Using radio telemetry to evaluate the depths inhabited by Murray cod (Maccullochella peelii peelii)

2009 ◽  
Vol 60 (4) ◽  
pp. 317 ◽  
Author(s):  
John D. Koehn
Keyword(s):  
Measurement Errors ◽  
Radio Telemetry ◽  
Habitat Preferences ◽  
Vertical Position ◽  
Depth Measurement ◽  
Depth Sensors ◽  
Eastern Australia ◽  
Radio Transmitters ◽  
Preliminary Study ◽  
Murray Cod

Radio telemetry is widely used in studies of freshwater fishes, but the vertical position of fish in riverine environments is rarely reported. The present study tested the application of radio transmitters fitted with depth sensors to determine the vertical position of Murray cod in the lower Ovens River in south-eastern Australia. As the scale of depths in rivers is usually limited (<10 m in the present study), there is a greater need to assess measurement error. The study first involved trials to define depth measurement errors, and a mean relative bias of 9% (range 1.5–14.8%) towards greater depth was recorded. These data were then used to correct the depths recorded from tagged fish. Although data from this preliminary study are somewhat limited, results from the tagged fish showed that by day they all occupied the lower 15% of the water column, indicating that Murray cod exhibit demersal behaviour, using bottom rather than mid-water habitats. Although the present study highlights the importance of tag trials in determining errors, it also indicates the potential application of this technique to understanding the depth-integrated habitat preferences of Murray cod and other species.

scholarly journals Robotic ecology: Tracking small dynamic animals with an autonomous aerial vehicle

2018 ◽  
Vol 3 (23) ◽  
pp. eaat8409 ◽  
Author(s):  
Oliver M. Cliff ◽  
Debra L. Saunders ◽  
Robert Fitch
Keyword(s):  
Radio Telemetry ◽  
Robotic Systems ◽  
Mammal Species ◽  
Estimation Algorithms ◽  
Winter Range ◽  
Limited Success ◽  
Radio Transmitters ◽  
Aerial Vehicle ◽  
Bayesian Data Fusion ◽  
Correct Estimate

Understanding animal movements that underpin ecosystem processes is fundamental to ecology. Recent advances in animal tags have increased the ability to remotely locate larger species; however, this technology is not suitable for up to 70% of the world’s bird and mammal species. The most widespread technique for tracking small animals is to manually locate low-power radio transmitters from the ground with handheld equipment. Despite this labor-intensive technique being used for decades, efforts to reduce or automate this process have had limited success. Here, we present an approach for tracking small radio-tagged animals by using an autonomous and lightweight aerial robot. We present experimental results where we used the robot to locate critically endangered swift parrots (Lathamus discolor) within their winter range. The system combines a miniaturized sensor with newly developed estimation algorithms to yield unambiguous bearing- and range-based measurements with associated measures of uncertainty. We incorporated these measurements into Bayesian data fusion and information-based planning algorithms to control the position of the robot as it collected data. We report estimated positions that lie within about 50 meters of the true positions of the birds on average, which are sufficiently accurate for recapture or observation. Further, in comparison with experienced human trackers from locations where the signal was detectable, the robot produced a correct estimate as fast or faster than the human. These results provide validation of robotic systems for wildlife radio telemetry and suggest a way for widespread use as human-assistive or autonomous devices.

The effects of translocation on the spatial ecology of tiger snakes (Notechis scutatus) in a suburban landscape

2005 ◽  
Vol 32 (2) ◽  
pp. 165 ◽  
Author(s):  
H. Butler ◽  
B. Malone ◽  
N. Clemann
Keyword(s):  
Spatial Ecology ◽  
Private Property ◽  
Radio Telemetry ◽  
Home Ranges ◽  
Residential Areas ◽  
Perceived Risks ◽  
Radio Transmitters ◽  
The Impact ◽  
Suburban Landscape ◽  
Very High

In many suburban parts of Australia the removal of snakes from private property by licenced snake catchers is employed to mitigate perceived risks to humans and their pets. The number of snakes translocated around greater Melbourne, Victoria, each year can be very high (at least many hundreds). However, the effects of translocation on the behaviour and welfare of individual snakes, and the impact on existing snake populations at release sites are unknown. We used radio-telemetry of ‘resident’ and translocated snakes to investigate the consequences of translocation on the spatial ecology of tiger snakes (Notechis scutatus) in a suburban parkland near Melbourne. Fourteen snakes (two female and four male residents, and four female and four male translocated snakes) implanted with radio-transmitters were tracked between spring 2002 and autumn 2003. Translocated snakes exhibited home ranges ~6 times larger than those of residents, although each group maintained core ranges of similar size. Translocated snakes travelled longer distances and were often located in residential areas adjacent to the park, whereas resident snakes were never located outside of the park.

Muskellunge Management: Fifty Years of Cooperation Among Anglers, Scientists, and Fisheries Biologists

2017 ◽  
Keyword(s):  
Aquatic Vegetation ◽  
Lake Michigan ◽  
Radio Telemetry ◽  
Habitat Preferences ◽  
Vegetation Coverage ◽  
Limiting Factor ◽  
Suitable Habitat ◽  
Spawning Habitat ◽  
Green Bay ◽  
Natural Reproduction

<em>Abstract</em>.—The identification, protection, and restoration of spawning habitat for Muskellunge <em>Esox masquinongy </em>in Green Bay, Lake Michigan are vital steps for re-establishing a self-sustaining population. This study was designed to locate spawning areas, document and model spawning habitat preferences, assess natural recruitment, and determine if suitable habitat was found throughout Green Bay (Fox River, lower Green Bay, Menominee River, and Little Sturgeon Bay). Radio transmitters were inserted into the oviduct of mature female Muskellunge prior to spawning and expelled transmitters were later located using radio telemetry to identify spawning locations. Between 2009 and 2010, 26 of 37 (70%) implanted transmitters were located as deposited at spawning locations. Using identified spawning locations, habitat selection was estimated for key environmental variables, and MaxEnt (maximum entropy) was utilized to model Muskellunge spawning habitat in the Menominee River, as it was the only study area where natural reproduction was documented. Menominee River Muskellunge showed significant preferences for spawning in areas with shallow bottom slopes (5%), with medium-to-high submerged aquatic vegetation coverage (>33%), where coarse woody debris was present, and where dominant substrates were sand or cobble. MaxEnt modeling predicted a ~2.5 magnitude greater likelihood of spawning at an average spawning location compared to an average background location. Comparisons of available habitat among study areas showed the Menominee River contained more spawning habitat with preferred characteristics. Results from this study are important steps in identifying spawning habitat as a potential limiting factor to successful Muskellunge reintroduction and models could be used to locate suitable areas to stock and guide delineation of critical spawning habitat to designate for protection.

A new species of frog in the Litoria ewingii species group (Anura: Pelodryadidae) from south-eastern Australia

Zootaxa ◽  
2020 ◽  
Vol 4858 (2) ◽  
pp. 201-230
Author(s):  
MICHAEL MAHONY ◽  
BEDE MOSES ◽  
STEPHEN V. MAHONY ◽  
FRANK L. LEMCKERT ◽  
STEPHEN DONNELLAN
Keyword(s):  
New Species ◽  
Conservation Status ◽  
Habitat Preferences ◽  
Nuclear Genome ◽  
Species Group ◽  
Nucleotide Polymorphisms ◽  
Population Declines ◽  
Genetic Groups ◽  
Eastern Australia ◽  
A New Species

Population declines and range contractions among Australian frogs that commenced in the early 1980s continue in some species that were once widespread. The generality of this pattern has been difficult to discern, especially for those species that are encountered rarely because they have restricted periods of calling activity with poorly defined habitat preferences, and are not common. Several lines of evidence indicate that Litoria littlejohni is such a species. This frog was once known from mid-eastern New South Wales to eastern Victoria, and evidence from wildlife atlas databases and targeted searches indicate that it has declined in large portions of its former range, leaving several populations that are isolated, in some cases restricted in distribution, and of small size. We investigated the relationships among populations using mitochondrial ND4 nucleotide sequences and single nucleotide polymorphisms (SNPs) from the nuclear genome. We found that northern and southern populations form two highly divergent genetic groups whose distributions abut at the southern margin of the Sydney Basin Bioregion and these genetic groups also show divergence in morphology and male advertisement calls. Here we describe the populations to the south of the Sydney Basin Bioregion as a new species and provide information on its distribution and ecology. In light of the apparent isolation and small size of known populations of the new species and the consequent restriction of the range of L. littlejohni, we assessed the conservation status of both species. 

Too close for comfort: a fishway exit and a hydro-power station inlet

2010 ◽  
Vol 61 (1) ◽  
pp. 23 ◽  
Author(s):  
Ivor G. Stuart ◽  
John D. Koehn ◽  
Tim A. O'Brien ◽  
John A. McKenzie ◽  
Gerry P. Quinn
Keyword(s):  
Management Strategies ◽  
Field Testing ◽  
High Water ◽  
Fish Passage ◽  
Native Fish ◽  
Power Station ◽  
Hydro Power ◽  
Murray River ◽  
Eastern Australia ◽  
Radio Transmitters

A major environmental issue for hydro-electric power generation is passage of fish through turbines, or entrainment onto trash racks. At Yarrawonga Weir, on the upper Murray River in south-eastern Australia, the positioning of a fish lock resulted in the potential for upstream migrating fish to be swept back into the adjacent power station by cross flows. In 2004, a 4.5-m long steel extension flume was attached to the exit to alleviate this problem. To determine the fate of native fish after exiting the extension flume, 72 individuals (305–1015 mm long) were implanted with radio-transmitters and released into the fish lock exit channel. In 2004 (power station inflows 10 300 ML day–1), the majority of fish exited successfully (44 of 45) and only a single fish (2%) was entrained into the power station. In 2005 (power station inflows 12 000 ML day–1), fish again exited successfully (26 of 27) but with a higher proportion entrained (5 of 27; 18%). This reduced success appeared to be related to strong transverse flows with high water velocities adjacent to the fish lock exit. The efficiency of fish passage at this site might be improved by altering water management strategies, integrating engineering and fish biology, and through field-testing of proposed solutions.

Spatial partitioning in the use of structural woody habitat supports the cohabitation of two cod species in a large lowland river

2016 ◽  
Vol 67 (12) ◽  
pp. 1835 ◽  
Author(s):  
J. A. Lieschke ◽  
J. P. Lyon ◽  
P. D. Moloney ◽  
S. J. Nicol
Keyword(s):  
Lowland River ◽  
Specific Interactions ◽  
Negative Consequences ◽  
Catch Per Unit Effort ◽  
Spatial Partitioning ◽  
Murray River ◽  
Eastern Australia ◽  
The Common ◽  
Species Specific ◽  
Murray Cod

Many freshwater fish worldwide have been shown to use Structural Woody Habitat (SWH) for a variety of reasons. The mid reaches of the Murray River, a large lowland river in south-eastern Australia, was surveyed by boat electrofishing, to investigate the use of SWH type (hollows, rootmass and solids), SWH distance to bank (near bank, intermediate to bank and mid-channel) and the interaction between SWH type and distance to bank. The study found that Murray cod catch per unit effort (CPUE) increased in near-bank areas when hollows were a component of the SWH. The CPUE of trout cod was higher when hollows were present. However, the interactions between distance to bank and hollow SWH were complex and dependent on presence or absence of rootmass. The species-specific interactions between SWH microhabitat and distance to bank found within this study has important relevance for stream managers. The common practice of realigning SWH favours Murray cod over trout cod, which could have negative consequences for the endangered trout cod. More broadly, managers may need to consider a balance of SWH type and where it is placed in the river for the species they are targeting when rehabilitating rivers via the introduction of SWH.

Scats can reveal the presence and habitat use of cryptic rock-dwelling macropods

2006 ◽  
Vol 54 (5) ◽  
pp. 325 ◽  
Author(s):  
Wendy R. Telfer ◽  
Anthony D. Griffiths ◽  
David M. J. S. Bowman
Keyword(s):  
Habitat Use ◽  
Radio Telemetry ◽  
Classification Tree ◽  
Habitat Preferences ◽  
Wet Season ◽  
Survey Tool ◽  
Faecal Pellets ◽  
Tropical Environments ◽  
The Tropics ◽  
Larger Sample

The rock-dwelling macropod species of the tropics of the Northern Territory, Australia, are behaviourally elusive and difficult to observe in their rugged habitats. Hence, little is understood about their ecology. We evaluated the potential of using scats (faecal pellets) as a survey tool for this faunal assemblage by: (1) developing a key to the scats of the species; (2) examining the rates of loss and decomposition of short-eared rock-wallaby (Petrogale brachyotis) scats in these tropical environments; and (3) comparing the distribution of scats of P. brachyotis with the species’ use of space and habitats as determined with radio-telemetry. Classification tree modelling discriminated the scats of the seven macropod species, primarily on the basis of width. The reliability of identification was greatly improved with larger sample sizes and inclusion of a habitat parameter. Rates of scat loss and decay were variable and the greatest losses occurred in the wet season, particularly on sandy soils. Scat censuses underestimated the total area used by P. brachyotis but the distribution of scats showed the same broad pattern of habitat use found by radio-telemetry. We conclude that scats can accurately indicate the presence and habitat preferences of rock-dwelling macropod species.

scholarly journals The accuracy of FOM instrument used in on-line pig carcass classification in the Czech Republic

2008 ◽  
Vol 52 (No. 6) ◽  
pp. 149-158 ◽  
Author(s):  
M. Šprysl ◽  
J. Čítek ◽  
R. Stupka ◽  
L. Vališ ◽  
M. Vítek
Keyword(s):  
Czech Republic ◽  
Measurement Errors ◽  
Muscle Thickness ◽  
The Czech Republic ◽  
High Agreement ◽  
Lean Meat ◽  
Depth Measurement ◽  
Operator Error ◽  
On Line

The objective of this study was to document the accuracy of the classification equipment used in the Czech Republic with respect to measurement errors in lean meat percentage prediction such as point of measurement error, equipment error as well as operator error. To this end, a total of 720 pigs were measured in one abattoir. One can say from the results that the correlations between correct and surrogate measurements of fat depth are high (0.95&minus;0.98), for muscle thickness they are lower ranging from 0.49 to 0.88, and for lean meat percentage they are in the range of 0.85&minus;0.95. The lowest correlation (0.49) was calculated for muscle depth measurement between the 2nd and 3rd last rib when the place of measurement was moved 1 cm in the caudal direction, which influenced the level of the FOM correlation. It was further demonstrated that for the second insertion the differences in lean meat percentage prediction ranged from &minus;6.07% to +9.29%. It was also demonstrated that various instruments provided identical measurements of fat depth (<i>r</i> = 0.57&minus;0.97), while for muscle depth the performance was worse (<i>r</i> = 0.38–0.78), which caused a fluctuation in the prediction of lean meat percentage with differences ranging from &minus;2.56% to +2.81%. It can also be concluded that a high agreement between operators was demonstrated for the determination of lean meat percentage (<i>r</i> = 0.71&minus;0.80).

Conservation of a rare arboreal mammal: habitat preferences of the Lumholtz's tree-kangaroo, Dendrolagus lumholtzi

2011 ◽  
Vol 33 (1) ◽  
pp. 5 ◽  
Author(s):  
Sigrid R. Heise-Pavlov ◽  
Sara L. Jackrel ◽  
Spenser Meeks
Keyword(s):  
Habitat Selection ◽  
Function Analysis ◽  
Habitat Preferences ◽  
Structural Features ◽  
Main Trunk ◽  
Faecal Pellets ◽  
Eastern Australia ◽  
North Eastern ◽  
Dendrolagus Lumholtzi ◽  
Selection Of

Success of conservation efforts of large and cryptic mammals is often limited due to a lack of knowledge of their habitat preferences. This study investigates factors that affect the habitat selection of the rare Lumholtz’s tree-kangaroo, Dendrolagus lumholtzi, using signs of its activity. The presence and absence of scratch marks on tree trunks and faecal pellets within a 100-cm radius around them were surveyed on 23 ha within a 65-ha large fragment of rainforest on the Atherton Tablelands, north-eastern Australia in order to classify trees as ‘actively used’ or ‘inactive’. Structural features of the 315 surveyed tree trunks were also recorded. Using discriminant function analysis, ‘actively used’ trees were found to have no epiphytes on the main trunk, less obstruction by neighbouring trees, shrubs or lianas within a 0.5-m radius of the trunk (particularly in the eastern direction), and a smaller diameter at breast height than ‘inactive’ trees. Smaller tree trunks and less obstruction may facilitate a more rapid movement into the canopy as well as provide potential escape routes from predators. More specific knowledge on factors that affect habitat selection of the Lumholtz’ tree-kangaroo will help in a reclassification of the threatened status of this species and assist in more effective conservation efforts.

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