scholarly journals Effects of forest fragmentation on reproductive effort and productivity of Indigo buntings (Passerina cyanea)

2005 ◽  
Author(s):  
◽  
Dana L. Morris
Keyword(s):  
Forest Fragmentation ◽  
Reproductive Output ◽  
Reproductive Effort ◽  
Female Offspring ◽  
Fragmented Landscape ◽  
Stress Hormone ◽  
Maternal Condition ◽  
Offspring Quality ◽  
Passerina Cyanea ◽  
Energetic Reserves

Forest fragmentation creates edge habitat that attracts nest predators that lower reproductive success and force birds to renest. To determine if predation-induced renesting causes a decline in condition of females and reduces productivity and offspring quality, I measured maternal condition and reproductive output of Indigo Buntings breeding in a fragmented and a contiguously forested landscape in Missouri. Renesting females had lower body condition than those that nested once successfully. As maternal condition declined with nesting attempt, stress hormone levels increased, suggesting poor-conditioned females lack the energetic reserves to meet increased demands. Additionally, females in poor condition produced small clutches and poor-conditioned nestlings. A higher proportion of nests containing all-female offspring indicates a bias in production of the smaller, less profitable sex in the fragmented landscape. These results suggest that increased reproductive effort associated with renesting imposes costs to breeding females and decreases their ability to invest in high quality offspring.

scholarly journals Large mothers, but not large fathers, influence offspring number in a caridean shrimp

2018 ◽  
Vol 96 (10) ◽  
pp. 1106-1113 ◽  
Author(s):  
D.E. Sganga ◽  
C. Tropea ◽  
M. Valdora ◽  
M.F. Statti ◽  
L.S. López Greco
Keyword(s):  
Reproductive Output ◽  
Growth Period ◽  
Female Offspring ◽  
Growth Increment ◽  
Adult Males ◽  
Lipid Concentration ◽  
Offspring Quality ◽  
Offspring Number ◽  
Males And Females ◽  
The Relationship

The relationship between parental mass and female reproductive output, as well as offspring quality, was studied in the red cherry shrimp (Neocaridina davidi (Bouvier, 1904)) under controlled laboratory conditions. Adult males and females of the same age were paired combining different shrimp masses. The number of hatched juveniles from large females was higher than that from small ones, but no influence of paternal mass was detected on this variable. Both the mass of newly hatched juveniles and their growth increment during a 60-day period were similar for all parental masses. Shrimps reached sexual maturity at the end of the growth period in all treatments, and their biochemical reserves (glycogen, lipid, and protein concentrations) were not associated with maternal and paternal masses. However, lipid concentration was higher in female offspring than in male offspring. The present results show that, unlike maternal mass, paternal mass had no effect on female reproductive output and offspring quality, suggesting that the contribution of males to offspring development was adequate regardless of male size.

The importance of recruitment patterns versus reproductive output in the persistence of a short-range endemic shrub in a highly fragmented landscape of south-western Australia

2012 ◽  
Vol 60 (7) ◽  
pp. 643 ◽  
Author(s):  
Neil Gibson ◽  
Colin Yates ◽  
Margaret Byrne ◽  
Margaret Langley ◽  
Rujiporn Thavornkanlapachai
Keyword(s):  
Short Range ◽  
Reproductive Output ◽  
Fruit Set ◽  
Seedling Recruitment ◽  
Fragment Size ◽  
Fragmented Landscape ◽  
Recruitment Failure ◽  
Degree Of Isolation ◽  
Number Of Seeds ◽  
Significant Mortality

Calothamnus quadrifidus subsp. teretifolius A.S.George & N.Gibson is a short-range endemic shrub whose habitat has been greatly reduced by clearing for agriculture. Reproductive output was high in all populations sampled, although there were large differences among populations in fruit set, the number of seeds per fruit and seed germination. These traits showed no relationship to population size, degree of isolation, or fragment size, which contrasts strongly with the patterns found in a widespread congener. Demographic studies in remnants with an intact understorey showed stable adult populations with continuous seedling recruitment. In contrast, there was consistent widespread failure of seedling and juvenile recruitment in degraded roadside remnants that also showed significant mortality of reproductive adults. In these degraded remnants, recruitment failure appears to be the primary cause of species decline.

scholarly journals Ancestral diet transgenerationally influences offspring in a parent-of-origin and sex-specific manner

2019 ◽  
Vol 374 (1768) ◽  
pp. 20180181 ◽  
Author(s):  
Carmen Emborski ◽  
Alexander S. Mikheyev
Keyword(s):  
Body Composition ◽  
Reproductive Output ◽  
Control Diet ◽  
Female Offspring ◽  
Specific Manner ◽  
Males And Females ◽  
Parent Of Origin ◽  
Full Factorial ◽  
Rapid Environmental Change

Parent-of-origin effects, whereby specific phenotypes are differentially inherited paternally or maternally, provide useful clues to better understand transgenerational effect transmission. Ancestral diet influences offspring phenotypes, including body composition and fitness. However, the specific role that mothers and fathers play in the transmission of altered phenotypes to male and female offspring remains unclear. We investigated the influence of the parent-of-origin's diet on adult progeny phenotypes and reproductive output for three generations in fruit flies ( Drosophila melanogaster ). Males and females reared on a control diet were exposed to the control diet or one of two altered (no- or high-) sugar treatment diets for a single generation. Flies from one of the two altered diet treatments were then mated to control flies in a full-factorial design to produce F 1 offspring and kept on control media for each following generation. We found parent-of-origin (triglyceride) and non-parent-of-origin (sugar) body composition effects, which were transgenerational and sex-specific. Additionally, we observed a negative correlation between intergenerational maternal reproductive output and triglyceride levels, suggesting that ancestral diet may affect fitness. This work demonstrates that ancestral diet can transmit altered phenotypes in a parent-of-origin and sex-specific manner and highlights that mechanisms regulating such transmission have been greatly overlooked. This article is part of the theme issue ‘The role of plasticity in phenotypic adaptation to rapid environmental change’.

Growth and Reproductive Energetics of three Scallop Species from British Columbia (Chlamys hastata, Chlamys rubida, and Crassadoma gigantea)

1991 ◽  
Vol 48 (2) ◽  
pp. 215-221 ◽  
Author(s):  
B. A. MacDonald ◽  
R. J. Thompson ◽  
N. F. Bourne
Keyword(s):  
British Columbia ◽  
Reproductive Output ◽  
Reproductive Effort ◽  
Shell Height ◽  
Somatic Growth ◽  
Somatic Tissue ◽  
Tissue Growth ◽  
Net Production ◽  
Available Energy ◽  
Gamete Production

Three scallop species from British Columbia display different strategies for partitioning available energy between somatic tissue growth and gamete production as they increase in age. The spiny scallop Chlamys hastata and the pink scallop Chlamys rubida only live about 6 yr and rarely exceed 80 mm in shell height whereas the rock scallop Crassadoma gigantea may reach 170 mm in height and live for 20 yr or more. Growth, reproductive output, and reproductive effort at any given age are higher in Chlamys hastata than in the smaller Chlamys rubida. Somatic growth in Crassadoma gigantea ceases completely in the final years, but in the short-lived species Chlamys hastata and Chlamys rubida, individuals continue to grow until they die. In long-lived pectinids the emphasis often shifts from somatic growth to gamete production before the midpoint of the life cycle, and our observations on Crassadoma gigantea are consistent with this trend. Short-lived species, however, invest relatively less in reproduction; in our study, reproductive output in Chlamys rubida did not exceed 40% of nonrespired assimilation (net production), and reproductive effort in Chlamys hastata did not reach 50% until the final year of life.

scholarly journals The Maintenance of Sex and David Lack's Principle

2016 ◽  
Author(s):  
Joachim Dagg
Keyword(s):  
Reproductive Output ◽  
Reproductive Effort ◽  
Experimental Studies ◽  
Optimal Number ◽  
Evolutionary Constraints ◽  
Immune Functions ◽  
Maintenance Of Sex ◽  
Mutant Female ◽  
The Cost ◽  
David Lack

Combining George C. Williams' idea that evolutionary constraints prevent asexual mutants from arising more frequently in low fecundity organisms, like mammals and birds, with an earlier one by David Lack that the brood size of these organisms has an optimum, and producing larger broods reduces their fitness, leads to a novel hypothesis about the maintenance of sex in them. All else equal, the eggs of an asexual mutant female should simply start developing without fertilisation, and there is no reason to assume that they would stop doing so after the optimal number of offspring has been produced. Without a way to control their reproductive output, asexual mutants should over-reproduce and suffer a cost of doing so. Experimental studies suggest that the cost of enlarged broods could limit the advantage of asexual mutants considerably. Moreover, research discovered that increased reproductive effort reduces immune functions of low fecundity organisms. This offers a surprising synthesis between Williams' constraint and Hamilton's parasite hypothesis on maintaining sex in low fecundity organisms: Compromised immune functions of asexual hosts may render them susceptible rather than adaptation on the side of parasites to overcome host resistance.

scholarly journals Experimental food supplementation increases reproductive effort in an antbird in subtropical Brazilian Atlantic Forest fragments

2014 ◽  
Author(s):  
James J Roper ◽  
André M. X. Lima ◽  
Angélica M. K. Uejima
Keyword(s):  
Food Availability ◽  
Reproductive Effort ◽  
Fragment Size ◽  
Food Limitation ◽  
Survival Rates ◽  
Food Supplementation ◽  
Fragmented Landscape ◽  
Forest Fragments ◽  
Daily Nest Survival ◽  
Nesting Patterns

Food limitation may interact with nest predation and influence nesting patterns, such as breeding season length and renesting intervals. If so, reproductive effort should change with food availability. Thus, when food is limited, birds should have fewer attempts and shorter seasons than when food is not limiting. Here we experimentally test that increased food availability results in increased reproductive effort in a fragmented landscape in the Variable Antshrike (Thamnophilus caerulescens) in southern Brazil. We followed nesting pairs in five natural fragments (4, 23, 24, 112, 214 ha) in which food was supplemented for half of those pairs, beginning with the first nest. Nest success in the largest (214 ha) fragment was 59%, compared to 5% in the 112 ha fragment and no nest was successful in the smallest (24 ha) fragment. Birds were seen, but evidence of nesting was never found in the two smallest fragments. Pairs with supplemented food were more likely to increase clutch size from two to three eggs, tended to renest sooner (20 d on average) than control pairs. Also, fragment size interacted with breeding and pairs in the largest fragment had greater daily nest survival rates, and so nests tended to last longer, and so these pairs had fewer nesting attempts than those in the 112 ha fragment while more than those in the smallest fragment with nesting (24 ha). Clearly, pairs increased their reproductive effort when food was supplemented in comparison to control pairs and fragment size seems to influence both predation risk and food abundance.

Managing confined populations: the influence of density on the home range and habitat use of reintroduced burrowing bettongs (Bettongia lesueur)

2004 ◽  
Vol 31 (4) ◽  
pp. 457 ◽  
Author(s):  
Graeme R. Finlayson ◽  
Katherine E. Moseby
Keyword(s):  
Home Range ◽  
Habitat Use ◽  
Food Availability ◽  
Reproductive Output ◽  
Reproductive Effort ◽  
High Density ◽  
Home Ranges ◽  
Low Density ◽  
Reproductive Condition ◽  
Behavioural Changes

The home range, reproductive condition and warren and habitat use of reintroduced female burrowing bettongs was compared within two enclosures in the Arid Recovery Reserve at estimated densities of 2.75 and 7.5 bettongs km–2. Bettongs at both densities exhibited similar behaviour, with females using an average of 2.7 warrens over six months and home ranges averaging 29 and 35 ha in the low- and high-density enclosure respectively. All five female bettongs studied in the low-density enclosure were carrying pouch young at the beginning and end of the six-month study but only one of the five females in the high-density enclosure was carrying pouch young after six months. Higher food availability may have accounted for the higher reproductive effort and slightly smaller home ranges observed in the low-density enclosure. Female bettongs at both densities favoured dune habitat over chenopod swales and all burrows were in dune habitat. Although some differences in reproductive output were observed, it is likely that densities are not yet high enough to cause significant behavioural changes.

scholarly journals Experimental food supplementation increases reproductive effort in an antbird in subtropical Brazilian Atlantic Forest fragments

2014 ◽  
Author(s):  
James J Roper ◽  
André M. X. Lima ◽  
Angélica M. K. Uejima
Keyword(s):  
Food Availability ◽  
Reproductive Effort ◽  
Fragment Size ◽  
Food Limitation ◽  
Survival Rates ◽  
Food Supplementation ◽  
Fragmented Landscape ◽  
Forest Fragments ◽  
Daily Nest Survival ◽  
Nesting Patterns

Food limitation may interact with nest predation and influence nesting patterns, such as breeding season length and renesting intervals. If so, reproductive effort should change with food availability. Thus, when food is limited, birds should have fewer attempts and shorter seasons than when food is not limiting. Here we experimentally test that increased food availability results in increased reproductive effort in a fragmented landscape in the Variable Antshrike (Thamnophilus caerulescens) in southern Brazil. We followed nesting pairs in five natural fragments (4, 23, 24, 112, 214 ha) in which food was supplemented for half of those pairs, beginning with the first nest. Nest success in the largest (214 ha) fragment was 59%, compared to 5% in the 112 ha fragment and no nest was successful in the smallest (24 ha) fragment. Birds were seen, but evidence of nesting was never found in the two smallest fragments. Pairs with supplemented food were more likely to increase clutch size from two to three eggs, tended to renest sooner (20 d on average) than control pairs. Also, fragment size interacted with breeding and pairs in the largest fragment had greater daily nest survival rates, and so nests tended to last longer, and so these pairs had fewer nesting attempts than those in the 112 ha fragment while more than those in the smallest fragment with nesting (24 ha). Clearly, pairs increased their reproductive effort when food was supplemented in comparison to control pairs and fragment size seems to influence both predation risk and food abundance.

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