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

2019 ◽  
Vol 40 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Falk Eckhardt ◽  
Cornelia Kraus ◽  
Peter M. Kappeler

Abstract The life histories and population dynamics of chameleons remain poorly known, most likely due to practical challenges related to their cryptic nature. However, several studies have indicated that some of these reptiles have unusually brief life histories. Specifically, one Madagascan chameleon (Furcifer labordi) was found to have an annual life cycle characterized by population-wide survival of the austral winter in the egg stage; a unique life history among tetrapods. In this study, we compare the life history of F. labordi with two locally sympatric congeners (F. cf. nicosiai and F. oustaleti) in Kirindy forest, western Madagascar, to determine how these species adjust their life histories to a highly seasonal and unpredictable climate. We found differences in lifespan, timing of hatching, growth rates, survival, reproductive rates, adult body size, and roosting heights among all three species. Moreover, two species exhibited relatively short lifespans: 6-9 months in F. labordi and 16-18 months in F. cf. nicosiai. In contrast, F. oustaleti is perennial and large-sized juveniles and adults aestivate during the dry season, but survival rates of adults seemed relatively low. Strikingly, the annual cohort of F. labordi was already adult when hatchlings of F. oustaleti and subsequently F. cf. nicosiai emerged. Our study suggests the co-existence of three different life histories with seasonal adjustment that might be related to the partitioning of overall food availability and contributes valuable life history data on enigmatic chameleon species.

Parasitology ◽  
1959 ◽  
Vol 49 (3-4) ◽  
pp. 374-386 ◽  
Author(s):  
R. J. Thomas

1. The life history of N. battus is described, and a comparative description of the life history of N. filicollis is given.2. The life histories of these two species are compared with those of N. spathiger and N. helvetianus, two closely related species, and are shown to follow the same basic pattern, with minor variations in timing which appear to be specific in nature, and not related to differences in culture methods or host species.3. The pathogenesis of Nematodirus species is discussed and related to the migration of larvae into the intestinal mucosa during development.


1932 ◽  
Vol 57 (1) ◽  
pp. 93-142 ◽  
Author(s):  
Elsie J. Cadman

Since 1860, in which year De Bary published his great work Die Mycetozoen, the investigation of the life-history of members of the Mycetozoa has aroused a considerable amount of interest, and a great deal of important research has been carried out in this connection. The group of organisms is particularly interesting, because it lies on the borderline between plant and animal kingdoms, and it is very possible that a detailed investigation of several species of the Mycetozoa might be of considerable assistance in elucidating certain obscure points in the life-histories of higher members of both the great natural groups. The term “Mycetozoa,” which we owe to De Bary, will be used throughout in preference to the older term “Myxogastres” invented by Fries (32, p. 2), and that of “Myxomycetes” first employed by Link (32, p. 2). “Mycetozoon,” or “fungus-like animal,” is a very appropriate description of a member of the group, since during part of its life-history it exhibits distinctly animal-like characters, and the individuals move rapidly by means of flagella, whilst later, during the development of the sporangium, a plant-like form is assumed. The combination of plant and animal characters has given rise to much discussion as to the position of the Mycetozoa in plant or animal kingdom, and the group has been claimed by both zoologists and botanists.


Crustaceana ◽  
2021 ◽  
Vol 94 (4) ◽  
pp. 413-429
Author(s):  
Ye Ji Lee ◽  
Won Gyu Park

Abstract The population dynamics of Stenothoe valida Dana, 1852 were studied at Cheongsapo beach of Busan, Republic of Korea, from March 2019 to March 2020. Sampling was conducted once a month at low tide during spring tides. Specimens were grouped by the cephalic length at 0.025 mm intervals, and classified into four categories: females, ovigerous females, males and juveniles. The sex ratio, defined as females : total males + females, exceeded 0.5 during most of the study period. Brood size was significantly coupled with ovigerous female size. Two to four cohorts appeared at each study period. New cohorts occurred at almost every sampling except in the samples Jun-2, and Nov-2. Life span was estimated at 1-2 months. The juvenile ratio, the ratio of ovigerous females, and the recruitment rate estimated by FiSAT were commonly high in summer and winter. The life history of S. valida was not coupled with water temperature, but had a strong seasonal pattern.


Koedoe ◽  
2004 ◽  
Vol 47 (1) ◽  
Author(s):  
R.F. Terblanche ◽  
H. Van Hamburg

Due to their intricate life histories and the unique wing patterns and colouring the butterflies of the genus Chrysoritis are of significant conservation and aesthetic value. Thisoverview probes into practical examples of butterfly life history research applicable to environmental management of this relatively well-known invertebrate group in South Africa. Despite the pioneer work on life histories of Chrysoritis in the past, more should be done to understand the life history of the butterflies in the wild, especially their natural host plants and the behaviour of adults and larvae. A system of voucher specimens of host plants should be introduced in South Africa. Although various host plant species in nature are used by the members of Chrysoritis, including the Chrysoritis chrysaor group, the choice of these in nature by each species is significant for conservation management and in the case of Chrysoritis aureus perhaps even as a specific characteristic.A revision of the ant genus Crematogaster will benefit the conservation management of Chrysoritis species since some of these ant species may consist of a number of specieswith much more restricted distributions than previously thought. Rigorous quantified tudies of population dynamics of Chrysoritis butterflies are absent and the introductionof such studies will benefit conservation management of these localised butterflies extensively.


2020 ◽  
Vol 117 (30) ◽  
pp. 18119-18126 ◽  
Author(s):  
Line S. Cordes ◽  
Daniel T. Blumstein ◽  
Kenneth B. Armitage ◽  
Paul J. CaraDonna ◽  
Dylan Z. Childs ◽  
...  

Seasonal environmental conditions shape the behavior and life history of virtually all organisms. Climate change is modifying these seasonal environmental conditions, which threatens to disrupt population dynamics. It is conceivable that climatic changes may be beneficial in one season but result in detrimental conditions in another because life-history strategies vary between these time periods. We analyzed the temporal trends in seasonal survival of yellow-bellied marmots (Marmota flaviventer) and explored the environmental drivers using a 40-y dataset from the Colorado Rocky Mountains (USA). Trends in survival revealed divergent seasonal patterns, which were similar across age-classes. Marmot survival declined during winter but generally increased during summer. Interestingly, different environmental factors appeared to drive survival trends across age-classes. Winter survival was largely driven by conditions during the preceding summer and the effect of continued climate change was likely to be mainly negative, whereas the likely outcome of continued climate change on summer survival was generally positive. This study illustrates that seasonal demographic responses need disentangling to accurately forecast the impacts of climate change on animal population dynamics.


1981 ◽  
Vol 59 (2) ◽  
pp. 305-314 ◽  
Author(s):  
Boris C. Kondratieff ◽  
J. Reese Voshell Jr.

The life history of Heterocloeon curiosum was compared in the impounded North Anna River (NAR) and the free-flowing South Anna River (SAR) in Virginia, U.S.A. The study site on the NAR was 32 km below Lake Anna, a surface-release reservoir. Heterocloeon curiosum was bivoltine in both rivers with two summer generations and probable overwintering in the egg stage. It passed through 10 larval instars (range 9–12) in both rivers. The density of larvae was twice as great in the SAR as the NAR. Factors which may have contributed to the lesser success of H. curiosum in the NAR included bottom scouring produced by sudden increases in discharge, absence of the macrophyte Podostemum, quality of available food, and alterations of the temperature regime. Of these four factors, temperature probably had the most significant effect. The emergence of the second generation was 1 month later in the NAR because the reservoir delayed the normal seasonal cooling of the river. The nonoptimal temperature regime appeared to significantly reduce the fecundity of H. curiosum in the NAR. Our data indicate that surface-release reservoirs may have subtle but significant effects on the life histories of benthic macroinvertebrates.


Parasitology ◽  
1911 ◽  
Vol 4 (4) ◽  
pp. 416-456 ◽  
Author(s):  
Marie V. Lebour

The study of the life-histories of digenetic Trematodes is as yet in its infancy. Many new adult forms are described every year, but very little is known of the life-history of any of these. It is even impossible in the majority of cases to say what sort of larval form is characteristic of any group. Having worked for some years at the study of Trematode larvae I thought it would be of some use to bring together all the work so far done on British marine cercariae in order to form a nucleus round which future work may be centred.


2011 ◽  
Vol 278 (1723) ◽  
pp. 3355-3363 ◽  
Author(s):  
Christopher Turbill ◽  
Claudia Bieber ◽  
Thomas Ruf

Survival probability is predicted to underlie the evolution of life histories along a slow–fast continuum. Hibernation allows a diverse range of small mammals to exhibit seasonal dormancy, which might increase survival and consequently be associated with relatively slow life histories. We used phylogenetically informed GLS models to test for an effect of hibernation on seasonal and annual survival, and on key attributes of life histories among mammals. Monthly survival was in most cases higher during hibernation compared with the active season, probably because inactivity minimizes predation. Hibernators also have approximately 15 per cent higher annual survival than similar sized non-hibernating species. As predicted, we found an effect of hibernation on the relationships between life history attributes and body mass: small hibernating mammals generally have longer maximum life spans (50% greater for a 50 g species), reproduce at slower rates, mature at older ages and have longer generation times compared with similar-sized non-hibernators. In accordance with evolutionary theories, however, hibernating species do not have longer life spans than non-hibernators with similar survival rates, nor do they have lower reproductive rates than non-hibernators with similar maximum life spans. Thus, our combined results suggest that (i) hibernation is associated with high rates of overwinter and annual survival, and (ii) an increase in survival in hibernating species is linked with the coevolution of traits indicative of relatively slow life histories.


1974 ◽  
Vol 22 (4) ◽  
pp. 743 ◽  
Author(s):  
MN Clayton

The morphology, development and life history of filamentous brown algae, in particular species of the commoner genera Feldmannia, Giffordia and Hecatonema, are described. Morphogenetic differences parallel the well known morphological distinctions between Feldmannia and Giffordia. Two 'species' of Feldmannia, F. globifer and F. simplex, are not distinct but rather exhibit continous variation of a clinal nature. Previous records of Giffordia secunda are shown to apply to Giffordia granulosa. Studies of living and type material of Ectocarpus sordidus indicate that its affinities lie with the genus Giffordia, to which it is transferred. Life histories of the various ectocarpalean taxa show many similarities and, with minor exceptions do not furnish additional useful taxonomic characters. The predominant means of reproduction amongst the Australian Ectocarpales are asexual, sexual processes being apparently of minor signi- ficance. Life history studies of Hecatonema maculans show it to be indistinct from juvenile stages of two members of the Dictyosiphonales, Desmotrichum undulatum and Punctaria latifolia. Five genera and six species are newly recorded for Australia. The genera are Acinetospoua, Hecatonenza, Kuckuckia, Kuetzingiella and Sovocarpus and the species are Acinetospora crinita (Carmichael ex Harvey in J. D. Hooker) Kornmann, Giffordia fuscata (Zanardini) Kornmann in Kuckuck, Giffordia intermedia (Rosenvinge) Lund, Hecatonema maculans (Collins) Sauvageau, Kuckuckia spinosa (Kiitzing) Kuckuck and Sorocarpus micromorus (Bory) Silva.


Sign in / Sign up

Export Citation Format

Share Document