Alaskan island wolves caused a deer population to plummet

Alaskan island wolves caused a deer population to plummet



Historically, wolves and sea otters likely lived in the study area, Pleasant Island, which is located in an island landscape adjacent to Glacier Bay about 40 miles west of Juneau. The island is about 20 square miles, uninhabited and accessible only by boat or float plane.

During the 1800s and much of the 1900s, populations of sea otters in this region were wiped out from fur trade hunting. Unlike wolves in the continental USA, Southeast Alaskan wolves were not hunted to local extinction. Only in recent decades, particularly with the reintroduction and legal protection of sea otters, have the populations of both species recovered and once again overlapped, providing new opportunities for predator-prey interactions between the two species.

Wolves on an Alaskan switched to primarily eating sea otters in just a few years, a finding scientists believe is the first case of sea otters becoming the primary food source for a land-based predator. Using methods such as tracking the wolves with GPS collars and analyzing their scat, the researchers found that in 2015 deer were the primary food of the wolves. By 2017, wolves transitioned to primarily consuming sea otters while the frequency of deer declined.

Sea otters are this famous predator in the near-shore ecosystem and wolves are one of the most famous apex predators in terrestrial systems. So, it’s pretty surprising that sea otters have become the most important resource feeding wolves. You have top predators feeding on a top predator.

The researchers studied the wolf pack on Pleasant Island and the adjacent mainland from 2015 to 2021. Gretchen Roffler, a wildlife research biologist with the Alaska Department of Fish and Game, and others from the department collected 689 wolf scats, many along the island’s shoreline.

Once the scat is collected, members of Levi’s lab in Oregon used molecular tools, such as DNA metabarcoding and genotyping of the scat, to identify individual wolves and determine their diets.

Roffler also captured and placed GPS collars on four wolves on the island and nine on the mainland. The researchers were curious whether wolves were traveling between the mainland and island, considering other scientists have found they are capable of swimming up to eight miles between land masses. Both the GPS collar data and genotypes of the scats confirmed they were not, indicating that the island wolf pack is stable and that the island is not a hunting ground for mainland wolves.

Locations from the GPS-collared wolves also provide evidence that the wolves are killing sea otters when they are in shallow water or are resting on rocks near shore exposed at low tide. Roffler and her crew have investigated wolf GPS clusters on Pleasant Island for three, 30-day field seasons since 2021 and found evidence of 28 sea otters killed by wolves.

“The thing that really surprised me is that sea otters became the main prey of wolves on this island,” Roffler said. “Occasionally eating a sea otter that has washed up on the beach because it died, that is not unusual. But the fact that wolves are eating so many of them indicates it has become a widespread behavior pattern throughout this pack and something that they learned how to do very quickly.

“And from the work we are doing investigating kill sites, we are learning that wolves are actively killing the sea otters. So, they aren’t just scavenging sea otters that are dead or dying, they are stalking them and hunting them and killing them and dragging them up onto the land above the high tide line to consume them.”

Shortly after wolves colonized Pleasant Island in 2013, the deer population on the island plummeted. With the wolves having consumed most of the deer, their main food source, Levi said he would have expected the wolves to leave the island or die off. Instead, the wolves remained and the pack grew to a density not previously seen with wolf populations, Levi said. The main reason, he believes, is the availability of sea otters as a food source.

The findings outlined by the same researchers showed that wolves were eating sea otters. This was documented throughout the Alexander Archipelago, a group of Southeastern Alaskan islands which includes Pleasant Island.

The research has now expanded to study wolves and sea otters in Katmai National Park & Preserve, which is in southwest Alaska, about 700 miles from Pleasant Island. Early research indicates that wolves are also eating sea otters there. In fact, at that location three wolves were killing a sea otter near the shore.

By Omnipoten
Selesai

Hackensack Meridian JFK Johnson Rehabilitation Institute Is Researching A Breakthrough Wearable Medical Device To Accelerate Healing After A Stroke

Hackensack Meridian JFK Johnson Rehabilitation Institute Is Researching A Breakthrough Wearable Medical Device To Accelerate Healing After A Stroke

Hackensack Meridian JFK Johnson Rehabilitation Institute is researching a breakthrough medical device that delivers electromagnetic therapy to the brain to accelerate healing after a stroke.

JFK Johnson is one of 20 rehabilitation hospitals nationwide enrolling patients in the EMAGINE Stroke Recovery Trial, which aims to enhance recovery and reduce disability after neurologic damage caused by stroke. The wearable device, which can be used in a hospital setting, outpatient clinic, and at home would augment JFK Johnson’s existing rehabilitation therapies.

“We’re participating in this innovative research and other clinical trials because we’re continually working to maximize the recovery of our patients and advance the science of stroke recovery,” said Sara Cuccurullo, chair, vice president and medical director of JFK Johnson Rehabilitation Institute and principal investigator of the study. “We want all of our patients to reach their highest quality of life.”

Dr. Cuccurullo is Professor, Chairman and Residency program director of the Department of Physical Medicine and Rehabilitation at Hackensack Meridian School of Medicine and Rutgers-Robert Wood Johnson Medical School. She is also Physician-in-chief of the Rehabilitation Care Transformation Service at Hackensack Meridian Health.  

The wearable device was given breakthrough status by the FDA after a pilot study showed promise. The study is funded by BrainQ, the technology company that developed the investigational device.

The device targets networks in the brain with a low-intensity, frequency-tuned electromagnetic field therapy. JFK Johnson Rehabilitation Institute is training rehabilitation specialists to guide patients and to train caregivers to use the device. The program is over 45 hour-long sessions, five times each week, with weekly follow-up from a JFK Johnson rehabilitation specialist.

JFK Johnson treats approximately 750 stroke patients each year.

“The patients we’re talking to are interested and tell us they want to do whatever they can to recover as fully as possible,” said Maria Belen Montealegre, OTD, OT/L, CSRS, Occupational Therapy Supervisor and Site Coordinator of the clinical trial. Stroke is a leading cause of serious, long-term disability. Every 40 seconds, someone in the United States experiences a stroke, according to the U.S. Centers for Disease Control and Prevention. 

“Stroke can be devastating. Improving outcomes for people recovering from stroke will have enormous impact for individuals and their families as well as far-reaching impact for our nation,” said Hayk Petrosyan, Senior Research Scientist at JFK Johnson Rehabilitation Institute.

The EMAGINE trial will enroll 150 randomized subjects nationwide within four to 21 days following a stroke.

“We are excited to join forces with Hackensack Meridian JFK Johnson Rehabilitation Institute in the EMAGINE study, which aims to open the window for post-stroke recovery in the subacute phase,” said Yotam Drechsler, CEO of BrainQ. “JFK Johnson’s dedication to excellence in stroke care and research is unparalleled and we look forward to working together to fundamentally change the outcomes for stroke survivors.”


By Omnipoten
Selesai

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