Navigation Links
Without intervention, Mariana crow to become extinct in 75 years
Date:12/20/2010

Researchers from the University of Washington say the Mariana crow, a forest crow living on Rota Island in the western Pacific Ocean, will go extinct in 75 years.

The extinction could happen almost twice as soon as previously believed.

The crow's extinction can be prevented with a bird management program that focuses on helping fledgling birds reach their first birthday, said James Ha, UW research associate professor in psychology.

Ha examined survival rates in 97 Mariana crows Corvus kubaryi that had been tracked between 1990 and 2010 by researchers. He found that 40 percent of fledgling crows made it to their first birthday.

The rapid decline of young birds is twice what researchers previously estimated.

"It's the first year of survival that's the most crucial," said Ha, lead author of a report on the research. "If only 40 percent of fledglings survive their first year, then we predict the species will go extinct in 75 years."

Ha and his co-authors published the report in the current issue of Bird Conservation International.

The 75-year extinction estimate is according to a population model that factors in the estimated number of existing Mariana crows 330 with the 40 percent first-year survival rate, average number of fledglings per nest and fertility of female birds. Using this model, Ha found that 91 birds would exist in 20 years and that in 75 years the species would be extinct.

Previously, biologists believed that the first-year survival rate of Mariana crows was higher, around 60 to 80 percent.

When Ha used those estimates in his population model, the outlook was not as grim for the birds. At 60 percent first-year survival rate, Mariana crows would dwindle to 218 birds in 20 years and become extinct in 133 years. And an 80 percent first-year survival rate projects that in 20 years there would be 453 birds, a growing population that would avoid extinction.

"According to the population model, if we can boost fledgling survival from 40 percent to 70 percent, the Mariana crows will be fine," Ha said.

Of the about 35 crow species, Mariana crows are considered rare and classified as critically endangered. Weighing about a half of a pound, Mariana crows are 40 percent smaller than other crows, such as the Northwest crow.

Monogamously-mating, Mariana crows live exclusively on Rota Island, populated by about 1,200 people and located 56 miles northeast of Guam. Rota is a U.S. territory and is up for consideration as a U.S. national park.

Ha and Renee Ha, co-author of the report and UW research scientist in psychology, fear that Rota faces the same avian demise as Guam, which has no forest birds.

Brown tree snakes introduced to the island after World War II wiped out native birds, such as the Guam flycatcher and the Rufous fantail.

The Has suspect that the uncontrolled increase of feral cats on Rota is leading to the decrease of Mariana crows, much like brown tree snakes led to the disappearance of forest birds on Guam.

The researchers say that a captive rearing program could save the Mariana crows. They hope to set up a rearing facility where they could incubate eggs from the wild, raise the fledglings until their first birthday and then release the grown birds into nesting sites on the island.


'/>"/>

Contact: Molly McElroy
mollywmc@uw.edu
206-543-2580
University of Washington
Source:Eurekalert  

Related biology news :

1. Fructose sets table for weight gain without warning
2. Disabling enzyme allows mice to gorge without becoming obese, new study finds
3. Crib-side studies help struggling newborns go home without feeding tubes
4. Sudden cardiac death without recognizable cause
5. New simulation shows consequences of a world without Earths natural sunscreen
6. Montana State grads work helps diagnose skin cancer without a biopsy
7. Nanofarming technology harvest biofuel oils without harming algae
8. Researchers create freestanding nanoparticle films without fillers
9. Molecular typesetting -- proofreading without a proofreader
10. Study finds DNA barcoding requires caution without closer examination
11. Reading the brain without poking it
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Without intervention, Mariana crow to become extinct in 75 years
(Date:1/3/2017)... VEGAS , Jan. 3, 2017 Onitor, ... the introduction of Onitor Track, an innovative biometric data-driven ... men, showcasing this month at the 2017 Consumer Electronics ... In the U.S., the World Health ... more than two-thirds of adults who are overweight or ...
(Date:12/20/2016)... Dec, 20, 2016   Valencell , the ... and STMicroelectronics (NYSE: STM), a global semiconductor ... applications, announced today the launch of a new, ... wearables that includes ST,s compact SensorTile ... biometric sensor system. Together, SensorTile and Benchmark ...
(Date:12/16/2016)... YORK , Dec. 16, 2016 The global wearable ... USD 12.14 billion by 2021 from USD 5.31 billion in 2016, ... ... is mainly driven by technological advancements in medical devices, launch of ... rising preference for wireless connectivity among healthcare providers, and increasing focus ...
Breaking Biology News(10 mins):
(Date:1/12/2017)... ... January 12, 2017 , ... Huffman Engineering, Inc. , a ... will work in the company’s Lincoln office as a chemical engineer. In his ... systems for customers in the life science manufacturing and water/wastewater industries. , Prior to ...
(Date:1/12/2017)... -- The report "Direct-Fed Microbials Market by Type (Lactic Acid Bacteria and Bacillus), ... - Global Forecast to 2022", published by MarketsandMarkets, the global market is estimated ... USD 1,399.6 Million by 2022, at a CAGR of 6.96% from 2016. ... ... MarketsandMarkets Logo ...
(Date:1/11/2017)... ... January 11, 2017 , ... ... optics and photonics , are commending the U.S. Congress and President Obama for ... by the President of the American Innovation and Competitiveness Act (AICA). , The ...
(Date:1/11/2017)... (PRWEB) , ... January 11, 2017 , ... ... company developing an innovative cellular response analysis platform to measure the proteomic function ... Phase I Small Business Innovation Research (SBIR) grant from the National Institute on ...
Breaking Biology Technology: