An update of the breeding population status of the critically endangered Mariana Crow Corvus kubaryi on Rota, Northern Mariana Islands 2013–2014

2017 ◽  
Vol 28 (3) ◽  
pp. 416-422 ◽  
Author(s):  
ANDRIA KRONER ◽  
RENEE ROBINETTE HA
Keyword(s):  
Total Population ◽  
Breeding Population ◽  
Critically Endangered ◽  
Population Recovery ◽  
Mariana Islands ◽  
Population Status ◽  
Single Population ◽  
Direct Count ◽  
Northern Mariana Islands ◽  
Viable Population

SummaryThe critically endangered Mariana Crow now exists in a single population on the island of Rota, Northern Mariana Islands. Targeted management requires an accurate measure of the population status of this species. In Mariana Crows the breeding population is both the easiest cohort to accurately survey and the most important segment of the population in terms of population recovery. The total number of Mariana Crow territorial pairs was estimated on the island of Rota using a direct count method, and total population size was calculated using a Chapman estimate. From September 2013 to April 2014, 46 crow pairs were found and up to an additional eight pairs were estimated in unsearched areas. The total population was estimated to be 178 individuals. This represents a 10–23% decline in pairs in the six years since 2007 and a 46–53% decline since 1998. This number is also considerably lower than the minimum 75 pairs recommended to maintain a viable population on Rota.

scholarly journals Population status and nest success of the Critically Endangered Mariana Crow Corvus kubaryi on Rota, Northern Mariana Islands

2014 ◽  
Vol 25 (2) ◽  
pp. 220-233 ◽  
Author(s):  
LAINIE ZARONES ◽  
ADRIENNE SUSSMAN ◽  
JOHN M. MORTON ◽  
SHELDON PLENTOVICH ◽  
SARAH FAEGRE ◽  
...  
Keyword(s):  
Nest Success ◽  
Survival Rates ◽  
Critically Endangered ◽  
Boiga Irregularis ◽  
Mariana Islands ◽  
Northern Mariana Islands ◽  
Critically Endangered Species ◽  
Species Survival ◽  
Neighbouring Island ◽  
Breeding Seasons

SummaryThe Mariana Crow Corvus kubaryi is a Critically Endangered species found only on the island of Rota, Northern Mariana Islands. It was extirpated from the neighbouring island of Guam by the introduced brown tree snake Boiga irregularis and the Rota population has been in decline since at least 1995. We identified only 60 pairs present on Rota in 2007 compared with an estimated 117 pairs in 1998, a decline of nearly 50% in nine years. The decline may be linked to proximity to human activities, though more data are needed. We monitored 204 crow nests between the 1996 and 2009 breeding seasons. Crows initiate clutches between August and April. The overall estimate of nest success was 25.7% (n = 204). On average 49% of pairs produced at least one fledgling per season. The mean number of fledglings per pair per year is 0.66. Mean clutch size was 2.6 (n = 82), mean number of nestlings was 1.4 (n = 106), and mean number of fledglings per nest was 1.3 (n = 68). Daily survival rates declined in later years, and increased during the nest cycle. The number of pairs with successful nests did not change during the study period, nor did the number of fledglings per pair. Predation appeared to be the primary cause of nest failure. The breeding season lasted around nine months and pairs re-nested after failure. Predation of adults and juveniles by cats, combined with possible inbreeding depression, habitat disturbance and human persecution appear to be the cause of decline of the Mariana Crow. We strongly recommend a programme of invasive predator control, habitat maintenance, and captive rearing to ensure the species’ survival.

Conservation of the critically endangered Achondrostoma occidentale (Pisces: Cyprinidae): integrating habitat data in restocking programs to improve population recovery

Gaia Scientia ◽  
2016 ◽  
Vol 10 (2) ◽  
pp. 1-9
Author(s):  
D. Mameri ◽  
C. Sousa Santos ◽  
M. F. Magalhães ◽  
J. I. Robalo
Keyword(s):  
Iberian Peninsula ◽  
River Basins ◽  
Fish Abundance ◽  
Critically Endangered ◽  
Ex Situ ◽  
Population Recovery ◽  
Age Classes ◽  
Younger Age ◽  
Risk Of Extinction

Cyprinid fauna endemic to the Iberian Peninsula is currently facing several human-caused threats which enhance their risk of extinction. The populations of the critically endangered Achondrostoma occidentale, occurring only in three small and intermittent Portuguese river basins, have been reinforced with fish bred ex-situ in order to minimize their risk of extinction. This study aimed to describe the restocking actions conducted and to identify and characterize the summer refugia that should become targets for restoration and further restocking. The results evidence population increments and a high representativeness of younger age classes in the restocked populations. The importance of annual monitoring of fish abundance to assess how the species is coping with the stochastic and deterministic stressors that may eventually compromise its survival is highlighted.

scholarly journals The persistent challenge of rheumatic fever in the Northern Mariana Islands

2010 ◽  
Vol 14 (3) ◽  
pp. e226-e229 ◽  
Author(s):  
Michael D. Seckeler ◽  
Leslie L. Barton ◽  
Rachel Brownstein
Keyword(s):  
Rheumatic Fever ◽  
Mariana Islands ◽  
Northern Mariana Islands

Recognizing Inland Expansion of Latte Period Agriculture From Multi-Disciplinary Data on Tinian, Commonwealth of the Northern Mariana Islands

2011 ◽  
Vol 6 (3) ◽  
pp. 375-397 ◽  
Author(s):  
Boyd Dixon ◽  
Huw Barton ◽  
James Coil ◽  
William Dickinson ◽  
Gail Murakami ◽  
...  
Keyword(s):  
Mariana Islands ◽  
Northern Mariana Islands
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