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Autumn habitat selection of the harvest mouse (Micromys minutus, Pallas 1771) in a rural and fragmented landscape

Vecsernyés, Fanny (2018) BION02 20172
Degree Projects in Biology
Abstract
The harvest mouse Micromys minutus has, through nest findings, been documented to live in wetlands in tall sedges and grasses in Central Europe. However, there is very little information on the type of habitat this species uses outside of nesting, because this rodent is difficult to capture in ordinary trapping set-ups. In France and Switzerland, the harvest mouse populations have decreased strongly in the past two centuries due to the drastic reduction of its favored habitat. The present study used radiotracking to examine a small population in Eastern France living in a fragmented rural landscape. The aim was to learn more about the habitat and vegetation selection of this population during autumn. The results showed that the most... (More)
The harvest mouse Micromys minutus has, through nest findings, been documented to live in wetlands in tall sedges and grasses in Central Europe. However, there is very little information on the type of habitat this species uses outside of nesting, because this rodent is difficult to capture in ordinary trapping set-ups. In France and Switzerland, the harvest mouse populations have decreased strongly in the past two centuries due to the drastic reduction of its favored habitat. The present study used radiotracking to examine a small population in Eastern France living in a fragmented rural landscape. The aim was to learn more about the habitat and vegetation selection of this population during autumn. The results showed that the most favored habitats were in patches of stinging nettles (Urtica dioica) and American goldenrod (Solidago gigantea) rather than in their supposedly preferred vegetation type, which are tall grass wetlands. The results also presented migrating behavior in three out of the eight monitored individuals, which lead to the discovery of a possible wintering area in an unmown grassy site around a plant dump. These results suggest that disturbed, but unmown areas are important for the harvest mouse as wintering vegetation and should be available in the surrounding of a reproduction site. The results also showed that wetland management must take into account the affinity of this mammal for areas invaded by American goldenrod, in order to prevent the harvest mouse populations from decreasing in those secondary habitats. (Less)
Popular Abstract
Harvest mice can have weird habitat preferences

The harvest mouse (Micromys minutus) is the smallest rodent living in Europe, but the populations have been decreasing substantially in France and Switzerland in the past century. Despite its name, it is mostly known to live in habitats like tall sedge wetlands and in tall grasses where it can build small nests to give birth in. If you are looking for this species, those nests are the easiest way to know if the harvest mouse is present in an area. However, since this mouse species is very discreet and small, scientists have a hard time to observe this animal in its natural habitat outside the reproductive season. That is why we decided to put GPS tags on harvest mice to see how they travel... (More)
Harvest mice can have weird habitat preferences

The harvest mouse (Micromys minutus) is the smallest rodent living in Europe, but the populations have been decreasing substantially in France and Switzerland in the past century. Despite its name, it is mostly known to live in habitats like tall sedge wetlands and in tall grasses where it can build small nests to give birth in. If you are looking for this species, those nests are the easiest way to know if the harvest mouse is present in an area. However, since this mouse species is very discreet and small, scientists have a hard time to observe this animal in its natural habitat outside the reproductive season. That is why we decided to put GPS tags on harvest mice to see how they travel and where they spend their time.

The first step was to capture the mice by using live traps. These devices were filled with sunflower seeds and adjusted to close when the mice entered, without hurting them. We placed the traps in a tall-sedge meadow in which harvest mice were known to reproduce. After capturing the mice, we cut some hair on their back with scissors to glue a 0.3 g transmitter between their shoulder blades. We then released the mice where we had caught them. After that, we came back every six hours with an antenna and a receiver to follow their movements. This method allowed us to know, with a 3-meter radius precision, in what kind of vegetation the harvest mice chose to stay. In total we followed eight different individuals during the autumn of 2017.

To our great surprise, most of the GPS points recorded were found in patches of the American goldenrod (Soldiago gigantea), an exotic and invasive plant, and in stinging nettles (Urtica dioica), instead of the tall-sedge meadow where we captured the mice. Two mice out of eight even chose to migrate to a nearby plant dump!
Why are those habitats interesting?
It is difficult to know why the mice selected those habitats instead of staying in their reproduction site. The most likely explanation is that they could find more food (seeds or insects) in these vegetation types than in the tall sedge. Harvest mice are known to “disappear” in autumn, and several specialists already suspect this species to migrate during autumn to find a better site to spend the winter. It could be that the tall sedge is not the ideal vegetation to forage and survive during autumn and winter, which could be the case in American goldenrod and stinging nettles.

This study showed that there is still much to uncover about the harvest mouse’s habitat preferences. Obviously, selection of vegetation types may vary between seasons. Furthermore, it might not always coincide with where we find their nests and where they reproduce. In future studies, radiotracking should be done at other seasons than autumn. Also, other harvest mice populations should be studied to compare their habitat preferences with the one followed during the present study.

Master’s Degree Project in Biology 45 credits 2018
Department of Biology, Lund University

Advisor: Jep Agrell & Fabrice Darinot
Department of Biology, Lund University & Réserve Naturelle Nationale du Marais de Lavours, France (Less)
Please use this url to cite or link to this publication:
author
Vecsernyés, Fanny
supervisor
organization
course
BION02 20172
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
8963637
date added to LUP
2018-11-29 14:18:28
date last changed
2018-11-29 15:55:14
@misc{8963637,
  abstract     = {The harvest mouse Micromys minutus has, through nest findings, been documented to live in wetlands in tall sedges and grasses in Central Europe. However, there is very little information on the type of habitat this species uses outside of nesting, because this rodent is difficult to capture in ordinary trapping set-ups. In France and Switzerland, the harvest mouse populations have decreased strongly in the past two centuries due to the drastic reduction of its favored habitat. The present study used radiotracking to examine a small population in Eastern France living in a fragmented rural landscape. The aim was to learn more about the habitat and vegetation selection of this population during autumn. The results showed that the most favored habitats were in patches of stinging nettles (Urtica dioica) and American goldenrod (Solidago gigantea) rather than in their supposedly preferred vegetation type, which are tall grass wetlands. The results also presented migrating behavior in three out of the eight monitored individuals, which lead to the discovery of a possible wintering area in an unmown grassy site around a plant dump. These results suggest that disturbed, but unmown areas are important for the harvest mouse as wintering vegetation and should be available in the surrounding of a reproduction site. The results also showed that wetland management must take into account the affinity of this mammal for areas invaded by American goldenrod, in order to prevent the harvest mouse populations from decreasing in those secondary habitats.},
  author       = {Vecsernyés, Fanny},
  language     = {eng},
  note         = {Student Paper},
  title        = {Autumn habitat selection of the harvest mouse (Micromys minutus, Pallas 1771) in a rural and fragmented landscape},
  year         = {2018},
}