Global Assessment of Reptile Distributions
  • Home
  • About
  • People
  • Activities
  • Meetings
  • Publications
  • Data
  • Links
  • Collaborations
  • BloGARD

Nocturnal activity does not prolong gekkotan lifespan

20/3/2020

0 Comments

 
In a recent publication in the Israel journal of ecology and evolution, we (Gavin Stark, Rachel Schwarz and Shai Meiri) showed that nocturnality does not prolong lifespan among the within gekkotan species. Species from the infraorder Gekkota are known to be predominately nocturnal as opposed to other lizard clades. Diurnal lizards demonstrate higher metabolic rates than nocturnal ones. Moreover, exposure to solar radiation is thought to reduce ectothermic longevity by increasing both metabolic costs and the rate of accumulating harmful mutations through UV radiation. Thus, we assume that by being nocturnal, ectothermic species may reduce their intrinsic mortality rates and thus live longer. We compared groups of nocturnal and diurnal species across all gekkotan families, and also compared all non-gekkotan species to geckos (740 lizard species, of which 185 are geckos) to test whether nocturnality select for longer lifespans. We found that geckos live relatively long for lizards of their size, however their activity time was found to be unrelated to longevity, contradicting our predictions. We suggest that mortality through extrinsic causes (e.g., predation) may impose much stronger selective pressures than intrinsic causes.
Picture
Mediodactylus kotschyi
Author: Gavin Stark
0 Comments

The Hot Eurasian nightlife - How do different environmental forces affect nocturnality in lizards?

10/10/2017

0 Comments

 
In a recent publication in Global Ecology and Biogeography we explored the prevalence of nocturnality amongst Eurasian lizard species and tried to understand what drives these patterns.
Most animals – at least those that live above ground – are active either during the day or during the night. Being active at either time of day carries with it unique benefits and challenges, and thus particular adaptations. Because of this being nocturnal or diurnal is a trait that is pretty rigid amongst closely related species.
Lizards as a group are thought to be ancestrally diurnal. Most of them remain so to this day. Furthermore, they are ectotherms and are predominantly small bodied tetrapods and could thus be particularly affected by the climatic differences between day and night. For this work we collected distribution range and activity time data for all 1,113 lizard species found throughout mainland Eurasia. We then looked at links between richness patterns of lizards with either temperature or productivity.

Picture
Cyrtodactylus trilatofasciatus (Photo: Lee Grismer)
We found that nocturnal lizards have the highest species richness in the tropics and in deserts, and their richness decreases when they get closer to the North Pole. Nocturnal lizards are precluded altogether from the coldest regions inhabited by lizards – in high mountains and the highest latitudes.
Picture
Stenodactylus sthenodactylus (Photo Uri Roll)
Ambient temperature has a strong influence on richness patterns of both diurnal and nocturnal lizards, where species numbers increase with an increase in temperature. Productivity was found to be more tightly related to the proportion of nocturnal species – again in a positive relationship.

We think that our results point towards the fact that low temperatures are a limiting factor for lizard activity period. It is possible that the year-round warm nights of tropic regions enabled lizards to move towards nocturnal activity. In hot deserts, perhaps the combination of hot days and aridity make diurnal activity less attractive, whereas nocturnal activity can provide shelter from these extreme conditions
Author: Enav Vidan
Picture
Stenodactylus doriae (Photo Uri Roll)
0 Comments

    Author

    Mainly maintained by Shai Meiri and Uri Roll

    Archives

    October 2022
    April 2022
    November 2021
    June 2020
    March 2020
    February 2020
    January 2020
    July 2019
    January 2019
    October 2018
    August 2018
    May 2018
    November 2017
    October 2017
    September 2017
    January 2017
    August 2016
    July 2016
    May 2016

    Categories

    All
    Africa
    Amniotes
    Australia
    Big Data
    Big-data
    Body Size
    Body-size
    Climate
    Clutch Size
    Clutch-size
    Competition
    Conservation
    Deserts & Drylands
    Diet
    Diversification
    Diversity Patterns
    Ecogeographic Rules
    Euroasia
    Evolution
    Extinctions
    Functional Diversity
    GARD History
    Geckos
    Hotspots
    In Memoriam
    Islands
    Island Syndrome
    Late Quaternary
    Latitudinal Diversity Gradient
    Lizards
    Longevity
    Metabolism
    New Guinea
    Nocturnality
    Palearctic
    Priritization
    Reproduction
    Speciation
    Tetrapods
    Tropics
    Type Specimens
    Viviparity
    Wikipedia

    RSS Feed

Powered by Create your own unique website with customizable templates.