Amphibians: Manipulate temperature of enclosure to improve development or survival to adulthood

How is the evidence assessed?
  • Effectiveness
    80%
  • Certainty
    58%
  • Harms
    20%

Source countries

Key messages

  • One replicated study in Spain found that salamander larvae had higher survival rates when reared at lower temperatures.
  • One replicated study in Germany found that the growth rate and development stage reached by harlequin toad tadpoles was faster at a higher constant temperature rather than a lower and varied water temperature.
  • One replicated study in Australia found that frog tadpoles took longer to reach metamorphosis when reared at lower temperatures.
  • One replicated, controlled study in Iran found that developing eggs reared within a temperature range of 12-25°C had higher survival rates, higher growth rates and lower abnormalities than those raised outside of that range.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A replicated study in 1994-2004 in Spain found that larvae of fire salamanders Salamandra salamandra had higher survival rates with a low temperature and food three times per week compared to a higher temperature and food three times or once per week. No larvae on a high temperature-low food frequency treatment survived to metamorphosis. Larvae on high temperature-high food frequency diets had a significantly lower survival (72%) than those on low temperature-high food frequency treatment (98%) and low temperature-low food frequency treatment (98%). Recently born larvae were kept at one of two temperature treatments, 20–25°C (high temperature) or 15–18°C (low temperature) under a 12h:12h light-dark regime. Larvae were fed to near satiation either once a week (low food frequency) or three times a week (high food frequency) with frozen chironomid worms. This schedule defined four treatments: high temperature-high food, high temperature-low food, low temperature- high food, and low temperature-low food.

    Study and other actions tested
  2. A replicated study in 2008–2011 in Cologne, Germany found that the growth rate and development stage reached by harlequin toad Atelopus flavescens larvae was faster at a higher constant temperature rather than a lower and varied water temperature, although no statistical tests were carried out. Tadpoles kept at a steady temperature of 24°C reached development stage (Gosner scale) 41 (which includes increases in length, mouthpart development and disappearance of the tail) in 100 days. Those kept at varying temperatures of 22-24°C took longer to reach the same stage (106-130 days). Delayed metamorphosis may be beneficial or detrimental to survival depending on the relative risk associated with different habitats. The tadpoles were from two reproduction events in December 2010 and January 2011.

    Study and other actions tested
  3. A replicated study in 1998 of captive great barred frogs Mixophyes fasciolatus at Melbourne Zoo, Australia found that tadpoles took longer to reach metamorphosis when kept at lower temperatures. Lower temperatures resulted in later metamorphosis (16-20°C: 120–132 days; 18-22°C: 80 days; 19–22°C: 99–108 days), although no statistical tests were carried out. Delayed metamorphosis may be beneficial or detrimental to survival depending on the relative risk associated with different habitats. Five groups of 75 tadpoles were housed in five separate tanks, two groups kept at kept at 19-22°C, two groups kept at 16-20°C, and one group kept at 18-22°C.

    Study and other actions tested
  4. A replicated study in 2014 in Shiraz, Iran found that developing eggs of green frog Bufotes viridis had higher survival rates, higher growth rates and lower abnormalities when reared in temperatures from 12 to 25°C, than those reared outside this range. Survival at different temperatures was as follows: 0°C = 50%, 2°C = 60%, 8°C = 75%, 12-25°C = 95-100%, 30°C = 75%, 33°C = 65%, 37°C = 50%, 40°C = 0%. Embryos developing at different temperatures (8, 15, 18, 25, and 30°C) showed a significant difference in the time required to reach development stage 25. At 8°C, eggs had developed to stage 25 after 280 hours, but after only 52 hours at 30°C. In a separate experiment, eggs reared at 0°C and 40°C exhibited no development and no embryos survived. A thermostat-controlled aquarium housed 18 chambers, starting with 150 eggs each, across a temperature gradient with a heater at one end and a chilling unit at the other.

    Study and other actions tested
Please cite as:

Jonas, C.S., Timbrell, L.L., Young, F., Petrovan, S.O., Bowkett, A.E. & Smith, R.K. (2019) Management of Captive Animals. Pages 539-567 in: W.J. Sutherland, L.V. Dicks, N. Ockendon, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2019. Open Book Publishers, Cambridge, UK.

 

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Management of Captive Animals

This Action forms part of the Action Synopsis:

Management of Captive Animals
Management of Captive Animals

Management of Captive Animals - Published 2018

Captive Animal Synopsis

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, terrestrial mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read latest volume: Volume 17

Go to the CE Journal

Subscribe to our newsletter

Please add your details if you are interested in receiving updates from the Conservation Evidence team about new papers, synopses and opportunities.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust