Ruth Brandt

Position: Graduate Student

Thesis title: Mating behaviour and habitat use in harvest mouse (Micromys minutus)

Prior to joining WildCRU, I have done a research MSc course in the Zoology Department of Tel Aviv University, in my native country of Israel, under the supervision of Dr. Arnon Lotem. My MSc thesis title was “Response rules of the House Sparrow (Passer domesticus) to the begging vocalizations of its young”. I studied for my undergraduate degree in Biology in the Hebrew University in Jerusalem. As part of the Amirim honours programme to which I belonged I did a research project in the Jerusalem Zoo entitled “Playmate choice in young mandrills (Mandrillus sphinx)”.

As I have always been interested in animal behaviour on the one hand, and conservation on the other, it only made sense to do my DPhil with WildCRU.

I started my DPhil working on mating behaviour in water shrews (Neomys fodiens) but they proved unsuitable for such a study (see details below, along with some conclusions from that study). I am now working with harvest mice (Micromys minutus) looking into mating behaviour, or more precisely – female mate choice, in a captive environment and population ecology in the field, as part of WildCRU’s Upper Thames Project.

Reasons for Discontinuing the Water Shrew Study:

A combination of several factors makes the water shrew in my opinion an unsuitable species in which to conduct a behavioural study within the time limits of a PhD study. These factors are:

Not enough is known about the natural history of the species. Basic data needed for the study of their mating behaviour - such as breeding physiology – is too incomplete for more complex questions - such as mating choice - to be answered;

• They are relatively slow breeders, a fact that makes it almost impossible to get a proper sample size in the relatively short time of a PhD study. Since catching a relatively large number of shrews from the wild is undesirable, and currently there are not enough captive animals from which to start with a big enough population, building a proper breeding colony would have taken too much time;
• Several technical issues need to be resolved before proper study of water shrew behaviour can commence. These issues require time to spend on preliminary experimentation, also too long a time for the time frame available for a PhD.

Marking water shrews – what not to do:

The biggest problem was finding a method of marking individual animals in a way that makes it possible to tell them apart by observation alone (ie, without handling). For example:

• several ways of paint-marking their fur proved unsuccessful, either because the paint does not show on their black fur (when using livestock dye) or because the animals tended to remove the marking within a few hours (when using white paint);
• fur clipping was attempted, but the water shrew’s under-fur is not light enough to contrast with their black over-fur, and so the clippings can barely be seen even when the animal is studied up close;
• the use of bird rings was considered, but not tested. My belief is that the shrews – which are very nervous about any handling and manipulation - will not take kindly to such an attachment and will try to remove the rings.