scholarly journals Contingent strategies of risk management by snowshoe hares

FACETS ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 407-422
Author(s):  
Douglas W. Morris
Keyword(s):  
Risk Management ◽  
Full Moon ◽  
Lepus Americanus ◽  
Moon Phase ◽  
Snowshoe Hares ◽  
Manipulative Experiments ◽  
Energetic State ◽  
New Moon ◽  
Adaptive Behaviours ◽  
Reduced Risk

Prey individuals employ several adaptive behaviours to reduce predation risk. We need to learn how those behaviours interact in an overall strategy of risk management, how strategies vary with changing conditions, and whether some behaviours might compensate for others. I addressed these issues with manipulative experiments evaluating how snowshoe hares’ ( Lepus americanus) vigilance varies with their giving-up densities (GUDs) in artificial food patches. I tested whether the results, collected when there was no evidence of predation, were congruent with an earlier study under higher predation. When predator sign was common, vigilance depended directly on habitat. But when risk was low, habitat’s influence on vigilance was indirect. Hares were least vigilant during the new moon where the distance to escape habitat was far, but only in open risky habitat. Hares were more vigilant during the full moon, but only at stations far from escape habitat. Moon phase and additional cover had no effect on GUDs that were highest at open risky stations far from escape habitat. The results suggest that reduced risk allowed hares to allocate less time to vigilance, but they needed to forage for similar amounts of food during each moon phase to maintain their energetic state.

scholarly journals Morfometri Portunus pelagicus Linnaeus, 1758 (Malacostraca : Portunidae) Pada Fase Bulan Yang Berbeda Di Perairan Betahwalang, Demak

2019 ◽  
Vol 8 (2) ◽  
pp. 204-210
Author(s):  
Errizal Machmud Putra ◽  
Rini Pramesti ◽  
Gunawan Widi Santosa
Keyword(s):  
Full Moon ◽  
Environmental Parameters ◽  
Moon Phase ◽  
Swimming Crab ◽  
The Moon ◽  
Portunus Pelagicus ◽  
Natural Factors ◽  
New Moon ◽  
Descriptive Method

Rajungan (Portunus pelagicus) merupakan komoditas unggulan Indonesia. Perairan Betahwalang, Kabupaten Demak memiliki sumberdaya rajungan yang  potensial dengan tingkat eksploitasi yang tinggi. Rajungan ini ditangkap setiap hari tanpa memperhatikan faktor alam berupa fase bulan yang menyebabkan menurunnya populasi. Informasi penangkapan berdasarkan fase bulan diperlukan agar populasi rajungan dapat terjaga. Tujuan Penelitian ini adalah mengkaji jumlah dan sebaran morfometri rajungan yang tertangkap pada fase bulan purnama dan bulan baru di perairan Betahwalang. Penelitian ini dilakukan dari November 2017 sampai Februari 2018 di perairan Betahwalang. Metode penelitian yang digunakan yaitu metode deskriptif. Penentuan lokasi penelitian berdasarkan area penangkapan rajungan di perairan Betahwalang. Pengambilan data dilakukan 8 kali dari tanggal 5 November 2017 sampai 18 Februari 2018. Pengambilan data berupa jumlah, lebar karapas, berat, jenis kelamin rajungan, dan parameter lingkungan. Hasil penelitian menunjukkan total rajungan tertangkap yaitu 448 ekor, 296 ekor pada Bulan Purnama dan 152 ekor pada Bulan Baru. Morfometri rajungan ukuran ≤ 10 cm pada Bulan Purnama 190 ekor lebih banyak dari Bulan Baru 90 ekor. Rajungan ukuran > 10 cm pada Bulan Baru 106 ekor lebih banyak dari Bulan Baru 62 ekor. Blue Swimming Crab (Portunus pelagicus) is Indonesia's flagship commodity. The waters of Betahwalang, Demak Regancy have potential Blue Swimming Crab resources with high levels of exploitation.  The crabs are catched every day regardless of natural factors, such as the moon phase that causes the population to decline. Blue Swimming Crab catch’s information based on the moon phase is required for the population to sustaine. The purpose of this research is to study the amount and distribution of Blue Swimming Crab morphometry catched on the full and new moon phase in Betahwalang waters. The study was conducted from November  2017 till February 2018 in the waters of Betahwalang. The research method used was descriptive method. Determination of research location based on Blue Swimming Crab catching area in Betahwalang waters. The data were collected 8 times from November 5, 2017 till February 18, 2018. Data were collected in number, width of carapace, weight, sex, and environmental parameters. The results showed total of catched crabs, were 296 crabs on Full Moon, and 152 crabs on New Moon. Blue Swimming Crab morphometry size ≤ 10 cm on Full Moon was 190 crabs more than New Moon was 90 crabs. Then, in Size> 10 cm on New Moon was 106 crabs more than New Moon was 62 crabs.

Activity of Microtus pennsylvanicus related to moon phase and moonlight revealed by the sand transect technique

1969 ◽  
Vol 47 (6) ◽  
pp. 1183-1186 ◽  
Author(s):  
G. J. Doucet ◽  
J. R. Bider
Keyword(s):  
Population Growth ◽  
Full Moon ◽  
Microtus Pennsylvanicus ◽  
Moon Phase ◽  
The Moon ◽  
Moon Phases ◽  
Paired Samples ◽  
Sampling Sequence ◽  
New Moon

Activity of Microtus pennsylvanicus was recorded as the number of crossings per day over a sand transect during four consecutive summers. Appropriate samples were selected to test the effects of both moon phases and moonlight on activity. Initially the results of tests comparing new moon to full moon phases showed that the voles were more active during new moon in only 3 of 10 discreet paired samples tested. However, when the effects of sampling sequence, phenology of population growth, date at which moon phases occurred, and, finally, the effect of climate were all considered as factors which could have affected the above results, it seemed reasonable to conclude that the new moon phase tended to be associated with higher activity. To establish if moonlight by itself, independent of phases, was a factor affecting the activity, tests were made during brightest and darkest nights of the lunar month and results indicated that moonlight did not affect the differences in activity found in the moon phase tests.

scholarly journals Biologi Kepiting Bakau Scylla Serrata, Forsskål, 1775 (Malacostraca : Portunidae) Berdasarkan Pola Pertumbuhan dan Parameter Pertumbuhan pada Bulan Oktober, November, Desember di Perairan Ketapang, Pemalang

2020 ◽  
Vol 9 (1) ◽  
pp. 87-93
Author(s):  
Naily Fitriyani ◽  
Chrisna Adhi Suryono ◽  
Ria Azizah Tri Nuraini
Keyword(s):  
Size Distribution ◽  
Full Moon ◽  
Condition Factor ◽  
Food Sources ◽  
Scylla Serrata ◽  
Survey Method ◽  
Growth Equation ◽  
Moon Phase ◽  
Mangrove Crab ◽  
New Moon

ABSTRAK: Desa Ketapang, Pemalang merupakan salah satu sumber potensi tangkapan kepiting yang memiliki nilai ekonomis tinggi. Tingginya permintaan pasar baik lokal maupun global menyebabkan  naiknya penangkapan kepiting tanpa adanya restocking sepanjang tahun. Hal ini mengkhawatirkan kondisinya di alam. Penelitian ini bertujuan untuk memonitoring kepiting bakau (Scylla serrata) di Perairan Desa Ketapang, Pemalang dengan mengetahui distribusi ukuran, pola pertumbuhan dan faktor kondisi, serta nilai parameter pertumbuhan berdasarkan persamaan Von Bertalanff. Penelitian ini dilakukan pada bulan Oktober-Desember 2019 dengan 2 kali pengambilan dalam 1 bulan (fase bulan purnama dan fase bulan baru). Metode pengumpulan data pada penelitian ini menggunakan metode survei. Data tangkapan kepiting bakau diperoleh dari hasil tangkapan nelayan yang ada di pengepul kepiting Desa Ketapang. Pengolahan data dilakukan dengan menggunakan Ms. Excel 2013 dan FISAT II. Distribusi ukuran rata-rata lebar karapas kepiting pada bulan purnama yaitu 40,38 ± 7,98 mm, sedangkan pada bulan baru yaitu 39,89 ± 6,48 mm. Pola pertumbuhan kepiting pada bulan Oktober – Desember 2019 menunjukkan pola pertumbuhan allometrik negative (b<3) dengan nilai faktor kondisi diatas 100, yang berarti wilayah Perairan Desa Ketapang mempengaruhi pertumbuhan kepiting dari segi sumber makanan. Didapatkan nilai persamaan pertumbuhan pada saat bulan purnama adalah Lt = 30.8 (1-exp(0.51(t+1.93264))) , sedangkan pada bulan baru adalah Lt = 30.5 (1-exp(4.56(t+0.19933))). ABSTRACT: Ketapang is one of village in Pemalang which has potential sources of crab catches that have high economic value. The high demand of local and global markets cause an increasing in crab catch without any restocking throughout the year. It is worrying about its condition in nature. The study aims to monitor mangrove crabs (Scylla serrata) in Ketapang waters, Pemalang by knowing the size distribution, pattern growth, condition factor, and the value of growth parameters based on The equation Von Bertalanff. The study has been conducted in October-December 2019 with 2 retrievals in 1 month (Full moon phase and New Moon phase). The method of collecting data on this study uses the survey method. Mangrove Crab capture Data is obtained from the catch of fishermen in the crab-Pinke Ketapang village. Data was analyse used Ms. Excel 2013 And FISAT II software. The average size distribution of crab carapace in the full moon is 40.38 ± 7.98 mm, while in the New Moon is 39.89 ± 6.48 mm. The pattern of crab growth in October – December 2019 showed negative allometri growth pattern (b<3) with condition factor value above 100, which means the water area of Ketapang village affects the growth of crabs in terms of food sources. Acquired value of growth equation during full moon is Lt = 30.8 (1-exp (0.51 (t + 1.93264))), while the new Moon is Lt = 30.5 (1-exp (4.56 (t + 0.19933))).

Moonlight is a key entrainer of lunar clock in the brain of the tropical grouper with full moon preference

BMC Zoology ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Kodai Fukunaga ◽  
Fumika Yamashina ◽  
Yuki Takeuchi ◽  
Chihiro Yamauchi ◽  
Akihiro Takemura
Keyword(s):  
Pituitary Gland ◽  
Full Moon ◽  
Clock Genes ◽  
Lunar Cycle ◽  
Moon Phase ◽  
Transcript Levels ◽  
New Moon ◽  
Cycle Dependent ◽  
Honeycomb Grouper ◽  
Reproductive Cycles

Abstract Background Many animals in coral reefs exhibit lunar cycles in their reproduction, showing synchronous gametogenesis and spawning at a particular moon phase. How these lunar reproductive cycles are endogenously regulated remains unknown, although changes in moonlight between the new moon and full moon are likely involved in this rhythmic event. Results This study evaluated the possible role of cryptochrome (cry1, cry2, cry3) in phase shifting and setting in the honeycomb grouper Epinephelus merra, which is a typical lunar spawner with full moon preference. qPCR analysis revealed that when fish were reared under alternating light-dark conditions, the transcript levels of cry1 and cry2, but not of cry3, in the diencephalon and pituitary gland showed daily variations. Weekly collection at midnight showed increases in the transcript levels of cry1 and cry2 in the diencephalon, but not the pituitary gland, from the first quarter moon through the last quarter moon. In comparison to the new moon, these transcript levels were significantly lower at all other sampling times. The artificial full moon conditions for 1 month resulted in increased cry transcript levels in both tissues at 2 (cry1) or 2 and 4 (cry2) weeks after the initiation of full moon conditions. Conclusions These results indicate the importance of transient changes in “brightness at night” in the response to moonlight for the phase shift and of “darkness at night” during the new moon for the phase set to the determined moon phase. We concluded that the moon phase-dependent oscillation of clock genes plays a role in lunar cycle-dependent behaviors in fish.

scholarly journals Kajian Morfometri Rajungan (Portunus pelagicus) Linnaeus, 1758 (Crustacea: Portunidae) pada Dua Fase Bulan yang Berbeda di Perairan Desa Tunggulsari, Rembang

2021 ◽  
Vol 10 (1) ◽  
pp. 109-116
Author(s):  
Wukir Berliana Pratiwi ◽  
Ria Azizah Tri Nuraini ◽  
Widianingsih Widianingsih
Keyword(s):  
Full Moon ◽  
Carapace Width ◽  
Major Influence ◽  
Lunar Phase ◽  
Exploratory Research ◽  
Moon Phase ◽  
Portunus Pelagicus ◽  
Moon Phases ◽  
Research Activities ◽  
New Moon

Fase bulan secara periodik mengalami perubahan dan menjadi faktor yang mempengaruhi perairan secara fisika, kimia, maupun biologi. Kondisi tersebut di wilayah perairan laut menimbulkan fenomena pasang surut yang memiliki pengaruh besar terhadap kehidupan biota laut seperti rajungan (Portunus pelagicus). Strategi penangkapan yang tepat dapat dilakukan dengan menentukan target satu spesies atau dengan cara melihat fase bulan. Penelitian ini bertujuan untuk melakukan kajian morfometri, nisbah kelamin, hubungan lebar berat, dan tingkat kematangan gonad rajungan (Portunus pelagicus) yang tertangkap nelayan pada fase bulan purnama dan bulan mati dari Perairan Desa Tunggulsari, Rembang. Pengambilan data dilakukan terhadap rajungan (Portunus pelagicus) yang tertangkap oleh nelayan dari perairan Desa Tunggulsari. Kegiatan penelitian dilakukan pada tanggal 9 Januari 2020, 28 Januari 2020, 10 Februari 2020, 25 Februari 2020, 10 Maret 2020, dan 24 Maret 2020. Hasil penelitian berdasarkan uji T statistik menunjukkan bahwa ada perbedaan komposisi rajungan dari fase bulan purnama dan bulan mati dengan selisih yang tidak signifikan. Rajungan yang tertangkap pada fase bulan purnama memiliki rata-rata ukuran berat dan lebar yang lebih kecil dibandingkan pada fase bulan mati. Analisis power curve hubungan lebar dan berat rajungan yang ada di perairan Desa Tunggulsari bersifat allometrik negatif yang berarti pertumbuhan lebar karapas lebih cepat dibandingkan beratnya.  The lunar phase periodically changes and becomes a factor that affects the waters physically, chemically, and biologically. These conditions in the marine waters cause tidal phenomena which have a major influence on marine life such as blue swimming crab (Portunus pelagicus). The right fishing strategy can be done by determining the target of one species or by looking at the phases of the moon. This study aims to study the morphometry, sex ratio, weight-width relationship, and maturity level of the crab gonads (Portunus pelagicus) caught by fishermen in the full moon and new moon phases of the Tunggulsari Waters, Rembang. The method used in this research is descriptive exploratory. Research activities were carried out on January 9, 2020, January 28, 2020, February 10, 2020, February 25, 2020, March 10, 2020, and March 24, 2020. The results of the study based on the statistical T test showed that there was an insignificant difference in the catch of the full moon and new moon phases. The crabs that are caught in the full moon phase have an average size of weight and width that is smaller than in the new moon phase. Analysis of the relationship between the width and weight of small crabs in the waters of Tunggulsari Waters is negative allometric, which means that the carapace width grows faster than its weight.

scholarly journals Moon phase effect on investor psychology and stock trading performance

2014 ◽  
Vol 41 (3) ◽  
pp. 182-200 ◽  
Author(s):  
Rayenda Brahmana ◽  
Chee-Wooi Hooy ◽  
Zamri Ahmad
Keyword(s):  
Online Survey ◽  
Full Moon ◽  
Investment Strategy ◽  
Quantitative Model ◽  
Moon Phase ◽  
Stock Trading ◽  
Content Type ◽  
Stock Market Performance ◽  
Quasi Experimental ◽  
New Moon

Purpose – This article aims to examine how investor moods and aggressiveness differ in their state and influence investor stock market performance associated with the moon phase. The mechanisms and impact of full moon gravity on investor stock trading performance are explored through an experimental approach and econometrics model. Design/methodology/approach – A time-series quasi-experimental study, using the full moon and new moon time periods, was coupled with a psychometric test of investors' behaviours, administered through an online survey, similar to a pre-post experiment. Confirmation of the results was achieved by using an econometric model, adopted from Dichev and Janes. Findings – This research found that investor psychology is influenced by the full moon, but no effect was recorded during the new moon phase. Confirmed by the paired t-difference test, the small correlation, in addition to the quantitative model, the results show the full moon impacts market behaviour during its orbital phase. Consequently, the authors surmise that the full moon does influence investor cognition and emotion disarray, mood disorders, and aggressiveness, resulting in poor stock trading performance. Practical implications – The need for an active investment strategy is the major implication of this study. During the full moon phase, investors tend to be more aggressive and moody and seek hedonic utility instead of the traditional economics utility, meaning that they tend to follow the sentiment of the market. Originality/value – This paper fulfils an identified need to study how the full moon affects investor stock trading performance.

scholarly journals Plankton population and physico-chemical properties of a lake of Jahangirnagar University campus, Bangladesh at various lunar rhythms

2016 ◽  
Vol 4 (2) ◽  
pp. 31-36
Author(s):  
Most Fahima Ahmed Anny ◽  
Ismot Ara
Keyword(s):  
Full Moon ◽  
Chemical Properties ◽  
Abundant Species ◽  
Lunar Cycle ◽  
Moon Phase ◽  
University Campus ◽  
Physico Chemical ◽  
Free Carbon Dioxide ◽  
New Moon ◽  
Abundant Phytoplankton

Planktonic biomass and physico-chemical properties of water from a lake at Jahangirnagar University, Bangladesh were studied during new moon, first quarter, full moon and last quarter phases from 16th June to 15th July 2015. Twenty four species of phytoplankton belonging to Chlorophyceae, Bacillariophyceae and Euglenophyceae were recorded. Maximum abundance (162-301 unit/l) of Chlorophyceae was recorded in first quarter phase followed by full moon phase (112-224 unit/l), new moon phase (85-222unit/l) and last quarter phase (60-125 unit/l), respectively. Chlorella vulgaris and Biddulphia aurita were the most abundant phytoplankton throughout the lunar period. Among the zooplankton, 5 species of Protozoa, 2 species of Rotifer, 3 species of Cladocera and 1 species of Ostracoda were recorded. Highest zooplankton was recorded in full moon phase (54-105 unit/l) and Daphnia cephalata was the most abundant species throughout the lunar cycle. Physico-chemical parameters indicate that the water temperature, colour, odour and pH were almost similar throughout the lunar cycle, whereas maximum dissolved oxygen (7.16 mg/l) and minimum (4.43 mg/l) were found during the last quarter and the full moon phase, respectively. The highest content of free carbon dioxide (4.36 mg/l) and chloride (22.8 mg/l) were recorded during first quarter and full moon phase accordingly.Jahangirnagar University J. Biol. Sci. 4(2): 31-36, 2015 (December)

Influence of moon phase on acoustic estimates of the abundance of fish performing daily horizontal migration in a small oligotrophic lake

2000 ◽  
Vol 57 (3) ◽  
pp. 581-590 ◽  
Author(s):  
Nathalie Gaudreau ◽  
Daniel Boisclair
Keyword(s):  
Littoral Zone ◽  
Full Moon ◽  
Relative Number ◽  
Sampling Strategy ◽  
Fish Populations ◽  
Pelagic Zone ◽  
Moon Phase ◽  
The Moon ◽  
Horizontal Migration ◽  
New Moon

We tested the influence of the moon phase on the relative number of fish performing daily horizontal migrations and we used this information to develop a sampling strategy that accounted for expected effects of the moon phase on fish behavior. Hydroacoustic surveys were performed over 3 days at each moon phase for the months of July and August (from the day before to the day after the new moon, the first and last quarter moon, and the full moon). Dace (Phoxinus eos × Phoxinus neogaeus) migrated from the littoral towards the pelagic zone at dusk and returned to the littoral zone at dawn. Their relative abundance (FRA) in the pelagic zone averaged 0.1 fish echo·m-3 during midday and 17.0 fish echoes·m-3 at night. The number of dace performing horizontal movements was eightfold larger during new-moon than full-moon nights. Simulations indicated that sampling fish populations six times during a 2-month period (once at full, new, and quarter moon; once during the day and once during the night) provided the most accurate estimates of FRA.

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