scholarly journals Spatial ecology of cane toads (Rhinella marina) in their native range: a radiotelemetric study from French Guiana

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jayna L. DeVore ◽  
Richard Shine ◽  
Simon Ducatez
Keyword(s):  
Invasive Species ◽  
Body Condition ◽  
Spatial Ecology ◽  
French Guiana ◽  
Source Region ◽  
Behavioural Flexibility ◽  
Native Range ◽  
Environmental Niche ◽  
Rhinella Marina ◽  
Free Ranging

AbstractLike most invasive species, cane toads have attracted less research in their native range than in invaded areas. We radio-tracked 34 free-ranging toads in French Guiana, a source region for most invasive populations, across two coastal and two rainforest sites. Coastal toads generally sheltered in pools of fresh or brackish water but nocturnally foraged on beaches, whereas rainforest toads sheltered in forested habitats, moving into open areas at night. Over five days of monitoring, native toads frequently re-used shelters and moved little between days (means = 10–63 m/site) compared to invasion-front toads from Australia (~ 250 m). Larger toads moved less between days, but displaced in more consistent directions. At night, foraging toads travelled up to 200 m before returning to shelters. Foraging distance was related to body condition at coastal sites, with toads in poorer body condition travelling farther. Rain increased the probability of coastal toads sheltering in the dry habitats where they foraged. Dispersal and rainfall were lower at coastal sites, and the strategies utilized by coastal toads to minimize water loss resembled those of invasive toads in semi-desert habitats. This global invader already exhibits a broad environmental niche and substantial behavioural flexibility within its native range.

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 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.

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.

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.

Cecropia peltata (trumpet tree).

2021 ◽  
Author(s):  
Nick Pasiecznik
Keyword(s):  
Invasive Species ◽  
Pioneer Species ◽  
Native Range ◽  
Coffee Plantations ◽  
Shade Tree ◽  
Botanical Gardens ◽  
Forest Clearance

Abstract C. peltata is an important pioneer species in its native range Americas following forest clearance. It has also been introduced into coffee plantations as a shade tree and into botanical gardens in Africa. However, its presence on the ISSG list of the 100 worst invasive species (ISSG, 2003) means that its notoriety as an invasive species may limit further introductions.

scholarly journals What’s for Dinner? Assessing the Value of an Edible Invasive Species and Outreach Actions to Promote Its Consumption

2021 ◽  
Author(s):  
Inês Cerveira ◽  
Vânia Baptista ◽  
Maria Alexandra Teodósio ◽  
Pedro Morais
Keyword(s):  
Invasive Species ◽  
Native Species ◽  
Aquatic Invasive Species ◽  
Native Range ◽  
Invasive Fish ◽  
Press Releases ◽  
Cynoscion Regalis ◽  
The Public ◽  
Native Resources ◽  
A New Species

Abstract Promoting the consumption of edible aquatic invasive species has gained popularity to minimize its impacts while easing pressure on native resources. Weakfish Cynoscion regalis (Bloch & Schneider, 1801) is one of the most recent invasive fish species in the Iberian Peninsula (Europe) which once sustained an important fishery in the native range (Northwest Atlantic Ocean). Portugal ranks third in the list of the world’s top fish consumers, so promoting a weakfish fishery could at least help minimize the impacts upon native species, since weakfish have innate traits that are likely appreciated by Portuguese fish consumers. However, introducing a new species to consumers is challenging owing to consumers’ habits and unfamiliarity with the species. So, we aimed to (i) evaluate the acceptance of weakfish by a panel of Portuguese fish consumers and (ii) create outreach actions – partnerships with local Chefs and press releases – to explain to a broader public what invasive species are and promote the consumption of edible aquatic invasive species. The survey that we conducted to Portuguese fish consumers showed that weakfish has great chances of being well accepted by the public – 90% of consumers would buy weakfish because they appreciated its appearance, flavour, and texture, besides being a wild fish. The outreach actions reached a few million people because 46 online articles were published, and three news pieces broadcasted on national television. Overall, our strategy greatly increased the public’s awareness about invasive species, which can be replicated elsewhere in the world.

scholarly journals Genomic and developmental characterisation of a novel bunyavirus infecting the crustacean Carcinus maenas

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jamie Bojko ◽  
Kuttichantran Subramaniam ◽  
Thomas B. Waltzek ◽  
Grant D. Stentiford ◽  
Donald C. Behringer
Keyword(s):  
Invasive Species ◽  
Carcinus Maenas ◽  
Virus Genome ◽  
Faroe Islands ◽  
Zinc Finger Domain ◽  
Native Range ◽  
Structural Protein ◽  
Rna Dependent Rna Polymerase ◽  
Negative Sense ◽  
Crustacean Host

Abstract Carcinus maenas is in the top 100 globally invasive species and harbours a wide diversity of pathogens, including viruses. We provide a detailed description for a novel bunyavirus (Carcinus maenas Portunibunyavirus 1) infecting C. maenas from its native range in the Faroe Islands. The virus genome is tripartite, including large (L) (6766 bp), medium (M) (3244 bp) and small (S) (1608 bp) negative sense, single-stranded RNA segments. Individual genomic segments are flanked by 4 bp regions of similarity (CCUG). The segments encode an RNA-dependent RNA-polymerase, glycoprotein, non-structural protein with a Zinc-Finger domain and a nucleoprotein. Most show highest identity to the ‘Wenling Crustacean Virus 9’ from an unidentified crustacean host. Phylogenomics of crustacean-infecting bunyaviruses place them across multiple bunyavirus families. We discuss the diversity of crustacean bunyaviruses and provide an overview of how these viruses may affect the health and survival of crustacean hosts, including those inhabiting niches outside of their native range.

Effects of canine heartworm (Dirofilaria immitis) on body condition and activity of free-ranging coyotes (Canis latrans)

2000 ◽  
Vol 78 (6) ◽  
pp. 1042-1051 ◽  
Author(s):  
Benjamin N Sacks ◽  
Karen M Blejwas
Keyword(s):  
Body Mass ◽  
Body Condition ◽  
Dirofilaria Immitis ◽  
Canis Latrans ◽  
Infected Group ◽  
Control Group ◽  
Canine Heartworm ◽  
Average Body Mass ◽  
Free Ranging ◽  
Average Body

We used radiotelemetry to study relationships among canine heartworm (Dirofilaria immitis) infection, body condition, and activity of free-ranging coyotes (Canis latrans). Average body mass at death was lower for 17 coyotes in a high-intensity infected group (mean = 33.6 heartworms) than for 18 coyotes in a control group (mean = 3.6 heartworms; p < 0.01). Coyotes in the infected group lost body mass at an average rate of 20% per year relative to the control group (p < 0.01). Bone marrow fat was negatively correlated with heartworm burden (R2 = 0.27; p < 0.01). Average body mass of coyotes at initial capture (i.e., potentially before infection) did not differ between infected and control groups (p = 0.90; 1–β = 0.70). Activity was negatively correlated with heartworm burden during the last 2 months of life (R2 = 0.30; p < 0.01), but no correlation was found 2–4 months before death. Activity of the infected group (n = 13) declined over time (p = 0.01), whereas no difference in activity was observed in the control group (n = 13; p = 0.50). Our findings indicate that heartworm infection reduced body condition and activity of coyotes but that nutritional status did not significantly affect susceptibility to infection.

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