herpetology – Barreleye Zoology


A recent study has revealed that T-shirt colour may affect the behaviour of the western fence lizard (Sceloporus occidentalis). So how did they do it, and what might this mean for the species and people who study it?


2 Southern Californian sites, one closed to the public and the other in a public park,  were used

Measuring T-shirt colours

The team used 4 T-shirts: one light blue, one dark blue, one grey and one red. To human eyes, the blue T-shirts appeared to match the colour of the lizards’ ventral patches. In order to determine how much each T-shirt stood out in the lizards’ habitat, one researcher was photographed wearing the T-shirts at both sites.

Measuring the lizards’ behaviour

Sites were sampled randomly, as was the order in which the T-shirts were worn. As the researcher walked towards a lizard, the animal’s movement was recorded. The distance at which the animals moved away (flight initiation distance, FID) was calculated using the formula FID = (horizontal distance)² + (height of lizard above ground)². After approaching the lizard, the researcher attempted to capture it using a noose. Adults were used in all trials. The sex of the lizard and the distance from starting point to capture were also recorded.


T-shirt colour influenced the distance which the lizards moved from the researcher (FID). The red T-shirt produced the longest FID, whereas the dark blue T-shirt produced the shorted FID.

Human activity levels were shown to have no impact on FID.

The greatest proportion of lizards were captured when dark blue T-shirts were worn. Red T-shirts produced the lowest capture rate.

The potential impact on the western fence lizard and the researchers who study it

Both researchers and tourists might reconsider their choice of clothes when in lizard habitat

As this was the first study to examine this, further research will need to be done in order to determine the full impact of clothing on lizards.

The original study can be found here at PLOS ONE


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