Eyes On The Reef; using remote cameras on cleaning stations to uncover the hidden habits of Maldivian manta rays

2018 ◽  
Author(s):  
Simon Hilbourne Simon Hilbourne
2021 ◽  
Vol 11 (12) ◽  
pp. 5503
Author(s):  
Munkhjargal Gochoo ◽  
Syeda Amna Rizwan ◽  
Yazeed Yasin Ghadi ◽  
Ahmad Jalal ◽  
Kibum Kim

Automatic head tracking and counting using depth imagery has various practical applications in security, logistics, queue management, space utilization and visitor counting. However, no currently available system can clearly distinguish between a human head and other objects in order to track and count people accurately. For this reason, we propose a novel system that can track people by monitoring their heads and shoulders in complex environments and also count the number of people entering and exiting the scene. Our system is split into six phases; at first, preprocessing is done by converting videos of a scene into frames and removing the background from the video frames. Second, heads are detected using Hough Circular Gradient Transform, and shoulders are detected by HOG based symmetry methods. Third, three robust features, namely, fused joint HOG-LBP, Energy based Point clouds and Fused intra-inter trajectories are extracted. Fourth, the Apriori-Association is implemented to select the best features. Fifth, deep learning is used for accurate people tracking. Finally, heads are counted using Cross-line judgment. The system was tested on three benchmark datasets: the PCDS dataset, the MICC people counting dataset and the GOTPD dataset and counting accuracy of 98.40%, 98%, and 99% respectively was achieved. Our system obtained remarkable results.


2018 ◽  
Vol 285 (1892) ◽  
pp. 20181582 ◽  
Author(s):  
Calum X. Cunningham ◽  
Christopher N. Johnson ◽  
Leon A. Barmuta ◽  
Tracey Hollings ◽  
Eric J. Woehler ◽  
...  

Top carnivores have suffered widespread global declines, with well-documented effects on mesopredators and herbivores. We know less about how carnivores affect ecosystems through scavenging. Tasmania's top carnivore, the Tasmanian devil (Sarcophilus harrisii) , has suffered severe disease-induced population declines, providing a natural experiment on the role of scavenging in structuring communities. Using remote cameras and experimentally placed carcasses, we show that mesopredators consume more carrion in areas where devils have declined. Carcass consumption by the two native mesopredators was best predicted by competition for carrion, whereas consumption by the invasive mesopredator, the feral cat ( Felis catus ), was better predicted by the landscape-level abundance of devils, suggesting a relaxed landscape of fear where devils are suppressed. Reduced discovery of carcasses by devils was balanced by the increased discovery by mesopredators. Nonetheless, carcasses persisted approximately 2.6-fold longer where devils have declined, highlighting their importance for rapid carrion removal. The major beneficiary of increased carrion availability was the forest raven ( Corvus tasmanicus ). Population trends of ravens increased 2.2-fold from 1998 to 2017, the period of devil decline, but this increase occurred Tasmania-wide, making the cause unclear. This case study provides a little-studied potential mechanism for mesopredator release, with broad relevance to the vast areas of the world that have suffered carnivore declines.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0244787
Author(s):  
Christopher L. Cosgrove ◽  
Jeff Wells ◽  
Anne W. Nolin ◽  
Judy Putera ◽  
Laura R. Prugh

Dall’s sheep (Ovis dalli dalli) are endemic to alpine areas of sub-Arctic and Arctic northwest America and are an ungulate species of high economic and cultural importance. Populations have historically experienced large fluctuations in size, and studies have linked population declines to decreased productivity as a consequence of late-spring snow cover. However, it is not known how the seasonality of snow accumulation and characteristics such as depth and density may affect Dall’s sheep productivity. We examined relationships between snow and climate conditions and summer lamb production in Wrangell-St Elias National Park and Preserve, Alaska over a 37-year study period. To produce covariates pertaining to the quality of the snowpack, a spatially-explicit snow evolution model was forced with meteorological data from a gridded climate re-analysis from 1980 to 2017 and calibrated with ground-based snow surveys and validated by snow depth data from remote cameras. The best calibrated model produced an RMSE of 0.08 m (bias 0.06 m) for snow depth compared to the remote camera data. Observed lamb-to-ewe ratios from 19 summers of survey data were regressed against seasonally aggregated modelled snow and climate properties from the preceding snow season. We found that a multiple regression model of fall snow depth and fall air temperature explained 41% of the variance in lamb-to-ewe ratios (R2 = .41, F(2,38) = 14.89, p<0.001), with decreased lamb production following deep snow conditions and colder fall temperatures. Our results suggest the early establishment and persistence of challenging snow conditions is more important than snow conditions immediately prior to and during lambing. These findings may help wildlife managers to better anticipate Dall’s sheep recruitment dynamics.


2020 ◽  
Author(s):  
Johannes Fischer ◽  
I Debski ◽  
GA Taylor ◽  
Heiko Wittmer

© The Ornithological Society of New Zealand Inc. We assessed the impact of interspecific interactions on the breeding success of the South Georgian diving petrel (Pelecanoides georgicus; SGDP), a Nationally Critical seabird species, by monitoring 20 burrows at Codfish Island (Whenua Hou), with remote cameras. Additionally, we tested the utility of remote cameras to study the breeding biology and activity patterns of the SGDP by pairing 5 remote cameras with RFID readers. We recorded 7 different species at SGDP burrow entrances. The common diving petrel (P. urinatrix) likely caused two monitored burrows to fail. These results suggest that remote cameras are useful tools to study such interactions. However, the cameras had extremely low SGDP detection rates (mean = 10.86%; se = 7.62%) when compared to RFID readers. These low detection rates may be explained by the small body size and the speed at which SGDPs enter/leave burrows. Therefore, remote cameras, or at least the model and setup we used, appear unsuitable to study breeding biology and activity patterns in this seabird species.


2006 ◽  
Vol 33 (5) ◽  
pp. 427 ◽  
Author(s):  
Brendan D. Cowled ◽  
Eddie Gifford ◽  
Michelle Smith ◽  
Linton Staples ◽  
Steven J. Lapidge

Conservative population declines of 73% were recorded in three independent feral pig populations in Welford National Park, Queensland, when PIGOUT® baits containing 72 mg of sodium fluoroacetate were used in a baiting program following prefeeding. Declines were measured using a prebaiting population census with remote cameras, followed by carcass recovery. The knockdown of susceptible feral pigs may have been higher than this, since any carcasses not recovered reduced the recorded efficacy. In addition, feral pigs know to have left the baiting area after trapping and telemetry-tagging, and subsequently not exposed to toxic baits, were included in the analysis. The use of remote cameras and carcass recovery appears to be a relatively accurate means of recording localised declines in feral pig populations. This method is applicable only when carcass recovery is possible, such as in open areas in the semi-arid rangelands. A decline of 86% of radio-tagged feral pigs attending bait stations was also recorded. Camera observations revealed no non-target consumption of baits. Measurement of sodium fluoroacetate–contaminated tissues from feral pigs showed that residues were too low to present a significant risk to recorded scavenging animals in the area. Some feral pigs vomited before death, with vomitus containing sodium fluoroacetate poison at high concentrations. No vomitus was consumed by non-target species. Almost all feral pigs were killed relatively rapidly after ingestion of sodium fluoroacetate and the signs observed in a small number of poisoned feral pigs did not indicate a significant welfare concern.


Zootaxa ◽  
2008 ◽  
Vol 1932 (1) ◽  
pp. 27-32 ◽  
Author(s):  
IVAN SAZIMA ◽  
ALFREDO CARVALHO-FILHO ◽  
CRISTINA SAZIMA

A new species of cleaner goby, Elacatinus phthirophagus sp. n., is described from Fernando de Noronha Archipelago, off northeastern Brazil. It differs from its congeners of the putative “randalli-evelynae” cleaning clade by the following combination of characters: mouth subterminal, pale (bright yellow in life) elliptical spot on dark snout, width of lateral pale (bright yellow in life) stripe almost equal as eye diameter (slightly narrower in live individuals), light purplish sheen (in life) extending laterally from below eye to tail origin, no blue line (in life) from below eye to end of opercular margin, teeth multiserial on the distal portion of both jaws, males with 3 enlarged and recurved teeth on dentary inner row. The new species was recorded at depths ranging from 3 to 18 m and is ubiquitous in the archipelago islets. It tends cleaning stations on coral heads, sponges, and rocky substrata, with up to 15 individuals present in large stations, particularly those on sponges. Elacatinus phthirophagus sp. n. was recorded to clean about 30 species of fish clients, including large carnivores such as the shark Carcharhinus perezi and smaller carnivores such as the grouper Cephalopholis fulva, besides small clients like the planktivorous damselfish Chromis multilineata and the zoobenthivorous butterflyfish Chaetodon ocellatus. The new species increases to three the number of cleaner gobies recorded for Southwestern Atlantic, one from the coast and two from oceanic islands.


Primates ◽  
2020 ◽  
Vol 61 (2) ◽  
pp. 175-179 ◽  
Author(s):  
José Guerrero-Casado ◽  
Ramón I. Cedeño ◽  
Jon C. Johnston ◽  
Micaela Szykman Gunther

2017 ◽  
Vol 77 ◽  
pp. 23-30 ◽  
Author(s):  
Kristen S. Ellis ◽  
Randy T. Larsen ◽  
Jericho C. Whiting ◽  
Tammy L. Wilson ◽  
Brock R. McMillan

2019 ◽  
Vol 5 (1) ◽  
pp. 62-70 ◽  
Author(s):  
Douglas Andrew Clark ◽  
Ryan Brook ◽  
Chelsea Oliphant-Reskanski ◽  
Michel P. Laforge ◽  
Kiva Olson ◽  
...  

We describe for the first time in the peer-reviewed literature observations of American black bear (Ursus americanus Pallas, 1780), grizzly bear (Ursus arctos Linnaeus, 1758), and polar bear (Ursus maritimus Phipps, 1774) at the same locations. Using remote cameras we documented 401 bear-visits of all three species at three camps in Wapusk National Park, Canada, from 2011–2017. These observations add to a growing body of evidence that grizzlies are undergoing a substantial range increase in northern Canada and the timing of our observations suggests denning locally. Polar and grizzly bears are of conservation concern regionally and internationally, so from the literature we assessed the potential effects on conservation efforts from interactions between these three species. In aggregate, those effects are likely to be positive for grizzlies and weakly negative for black and polar bears; further research is needed. Range overlap of these three species in this dynamic ecotonal region should not be viewed as a threat to any of them, but rather as an ecological response to environmental change that needs to be better understood.


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