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Why did the harvest mouse cross the road? The use of RFID in answering this question

Emily Howard-WilliamsDr David Wallis

Dr James Littlemore

The Project

• Post release behavioural ecology of the harvest mouse (Micromys minutus)

• PhD Project

• Fourth Year – part time

• University of Northampton

• The Thomas Harrison Trust

• Peoples Trust for Endangered Species

Background

• United Kingdom’s smallest rodent

• Behavioural ecology differs between seasons

• Diet

The harvest mouse

The harvest mouse

Figure 1. Global harvest mouse distribution. (IUCN, 2012)

Factors associated with their decline

Intensive farming

practices

Removal of hedgerows

Changes to cutting regimes

Reduced habitat

connectivity

Pesticide use

• 71% loss over 18 years (Sargent et al., 1997)

• Decline resulted in the species being included in national Biodiversity Action Plans in 2007 (JNCC, 2010)

• Chester Zoo embarked on a reintroduction programme

• No legislative protection (Natural Environment and Rural Communities Act, 2006)

Conservation

• Live trapping

• Nest searches- Presence/absence

• Bait pots and DNA analysis (Morris et al., 2013)

• Radio Tracking

Monitoring methods

Live trapping

– Trap sensitivity

– Interspecies competition

Nest searches

– Surveyor experience

– Nests often overlooked

– Cannot predict population size

The problem

Bait Pots and DNA– Expensive

– Degradation

Radio tracking– Expensive

– Invasive

– Short term

Overall they are easily overlooked and not commonly encountered in the wild

The problem

• Alternative monitoring method

• Relatively cheap

• Longer term that radio tracking

• Reduced occupation rates by other species

Key areas for development

The Solution

• Radio Frequency Identification (RFID) can overcome some of the monitoring challenges (Wallis, 2012)

– What is RFID?

– Benefits

– Different data set compared to radio tracking

– Records tagged individuals in a prescribed location

• 7mm chips and suitable implanter

• Available from Loligo systems (Denmark)

• Developed chipping method

• Initially practiced on dead harvest mice

• Licence (Whitehead, 2012)

Microchipping

Testing equipment

(Wallis, 2013)

Version Two

Do harvest mice cross roads?

• This is a key question?

• 245,000 miles of road in Great Britain (Williams, 2013)

• None have focused on/encountered harvest mice

• The hostile environment of the road surface (McGregor et al., 2008)

• Cover (Oxley et al., 1974)

Gene flow

• Ecological networks are key in promoting genetically healthy and sustainable populations

• Meek (2011), commented that connected ecological networks are a vital habitat feature for harvest mice

• 95% Mortality

Experimental design

• 20 Microchipped mice were released into a 60x2.4 m enclosure.

• Two cross sections of road – 4.8m and 7.2m

• Mice were released at one end of the enclosure

• Boldness testing – linked to individuals crossing the road (Bremner‐Harrison et al., 2004; McPhee, 2004)

Experimental design

• Set up an experiment to find out

• 20 Micro chipped mice were released into a 60x2.4 m enclosure.

• Two cross sections of road – 4.8m and 7.2m

• Mice were released at one end of the enclosure

• Boldness testing – linked to individuals crossing the road

The release

Results

0

1

2

3

4

5

6

708 682 683 652 704 723 742 752 761 771 773 785 801 802 808 809 824 848 850

Nu

mb

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of

trap

s p

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Individual chip number

Figure 2 – number of trap points visited per individual. Red indicates individuals that crossed the 4.8 m road

Results

Figure 3 – Individual visits to trapping points, plot area increases with number of reads

• Behaving as other male mammals do. They disperse more readily than females (Wolff, 1994)

• None crossed the wider 7.2 m road, yet.

• 10 % likelihood of crossing

Why DID the harvest mouse cross the road?

• Detection dog surveys to establish presence

– Are they a more reliable method than nest surveys?

• Further release to repeat the road study

• Use electronic readers to confirm detection dog reliability

The next step

• Individual identification

• Reduced effort

• Continuous monitoring

• Lifetime data

Summary

• Supervisory team

• Dr. David Wallis

• Lois Mayhew

• Peoples Trust for Endangered Species

• Thomas Harrison Trust

• Shepreth Wildlife Park, New Forest Wildlife Park, New Quay Zoo, Battersea Park Zoo and the Chestnut Centre – donating harvest mice

• Penny Rudd – Chester Zoo

Acknowledgments

.•Bremner‐Harrison, S., Prodohl, P. and Elwood, R. W. (2004) Behavioural trait assessment as a release criterion: Boldness predicts early death in a

reintroduction programme of captive‐bred swift fox (vulpes velox). Animal Conservation. 7 (3), 313-320.•Harris,S., Morris,P., Wray,S. and Yalden,D. (1995) A review of British mammals: population estimates and conservation status of britishmammals other than

cetaceans. UK: JNCC.•Harris, S. (1979) History, distribution, status and habitat requirements of the harvest mouse (micromys minutus) in britain. Mammal Review. 9 (4), 159-

171.•IUCN (ed.)(1998) IUCN Guidelines for Re-introductions. Switzerland; Cambridge: IUCN and SSC Re-introduction Speacialist Group;.•IUCN (2012) (2012) Micromys minutus [online]. iucn. Available from: http://www.iucnredlist.org/details/13373/0 [Accessed 17/10/12,•JNCC.(2010) UK priority species pages – Version 2. JNCC.•McGregor, R. L., Bender, D. J. and Fahrig, L. (2008) Do small mammals avoid roads because of the traffic? Journal of Applied Ecology. 45(1), 117-123.•McPhee, M. (2004) Generations in captivity increases behavioral variance: Considerations for captive breeding and reintroduction programs. Biological

Conservation. 115 (1), 71-77.•Meek,M.(2011) Suffolk’s Harvest Mice in Focus. UK: PTES.•Morris, C., O'Reilly, C., Turner, P., Halliwell, L., O'Mear, D. and Sheerin, E., (2013) A novel and non-invasive method for dectecting the harvest mouse

(Micromys minutus). Mammal News, Summer 2013, pp. 22•Natural Environment and Rural Communities Act 2006. London: England and Wales•Oxley, D., Fenton, M. and Carmody, G. (1974) The effects of roads on populations of small mammals. Journal of Applied Ecology. , 51-59.•Riordan, P., Lloyd, A. and Macdonald, D. (2009) Do harvest mouse nest surveys results predict population size? People's Trust for Endangered Species.•Rudd, P. (Curator - Chester Zoo) 21/01/2012. e-Mail to E. Howard-Williams•Sargent, G., Pottie, S. and Harris, S., (1997) Look out for mammals. The Mammal News, Summer, pp. 110•Wallis, D. (2012) Design Of An Autonomous Electronic System To Monitor Small Mammals With Radio Frequency Identification. FdScThesis, The University

of Northampton, unpublished.•Whitehead, S. (Sheila.Whitehead@homeoffice.gsi.gov.uk) 05/07/2012. e-Mail to E. Howard-Williams•Whitehead, S. (Sheila.Whitehead@homeoffice.gsi.gov.uk) 01/04/2012. e-Mail to E. Howard-Williams•Williams,M.(2013) Road lengths in Great Britain: 2012. UK: Department for transport.•Wolff, J. O. (1994) More on juvenile dispersal in mammals. Oikos. 71 (2), 349-352.

References

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