In a recent paper from Behavioural Ecology, the Emlen lab examines the cost of male ornamentation of the Japanese rhinoceros beetle (Trypoxylus dichotomus) on flight. (click here for the link to the full article) Sexual selected traits such as horn size are expected to pose significant fitness costs to the males as has been previously discussed. In this study, the author found that male flight in terms of speed and distance was no different from females and there was also no difference among males morphs. Oh wait…did I mention they used radiotelemetry on beetles??!!! They fit the beetles with mega-tiny radio transmitters!
This study also measured compensatory morphological traits and found that increased horn size was linked to larger wing size as well as greater flight muscle mass.
This paper is definitely worth a read and the authors offer a few interesting explanations for failing to observe differences in flight speed and distance among male morph and compared to females.
The Japanese rhinoceros beetle (Trypoxylus dichotomus) inhabits Japan, China, Taiwan, and Korea. They are sexually dimorphic and the males utilize their ornaments in battle against one another. In Japan, these beetles are known as kabutomushi and are extremely popular as pets. The video below shows just how popular they are with Japanese children.
Male Emei music frogs (Babina dauchina) use vocal signals to advertise to females. These calls reflect genetic qualities such as physical condition, but females are also interested in resources like territories and nests. Males of this species construct burrows along pond edges and recently a group discovered that the calls from inside the nest differ from those made outside the nest. This evidence was presented in an article in Biology Letters (J. Cui, Y. Tang and P. Narrins 2012 click here for the link).
The authors found distinct differences in frog calls between inside and outside in terms of frequency range and note durations. They posit that the males are encoding information about their nest such as burrow mouth size and depth. Beyond this, females were given phonotaxis preference tests and indeed prefer the inside calls to outside calls. In short, the ladies prefer a man with his own flat. Watch the video below for an example of a call from inside a nest.
It would be interesting to see the specific female preference assesment when the call is broken down to the specific elements representing the architectural features of the nest. Does the female prefer a deeper nest and how strong is this preference?
Is it possible that males are simply altering their calls as a result of calling from inside the nest?
Ascarosides are small molecule pheromones in nematodes that regulate a number of behaviors like attraction, repulsion, aggregation with other worms and entry into dauer or environmental diapause. In a recent publication from the Sternberg lab in Current Biology (click here for a link to the article) ascarosides were analyzed by mass spectrometry across nematode species. The authors found that in general ascarosides are species specific and cluster not only by phylogeny, but also by environmental or life history niche. Below the figure from the paper illustrates the relationship of specific ascaroside presence and abundance with phylogeny, life history and mode of reproduction.
Interestingly, the authors also look at specific isolates of the “wild type” of the commonly used model organism, Caenorhabditis elegans and found differences within the same species. These differences however, are quite small when compared to the differences observed across species.
Mothers often take drastic measures to care for their young and the Great White Pelican is no exception. Check out the video below from the BBC “Life” series.
A recent article by Dussutour and Simpson ( click here for the link) found that when black garden ants (Lasius niger) were fed a high protein to carbohydrate ratio in their diet, lifespan decreased by a factor of 10!! The authors emphasize this result is due to the high level of protein and not the lack of carbohydrates. This was known to occur in solitary insects, but this study demonstrates the phenomenon in a colony.
The superb lyre bird (Menura novaehollandiae) has the incredible ability to imitate the songs of other birds and even some environmental noise.
Check out the incredible video below from the BBC’s “Life of Birds”.
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