Vixens Are More "Liberal" Than Dog Foxes

 

A long-term study led by Professor Stephen Harris and his team at the University of Bristol uncovered surprising behavioral patterns in red foxes (Vulpes vulpes).

After radio collar tracking urban fox populations for over 25 years, the research found that Dog foxes are remarkably loyal, often staying single for the rest of their lives if they lose their mate. This loyalty was thought to be linked to Dog fox role in raising offspring and maintaining territory stability.

Vixens, whose reproductive success depends on securing a mate each breeding season, tend to form new partnerships relatively quickly.

The study highlights the contrasting strategies between the dog fox and vixens: while males invest in long-term pair bonds and territorial defense, females prioritize reproductive timing and opportunity.

This research offers rare insight into the complex emotional and social dynamics of wild animals and challenges the assumption that monogamy is rare in mammals.

Fox tactics could inspire territorial design

 

Press release issued:

10 March 2011

A new study into the exclusion tactics adopted by urban foxes suggests that the transient nature of animal territory is a result of a complex system of individual-level interactions.

The size of an animal’s territory is ultimately dependent on how long it can exert its control before intruders cross the boundaries into its space. The precise nature of such changeable territorial boundaries is revealed in a new study which offers fresh insights from the combined perspectives of biological sciences, mathematics and engineering.

Researchers from the University of Bristol used thirty years of data regarding the movements of the urban red fox to construct and verify a mathematical model on which their analysis was based.  A trade-off between two factors emerged as key determinants of territoriality – the time necessary for an animal to move between its own boundaries and the time span during which the fox could maintain its scent trail within that territory.

In 1994, when a disease called sarcoptic mange infected and killed most of Bristol's fox population, Professor Stephen Harris noticed that as the animals on one territory died, the neighbouring animals were able to move in and take over within a matter of three or four days. He assumed that this was because the scent marks of the original fox population were no longer fresh.

This new study, published in PLoS Computational Biology, shows how important it is for a fox to renew its scent marks frequently, further demonstrating the transient nature of populations, and disputing previously held beliefs that scent marks serve as a long-term message and indicator of territorial boundaries.

Lead author Dr Luca Giuggioli, a Complexity Sciences lecturer in the Department of Engineering Mathematics and the School of Biological Sciences, said: “Understanding how organisms move and interact has implications far beyond behavioural ecology. This model may, for instance, shed light on the processes responsible for the formation of territorial boundaries in early human hunter-gatherer societies, and eventually help predict how the size of modern day countries will evolve.”

Co-author Jonathan Potts added: “Our theoretical framework might also inspire designs in collective robotics. From very simple rules, the individuals divide space into territories, and if one individual should fail, its territory is taken over. Building an army of territorial robots that move according to these rules could be an efficient and robust way to deal with dangerous tasks over a wide spatial area, such as clearing minefields.”

Dr Giuggioli added: “This study is one classic example in which answering a biological question with the help of Complexity Sciences tools provides far reaching results, challenging long-held preconceptions and opening up the possibilities in areas of science unrelated to where the questions originated.”

Paper: Animal interactions and the emergence of animal territoriality, by Luca Giuggioli, Jonathan Potts, Stephen Harris.  Published in PLoS Computation Biology.

 

Ljungan Virus and Foxes

 

 Ljungan Virus is quite "a thing" at the moment with a lot of research being carried out -not for wildlife health but human -that attracts the money.

With our necropsy study we found that babesia and leptospirosis were heavy hitters amongst foxes so it  only makes sense that as foxes main prey are rodents such as rats, voles, etc I at least mention the topic (it has been noted in Red Foxes but sadly the UK is far from open when it comes to research papers -unlike the US or Europe.

From Wikipedia: https://en.wikipedia.org/wiki/Ljungan_virus

Ljungan virus was first discovered in the mid-1990s after being isolated from a bank vole near the Ljungan river in Medelpad county, Sweden.^[2] It has since been established that Ljungan virus, which is also found in several places in Europe and America, causes serious illness in wild as well as laboratory animals.^[3][4][5][6] Several scientific articles have recently reported findings indicating that Ljungan virus is associated with malformations, intrauterine fetal death, and sudden infant death syndrome in humans.^{[7][8][9][10]} In addition, studies are being conducted worldwide to investigate the possible connection of the virus to diabetes, neurological and other illnesses in humans.^[11][12]

Ljungan virus belongs to the genus Parechovirus of the family Picornaviridae. Other members of this viral family include poliovirus, Hepatitis A virus, and the viruses that cause the common cold (rhinovirus).^[13] One of the earliest scientific discoveries regarding Ljungan virus was that infected wild rodents developed diabetes if they were exposed to stress.^[14] This has led to speculation that this disease may be the underlying cause of fluctuating rodent populations in Scandinavia; when rodents increase to high densities, they find it difficult to defend territory and obtain food, and then become more susceptible to predation. This stressful situation results in disease, death and population decline, leading to a pattern of cyclic variation in population size over time.^[4]

There was a 2014 paper (see abstract below)

Ljungan virus is endemic in rodents in the UK

Anne-Marie Salisbury 1, Michael Begon, Winifred Dove, Bo Niklasson, James P Stewart

. 2014 Mar;159(3):547-51.

 doi: 10.1007/s00705-013-1731-6. Epub 2013 May 12.

abstract

"Ljungan virus is a recently identified member of the family Picornaviridae that was isolated from bank voles in Sweden. LjV has been associated with [corrected] type 1 diabetes-like symptoms and myocarditis in bank voles (Myodes glareolus), and it has been suggested that it has zoonotic potential. 

"Here, we show for the first time that Ljungan virus is prevalent (20-27 % positive by PCR) in four species of UK rodent (Myodes glareolus [bank vole], Apodemus sylvaticus [wood mouse], Microtus agrestis [field vole] and Mus musculus [house mouse]). 

"Sequence analysis showed that Ljungan virus of genotypes 1 and 2 were present, although genotype 1 was more prevalent and more frequently associated with brain tissue.

"This study highlights the prevalence of Ljungan virus in the UK and the need for assessment [corrected] of its zoonotic potential."

Leptospirosis and Foxes

  Abstract from Acute lethal leptospirosis in a red fox (Vulpes vulpes) Journal of Comparative Pathology Volume 201, February 2023, Pages 77-80

Author links open overlay panel, , Nenad Turk b, , 

Leptospirosis, caused by pathogenic spirochaetes belonging to the genus Leptospira, is a globally distributed zoonosis that can affect many species of domestic and wild animals, and humans. The red fox (Vulpes vulpes) is a native species in Croatia and, due to constant food availability and lack of interspecies competition, is becoming more abundant in urban and suburban areas. 

Although antibodies for Leptospira spp have been detected in red foxes, lethal disease has not been reported. We necropsied a young, male red fox that had jaundice, multifocal haemorrhages in the heart, lungs and urinary bladder, hepatomegaly, non congestive splenomegaly and slight yellow discolouration of the renal cortex and medulla. Histology revealed multifocal haemorrhages in parenchymal organs, thrombi within lung septal capillaries and other blood vessels, interstitial lymphocytic and plasmacytic nephritis and erosions of the gastric mucosa. 

A microscopic agglutination test on the post-mortem cardiac blood clot revealed a high titre to Leptospira interrogans serovar Icterohaemorrhagiae, which implies contact with rats, which are natural reservoirs of this serovar in Croatia. 

The gross and histological findings in this fox were similar to those in dogs with leptospirosis, indicating that fatal leptospirosis can occur in foxes and suggesting that this species can act as a source of infection for other animals and humans.

Badger Stats for 2022 -2026 up To 12 04

 

https://www.lulu.com/shop/terry-hooper/bristol-fox-and-badger-death-registers-2022-2025/paperback/product-7k6kdre.html?page=1&pageSize=4

Badger deaths up to this date in 

2022 10 

2023 13 

2024 13 

2025 31 

2026 40

as reporting gotten 'better' the number has increased. Statistically that would mean this year up to today, deaths would be around 100+ 

All stats are published online at the blog and hard copies can be purchased to help fund the work although neither the fox or badger death registers or published stats have attracted any comment or attention. 

This is the last year I do this.

Not Good Reading

 Total KNOWN dead foxes and badgers up to 10 04 2026

Foxes 93

Badgers 30

Badger Groups...Who Ignore Other Badger Groups

 

I have had two angry messages from people in an area of Bristol asking WHAT I did to the badgers. I know the area but explained that I, personally, had done nothing to any badgers.

It took a while but it turns out that, once again, Somerset Badger Group came to Bristol and trapped and then treated a badger but decided that the local badger group had no business knowing. Not even a message to let me know of a badger needing treatment when they KNOW we have a level 3 trained wildlife rescuer (whom they have contacted before) as well as wildlife friendly vets.

Apparently, since that trapping `the badgers have been acting out of character" and avoiding the trapping area.

This is the third time in a year I have been told Somerset Badger Group has come to Bristol the last two occasions we have no idea what happened to the badgers.

I have forwarded info on dead badgers in Somerset reported to me several times as well as other info. They have refused to cooperate or send details of dead badgers in Bristol reported to them.

So from now on no more friendly sending of info and badger issues in North Somerset we will deal with,

Cooperation works two ways.