Is The Fox A Good Environmental Indicator?

I was asked why it was important to find out about fox health as well as what is killing them -other than cars and 'fun' shooters.  The answer is simple; foxes, like wolves, coyotes and jackals are what can be termed "Environmental health indicators". It can be simplified with "Prey and Predator".

In area where there are large numbers of deer woodland and local vegetation suffer as numbers grow and the her only moves on after local food sources decline. In the next area they move to a similar situation arises while the previous area may take decades to recover.  Where wolves have been introduced not only do the weak and sick deer numbers drop but deer herds tend to not remain static, They keep moving to avoid the predators and vegetation can continue to grow.

Plants and wild flowers as well as fruit growing attracts insects of all types as well as reptiles and smaller mammals.  These in turn are food sources for omnivores and carnivores -like foxes wolves and coyotes have been observed/filmed eating fruit when it is plentiful. In other words the eco system is well balanced with plenty of vegetation, insects, mammals, reptiles, amphibians and birds.

If the main prey animal of a carnivore dies out or are dying from disease then the carnivore also suffers. In the 1950s we say foxes starving in the SE of England as the rabbit population was devastated by human released myxomatosis.  Other species have suffered similarly when their main prey item is dying off.

A good, clean ecosystem means that species will breed and the chances of a good number of young surviving is better.  Some species regulate breeding so that in poor years when food sources are poor there will be no young. In good years there are young as no obstacles in feeding them.   For country foxes that means that as long as there are plenty of rabbits they will do well and fewer rabbits means less crop damage. Farmers pay out a lot of money for people to kill both foxes (which do not do the harm as pro hunt propaganda would have you believe) when the fox is the best and most efficient pest control you can get for free.  One farmer noted that a fox had been on his farm for years and never caused a problem and it had made his farm virtually rat free.

The Town Fox has its main source of food in rats and mice. One gentleman at a public building knows that the resident fox catches and kills rats as each week he adds up the number of rat tails (the only part of a rat foxes do not eat) and over a weekend he counted 16.  Others -including farmers- note the number of rat tails they find and that is a good indicator that the fox does good work.  A fox is far better for the environment than poisons that can kill cats, badgers, hedgehogs as well as birds of various types.

Plenty of badgers indicate a good environment although their number is reaching a critical point.  Town badgers do well, apart from roads and cars, and so that is a good indicator of the environment.

Of course, the fox often has an unwanted companion in the magpie.  This relationship is even depicted in medieval art. A fox may leave behind scraps or may be harassed enough that its kill can be stolen -something like this was filmed in London in 2024 where a fox was hunting and killed a rat while magpies hopped back and forth.

Every predator has a bird that will scavenge from it.

Therefore, when foxes die something is wrong.  Sadly there is nothing that can be done about cars and roads but when a previously healthy fox collapses and dies  or is found dead in a garden questions need to be asked. A fox can look outwardly very healthy and yet be found to have internal injuries that led to its death after being hit by a car. People automatically start calling it a "fox poisoner" at work. A fox hit by a car can move on until the internal damage takes its toll.  Until there is a post mortem examination we are often left with a question mark over a fox death.

When it comes to foxes that look healthy but are struggling or seen to deteriorate fast there has to be  an investigation. It is never poisoning until a post mortem and testing is carried out. To date we have had only one secondary poisoning cases where a fox ate a poisoned rat. Babesia, verminous pneumonia (lung worm) and other causes have been found but when, as recently, we have fox cubs collapse and start shutting down and are jaundiced then we have to be concerned.

Concerned because, as I discovered by talking to rescues, "this happens every years" and some vets state canine hepatitis is to blame -having not carried out any tests- or "adenovirus which is rampant in UK foxes".  After all of the foxes examined to date there has not been one single case of adenovirus so it is far from "running rampant". All of the symptoms described from previous years as well as 2024 match what we have seen and found to be leptospirosis. If this is happening every year then it explains, in part, why fox numbers are dropping so low.

Our question is: can we do anything about it?  Vaccinating every fox we can find is expensive an no government would fund a massive trap, vaccinate and release programme. This appears to be an environmental situation and the death of so many cubs is yelling this at us.

The question then becomes what if anything we can do about the environmental problem.  We may have goner too far and ignored problems for far to long to be able to do anything. Even if, as the British Trust for Ornithology suggested after its mammal survey, the fox is Red Listed as a protected species (meaning nothing in the UK) what can we do?

Poisons, cars and environmental damage are already taking their toll which, with the badger heading toward the precipice and foxes declining in numbers it is very likely that both will either become extinct in the countryside and just about hang on in towns and cities where developers are always out to grab scenic green sites to build on and destroy more wildlife habitat.

Looking at what is happening to foxes is therefore very important.  The question is whether people will learn from what we find and take action?

An explanation of leptospirosis can be found here along with the fact that  the fox is not the problem here

https://foxwildcatwolverineproject.blogspot.com/2024/08/leptospirosis-why-is-it-killing-so-many.html