The Significance of Persistent Vocalisation By the Spring Peeper, Pseudacris Crucifer (Anura: Hylidae)

Behaviour ◽  
1989 ◽  
Vol 108 (3-4) ◽  
pp. 197-208 ◽  
Author(s):  
David V. Lykens ◽  
Don C. Forester ◽  
W. Keith Harrison

Abstract1. Male spring peepers exhibit individual variation in calling persistence within as well as between nights. 2. Weather conditions influence nightly variation in calling persistence throughout the reproductive season, but there is a pronounced decrease in calling persistence late in the season which appears to be independent of climate. 3. In four speaker experiments simulating males calling 20, 40, 60, and 80% of the time, there is a positive correlation between time spent calling and mating success. 4. On nights when there is significant variation in calling persistence, females likely respond to those males which are most persistent (i.e. , produce the most conspicuous calls). 5. In four speaker experiments simulating males calling 80, 85, 90 and 95% of the time, mating success is random, suggesting that during periods of peak mating activity the importance of female choice is diminished. 6. Calling persistence is not correlated with body size, therefore males of any age or size class have an opportunity to experience mating success. 7. Anuran vocalization is known to be energetically expensive, and persistent callers (regardless of their size) are likely in good physical condition. 8. We suggest that by responding (either actively or passively) to the most conspicuous calls, females convey to their offspring an advantage above and beyond that accrued by random mating.

2014 ◽  
Vol 60 (6) ◽  
pp. 700-711 ◽  
Author(s):  
Nina A. Vasilieva ◽  
Ekaterina V. Pavlova ◽  
Sergey V. Naidenko ◽  
Andrey V. Tchabovsky

Abstract Life-history theory predicts that in hibernators age of maturation is related positively to body size and negatively to the duration of active season aboveground. Yellow souslik is a large-sized ground squirrel with long hibernation, which suggests late maturation. We used four-year field observations of marked individuals to determine the age of maturation in males through analysis of age-dependent variation in body size, mass, androgen status, timing of spring emergence, ranging patterns and social behavior during the mating season. Yearling males were smaller, lighter, had lower level of fecal testosterone, emerged later and had smaller home ranges than older males. Social activity and the number of females encountered did not differ between age classes. After the second hibernation none of the studied parameters varied with age. Cluster analysis revealed two behavioral tactics: “active” males (adults only) emerged earlier, ranged more widely, initiated more contacts, encountered more females and were heavier than “passive” males (both yearling and adult). Thus, males of S. fulvus reached adult size and matured after two hibernations, which is relatively fast for such a big species with short active period. Indirect evidence for copulations and high variation among yearlings in all parameters suggest that some of them might successfully compete with adults. Active tactic of wandering and searching for females is energetically costly, and probably only adult males in good physical condition can afford it, whereas passive tactic of residing is energy saving and good for adults in poor condition and for yearlings that are continuing to grow.


1990 ◽  
Vol 40 (4) ◽  
pp. 648-652 ◽  
Author(s):  
R.M. Neems ◽  
A.J. McLachlan ◽  
R. Chambers
Keyword(s):  

2007 ◽  
Vol 73 (6) ◽  
pp. 987-997 ◽  
Author(s):  
M.A. Serrano-Meneses ◽  
A. Córdoba-Aguilar ◽  
V. Méndez ◽  
S.J. Layen ◽  
T. Székely

Author(s):  
Janne I. Kaariainen ◽  
Brian J. Bett

The benthic body size miniaturization hypothesis states that deep-sea communities are dominated by organisms of smaller body size, although some field studies have produced contradictory results. Using appropriate sample sets, this study tests this hypothesis by contrasting the benthic communities of the Fladen Ground (North Sea, 150 m) and the Faroe–Shetland Channel (1600 m). Samples were collected for large (500 μm) and small macrofauna (250–355 μm), meiofauna (45 μm) as well as an intermediate sized ‘mesofauna’ (180 μm) to ensure comprehensive coverage of the full meio- and macro-faunal body size-range. The body size structure of the benthos was compared using two methods. The more widely used average individual biomass method involves dividing the total sample biomass by sample abundance. Additionally, body size accumulation curves were constructed by assigning all specimens into a logarithmic size-class and then plotting the cumulative percentage of individuals present in each size-class. The results seem to support the hypothesis that the deep-sea environment is a small organism habitat. Although these findings only represent two locations, the overall body size accumulation curves clearly display a statistically significant shift towards smaller body sizes at the deeper site. The magnitude of the effect is appreciable with median metazoan body size reducing from 14.3 μg wet weight in the Fladen Ground to 3.8 μg wet weight in the Faroe–Shetland Channel. The average individual biomass measurements are shown to be of limited value and can lead to potentially misleading conclusions if the underlying size structure is not analysed in detail.


2010 ◽  
Vol 100 (2) ◽  
pp. 287-292 ◽  
Author(s):  
ANTHONY HERREL ◽  
JENNIFER A. MOORE ◽  
EVAN M. BREDEWEG ◽  
NICOLA J. NELSON

1986 ◽  
Vol 64 (1) ◽  
pp. 8-11
Author(s):  
Louise Vallières ◽  
Antoine Aubin

Copepod populations of three temporary freshwater pools (Alnus unit, Carex unit, and Molinia unit) were studied using a standard approach (species versus abiotic factors) and a holistic one (body size and feeding ecology). Multiple regression analyses of data indicate that the physical and chemical features of water (temperature, pH, dissolved oxygen, mineral content, and depth) explain 62 to 98% of the variability of carnivorous copepods, while the abundance of their prey accounts for much less. No size class of prey seems to be preferred. The abundance of decaying organic matter, typical of such pools, would result in an overabundance of prey. Predators would then be under the control of nonalimentary factors.


2001 ◽  
Vol 61 (3) ◽  
pp. 661-669 ◽  
Author(s):  
Gianmaria Carchini ◽  
Flavia Chiarotti ◽  
Marco di Domenico ◽  
Marco Mattoccia ◽  
Giacomo Paganotti

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