Echidna: Extraordinary Egg‐Laying Mammal. Australian Natural History Series. By Michael  Augee, , Brett  Gooden, and , Anne  Musser. Collingwood (Australia): CSIRO Publishing. $36.00 (paper). vii + 136 p; ill.; index. ISBN: 0‐643‐09204‐8. 2006.

2007 ◽  
Vol 82 (4) ◽  
pp. 428-428
Author(s):  
Ken Ashwell
Keyword(s):  
Natural History ◽  
Egg Laying ◽  
Csiro Publishing

scholarly journals Demography of the land snail Tikoconus (Tikoconus) costarricanus (Stylommatophora: Euconulidae) in tropical low montane and premontane forests, Costa Rica

2019 ◽  
Vol 67 (6) ◽  
Author(s):  
Zaidett Barrientos
Keyword(s):  
Costa Rica ◽  
Natural History ◽  
Leaf Litter ◽  
Secondary Forest ◽  
Land Snail ◽  
Egg Laying ◽  
Land Snails ◽  
Tropical Species ◽  
Spearman Correlation ◽  
Mature Forest

Abstract. Introduction: Ecology and natural history of neotropical land snails is almost unknown. Objetive: In this paper I analyse the population dynamics of Tikoconus (Tikoconus) costarricanus Barrientos, in prep., an understory endemic euconulid. Methods: I compared T. costarricanus’ demography patterns in tropical montane forests in central Costa Rica in three habitats with different restoration techniques: a mature forest, a secondary forest and a Cuppressus lusitanica plantation. I collected data in three month periods during a year. I analysed population size in relation with habitat, sampling date, leaf litter humidity, depth and quantity; and specimen size in relation with habitat and sampling date. I also kept some specimens in terraria and described part of their natural history. Results: The species is more abundant in mature forest (Ø = 0.174 ind/m2). The number of specimens in each habitat was constant throughout the year (Kruskall-Wallis = 2.0118, p = 0.57, NS) and hatching occurs in the middle and last months of the rainy season (Kruskall-Wallis = 17.3061, p = 0.00061, **). Number of specimens is related with leaf litter humidity (Spearman correlation, r = 0.3524, n = 232, p = 0.000, **), amount (Spearman correlation, r = 0.3922, n = 232, p = 0.000, **) and depth (Spearman correlation, r = 0.2543, n = 232, p = 0.000, **). This relationship is explained by the high and stable humid environment provided by leaf litter. During the drier months some specimens migrate from the foliage to the leaf litter. Eggs (Ø = 1mm) are laid on moss or soil and the young spend the first 2 or 3 weeks of their life on moss. Egg masses are small (Ø = 4 eggs), and shells look bubbly. Egg development time (20 days) was longer than in other tropical species. Adult pigmentation appears around two months after hatch. In the only case observed egg laying began 5 months after hatching and the specimen lived 9 months. Conclusions: Although no conclusive, these data point to a fragile species susceptible to habitat and climate change. Restorations techniques should consider leaf litter features in order to protect endemic neotropical humid dependent diversity.

scholarly journals Realities of rarity: climatically and ecologically restricted, critically endangered Kandian Torrent Toads (Adenomus kandianus) breed en masse

2015 ◽  
Author(s):  
Madhava Meegaskumbura ◽  
Nayana Wijayathilaka ◽  
Nirodha Abayalath ◽  
Gayani Senevirathne
Keyword(s):  
Natural History ◽  
Dna Barcoding ◽  
Forest Cover ◽  
Developmental Stages ◽  
Habitat Associations ◽  
Egg Laying ◽  
Healthy Population ◽  
Rrna Gene ◽  
Isolated Populations ◽  
Area Of Occupancy

Endemic to Sri Lanka, genus Adenomus contains two torrent-associated toad species whose ecology and natural history in the wild is virtually unknown. Adenomus kelaartii is relatively common, with a wide geographic distribution. Its sister species, A. kandianus, however, is restricted to two isolated populations in fast-disappearing montane and sub-montane forests. Formally declared extinct after not being recorded for over a century, following several years of surveying, a few A. kandianus were found in 2012 and referred to as "the world's rarest toad." However, tadpoles of A. kandianus bearing unique ventral suckers were soon discovered, but the rarity of the adult and the profusion of tadpoles were never explained. Here, using ecological methods, niche modeling and DNA-barcoding, we aim to understand the ecology, natural history and distribution of this rare toad. Following a two-year study of occurrence, habits and habitat associations of adults and larvae, we show this to be a secretive species with a patchy distribution. During non-mating periods female toads (N = 23) were found in primary forests habitat up to 650 m away from the breeding streams, and predominantly males in the riparian zone (12 males, 2 females). Following heavy rain they form large (N = 388) but patchy mating congregations in torrential streams (six sites; range 0−95 mating pairs; mean = 25, SD = 38.16, CV = 152%). Amplexed pairs swim synchronously, enabling them to traverse fast currents. Egg-laying sites remain unknown, but ability to dive, vocalize underwater, and characteristics of the eggs, suggests that they lay eggs in dark recesses of the stream. Quadrat sampling of tadpoles show microhabitat partitioning (in depth, flow-rate and substrate conditions) within the stream: the greatest diversity of larval developmental stages (25-42) in slow-flowing (depth, 0.75−1.5 m) rocky areas; more robust stages (31−39) bearing sucker discs utilise rocky-rapids (depth, 0.25−0.75 m); metamorphic stages (43-45) use stream margins (depth, <0.25 m); slow flowing silt covered areas of the stream were unoccupied, irrespective of the depth. DNA barcoding of the 16S rRNA gene fragment from the two known localities confirms the identity of the Pedro population also as A. kandianus. The uncorrected pairwise genetic distance of 0.1−0.7% suggests historical gene flow between the two populations. Distribution modeling (using MaxEnt), with forest-cover layers added, predicts a very small remaining area of suitable habitats (an area of occupancy of 16 km2 and an extent of occurrence of 128 km2) isolated by habitats that are not conducive to these toads. While the healthy population recorded at one site gives hope for the survival of the species, long-term conservation of this climatically and ecologically restricted species hinges largely on the preservation of cloud and riparian forests and the unpolluted high-flow torrents.

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