard Vonnegut [yes, Kurt's older brother]). He discovered that putting  dry ice directly into clouds, it encourages precipitation. Later found that silver iodide would have the same effect. 

There have been many projects related to cloud seeding ; Project Skywater, Project Stormfury and even Operation Popeye! Researched surged and then dwindled in the 1970s due to inconclusive results, rainy seasons and environmentalists reluctance to mess with the natural weather cycles; not to mention the fact that silver iodide is listed as a toxic chemical by the EPA (read about their evaluation of it for cloud seeding).

OnEarth Magazine has written a great article on this topic and you can read the complete article here to find out more and exactly what Operation Popeye was. "A-gah-gah-gah-gah-gah-gah!"

The library has great databases to find out more as well. Go here to research more.

References:

Strand, G., 2013. Silver lining playbook. http://www.onearth.org/articles/2013/09/cloud-seeding-may-sound-wacko-but-could-it-save-us-from-droughts

 

Image credit: http://powsley.blogspot.com/2012_03_01_archive.html

The Need for Speed

Biomechanics of the cheetah (Acinonyx jubatus)

You may be asking why this video is relevant to the biomechanics of a cheetah. Many people are aware that the cheetah is the fastest land animal on earth, so when the child in the video makes the suggestion to tape a cheetah to his grandmother’s back to increase her speed… you would think that made sense!  However, research has shown that agility may be more important than actual speed when hunting.

The ability of a cheetah to stop and turn quickly is the key to a successful hunt. Captive cheetahs have been clocked at around 62 miles per hour (100 kilometers). To find out exactly what happens in wild cheetahs, researchers at the Royal Veterinary College in London spent 10 years perfecting a collar that had the ability to track the biometrics of the animal (e.g.speed, slow downs, turns). The collars were active for one year, allowing for enormous data sets to be collected.

“When activated, the collar records the animal's position, velocity, and direction it's heading up to 300 times a second and relays that data via radio signals to the researchers. Three female and two male cheetahs wore these collars for 18 months, during which 367 hunting "runs" were recorded” (Pennisi, 2013).

Surprisingly, research had shown that the cheetah slowed down their speeds by 60% in order to outmaneuver their prey. The rate of speed up and down was double that of polo horses and 4x faster than any human. Still, with this amazing ability, the cheetah only brings down the prey 1 in four times.

They also discovered that cheetah also hunt in the bushes and vegetation and was not restricted to dawn, but was also done during the day. Researchers made new discoveries and found the Cheetah was not like previously thought. They are now studying other species.

references: 

Image credit:

http://en.wikipedia.org/wiki/File:Cheetah_Feb09_02.jpg

 

Pennisi, E., 2013. Science Magazine. http://news.sciencemag.org/2013/06/cheetah-agility-more-important-speed

My how you’ve changed!

Speciation and killer whales in the North Atlantic

Overview of Speciation

A species is can be defined as a group of individuals that interbreed in nature. Speciation is a lineage-splitting event that produces two or more separate species. The cause of normal speciation can be related to geographic isolation and a reduction in gene flow. Groups  evolve with genetic differences (Berkley, n.d.). “These need not be huge genetic differences. A small change in the timing, location, or rituals of mating could be enough. But still, some difference is necessary. This change might evolve by natural selection or genetic drift”(Morell, V., 2013). Below are some of the different modes of speciation.

Mode of speciation:  new species formed from:

Allopatric                     geographically isolated populations

Peripatric                     small population isolated  

                                    At edge of larger

                                    Population

Parapatric                    continuously distributed

                                    population                                                                                                                                                                                     

You may follow the link in the references for a more in depth look at speciation.

Killer whales of the North Atlantic

There is a debate among biologists as to whether it is possible that a new species can arise in populations that have no geographic barriers. This process is known as sympatric speciation. Killer whales have multiple genetically distinct populations with different prey preferences in the North Pacific and Antarctic, but they have not been formally described as separate species.

This separation is due to prey preference. With enough time, the two populations would become genetically distinct. Orca’s in the North Atlantic have different hunting tactics and have been observed to be learned behaviors. Cultural differences may contribute to driving the populations apart.

At this time, researchers have not yet found any genetic difference in the North Atlantic whales; however opinions tend to sway towards these animals being at the beginning stages of speciation; which is a very long process. The prey preference is not yet causing genetic change, but given time it may lead to this.

References:

Berkley, Evolution 1010. Online. Available at: http://evolution.berkeley.edu/evosite/evo101/VADefiningSpecies.shtml [Accessed on 09/05/2013].

Morell, V., 2013. Science Daily. North Atlantic  Killer whales may be branching into two species. Online. Available at: http://news.sciencemag.org/evolution/2013/08/north-atlantic-killer-whales-may-be-branching-two-species