Ticks are widespread throughout the countryside and in areas of rough vegetation and forestry. They are not confined only to National Parks or Nature Reserves. The issue of warning notices is a matter for the HSE/Local authorities to consider. Any such signs would need to be countrywide as opposed to specifically located in particular National Parks or Nature Reserves. The National Parks & Wildlife Service of my Department is willing to engage with the Local Authorities on any county-wide initiatives they (or the HSE) wish to propose.
Ticks can be found on a variety of domesticated and wild animals including sheep, goats, horses, cattle, dogs, deer and various wild mammal species. Information on Lyme Disease is available to the public from the HSE website http://www.hpsc.ie/a-z/vectorborne/lymedisease/informationforthepublic/. The HSE booklet on lyme disease also contains useful information in this regard.
With regard to Killarney National Park, information on ticks is contained within the health and safety section of the dedicated park website for members of the public who intend on visiting the National Park: https://www.killarneynationalpark.ie/plan-your-visit/safety-in-the-park/ and is also available in the visitor centre at Killarney House. The HSE booklet is also available to download from the Killarney National Park website: https://www.killarneynationalpark.ie/wp-content/uploads/2018/11/Lyme-DL-April2017-D2.pdf.