scholarly journals Sighting patterns reveal unobserved pupping events to revise reproductive rate estimates for Hawaiian monk seals in the main Hawaiian Islands

2020 ◽  
Author(s):  
Stacie J. Robinson ◽  
Albert L. Harting ◽  
Tracy Mercer ◽  
Thea C. Johanos ◽  
Jason D. Baker ◽  
...  
Keyword(s):  
Hawaiian Islands ◽  
Reproductive Rate ◽  
Monk Seals

Significance of wounding to female reproductive success in Hawaiian monk seals (Monachus schauinslandi) at Laysan Island

1993 ◽  
Vol 71 (3) ◽  
pp. 469-474 ◽  
Author(s):  
Lisa M. Hiruki ◽  
Ian Stirling ◽  
William G. Gilmartin ◽  
Thea C. Johanos ◽  
Brenda L. Becker
Keyword(s):  
Reproductive Success ◽  
Adult Male ◽  
Reproductive Rate ◽  
Lactation Period ◽  
Female Reproductive Success ◽  
Monachus Schauinslandi ◽  
Lower Survival Rate ◽  
Adult Females ◽  
Pup Survival ◽  
Monk Seals

We studied reproductive rate, length of lactation period, pup survival, and mortality of injured and uninjured female Hawaiian monk seals (Monachus schauinslandi) on Laysan Island, northwestern Hawaiian Islands, in 1983 – 1989. The severity and timing of nonfatal injuries were influential in determining their effect on female reproductive success. There was a tendency towards a shorter mean lactation period and lower survival rate of pups for females with major injuries than for uninjured females. Females with minor injuries were similar to uninjured females in terms of reproductive rate, length of lactation, and pup survival. For females injured shortly before the birth of their pup or during lactation, pup survival was lower than for uninjured females, whereas for females injured during the year prior to pupping, measures of reproductive success were not significantly different from those for uninjured females. Immature (aged 4 – 8 years) females entering the reproductive population were injured by adult male seals significantly more often than females aged 0 – 3 years, but at a similar rate to adult females. The major effect of injuries on female reproductive success is an increase in female mortality: 87.5 % of the adult females (n = 16) that died on Laysan Island in 1983 – 1989 sustained injuries from adult male seals.

scholarly journals Foraging interaction between monk seals and large predatory fish in the Northwestern Hawaiian Islands

2008 ◽  
Vol 4 ◽  
pp. 299-308 ◽  
Author(s):  
FA Parrish ◽  
GJ Marshall ◽  
B Buhleier ◽  
GA Antonelis
Keyword(s):  
Hawaiian Islands ◽  
Predatory Fish ◽  
Northwestern Hawaiian Islands ◽  
Monk Seals

scholarly journals Population‐level impacts of natural and anthropogenic causes‐of‐death for Hawaiian monk seals in the main Hawaiian Islands

2020 ◽  
Author(s):  
Albert L. Harting ◽  
Michelle M. Barbieri ◽  
Jason D. Baker ◽  
Tracy A. Mercer ◽  
Thea C. Johanos ◽  
...  
Keyword(s):  
Causes Of Death ◽  
Hawaiian Islands ◽  
Population Level ◽  
Monk Seals

Movements and home ranges of monk seals in the main Hawaiian Islands

2017 ◽  
Vol 33 (4) ◽  
pp. 1080-1096 ◽  
Author(s):  
Kenady Wilson ◽  
Charles Littnan ◽  
Andrew J. Read
Keyword(s):  
Hawaiian Islands ◽  
Home Ranges ◽  
Monk Seals

Organochlorine contaminants in endangered Hawaiian monk seals from four subpopulations in the Northwestern Hawaiian Islands

2008 ◽  
Vol 56 (2) ◽  
pp. 231-244 ◽  
Author(s):  
Gina M. Ylitalo ◽  
Matthew Myers ◽  
Brent S. Stewart ◽  
Pamela K. Yochem ◽  
Robert Braun ◽  
...  
Keyword(s):  
Hawaiian Islands ◽  
Organochlorine Contaminants ◽  
Northwestern Hawaiian Islands ◽  
Monk Seals

Survey for Selected Pathogens and Evaluation of Disease Risk Factors for Endangered Hawaiian Monk Seals in the Main Hawaiian Islands

EcoHealth ◽  
2006 ◽  
Vol 3 (4) ◽  
pp. 232-244 ◽  
Author(s):  
Charles L. Littnan ◽  
Brent S. Stewart ◽  
Pamela K. Yochem ◽  
Robert Braun
Keyword(s):  
Risk Factors ◽  
Disease Risk ◽  
Hawaiian Islands ◽  
Monk Seals

Prevalence of interactions between Hawaiian monk seals (Nemonachus schauinslandi) and nearshore fisheries in the main Hawaiian Islands

2017 ◽  
Vol 23 (1) ◽  
pp. 25 ◽  
Author(s):  
K. S. Gobush ◽  
T. A. Wurth ◽  
J. R. Henderson ◽  
B. L. Becker ◽  
C. L. Littnan
Keyword(s):  
Hawaiian Islands ◽  
Mortality Factors ◽  
Large Circle ◽  
Gill Net ◽  
Seal Population ◽  
Positive Growth ◽  
One Year ◽  
Fisheries Interactions ◽  
Monk Seals ◽  
Interaction Versus

We determine the prevalence and characteristics of interactions between the Hawaiian monk seal (Nemonachus schauinslandi) and nearshore fisheries in the main Hawaiian Islands and examine impacts to the subpopulation. We documented 139 monk seal–fisheries interactions between 1976 and 2014: 132 hookings typically involving large circle hooks accompanied by slide-bait rigging, and 7 gill-net entanglements. We individually identified 297 monk seals between 1988 and 2014 and recorded that 83 (28%) of these had at least one documented hooking or entanglement. Most individuals were aged two years or younger and a quarter of them were hooked or entangled multiple times. Documented fisheries interactions typically occurred at a monk seal’s natal island and most frequently on Kauai and Oahu. Fisheries interaction was directly implicated in 11 monk seal deaths and was slightly higher in frequency than other known mortality factors. The proportion of monk seals alive one year after a documented fisheries interaction varied by age class and ranged between 76% and 84%. Survival one year later for monk seals with a documented fisheries interaction versus matched controls (all age classes combined) was not significantly different. Nonetheless, fully understanding the scale and impacts of fisheries interactions, as well as mitigating these impacts, is important if the monk seal population of the main Hawaiian Islands is to maintain a positive growth trajectory.

scholarly journals Integrating multiple technologies to understand the foraging behaviour of Hawaiian monk seals

2017 ◽  
Vol 4 (3) ◽  
pp. 160703 ◽  
Author(s):  
Kenady Wilson ◽  
Charles Littnan ◽  
Patrick Halpin ◽  
Andrew Read
Keyword(s):  
Foraging Behaviour ◽  
Management Strategies ◽  
Hawaiian Islands ◽  
Ground Truth ◽  
Dive Depth ◽  
Body Motion ◽  
Sea Floor ◽  
Overall Dynamic Body Acceleration ◽  
Bayesian Logistic Regression ◽  
Monk Seals

The objective of this research was to investigate and describe the foraging behaviour of monk seals in the main Hawaiian Islands. Specifically, our goal was to identify a metric to classify foraging behaviour from telemetry instruments. We deployed accelerometers, seal-mounted cameras and GPS tags on six monk seals during 2012–2014 on the islands of Molokai, Kauai and Oahu. We used pitch, calculated from the accelerometer, to identify search events and thus classify foraging dives. A search event and consequent ‘foraging dive’ occurred when the pitch was greater than or equal to 70° at a depth less than or equal to −3 m. By integrating data from the accelerometers with video and GPS, we were able to ground-truth this classification method and identify environmental variables associated with each foraging dive. We used Bayesian logistic regression to identify the variables that influenced search events. Dive depth, body motion (mean overall dynamic body acceleration during the dive) and proximity to the sea floor were the best predictors of search events for these seals. Search events typically occurred on long, deep dives, with more time spent at the bottom (more than 50% bottom time). We can now identify where monk seals are foraging in the main Hawaiian Islands (MHI) and what covariates influence foraging behaviour in this region. This increased understanding will inform management strategies and supplement outreach and recovery efforts.

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