Acoustic tracking: issues affecting design, analysis and interpretation of data from movement studies

2012 ◽  
Vol 63 (4) ◽  
pp. 312 ◽  
Author(s):  
Jason Richard How ◽  
Simon de Lestang
Keyword(s):  
Acoustic Telemetry ◽  
Full Moon ◽  
Water Movement ◽  
Lunar Cycle ◽  
Time Of Day ◽  
Detection Distance ◽  
Detection Rates ◽  
Detection Frequency ◽  
Analytical Work ◽  
Power Outputs

Acoustic telemetry systems are an increasingly common way to examine the movement and behaviour of marine organisms. However, there has been little published on the methodological and analytical work associated with this technology. We tested transmitters of differing power outputs simultaneously in several trials, some lasting ~50 days, to examine the effects of power output and environmental factors (water movement, temperature, lunar cycle and time of day). There were considerable and volatile changes in detections throughout all trials. Increased water movement and temperature significantly reduced detection rates, whereas daytime and full-moon periods had significantly higher detection rates. All nine transmitters (from seven transmitter types tested) showed a sigmoidal trend between detection frequency and distance. Higher-powered transmitters had a prolonged detection distance with near-maximal detections, whereas lower-powered transmitters showed an almost immediate decline. Variation of detection frequency, transmitter type and the modelled relationship between distance and detection frequency were incorporated into a positioning trial which resulted in markedly improved position estimates over previous techniques.

Lunar Cycle Influences Reproductive Performance of Crossbred Brahman Cows Under Tropical Conditions

2021 ◽  
pp. 074873042098363
Author(s):  
Alejandro A. Aguirre ◽  
Roberto A. Palomares ◽  
Aitor D. De Ondiz ◽  
Eleazar R. Soto ◽  
Mariana S. Perea ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Full Moon ◽  
Lunar Cycle ◽  
The Moon ◽  
Crossbred Cows ◽  
Lunar Phases ◽  
Tropical Conditions ◽  
Service Conception ◽  
New Moon ◽  
Postpartum Estrus

Evidence has accumulated over the years indicating that the moon influences some aspects of the reproductive activity in animals and humans. However, little is known about the influence of the lunar cycle on the reproductive performance of cows under tropical conditions, where the environment strongly affects reproduction. This retrospective study was conducted with the aim of assessing the influence of the lunar cycle on some reproductive traits of tropical crossbred cows managed in a pasture-based system. Data from 5869 reproductive records from two commercial farms localized in the Maracaibo Lake Basin of Zulia State, Venezuela, were analyzed. Variables studied were first service conception rate, calving frequency, first postpartum estrous frequency, and pregnancy frequency. In addition to the lunar cycle, the effects of farm, season, and predominant breed were also considered. Data were analyzed using logistic regression and general linear model from SAS. First service conception was affected by lunar phases and predominant breed, but not by farm or season. For frequencies of calving, first postpartum estrus, and pregnancy, there was no main effect of farm, season, and predominant breed, whereas the effect of lunar phases was highly significant. First service conception was significantly greater in waning than in crescent phase of the lunar cycle. Frequencies of calving, first estrus, and pregnancy were highly correlated and showed greater figures around full moon and new moon. In conclusion, lunar cycle influenced first service conception, attaining greater values in the waning phase of the moon cycle. Frequencies of calving, first postpartum estrus, and pregnancy in crossbred cows showed a clear bimodal rhythm, whose greatest values coincided with new moon and full moon.

scholarly journals Lessons learned from comparing spatially explicit models and the Partners in Flight approach to estimate population sizes of boreal birds in Alberta, Canada

The Condor ◽  
2020 ◽  
Vol 122 (2) ◽  
Author(s):  
Péter Sólymos ◽  
Judith D Toms ◽  
Steven M Matsuoka ◽  
Steven G Cumming ◽  
Nicole K S Barker ◽  
...  
Keyword(s):  
North America ◽  
Time Of Day ◽  
Lessons Learned ◽  
Population Estimates ◽  
Spatially Explicit ◽  
Species Variation ◽  
Detection Distance ◽  
Spatially Explicit Models ◽  
Population Sizes ◽  
Partners In Flight

Abstract Estimating the population abundance of landbirds is a challenging task complicated by the amount, type, and quality of available data. Avian conservationists have relied on population estimates from Partners in Flight (PIF), which primarily uses roadside data from the North American Breeding Bird Survey (BBS). However, the BBS was not designed to estimate population sizes. Therefore, we set out to compare the PIF approach with spatially explicit models incorporating roadside and off-road point-count surveys. We calculated population estimates for 81 landbird species in Bird Conservation Region 6 in Alberta, Canada, using land cover and climate as predictors. We also developed a framework to evaluate how the differences between the detection distance, time-of-day, roadside count, and habitat representation adjustments explain discrepancies between the 2 estimators. We showed that the key assumptions of the PIF population estimator were commonly violated in this region, and that the 2 approaches provided different population estimates for most species. The average differences between estimators were explained by differences in the detection-distance and time-of-day components, but these adjustments left much unexplained variation among species. Differences in the roadside count and habitat representation components explained most of the among-species variation. The variation caused by these factors was large enough to change the population ranking of the species. The roadside count bias needs serious attention when roadside surveys are used to extrapolate over off-road areas. Habitat representation bias is likely prevalent in regions sparsely and non-representatively sampled by roadside surveys, such as the boreal region of North America, and thus population estimates for these regions need to be treated with caution for certain species. Additional sampling and integrated modeling of available data sources can contribute towards more accurate population estimates for conservation in remote areas of North America.

scholarly journals Lunar periodicity in catch rate and reproductive condition of adult eastern king prawns, Penaeus plebejus, in coastal waters of south-eastern Queensland, Australia

1996 ◽  
Vol 47 (1) ◽  
pp. 67 ◽  
Author(s):  
AJ Courtney ◽  
DJ Die ◽  
JG McGilvray
Keyword(s):  
Coastal Waters ◽  
Full Moon ◽  
Lunar Cycle ◽  
Catch Rate ◽  
Lunar Phase ◽  
Reproductive Condition ◽  
Ovary Weight ◽  
South Eastern ◽  
New Moon ◽  
Catch Rates

This study examined the lunar and die1 variation in catch rates and reproductive condition of adult eastern king prawns, Penaeus plebejus, in relatively deep (160 m) coastal waters off south- eastern Queensland. Females numerically dominated catches over most of the lunar cycle and constituted 76% of the weight of the catch. Analysis of variance (ANOVA) revealed an interaction between lunar phase and sex; catches peaked during Lunar Phase 3 (full moon � 3 days) and were particularly marked for males. This was the only period during the lunar cycle when the sex ratio approached 1 : 1. There was also an interaction between trawl-time and sex; male catch rates were at a minimum early in the evening, whereas female catch rates were at a maximum then and declined throughout the night. Trawler logbook catch rate data from the same area over a similar period indicated an interaction between lunar cycle and lunar phase. ANOVA revealed an effect of the interaction between phase and sex on the incidence of soft prawns; the incidence of soft males increased during Phase 4 (half moon waning to new moon � 3 days). Ovary weight also varied between phases and was higher during Phases 2 (half moon waxing to full moon � 3 days) and 4 (half moon waning to new moon � 3 days). Trends in the ovary weight and the incidence of histologically mature and ripe females suggested there are two periods of increased spawning activity during each lunar cycle. A cyclic regression fitted to the data explained 93% of the variation in the incidence of ripe females between samples. The influence of these cyclic trends in catch rate and reproductive condition should be considered when monitoring the spawning stock in the fishery and when planning sampling strategies in any future reproductive studies.

Lunar Cycle Influences Production of Tilapia (Oreochromis spp) Eggs in an Intensive Outdoor Production System in the Tropics

2022 ◽  
pp. 074873042110694
Author(s):  
Miguel F. Perea ◽  
Daniel A. Perdomo ◽  
Zenaida A. Corredor ◽  
Mario González ◽  
Hugo Hernandez-Fonseca ◽  
...  
Keyword(s):  
Production System ◽  
Full Moon ◽  
Farming Systems ◽  
Fish Farming ◽  
Reproductive Activity ◽  
Lunar Cycle ◽  
Natural Environments ◽  
The Moon ◽  
Commercial Fish ◽  
The Tropics

A robust body of evidence has demonstrated that the lunar cycle plays an important role in the reproduction of fish living in natural environments. However, little is known about the influence of the moon on tilapia reproductive activity in intensive fish farming systems. This study aims to evaluate the influence of the lunar cycle on the reproductive performance of tilapias in an intensive outdoor tropical production system in Latin America. Records of two tilapia strains (Nile tilapia [ Oreochromis niloticus; n = 75] and Red tilapia [ Oreochromis spp.; n = 1335]) reared in concrete tanks in a commercial fish farm were analyzed. Over a 3-year period, 60,136 captures were made in intervals of 12 to 14 days and 6,600 females were manually spawned. The number of females spawned and the volume of eggs collected from each tank ( n = 9) were recorded. Data was analyzed by the general linear model and means were compared by least squares means method. A very slight or no variation was observed when the lunar cycle was split into two halves (crescent and waning). The proportions of females spawned and the volume of eggs per spawned female and per female in the tank varied considerably across the eight periods of the lunar cycle, with greater values in the waning than in the crescent phase. A significantly greater proportion of tilapia spawned and yielded more eggs around the full moon than around the new moon and remaining days of the lunar cycle. The moon cycle affected the reproductive activity of tilapia, which were more reproductively active around the full moon and most of the waning phase.

Factors affecting the detection of possums by spotlighting in Western Australia

2005 ◽  
Vol 32 (8) ◽  
pp. 689 ◽  
Author(s):  
A. F. Wayne ◽  
A. Cowling ◽  
J. F. Rooney ◽  
C. G. Ward ◽  
I. B. Wheeler ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Lunar Cycle ◽  
Survey Method ◽  
Brushtail Possum ◽  
Start Time ◽  
Detection Rates ◽  
Eucalyptus Marginata ◽  
Factors Affecting ◽  
Abundance Estimates ◽  
Time Required

This paper describes how environmental factors, survey method procedures and differences in forest structure resulting from logging relate to the detection of koomal (common brushtail possum, Trichosurus vulpecula hypoleucus) and ngwayir (western ringtail possum, Pseudocheirus occidentalis). A total of 169 vehicle-based spotlight surveys of possums within native jarrah (Eucalyptus marginata) forest was conducted on three transects over eight years (1996–2003). Up to 5.7 koomal and up to 3.3 ngwayir were detected per kilometre per transect side. Only one ngwayir was detected during the eight surveys conducted between 2001 and 2003. More koomal were seen in spring and autumn (i.e. September–November and March–May respectively) and more ngwayir were seen between October and April. Although surveys were not conducted on very rainy or excessively windy nights, fewer possums were nonetheless seen on nights following rainy days and on cold nights. Cloud cover also affected sightings of koomal. The time taken to complete the surveys increased in conjunction with the number of possums detected, on account of the time required to record data. The importance of standardising travelling speed also is emphasised. Possum spotlight counts differed between recently logged and unlogged areas. However, these findings were not supported by complementary koomal abundance estimates derived from trapping, suggesting that vegetation structure may affect detectability. Factors such as the lunar cycle, wind speed and survey start time after sunset did not significantly affect detection rates of either species. On the basis of these findings, specific survey conditions can be selected to improve spotlight detection efficiency.

Crisis Calls and Lunar Cycles: A Twenty-Year Review

1992 ◽  
Vol 71 (3) ◽  
pp. 779-785 ◽  
Author(s):  
Gail Byrnes ◽  
I. W. Kelly
Keyword(s):  
Crisis Intervention ◽  
Full Moon ◽  
Lunar Cycle ◽  
Lunar Phase ◽  
Lunar Cycles ◽  
Poison Centers

12 studies are reviewed that have examined the relationships among crisis calls to police stations, poison centers, and crisis intervention centers and the synodic lunar cycle. On the basis of the studies considered it is concluded that no good foundation exists for the belief that lunar phase is related to the frequency of crisis calls. In addition, there is no evidence whatsoever for the contention that calls of a more emotional or “out-of-control” nature occur more often at the full moon.

scholarly journals TIMING OF LARVAL RELEASE BY REEF CORAL Pocillopora damicornis AT PANJANG ISLAND, CENTRAL JAVA

2018 ◽  
Vol 33 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Munasik ◽  
Suharsono ◽  
J. Situmorang ◽  
H. N. Kamiso
Keyword(s):  
Full Moon ◽  
Reef Coral ◽  
Lunar Cycle ◽  
Tidal Range ◽  
Pocillopora Damicornis ◽  
Larval Release ◽  
Double Peaks ◽  
Central Java ◽  
New Moon ◽  
Peak Release

Monthly larval release by the coral Pocillopora damicornis at Panjang Island, Central Java was investigated. Corals were collected from windward and leeward and maintained in outdoor, flow-trough system to quantify nightly release of larvae. Larval release of the coral occurs every month throughout the year, and its planulation increased during dry monsoon. Monthly planulation occurs from new moon to full moon and possesses in different pattern between single and paired colonies. Planulation in paired colonies occurred in single peak and more synchronized in each colony however single colonies planulated in double peaks and less synchronized in each colony. This study confirmed that planulation period of P. damicornis at Panjang Island over a range of lunar phases with shorter periods of peak release which predominantly controlling by tidal range rather than lunar cycle.

scholarly journals Reproductive phenology across the lunar cycle: parental decisions, offspring responses, and consequences for reef fish

2020 ◽  
Author(s):  
Jeffrey Shima ◽  
CW Osenberg ◽  
SH Alonzo ◽  
EG Noonburg ◽  
P Mitterwallner ◽  
...  
Keyword(s):  
Reef Fish ◽  
Egg Production ◽  
Life History Theory ◽  
Environmental Changes ◽  
Full Moon ◽  
Lunar Cycle ◽  
Adaptive Plasticity ◽  
Birth Date ◽  
Reproductive Phenology ◽  
New Moon

© 2020 by the Ecological Society of America Most organisms reproduce in a dynamic environment, and life-history theory predicts that this can favor the evolution of strategies that capitalize on good times and avoid bad times. When offspring experience these environmental changes, fitness can depend strongly upon environmental conditions at birth and at later life stages. Consequently, fitness will be influenced by the reproductive decisions of parents (i.e., birth date effects) and developmental decisions (e.g., adaptive plasticity) of their offspring. We explored the consequences of these decisions using a highly iteroparous coral reef fish (the sixbar wrasse, Thalassoma hardwicke) and in a system where both parental and offspring environments vary with the lunar cycle. We tested the hypotheses that (1) reproductive patterns and offspring survival vary across the lunar cycle and (2) offspring exhibit adaptive plasticity in development time. We evaluated temporal variation in egg production from February to June 2017, and corresponding larval developmental histories (inferred from otolith microstructure) of successful settlers and surviving juveniles that were spawned during that same period. We documented lunar-cyclic variation in egg production (most eggs were spawned at the new moon). This pattern was at odds with the distribution of birth dates of settlers and surviving juveniles—most individuals that successfully survived to settlement and older stages were born during the full moon. Consequently, the probability of survival across the larval stage was greatest for offspring born close to the full moon, when egg production was at its lowest. Offspring also exhibited plasticity in developmental duration, adjusting their age at settlement to settle during darker portions of the lunar cycle than expected given their birth date. Offspring born near the new moon tended to be older and larger at settlement, and these traits conveyed a strong fitness advantage (i.e., a carryover effect) through to adulthood. We speculate that these effects (1) are shaped by a dynamic landscape of risk and reward determined by moonlight, which differentially influences adults and offspring, and (2) can explain the evolution of extreme iteroparity in sixbars.

scholarly journals Use of unmanned aerial vehicles (UAVs) for mark-resight nesting population estimation of adult female green sea turtles at Raine Island

2020 ◽  
Author(s):  
Andrew Dunstan ◽  
Katherine Robertson ◽  
Richard Fitzpatrick ◽  
Jeff Pickford ◽  
Justin Meager
Keyword(s):  
Cost Effective ◽  
Accurate Method ◽  
Time Of Day ◽  
Correction Factors ◽  
Underwater Video ◽  
Survey Period ◽  
Detection Rates ◽  
Green Sea Turtles ◽  
Abundance Estimates ◽  
Aerial Vehicle

AbstractNester abundance is a key measure of the performance of the world’s largest green turtle rookery at Raine Island, Australia. Abundance surveys have been undertaken in waters adjacent to Raine Island reef using mark-resight counts by surface observer (SO), underwater video (UWV) and unmanned aerial vehicle (UAV) (since 1984, 2013 and 2016 respectively). UAV and UWV may provide more cost-effective and less biased alternatives, but estimates must be comparable with the historical estimates. Here we compare the three methods.The relative likelihood of resighting a marked turtle was significantly higher by SO than the other methods, which led to lower mark-resight population estimates than by UAV or UWV. Most (96%) variation in resighting probabilities was associated with survey period, with comparatively little variation between consecutive days of sampling or time of day. This resulted in preliminary correction factors of 1.53 and 1.73 from SO-UWV and SO-UAV, respectively. However, the SO and UWV estimates were the most similar when turtle densities were the lowest, suggesting that correction factors need to take into account turtle density and that more data are required.We hypothesise that the UAV and UWV methods improved detection rates of marked turtles because they allowed subsequent review and frame-by-frame analysis, thus reducing observer search error. UAVs were the most efficient in terms of survey time, personnel commitment and weather tolerance compared to the SO and UWV methods.This study indicates that using UAVs for in-water mark-resight turtle abundance estimation is an efficient and accurate method that can provide an accurate adjustment for historical abundance estimates. Underwater video may continue to be useful as a backup alternative to UAV surveys.

The Lunar Cycle Influences Time of Roost Departure in The Common Blossom Bat, Syconycteris australis.

1998 ◽  
Vol 20 (1) ◽  
pp. 21
Author(s):  
B.S. Law
Keyword(s):  
Full Moon ◽  
Behavioural Change ◽  
Lunar Cycle ◽  
Dark Phase ◽  
The Moon ◽  
The Common

Observations of radio-tagged Common Blossom Bats Syconycteris australis on the Atherton Tablelands, Queensland indicate that the time of departure from roost areas is related to the lunar cycle. During the dark phase of the moon, bats leave their roost between 5-20 mins after dark. Departure times are delayed up to 4 hrs between the period of the first quarter and full moon when the moon is bright after dusk. The predatory role of owls at night is suggested as the probable cause of this behavioural change.

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