Dispersal distances of radio-tracked cane toads in French Guiana

Like 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.

Methods
We captured adult cane toads in the field in four sites in French Guiana, within the species' native rnage. We atatched transmitters with waistbelts, and located the toads by day and by night for 5 days. We recorded distances moved per dispalcement,a nd cumulatively, and whether or not the toad returned to the same diurnal shelter on successive days.

Usage Notes
The file "cane toad tracking dataset" contains expanded headiongs to explain all variables

与大多数入侵物种相似，甘蔗蟾蜍在其原生地域所吸引的研究关注度远不及入侵地区。本研究在法属圭亚那对34只野生甘蔗蟾蜍进行了无线电追踪，法属圭亚那为多数入侵种群提供了源头。沿海地区的蟾蜍通常在淡水或咸淡水池塘中寻找庇护，但在夜间则在海滩上进行觅食，而雨林地区的蟾蜍则选择在森林生境中躲避，夜间才进入开阔地带。在五天的监测期间，本地蟾蜍频繁地重复使用庇护所，日间移动距离微乎其微（平均每天10-63米/地点），与来自澳大利亚的入侵前沿蟾蜍（约250米）相比。体型较大的蟾蜍在日间移动距离更短，但位移方向更为一致。夜间觅食的蟾蜍在返回庇护所前，可移动至200米远。沿海地区的觅食距离与蟾蜍的身体状况相关，身体状况较差的蟾蜍觅食距离更远。降雨增加了沿海蟾蜍在觅食区域干燥生境中寻找庇护的可能性。沿海地区的扩散和降雨量较低，沿海蟾蜍为减少水分流失所采取的策略与入侵半沙漠生境的入侵蟾蜍相似。这一全球性入侵者已在原生地域展现出广泛的环境生态位和显著的行为灵活性。

方法
我们在法属圭亚那四个地点捕获了成年甘蔗蟾蜍，这些地点位于该物种的原生分布范围内。我们使用腰带式发射器对其进行了标记，并在白天和夜间对其进行了5天的定位。我们记录了每次位移的距离、累积移动距离，以及蟾蜍是否在连续的几天中返回同一日间庇护所。

使用说明
文件“甘蔗蟾蜍追踪数据集”包含了所有变量的详细说明。