How does mange spread? There are three possible ways:
- Direct Contact: The primary route of transmission is direct contact between infected and uninfected foxes. This can occur during social interactions, mating, or fighting.
- Indirect Contact: Mites can survive for a period in the environment, particularly in bedding, dens, and shared feeding areas. Foxes can become infected by coming into contact with these contaminated surfaces.
- Mother to Pup Transmission: Infected mothers can transmit mange to their pups during nursing and close contact in the den. This vertical transmission is a significant factor in maintaining the disease within populations.
Remember by the statement of the Fox Study under Professor Stephen Harris (University of Bristol) as well as other fox watchers from the time; up until 1994 mange "was unknown in the Bristol fox population".
We need to look at facvtors that could influence the spread of mange and these are:
- Mite Density: The number of mites present on an infected fox directly affects the likelihood of transmission. Heavily infested animals are significantly more contagious.
- Environmental Conditions: Cooler, humid conditions favor mite survival outside the host, increasing the risk of indirect transmission.
- Fox Population Density: Higher fox densities, particularly in urban areas, increase the frequency of contact and thus transmission rates.
- Fox Immunity: Some foxes may have a degree of natural immunity or resistance to mange, which can influence their susceptibility to infection and transmission.
Here we can see whyt just onbe fox being blamed for a mange outbreak that killed an estimated 95% of the fox population.
1. How and why did an urban fox suddenly decide that it would leave the easier urban life and venture into the countryside? Foxes do wander but if they have a habitat with food, shelter etc. they tend to stay reasonably close to home. How attached foxes are to home territory was shown in a 19th century hunting book in which a fox was sent to a hunt that had literally run out of foxes to kill. The fox was released and then completed an 80 miles journey home. It did so a second time and the same fox with a nick in its ear travelled "home".
Foxes are very territorial.
2 If the fox was radio collared and the team knew it had left the City why was it not tracked since such a move from town to country could reveal unique information ?
3. Following on from (2) above: "The fox suddenly returned " to the City and carrying mange. This makes no sense; the fox left tyhe City and was not tracked (allegedly) but the team were on site to be able to report it had returned and also that it had mange -based on the radio collar data? Also; just how exactly did the team know that this fox had brought mange into the city population and had not been infected by another fox in the City?
There is also the question of how this one particular fox was followed showing that it was "Patient A"? Foxes do not just wander all over other foxes territory dropping the mites everywhere. Foxes challenge strangfe foxes entering their territory and do not let them hang around. This takes us to the next points:
4. At exactly what geographical location did this collared fox suddenly leave the City?
5. At exactly what geographical location did this wandering fox return into the City?
6. At what date was it clearly identified that this fox had mange?
7. There were fox watchers who provided basic first aid to foxes who cooperated with the University team so why was it that none of them were alerted to the presence of mange? I was not and I know a lot of the old watchers were not told. Why?
8. At what date did this fox leave the City? During dispersal season (from June on) then one might imagine a young fox venturing out and this is mainly amongst dog foxes -we are not even told whether the fox in question was a Dog or Vixen.
9. At what date did the fox return? How long was it gone for?
No one from the old University study appears contactable and, as noted elsewhere on this blog, University of Bristol denies all knowledge and has absolutely no records on anything that was done.
10. If this collared fox was tracked then what data was there on the movements around the City that show how it spread mange mites to an entire population?
I have, obviously, spent more years than I care to studying this outbreak as well as discussing it with other naturalists -mainly outside the UK since no one appears to be concentrating on fox research here other than myself. In every case I have been told that based on the size of the City as well as the guessed at fox population at the time one fox coulkd not have been responsible for wiping out 94-95% of the population.
This is the problem we are faced with. A University that had every opportunity to forward data before it was all "expunged" from the system and members of the fox study that refused to respond to plain and simple questions that anyt naturalist or zoologist would ask. This is why the Freedom of Information Act request was made. 94-95% of an urban fox population was wiped out within a year and this has never happened in any other town or City in the UK where mange is known and all the data is...gone.
There is an alterantive and that is that the study by University Bristol (that it knows nothing about) was flawed from start to finish. Although none of the old fox watchers had ever encountered mange is it possible that it was present but that the team never bothered noticing it until "Patient A"? It seems unlikely really since ex RSPCA Inspectors I knew had never encountered mange in Bristol before 1994 and they were shocked by how fast it spread ("It spread unbelievably quickly").
Stephen Harris and Phil Baker in Urban Foxes (Whittet Books, 2009 -updated edition) state:
"In Bristol, for example, before mange arrived, the mortality rate of dominany=t animals was low..." (p 30)
Then:
"...in Bristol , where we were able to catch and mark nearly all of the resident adults..." (p. 30
But the book also gives a slightly different account as to "Patient A":
"Bristol was free of mange up unmtil 1994, when one of our study foxes was captured in May suffering from the diseasde and put to sleep. Unfortunately, his arrival hertalded a dramatic downturn in the fortunes of Bristol's fox population. At the time he was caught, there were 46 adult foxes and their cubs in the groups that we were studying. From this singlke animal, the infection spread throughout his own group and to the foxes in neighbouring groups. During the summer of 1995, three of the study groups disappeared completely, followed by another in autumn 1995. The last groups disappeared during the winter of 1995; ironically, the last two animals actually died after being hit by cars rather than from mange. All the foxes on our study area died, and we estimated that over 95% of all the foxes in Bristol died. ..." (p 120)
In the updated edition it is stated:
"In the space of just twenty months, the population had declined from approximately 30 adults per square kilometre to less than one per square kilometre. Six years after the disease appeare4d, the fox population is slowly recovering, but still less than 10% of what it was pre-mange" (p 120)
I am no mathematician but May to December 1995 is not 20 months it is 8 months. Again, this is missing data and it makes no sense when you read it. It also leaves out the leaving the City and returning part of the story. I am somewhat shocked that they caught and had the manged fox killed. They knew that mange was treatable
Last two foxes were "ironically" killed by cars. Well, I find that a dumb statement and I cannot see any irony in them dying that way.
"we were able to catch and mark nearly all of the resident adults" now foxes are bloody hard to trap so I assume that they are referring to foxes in their "study groups" because if the claim was referring to the entire fox population of Bristol that would be one mighty lie. We should also note that they refer to wandering "itinerant" foxes so we are going entirely, I believe, by the study groups -but they do state: "over 95% of all the foxes in Bristol died. ..." here is where all of the missing data creates a bigger problem. Yes, we know the population was devastated and I would estimate likely 96% of it but who was supplying the group with fox death numbers? How did they assess (estimate) the per centage of the popuilation that died?
I can find no data on mange outbreaks beyond the City itself at that period which raises questions. Again, Patient A is blamed for the outbreak.
Hopefully, the Reader can see why I have been trying to get the data for over 30 years? I set up the British Fox Study in Bristol in 1976 and I did forward data to the University group and specialising in wild canids I want to know the details of how mange got into the City and how it spread and killed 95-96% of the fox population in 1995 (a year with 20 months it seems)? It is not some silly chase for the truth but naturalists, zoologists and even wildlife rescues need to know whether such a mange epizootic can occur again.
I am in no position to point any fingers of blame and suggest that mange was released not through just one fox but several but people see the ominous side of "study groups" and a study fox suddenly getting mange that wipes out a population while a team sits back and studies the spread and result.
With the Universitystating they know nothing" and no one involved being contactable we are left with a one off event and I will point out that the spread could have been far less devastating had foxes been treated but, as will be pointed out, that would cost money and, after all "just foxes".
