Analysis of the Population Dynamics of an Endangered Lizard (Xenosaurus Grandis) through the Use of Projection Matrices

Zúñiga‐Vega, J. Jaime; Valverde, Teresa; Rojas-González, R. Isaac; Lemos‐Espinal, Julio A.

doi:10.1643/0045-8511(2007)7[324:aotpdo]2.0.co;2

Cited by 24 publications

(19 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…). This finding supports previous studies on other lizard species, which have shown that hatchling and juvenile survival can exert strong effects on population growth ( λ ) (Zuniga‐Vega et al ., ; Wolf et al ., ). In many lizard species, variation in fecundity also influences population growth rates (Sinervo et al ., ).…”

Section: Discussionmentioning

confidence: 98%

“…For example, elasticity analyses demonstrated that hatchling survival had the greatest contribution to population growth (k) in populations of the horned lizard Phrynosoma cornutum (Wolf et al, 2014). Likewise, in the crevice-dwelling lizard Xenosaurus grandis, juvenile survival strongly influenced k in some years (Zuniga-Vega et al, 2007). Clearly, knowledge on how higher nest temperatures influence hatchling survival in the wild is crucial for identifying oviparous species at risk from climate warming.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Communal nesting under climate change: fitness consequences of higher incubation temperatures for a nocturnal lizard

Dayananda

Gray

Pike

et al. 2016

Global Change Biology

View full text Add to dashboard Cite

Communal nesting lizards may be vulnerable to climate warming, particularly if air temperatures regulate nest temperatures. In southeastern Australia, velvet geckos Oedura lesueurii lay eggs communally inside rock crevices. We investigated whether increases in air temperatures could elevate nest temperatures, and if so, how this could influence hatching phenotypes, survival, and population dynamics. In natural nests, maximum daily air temperature influenced mean and maximum daily nest temperatures, implying that nest temperatures will increase under climate warming. To determine whether hotter nests influence hatchling phenotypes, we incubated eggs under two fluctuating temperature regimes to mimic current 'cold' nests (mean = 23.2 °C, range 10-33 °C) and future 'hot' nests (27.0 °C, 14-37 °C). 'Hot' incubation temperatures produced smaller hatchlings than did cold temperature incubation. We released individually marked hatchlings into the wild in 2014 and 2015, and monitored their survival over 10 months. In 2014 and 2015, hot-incubated hatchlings had higher annual mortality (99%, 97%) than cold-incubated (11%, 58%) or wild-born hatchlings (78%, 22%). To determine future trajectories of velvet gecko populations under climate warming, we ran population viability analyses in Vortex and varied annual rates of hatchling mortality within the range 78- 96%. Hatchling mortality strongly influenced the probability of extinction and the mean time to extinction. When hatchling mortality was >86%, populations had a higher probability of extinction (PE: range 0.52- 1.0) with mean times to extinction of 18-44 years. Whether future changes in hatchling survival translate into reduced population viability will depend on the ability of females to modify their nest-site choices. Over the period 1992-2015, females used the same communal nests annually, suggesting that there may be little plasticity in maternal nest-site selection. The impacts of climate change may therefore be especially severe on communal nesting species, particularly if such species occupy thermally challenging environments.

show abstract

Section: Discussionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Communal nesting under climate change: fitness consequences of higher incubation temperatures for a nocturnal lizard

Dayananda

Gray

Pike

et al. 2016

Global Change Biology

View full text Add to dashboard Cite

show abstract

“…Furthermore, the intensity of predation is often stronger on the continent than on islands; thus, lizards in continental environments should grow faster, reaching sexual maturity at smaller sizes as a strategy to offset costs on fitness Zúñiga-Vega, Valverde, Rojas-González, & Lemos-Espinal, 2007). Therefore, the availability of food and predation intensity are two factors that probably play an important role in the variation of growth rate patterns of males and females in our study population.…”

Section: Discussionmentioning

confidence: 97%

“…Another reason could be related to environmental pressures; anole species inhabiting islands grow more slowly than those on the mainland (Andrews, ; Goodman, ; Hernández‐Salinas, Ramírez‐Bautista, Pavón, & Rosas Pacheco, ). Furthermore, the intensity of predation is often stronger on the continent than on islands; thus, lizards in continental environments should grow faster, reaching sexual maturity at smaller sizes as a strategy to offset costs on fitness (Novosolov & Meiri, ; Zúñiga‐Vega, Valverde, Rojas‐González, & Lemos‐Espinal, ). Therefore, the availability of food and predation intensity are two factors that probably play an important role in the variation of growth rate patterns of males and females in our study population.…”

Section: Discussionmentioning

confidence: 99%

Ecology of the growth of Anolis nebulosus (Squamata: Dactyloidae) in a seasonal tropical environment in the Chamela region, Jalisco, Mexico

Hernández‐Salinas

Ramírez‐Bautista

Cruz‐Elizalde

et al. 2019

Ecology and Evolution

View full text Add to dashboard Cite

Juvenile growth rates are thought to be restricted by available food resources. In animals that grow throughout the year, such as tropical lizards, growth is therefore predicted to be faster during the rainy season. We test this prediction using a population of Anolis nebulosus by describing the growth trajectories of both sexes using nonlinear regression models, and we then correlate the growth rates of individuals with food available in the environment, precipitation, and temperature. The Von Bertalanffy model fits the growth rates of the females better, while the logistic‐by‐length model fits the males better. According to both models, the males grew faster than females, reaching slightly smaller sizes at adulthood. Males reached sexual maturity when 35 mm long, at an age of seven months, and females matured at 37 mm (SVL), taking nine months to reach this size. In 1989, juvenile males and females grew more in both seasons (rainy and dry) than adults; for 1990, there were no differences by season or between age classes. These results are interesting since in the 1989 and 1990 rainy seasons, practically the same orders of prey and the greatest abundance of prey available in the environment were registered. A possible explanation could be that predation was more intense in 1990 than in 1989. There is little evidence that food, temperature, and humidity affect growth rates of A. nebulosus , refuting our predictions. This is mainly due to the low variation in growth observed in 1990. Therefore we think that the growth of this species reflects a complex combination of ecological and genetic factors.

show abstract

“…The proportion of resident lizards observed in the summer of a given year that were recaptured again in the summer of the following year was considered as an estimate of the annual survival rate. Our confidence on the accuracy of these survival estimates is based upon three main reasons: 1) this method is appropriate for organisms with low mobility or high philopatry such as xenosaurid lizards whose mean distance moved during their whole lifespan is minimal (between 5.47 and 12.26 m) and that remain in the same crevice (or set of three close crevices at the most) during long periods of time (Lemos-Espinal, Smith and Ballinger, 2003;Zamora-Abrego, 2004;Zúñiga-Vega et al, 2007). In consequence, we were able to know with high reliability where to locate individual lizards on each sampling occasion.…”

Section: Survival Estimatesmentioning

confidence: 99%

Demography of Xenosaurus platyceps (Squamata: Xenosauridae): a comparison between tropical and temperate populations

et al. 2008

View full text Add to dashboard Cite

There appears to be variation in life-history strategies even between populations of the same species. For ectothermic organisms such as lizards, it has been predicted that demographic and life-history traits should differ consistently between temperate and tropical populations. This study compares the demographic strategies of a temperate and a tropical population of the lizard Xenosaurus platyceps. Population growth rates in both types of environments indicated populations in numerical equilibrium. Of the two populations, we found that the temperate population experiences lower adult mortality. The relative importance (estimated as the relative contribution to population growth rate) of permanence and of the adult/reproductive size classes is higher in the temperate population. In contrast, the relative importance for average fitness of fecundity and growth is higher in the tropical population. These results are consistent with the theoretical frameworks about life-historical differences among tropical and temperate lizard populations.

show abstract

Analysis of the Population Dynamics of an Endangered Lizard (Xenosaurus Grandis) through the Use of Projection Matrices

Cited by 24 publications

References 38 publications

Communal nesting under climate change: fitness consequences of higher incubation temperatures for a nocturnal lizard

Communal nesting under climate change: fitness consequences of higher incubation temperatures for a nocturnal lizard

Ecology of the growth of Anolis nebulosus (Squamata: Dactyloidae) in a seasonal tropical environment in the Chamela region, Jalisco, Mexico

Demography of Xenosaurus platyceps (Squamata: Xenosauridae): a comparison between tropical and temperate populations

Contact Info

Product

Resources

About