scholarly journals Consuming Costly Prey: Optimal Foraging and the Role of Compensatory Growth

2021 ◽  
Vol 8 ◽  
Author(s):  
Randall Brian Langerhans ◽  
Taylor R. Goins ◽  
Kenzi M. Stemp ◽  
Rüdiger Riesch ◽  
Márcio S. Araújo ◽  
...  

Some prey are exceptionally difficult to digest, and yet even non-specialized animals may consume them—why? Durophagy, the consumption of hard-shelled prey, is thought to require special adaptations for crushing or digesting the hard shells to avoid the many potential costs of this prey type. But many animals lacking specializations nevertheless include hard-bodied prey in their diets. We describe several non-mutually exclusive adaptive mechanisms that could explain such a pattern, and point to optimal foraging and compensatory growth as potentially having widespread importance in explaining costly-prey consumption. We first conducted a literature survey to quantify the regularity with which non-specialized teleost fishes consume hard-shelled prey: stomach-content data from 325 teleost fish species spanning 82 families (57,233 stomach samples) demonstrated that non-specialized species comprise ~75% of the total species exhibiting durophagy, commonly consuming hard-shelled prey at low to moderate levels (~10–40% as much as specialists). We then performed a diet survey to assess the frequency of molluscivory across the native latitudinal range of a small livebearing fish, Gambusia holbrooki, lacking durophagy specializations. Molluscivory was regionally widespread, spanning their entire native latitudinal range (>14° latitude). Third, we tested for a higher frequency of molluscivory under conditions of higher intraspecific resource competition in Bahamian mosquitofish (Gambusia spp.). Examining over 5,300 individuals, we found that molluscivory was more common in populations with higher population density, suggesting that food limitation is important in eliciting molluscivory. Finally, we experimentally tested in G. holbrooki whether molluscivory reduces growth rate and whether compensatory growth follows a period of molluscivory. We found that consumption of hard-shelled gastropods results in significantly reduced growth rate, but compensatory growth following prior snail consumption can quickly mitigate growth costs. Our results suggest that the widespread phenomenon of costly-prey consumption may be partially explained by its relative benefits when few alternative prey options exist, combined with compensatory growth that alleviates temporary costs.

2005 ◽  
Vol 8 (5) ◽  
pp. 766-770 ◽  
Author(s):  
A.K.M. Rohul Amin . ◽  
M.A.J. Bapary . ◽  
M.S. Islam . ◽  
M. Shahjahan . ◽  
M.A.R. Hossain .

2020 ◽  
Vol 60 (6) ◽  
pp. 852
Author(s):  
Luiz H. P. Silva ◽  
Pedro V. R. Paulino ◽  
Pedro D. B. Benedeti ◽  
Mauricio M. Estrada ◽  
Lyvian C. Alves ◽  
...  

Context Previously feed-restricted cattle may exhibit compensatory growth during the finishing phase. However, the efficiency in converting feed into carcass should be evaluated since cattle undergoing compensatory growth usually have high non-carcass weight gain. Aims The objective of this study was to evaluate the effect of growth rate throughout the post-weaning growing phase on subsequent feed efficiency, carcass gain, and gain composition. Methods Thirty-nine weaned young Nellore bulls averaging 230.4 ± 5.62 kg of bodyweight and 8.5 ± 0.25 months of age were used. Initially, five bulls were slaughtered as a reference initial group. The remaining bulls were randomly assigned to one of three nutritional plans to achieve Low (0 kg/day), Medium (0.6 kg/day) or High (1.2 kg/day) average daily gain (ADG) throughout the post-weaning growing phase, followed by high growth rate during the finishing phase. One-half of the bulls from each treatment were slaughtered at the end of the post-weaning growing phase, and the other one-half after the finishing phase. During both phases the feed intake, apparent digestibility, performance, and body composition were evaluated. Key results Throughout the post-weaning growing phase, High bulls had greater ADG and more efficiently converted feed into carcass, compared with other nutritional plans (P < 0.01). Throughout the finishing phase, Low bulls had greater ADG, carcass gain, and feed efficiency than High and Medium bulls (P < 0.01). Previous feed restriction did not affect (P > 0.05) apparent digestibility. During the finishing phase, previously restricted bulls fully compensated for the lost visceral organ weight, whereas the losses of bodyweight and carcass weight were only partially compensated. Throughout finishing, Low bulls had the greatest feed efficiency and profitability among nutritional plans. However, considering the overall experiment, Hight bulls converted feed into carcass more efficiently than Low bulls (P = 0.02), but did not differ from Medium (P > 0.05). Conclusions Although previously restricted bulls had greater performance and efficiency throughout finishing, the improvement was not enough to reach the same carcass weight at the same age of the unrestricted bulls. Implications Despite the greater profitability of previously restricted bulls throughout finishing, unrestricted bulls were more profitable considering both growing and finishing phases.


2007 ◽  
Vol 139 (1) ◽  
pp. 1-44 ◽  
Author(s):  
H.V. Danks

AbstractThe many components of seasonal adaptations in insects are reviewed, especially from the viewpoint of aspects that must be studied in order to understand the structure and purposes of the adaptations. Component responses include dispersal, habitat selection, habitat modification, resistance to cold, dryness, and food limitation, trade-offs, diapause, modifications of developmental rate, sensitivity to environmental signals, life-cycle patterns including multiple alternatives in one species, and types of variation in phenology and development. Spatial, temporal, and resource elements of the environment are also reviewed, as are environmental signals, supporting the conclusion that further understanding of all of these seasonal responses requires detailed simultaneous study of the natural environments that drive the patterns of response.


2021 ◽  
Vol 3 (1) ◽  
pp. 19
Author(s):  
Sarah Kristi Pertiwi ◽  
Khairul Rizal ◽  
Yudi Triyanto

Kacang Panjang (Vigna sinensis L.) merupakan salah satu tanaman sayuran sebagai sumber vitamin dan mineral. Kacang panjang (Vigna sinensis L.) juga merupakan jenis kacang-kacangan yang banyak diusahakan di Indonesia. Desa Gunung Selamat merupakan salah satu desa dengan penghasilan tanaman palawija yang beragam salah satunya kacang panjang (Vigna sinensis L.). Namun, pengabdian masyarakat ini dilakukan karena banyak permasalahan yang dihadapi oleh petani sehingga menyebabkan pertumbuhan kacang panjang (Vigna sinensis L.)� menurun. Turunnya produksi ini antara lain disebabkan oleh iklim, tanah, pupuk, hama dan penyakit. Maka dari itu pengabdian masyarakat ini dilakukan untuk meningkatkan pertumbuhan tanaman serta mengurangi penggunaan pupuk sintetik yang dapat merusak ekosistem tanah, maka dari itu diberi perlakuan penyiraman pupuk organik cair pada tanah serta penyemprotan pestisida nabati dari daun pepaya untuk mencegah hama dan penyakit yang menyerang tanaman kacang panjang (Vigna sinensis L.). Perlakuan ini dibuat untuk melihat hasil respon tingkat pertumbuhan pada tanaman kacang panjang (Vigna sinensis L.).Long beans (Vigna sinensis L.) are a vegetable plant as a source of vitamins and minerals. Long beans (Vigna sinensis L.) are also a type of legume that is widely cultivated in Indonesia. Gunung Selamat Village is one of the villages with a variety of agricultural crops, one of which is long beans (Vigna sinensis L.). However, this community service was carried out because of the many problems faced by farmers, which caused the growth of long beans (Vigna sinensis L.) to decline. The decline in production was caused, among others, by climate, soil, fertilizers, pests and diseases. Therefore, this community service is carried out to increase plant growth and reduce the use of synthetic fertilizers that can damage the soil ecosystem, therefore it is given the treatment of sprinkling liquid organic fertilizers on the soil and spraying vegetable pesticides from pepaya leaves to prevent pests and diseases that attack long bean plants (Vigna sinensis L.). This treatment was designed to see the results of the growth rate response in long bean plants (Vigna sinensis L.).


2010 ◽  
Vol 26 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Horacio Salomón Ballina-Gómez ◽  
Silvia Iriarte-Vivar ◽  
Roger Orellana ◽  
Louis S. Santiago

Abstract:Defoliation, often caused by herbivory, is a common cause of biomass loss for plants that can affect current and future growth and reproduction. There are three models that predict contrasting compensatory growth responses of plants to herbivory and resource availability: (1) Growth rate model, (2) Compensatory continuum hypothesis and (3) Limiting resource model. The predictions of these three models were tested on the tree Brosimum alicastrum and the liana Vitis tiliifolia. Seedlings were subjected to three levels of experimental defoliation (0%, 50% and 90% leaf removal) along a light resource gradient (1%, 9% and 65% of full sun). In both species, defoliation significantly increased leaf production rate and relative growth rate of leaf area, but not of biomass. Net assimilation rate was the strongest driver of biomass growth in both species, but leaf area ratio and specific leaf area were also important in B. alicastrum. Compensatory responses of leaf area growth in B. alicastrum were significantly greater in higher than lower light availability, consistent with the compensatory continuum hypothesis predictions, but in contrast to the growth rate model predictions. The limiting resource model offered an explanation for all possible experimental outcomes by directly considering the effects of environmental differences in resource availability.


Author(s):  
Roger Lines

SynopsisBecause of the wide latitudinal range of Sitka spruce, trees of different origin show very large differences in growth rate and adaptability when grown on a variety of sites in Britain. The Forestry Commission has forty-eight seed origin trials, planted between 1929 and 1975, which are now beginning to provide a good overall picture of this variation. On the other hand, differences in morphology and colour are relatively minor, so that it is very difficult to identify the seed origin of a stand of trees on visual grounds alone. Southerly origins (below Latitude 47°N) grow fastest, but they suffer more severe frost damage, particularly in the nursery, and tend to have lower density timber than those from 53°N or above.


1966 ◽  
Vol 17 (3) ◽  
pp. 375 ◽  
Author(s):  
ID Wardrop

The effect of the plane of nutrition in the first 13 weeks of post-natal life of cattle on their subsequent growth rate, body shape, and carcass composition up to 12 months of age was studied. No compensatory growth to 12 months of age was observed in calves reared to 13 weeks on low planes of nutrition. There were no significant differences between Friesian and Hereford x Friesian calves, or between males and females in empty body weight or weight gains. Treatment up to 13 weeks of age had no effect on heart girth, round, head length and width, and cannon bone length, but the remaining body measurements were reduced by low planes of nutrition during this period. Differences in carcass composition were largely a reflection of the differences in empty body weight. The carcasses of the males were heavier than those of the females and the females contained a higher proportion of fat. Carcass composition, as estimated by shin dissection, indicated that Friesian calves contained more muscle than the Hereford x Friesians, and the males more muscle than the females.


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