Highly variable lifespan in an annual reptile, Labord’s chameleon (Furcifer labordi)

Abstract

Among tetrapods, the current record holder for shortest lifespan is Labord's chameleon, Furcifer labordi. These reptiles from the arid southwest of Madagascar have a reported lifespan of 4-5 months during the annual rainy season and spend the majority of their life (8-9 months) as a developing embryo. This semelparous, annual life history is unique among tetrapods, but only one population (Ranobe) in the southernmost distribution range has been studied. We therefore investigated the potential for environmentally-dependent variability in lifespan in a population in Kirindy Forest, which has a much longer warm rainy season. While no adults were found after March in Ranobe, the disappearance of adults was delayed by several months in Kirindy. Our data also revealed sex-biased mortality, suggesting that females have a longevity advantage. Furthermore, we found that, after an unusually long previous rainy season, one female was capable of surviving until a second breeding season. Keeping F. labordi in cages under ambient conditions demonstrated that also males can also survive until the next season of activity under these conditions. Our study therefore revealed considerable variability in the extreme life history of this tetrapod that is linked to variation in ecological factors.The fast-slow continuum is the dominant axis of life-history variation in tetrapods. Fast-living species are characterized by fast growth, high reproductive rates, high aging rates and short lifespans, compared to their slow-living counterparts [1][2][3] . Among tetrapods, the most extreme example for short lifespan is provided by Labord's chameleon, Furcifer labordi. During their study in the arid southwest of Madagascar in Ranobe, Karsten et al. 4 reported synchronous hatching of F. labordi with the onset of the annual rainy season in November. Here, early life of this chameleon is characterized by fast growth, resulting in sexual maturity at less than two months of age. After mating, senescent decline becomes apparent, and by the end of the rainy season in March, a population wide die-off of both sexes occurs. Thus, with an incubation period of 8-9 month, F. labordi spend the majority of their lifetime as a developing embryo in the egg, probably as an adaption to the highly seasonal climate. High adult mortality combined with relatively high juvenile survival might have ultimately selected for this semelparous, annual life history 5,6 . Semelparity, the strategy to invest in only one mating event, is rare among tetrapods, including a few small-sized marsupial species from the families Didelphidae and Dasyuridae. However, in these marsupials the die-off following the mating season is restricted to males, while some females survive to breed a second time 7 . Strong prey seasonality leading to a short breeding season has been proposed to explain obligate male semelparity in these marsupials 8 . Interestingly, males that were captured before the mating season and prevented from competing for mates survived for more than two years 9,10 . Less ...

Are trade‐offs really the key drivers of ageing and life span?

“…We note that this literature needs to be interpreted with some caution, given the substantial differences in a species' measured life span depending on conditions. For example, the Labord's chameleon (Furcifer labordi), which normally lives only 4-5 months in the wild and is the record holder for shortest life span among tetrapods, was shown to live up to 16 months if kept under ambient conditions; its life span also varies greatly across habitats and environmental conditions (Eckhardt, Kappeler, & Kraus, 2017).…”

Life histories, demographies and population dynamics of three sympatric chameleon species (Furcifer spp.) from western Madagascar

“…30 km north of Toliara), both sexes disappear synchronously at 4-5 months of age (Karsten et al, 2008), lifespan near the northern distribution range (Kirindy Forest, ca. 60 km northeast of Morondava) is prolonged in both sexes to 6-9 months (Eckhardt, Kappeler and Kraus, 2017). Males from Kirindy were also significantly larger than their conspecifics from Ranobe (Eckhardt, Kappeler and Kraus, 2017).…”

“…60 km northeast of Morondava) is prolonged in both sexes to 6-9 months (Eckhardt, Kappeler and Kraus, 2017). Males from Kirindy were also significantly larger than their conspecifics from Ranobe (Eckhardt, Kappeler and Kraus, 2017). Moreover, following an unusually long rainy season, one female at Kirindy survived until the next breeding season, and some caged individuals of both sexes survived the entire austral winter (Eckhardt, Kappeler and Kraus, 2017).…”

“…Reptiles contain both the longest-lived tetrapod species (tortoises; Patnaik, 1994;De Magalhaes and Costa, 2009), as well as the shortest-lived one: Labord's chameleon, Furcifer labordi. These chameleons from the deciduous dry forests in western Madagascar have a lifespan of only 4-9 months (Karsten et al, 2008;Eckhardt, Kappeler and Kraus, 2017), probably as an adaptation to the biphasic and highly variable annual climate. At the beginning of the local rainy season in November, hatchlings emerge that grow rapidly, achieving sexual maturation after 2-3 months.…”

Parasite burden in a short-lived chameleon, Furcifer labordi

“…Labord's chameleon ( Furcifer labordi ) from the highly seasonal deciduous dry forests in western and southwestern Madagascar has a post-hatching lifespan of only 4–9 months (Karsten et al, 2008; Eckhardt et al, 2017). This extreme life history makes this species an interesting model to study potential mechanisms of accelerated senescence, especially because longer-lived sympatric congeners are available for comparative studies.…”