Road Kill

 Travelling through the Cotswolds recently (15/1/24) on a cold but sunny day, we came across a wake of buzzards feasting on some roadkill. Optional collective nouns for buzzards are a kettle, soar, or committee of buzzards.

Video 1: Buzzards and Roadkill

The road (B4077) from Tewkesbury to Stow-on-the Wold (and vice versa) is an exceedingly pleasant, largely traffic-free, drive through the Cotswolds. Roadkill - including deer, badgers, hedgehogs, rabbits, squirrels, pheasants and other birds - is a fairly common sight despite the relatively low traffic volumes.

The noun 'roadkill' started to become part of common parlance in the UK around about 1960 according to Google Books Ngram Viewer ...

Figure 1: Prevalence of the Word 'Roadkill' in English Literature

... with a rapid rise in usage from about 1983 onwards (Figure 1). Presumably there was road kill before 1960, but maybe not enough for it to be a topic that people discussed or wrote about?

That traffic volumes are a major factor in determining the amount of roadkill was demonstrated by recent studies on the effect of Covid-19 lockdowns on wildlife fatalities; see here, here, here, and here. This Japanese study indicated no reduction in wildlife collisions during the pandemic despite the fact that there was a positive correlation between traffic volume and roadkill numbers before the pandemic.

Figure 2 plots the passenger kilometres travelled, according to mode of travel, from 2012 to 2022. Other modes include buses, trains/trams, cycles, motorcycles and domestic flights. The effect of the pandemic is clear to see.

Figure 2: Passenger kilometres (Great Britain) by Travel Mode (2012 -2022)

Roadkill numbers (Figure 3 taken from here) mirror the changes in passenger kilometres and, particularly, those associated with cars and vans.

Figure 3: Roadkill Numbers (UK) from 2010 - 2020

Roadkill is a major cause of wildlife mortality worldwide as well as in the UK. If we are to protect our wildlife biodiversity then we need to quantitatively monitor roadkill species and devise strategies to minimise fatalities.  There are a number of citizen science projects that record roadkill if you are interested in this topic; for example, The Road Lab (formerly Project Splatter!!) and the People's Trust for Endangered Species.