Quantitative characterisation of the trajectories of moving animals is an important component of many behavioural and ecological studies, however methods are complicated and varied, and sometimes require well‐developed programming skills to implement. Here, we introduce trajr, an R package that serves to analyse animal paths, from unicellular organisms, through insects to whales. It makes a variety of statistical characterisations of trajectories, such as tortuosity, speed and changes in direction, available to biologists who may not have a background in programming. We discuss a range of indices that have been used by researchers, describe the package in detail, then use movement observations of whales and clearwing moths to demonstrate some of the capabilities of trajr. As an open‐source R package, trajr encourages open and reproducible research. It supports the implementation of additional methods by providing access to trajectory analysis “building blocks,” allows the full suite of R statistical analysis tools to be applied to trajectory analysis, and the source code can be independently validated.
Clearwing moths are known for their physical resemblance to hymenopterans, but the extent of their behavioural mimicry is unknown. We describe zigzag flights of sesiid bee mimics that are nearly indistinguishable from those of sympatric bees, whereas sesiid wasp mimics display faster, straighter flights more akin to those of wasps. In particular, the flight of the sesiids , and resembles both and stingless bees and, to a lesser extent, dwarf honeybees, whereas the sesiid sp. resembles sp. wasps. These findings represent the first experimental evidence for behavioural mimicry in clearwing moths.
Heterosphecia tawonoides Kallies, a ''lost'' species of clearwing moth known only from a single specimen from 1887 (the holotype, which is missing important morphological features), was observed and filmed for the first time in its natural habitat. Our studies have shown that it is associated with Malaysian primary lowland dipterocarp forests, ecosystems which are vanishing rapidly due to extensive human activity. This is the first record of H. tawonoides in Malaysia. Behavioral aspects, such as mud-puddling among bees and acoustic mimicry, are discussed and shown in a video. A morphological redescription, including features visible on live individuals only, is provided. The DNA barcode sequence is given, with comparison to closely related species.
A metallic blue, new species of clearwing moth from Thailand is described and shown on video. With its spectacular colouration, long hind legs and an incredible illusion of a wasp-waist, complemented by behavioural imitations, this sesiid is a striking spider wasp mimic. Notes on possible mimicry models, behaviour and conditions of occurrence are given. COI DNA barcode sequence is provided. This is the first country record of Melanosphecia Le Cerf 1916 for Thailand and the first representative of this genus to be filmed in its natural habitat.
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