Studies have indicated that deer feed a large proportion of the tick population. Reducing deer numbers has shown to decrease the number of ticks in certain areas. However, in some studies, certain species of adult ticks (which favour deer to complete their life cycle) have adapted to smaller hosts, such as hare, when the deer are removed.
In some areas where red deer and mountain hares do not occur, sheep are dipped or doused with acaricide four times or more per year before being turned out. Treating sheep this way allows them to mop up ticks, which die when they come into contact with the acaricide residue on the fleece. This method has been successful in reducing tick numbers.
The Game Conservancy Trust is currently conducting trials in the Scottish Highlands to test whether using sheep as “tick mops” can also be successful in controlling ticks in areas where there are deer and hares.
Using deer and hares as a method of mopping up ticks has also been considered. However, acaricides, which are licensed for use on domestic livestock and pets in the UK, are currently not licensed for use on any type of wildlife.
Treated sheep help to mop up ticks
Until the EU ban of the herbicidal product Asulam in 2011, the spraying of bracken from mid July to the end of August often took place in order to control its growth.
Bracken is an ideal habitat for ticks. This is because its dense growth keeps humidity levels high. Once it withers and dies, it creates a moist layer for ticks to remain in.
Bracken is growing out of control in certain areas, particularly throughout heather moorland. Non-chemical methods of bracken management have taken a minor role, such as harvesting for biomass, or for use as winter bedding for livestock but this tradition mostly died out as modern farming methods took over, Research into biological methods of bracken control has made little progress and its employment in Britain is unlikely in the foreseeable future due to the associated legal, environmental and socio-economic problems. In certain areas, this plant is invading moorland at a rate of 5% per year.
The control of bracken is vital to the survival of numerous species of flora and fauna as well as playing its part in reducing tick populations. The spread of bracken as a result of this ban will almost certainly lead to increased tick numbers.
From December 31st 2011, the sale and supply of Asulam was prohibited, and stocks to be used by 31 December 2012.
Further information about bracken and a summary of the Asulam ban can be obtained from The Bracken Control Group, which was formed in response to the Asulam ban.
Bracken was sprayed with herbicide
For centuries moorland has been burned to manage the vegetation and to stimulate new growth. Another benefit of this practice is that it can also help to control tick numbers. However, it must be very carefully managed.
Carefully managed moorland burning helps control tick numbers