Great crested newt activity while overwintering in ponds – Information request

Written by Andrew Smart, Head of Science and Research

Froglife are interested in gathering information about great crested newts overwintering and remaining active in ponds in the UK during the months of November to February. We would appreciate anyone who has any winter records of great crested newts active in their garden ponds or local ponds contacting us by email on: winterGCN@froglife.org (see below for details).

Following a recent article on overwintering and neoteny, Froglife has been made aware of a garden pond where great crested newts continue to show activity while overwintering in the pond.  While small numbers of newts have been known to overwinter, its not something that has ever been widely recorded. 

Griffiths et al (2010) found that milder wet winters are linked to low survival rates in great crested newts, with overwintering animals away from the pond being unable to feed but continuing to deplete energy reserves. Investigations of the metabolic rates of overwintering alpine newt (Kristín and Gvoždík, 2014) found that individual metabolic rate was related to body mass loss, which in turn is linked to reproductive success, immune response and future survival. Griffiths et al found the implications of any potential change in climatic conditions on a regional scale could result in the loss of metapopulations while variation in survival of individual populations may be linked to changes in summer climate. 

With milder winters in the UK it may be that some newts that previously adopted a higher-risk strategy (exposure to winterkill) of overwintering in ponds may find themselves able to feed and be in better condition at the start of the breeding season. Triturus carnifex (Mori et al 2017) have been found to remain present in ponds in Italy throughout the year with low numbers recorded in December, January and February. In Norway (Dervo et al 2018) great crested newts have been found to migrate as much as 1300m to find suitable hibernation sites to escape the cold; searching for hibernacula is another energy cost, dehydration and predation risk that could make partial migration a strategy that could be beneficial in warmer winters.

Partial migration is known in other newt species including the red spotted newt (Notophalmus viridens) in the USA, where a study (Grayson et al, 2011) found that animals were able to switch overwintering strategy and that density influenced the probability of remaining in a pond overwinter.  Variation in reproductive success over time resulted in the maintenance of both resident and migratory strategies.

Froglife would appreciate anyone who has any winter records of great crested newts active in their garden ponds or local ponds contacting us by email on: winterGCN@froglife.org with the following details:

• dates of activity
• one of: OS Grid reference / ‘what three words’ location code/ postcode (or address of garden pond)
• Approximate area of pond
• Approximate depth of pond
• Any information about numbers seen and activity

Please remember that great crested newts are protected from disturbance under the Wildlife and Countryside Act and a licence is needed to survey.  Obviously, any animal overwintering is at risk if disturbed, so please, if you are licenced don’t undertake any extensive torchlight surveys that could disturb animals and deplete energy levels; at this stage all we are interested in is a set of records to determine the extent of activity and location.

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