scholarly journals Long distance homing in the cane toad (Rhinella marina) in its native range

2021 ◽  
Author(s):  
Daniel A Shaykevich ◽  
Andrius Pasukonis ◽  
Lauren A O'Connell
Keyword(s):  
Home Range ◽  
Life Histories ◽  
French Guiana ◽  
Spatial Behavior ◽  
Native Range ◽  
Cane Toad ◽  
Short Term ◽  
Long Distance ◽  
Rhinella Marina ◽  
Current Paradigm

Many animals exhibit complex navigation over different scales and environments. Navigation studies in amphibians have largely focused on species with life histories that require advanced spatial capacities, such as territorial poison frogs and migratory pond-breeding amphibians that show fidelity to mating sites. However, other species have remained relatively understudied, leaving the possibility that well-developed navigational abilities are widespread. Here, we measured short-term space use in non-territorial, non-migratory cane toads (Rhinella marina) in their native range in French Guiana. After establishing home range, we tested their ability to return to home following translocations of 500 and 1000 meters. Toads were able to travel in straight trajectories back to home areas, suggesting map-like navigational abilities similar to those observed in amphibians with more complex spatial behavior. These observations break with the current paradigm of amphibian navigation and suggest that navigational abilities may be widely shared among amphibians.

scholarly journals Long distance homing in the cane toad (Rhinella marina) in its native range

2021 ◽  
Author(s):  
Daniel A. Shaykevich ◽  
Andrius Pašukonis ◽  
Lauren A. O'Connell
Keyword(s):  
Life Histories ◽  
Site Fidelity ◽  
French Guiana ◽  
Spatial Behavior ◽  
Native Range ◽  
Short Term ◽  
Long Distance ◽  
Amphibian Species ◽  
Rhinella Marina ◽  
Current Paradigm

Many animals exhibit complex navigation over different scales and environments. Navigation studies in amphibians have largely focused on species with life histories that require accurate spatial movements, such as territorial poison frogs and migratory pond-breeding amphibians that show fidelity to mating sites. However, other amphibian species have remained relatively understudied, leaving open the possibility that well-developed navigational abilities are widespread. Here, we measured short-term space use in non-territorial, non-migratory cane toads (Rhinella marina) in their native range in French Guiana. After establishing site fidelity, we tested their ability to return home following translocations of 500 and 1000 meters. Toads were able to travel in straight trajectories back to home areas, suggesting navigational abilities similar to those observed in amphibians with more complex spatial behavior. These observations break with the current paradigm of amphibian navigation and suggest that navigational abilities may be widely shared among amphibians.

Changes in urinary testosterone and corticosterone metabolites during short-term confinement with repeated handling in wild male cane toads (Rhinella marina)

2011 ◽  
Vol 59 (4) ◽  
pp. 264 ◽  
Author(s):  
Edward J. Narayan ◽  
Frank C. Molinia ◽  
John F. Cockrem ◽  
Jean-Marc Hero
Keyword(s):  
Adult Male ◽  
Reproductive Effort ◽  
Hormone Secretion ◽  
Reproductive Hormone ◽  
Cane Toad ◽  
Short Term ◽  
Rhinella Marina ◽  
Testosterone Secretion ◽  
Metabolite Concentrations ◽  
Corticosterone Metabolites

Stressors generally decrease testosterone secretion and inhibit reproduction in animals. Urinary testosterone and corticosterone metabolite concentrations were measured in adult male cane toads (Rhinella marina) at the time of capture from the wild and during 24 h of confinement with repeated handling. Mean urinary testosterone concentrations increased 2 h after capture, were significantly elevated above initial concentrations at 5 h, and then declined. Mean testosterone concentrations remained elevated 24 h after capture. Mean urinary corticosterone concentrations increased after capture, were significantly elevated above initial concentrations at 2 h, and remained elevated thereafter. This is the first report in amphibians of an increase in testosterone excretion after capture from the wild, with previous studies showing either no change or decline in testosterone. This finding may be associated with the mating strategy and maintenance of reproductive effort in the cane toad, a species that shows explosive breeding and agonistic male–male interactions during breeding. The finding that testosterone excretion increases rather than decreases after capture in male cane toads shows that it should not be generally assumed that reproductive hormone secretion will decrease after capture in amphibians.

Orientation and homing behavior as a measure of affinity for the home range in two species of Iguanid lizards

1991 ◽  
Vol 12 (4) ◽  
pp. 373-384 ◽  
Author(s):  
Craig Guyer
Keyword(s):  
Home Range ◽  
Life Histories ◽  
Egg Laying ◽  
Single Site ◽  
Long Distance ◽  
Homing Behavior ◽  
Sceloporus Graciosus ◽  
Gravid Females ◽  
The Relationship ◽  
Natural Means

AbstractThe relationship between home range affinity and homing ability was studied in Phrynosoma douglassi and Sceloporus graciosus in southeastern Idaho. Movement patterns for P. douglassi were typical of an animal moving from one site of activity to other sites, whereas S. graciosus movements were typical of an animal using a single site of activity. Only S. graciosus was able to orient towards the home range when displaced, indicating an affinity for this site. Adult S. graciosus oriented and homed more consistently than did juveniles. P. douglassi did not orient homeward when displaced and returned less frequently than did S. graciosus. Recapture locations along with data regarding homeward orientation and homing indicate that P. douglassi has a lesser affinity than does S. graciosus for the home range. Some gravid females of both species left the home range to deposit eggs or young and later returned. Use of areas outside the home range for egg-laying and birthing and movements out of the home range resulting from chases by predators may represent natural means of displacement that select for homing behavior. Because most lizards experience only short displacements during their life histories, long distance homing reported for snakes, turtles, and salamanders is absent.

scholarly journals Increased rates of dispersal of free-ranging cane toads (Rhinella marina) during their global invasion

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Richard Shine ◽  
Ross A. Alford ◽  
Ryan Blennerhasset ◽  
Gregory P. Brown ◽  
Jayna L. DeVore ◽  
...  
Keyword(s):  
French Guiana ◽  
Native Range ◽  
Rhinella Marina ◽  
Range Edge ◽  
Population Spread ◽  
Eastern Australia ◽  
Tropical Australia ◽  
Free Ranging ◽  
Global Invasion ◽  
Daily Changes

AbstractInvasions often accelerate through time, as dispersal-enhancing traits accumulate at the expanding range edge. How does the dispersal behaviour of individual organisms shift to increase rates of population spread? We collate data from 44 radio-tracking studies (in total, of 650 animals) of cane toads (Rhinella marina) to quantify distances moved per day, and the frequency of displacement in their native range (French Guiana) and two invaded areas (Hawai’i and Australia). We show that toads in their native-range, Hawai’i and eastern Australia are relatively sedentary, while toads dispersing across tropical Australia increased their daily distances travelled from 20 to 200 m per day. That increase reflects an increasing propensity to change diurnal retreat sites every day, as well as to move further during each nocturnal displacement. Daily changes in retreat site evolved earlier than did changes in distances moved per night, indicating a breakdown in philopatry before other movement behaviours were optimised to maximise dispersal.

scholarly journals Discovery of Novel Viruses Associated With the Invasive Cane Toad (Rhinella marina) in Its Native and Introduced Ranges

2021 ◽  
Vol 12 ◽  
Author(s):  
Alice G. Russo ◽  
Emma F. Harding ◽  
Grace J. H. Yan ◽  
Daniel Selechnik ◽  
Simon Ducatez ◽  
...  
Keyword(s):  
Invasion History ◽  
The Novel ◽  
Native Range ◽  
Cane Toad ◽  
Pcr Screening ◽  
Rhinella Marina ◽  
Low Genetic Diversity ◽  
Native And Introduced Ranges ◽  
Metagenomic Approach

Cane toads (Rhinella marina) are notoriously successful invaders: from 101 individuals brought to Australia in 1935, poisonous toads now cover an area >1.2 million km2 with adverse effects on native fauna. Despite extensive research on the role of macroparasites in cane toad invasion, viral research is lagging. We compared viral prevalence and diversity between toads in their native range (French Guiana, n=25) and two introduced ranges: Australia (n=151) and Hawai’i (n=10) with a metatranscriptomic and metagenomic approach combined with PCR screening. Australian toads almost exclusively harbor one of seven viruses detected globally. Rhimavirus-A (Picornaviridae) exhibited low genetic diversity and likely actively infected 9% of sampled Australian toads extending across ~2,000km of Northern Australia and up to the current invasion front. In native range cane toads, we identified multiple phylogenetically distinct viruses (Iridoviridae, Picornaviridae, Papillomaviridae, and Nackedna-like virus). None of the same viruses was detected in both ranges, suggesting that Australian cane toads have largely escaped the viral infection experienced by their native range counterparts. The novel native range viruses described here are potential biocontrol agents, as Australian toads likely lack prior immunological exposure to these viruses. Overall, our evidence suggests that there may be differences between viruses infecting cane toads in their native vs. introduced ranges, which lays the groundwork for further studies on how these viruses have influenced the toads’ invasion history.

scholarly journals Fauna and vegetation responses to fire and invasion by toxic cane toads (Rhinella marina) in an obligate seeder-dominated tropical savanna in the Kimberley, northern Australia

2015 ◽  
Vol 42 (4) ◽  
pp. 302 ◽  
Author(s):  
Ian J. Radford ◽  
Richard Fairman
Keyword(s):  
Vegetation Change ◽  
Fire Regimes ◽  
Ground Layer ◽  
Cane Toad ◽  
Short Term ◽  
Rhinella Marina ◽  
Structural Recovery ◽  
Invasion Impacts ◽  
Riparian Habitats ◽  
Large Predators

Context Changed fire regimes are an important threatening process to savanna biodiversity. Fire-sensitive vegetation such as pindan and its fauna may be particularly susceptible to fire impacts. Invasion by alien species is an additional threatening process. The toxic anuran Rhinella marina is a well publicised invader of savannas. Little is known of impacts in many habitats. Aims To test the hypotheses (1) that fire responses among pindan fauna are greater than general savanna responses, and (2) that cane toad-invasion impacts will be reduced relative to riparian habitats. Methods Reptiles, frogs, invertebrates and mammals were surveyed seven times from 2008 to 2012, four times before and three times following R. marina invasion. Time since last fire was recorded during each survey. Vegetation change was measured. Key results Pindan vegetation structural recovery took 4–5 years, whereas fauna recovery took only 1 year. Ground active agamids, combined Scincidae, fossorial skinks and ground-layer invertebrates responded positively to recent fire. Skinks of Ctenotus spp. declined in size after fire. Short-term fauna responses reflect rapid re-establishment of herbaceous cover. Fauna responses were detected following R. marina invasion, including increases in frogs of Uperoleia spp. and skinks of Carlia spp., and decreases in Lerista griffini and ground-layer invertebrates. Insufficient data were available to test for responses among large predators; however, >50% lower Varanus spp. trap success occurred post-invasion. No invasion response was detected among small mammals. Conclusions Pindan fauna fire responses were similar to those of savannas. Fauna responses to Rhinella marina invasion were relatively minor compared with those previously reported in riparian habitats and this may be related to the lower abundance of the invader here than in previous studies in riparian or more fertile habitats. Implications The dominant obligate seeding tree in pindan woodland, A. tumida, requires >4 years with no high-intensity fires for re-establishment of the dominant tree. Fire management should aim to minimise extensive fires to reduce impacts on fire-sensitive fauna. Persistence of large predators after cane-toad invasion suggests possible refuge value of low-productivity pindan savannas.

scholarly journals SUCCESSFUL PREDATION OF INVASIVE SOUTH AMERICAN CANE TOADS (RHINELLA MARINA) BY SOUTHERN WATERSNAKES (NERODIA FASCIATA)

2021 ◽  
Author(s):  
Jordan Donini ◽  
J. Sean Doody
Keyword(s):  
Field Data ◽  
South American ◽  
Native Range ◽  
Cane Toad ◽  
Sympatric Populations ◽  
Rhinella Marina ◽  
Toxin Resistance ◽  
Southwest Florida ◽  
Nerodia Fasciata ◽  
In The Wild

South American Cane Toads (Rhinella marina) have been introduced into several regions outside of their native distribution. Outside of their native range, few predators have been documented preying upon R.marina due to their potent toxins secreted in defense. However, prevalence of a toxin resistance gene makes it possible for some snakes of the sub-family Natricinae to consume native toads. We documented successful consumption of the invasive cane toad by the Southern Watersnake (Nerodia fasciata) in southwest Florida, both in the wild and in the laboratory. Southern Watersnakes from populations that existed both with and without cane toads successfully consumed toad prey without obvious ill-effect. Southern Watersnakes in southwest Florida are thus resistant to, and readily consume cane toads, an otherwise relatively predator-free invasive species in Florida. More dietary field data and controlled experiments that measure resistance to multiple prey items, sizes, and frequency will serve to determine the extent to which Southern Watersnakes can impact the size and structure of sympatric populations of cane toads.

Encounters between freshwater crocodiles and invasive cane toads in north-western Australia: does context determine impact?

2020 ◽  
Vol 41 (1) ◽  
pp. 94-101
Author(s):  
Gregory S Clarke ◽  
Cameron M Hudson ◽  
Richard Shine
Keyword(s):  
Western Australia ◽  
French Guiana ◽  
Native Range ◽  
Taste Aversion Learning ◽  
Rhinella Marina ◽  
Physiological Tolerance ◽  
Crocodylus Johnstoni ◽  
A Site ◽  
Riverine Systems ◽  
North Western

ABSTRACT The potent defensive chemicals of cane toads (Rhinella marina) protect them against predators that lack coevolved physiological tolerance to those toxins. That relative invulnerability may explain why major injuries (such as limb loss) appear to be rare in cane toads from most of their global range; however, we noted frequent predator-induced injuries (>4% of adults) in samples from within the toad’s native range (in French Guiana) and from a site (Lake Argyle) in north-western Australia. Toads at Lake Argyle enter the edge of the lake at night to rehydrate, exposing them to foraging freshwater crocodiles (Crocodylus johnstoni). Crocodiles rarely consume toads, but the attacks often result in loss of a limb. Because limbs contain relatively little toxin, attacks to the limbs expose a crocodile to nauseating but non-lethal amounts of toxin; and hence, facilitate taste aversion learning by the predator. The context of the encounters, such as differences in geography, may help to explain why the invasion of cane toads has not significantly impacted on crocodile populations at this site, in contrast to heavy impacts reported from nearby riverine systems.

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