Har­vest mice nest­ing

BBC Wildlife Magazine - - Q&A - Emily Marn­ham

1 DO HAR­VEST MICE BUILD MORE THAN ONE NEST?

Yes. Har­vest mice build two types of nest: non-breed­ing (used year-round as tem­po­rary shel­ters) and breed­ing (used in the sum­mer for rais­ing young). Both males and fe­males con­struct the non-breed­ing nests, which are roughly 4cm in di­am­e­ter and of­ten low to the ground, but only the female builds a breed­ing nest, 10 days be­fore giv­ing birth. This is slightly larger at 6–10cm in di­am­e­ter and is usu­ally sited at least 30cm above the ground.

2 HOW IS THE SPHERE-LIKE SHAPE CREATED?

Har­vest mice weave their spher­i­cal nests from liv­ing plants, such as grasses and reeds, which pro­vide a strong sup­port­ing struc­ture. A mouse starts by split­ting the wide blades into strips (along the veins to re­tain strength), then weaves them into a loose ball using its paws and mouth. Next, it works from the in­side, adding more strips of grass and pulling the frame­work tightly to­gether. The spher­i­cal shape (and lack of an ob­vi­ous en­trance) pro­vides a se­cure place for a mother to raise her young, and also helps to main­tain a suit­able nest tem­per­a­ture.

3 WHY NEST HIGH UP IN THE GRASS?

Har­vest mice spend most of their time feed­ing in the ‘stalk zone’ (at least 30cm above ground in grasses; 1m in reeds), so it makes sense to nest in the same area. Nest­ing off the ground also af­fords some pro­tec­tion from preda­tors, but the nest must be supported by and se­cured to the sur­round­ing veg­e­ta­tion. This means har­vest mice are un­able to breed in ar­eas where the grass or reeds are too short, too thin or too weak. The loss of habi­tat that ful­fils the species’ nest­ing needs is thought to be one of the main causes of its de­cline.

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.