scholarly journals Sublethal effects of natural parasitism act through maternal, but not paternal, reproductive success in a wild population

Ecology ◽  
2019 ◽  
Vol 100 (8) ◽  
Author(s):  
Olivia Hicks ◽  
Jonathan A. Green ◽  
Francis Daunt ◽  
Emma J. A. Cunningham ◽  
Mark Newell ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Sublethal Effects ◽  
Wild Population ◽  
Natural Parasitism

Age and experience affect the reproductive success of captive Loggerhead Shrike (Lanius ludovicianus) subspecies

2017 ◽  
Vol 95 (8) ◽  
pp. 547-554 ◽  
Author(s):  
T.L. Imlay ◽  
J.C. Steiner ◽  
D.M. Bird
Keyword(s):  
Reproductive Success ◽  
Wild Population ◽  
Trade Offs ◽  
Age Related ◽  
Captive Populations ◽  
Experienced Male ◽  
Lanius Ludovicianus ◽  
Fledgling Success ◽  
Loggerhead Shrike ◽  
Effect Of Age

Two explanations are often used to interpret the positive relationship between reproductive success and age: (1) trade-offs between current and future breeding and (2) age-related improvements in competence. Captive populations provide a unique opportunity to test these explanations because several mechanisms that result in age-related improvements in competence are managed. We modelled the effect of age and experience on the reproductive success of captive migrant Loggerhead Shrike (Lanius ludovicianus L., 1766) subspecies (formerly Lanius ludovicianus migrans W. Palmer, 1898). Female shrikes had the highest reproductive success during mid-life and lower success at 1–2 years of age and over 10 years. Both experienced male and female shrikes had higher fledgling success than inexperienced individuals. Although captive populations breed in controlled settings with few limitations, this work suggests that both explanations (i.e., trade-offs and age-related improvements in competence) are important for understanding reproductive success. Furthermore, management of the captive shrike population can be informed by these relationships to maximize the number of young produced for release to supplement the wild population.

VARIATION IN MALE REPRODUCTIVE SUCCESS IN A WILD POPULATION OF REINDEER

2005 ◽  
Vol 69 (3) ◽  
pp. 1163-1170 ◽  
Author(s):  
KNUT H. RØED ◽  
ØYSTEIN HOLAND ◽  
HALLVARD GJØSTEIN ◽  
HELGE HANSEN
Keyword(s):  
Reproductive Success ◽  
Wild Population ◽  
Male Reproductive Success

scholarly journals Attentive red squirrel mothers have faster-growing pups and higher lifetime reproductive success

2019 ◽  
Author(s):  
Sarah E Westrick ◽  
Ryan W Taylor ◽  
Stan Boutin ◽  
Jeffrey E Lane ◽  
Andrew G McAdam ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Individual Variation ◽  
Maternal Care ◽  
Wild Population ◽  
Lifetime Reproductive Success ◽  
Red Squirrels ◽  
Trade Off ◽  
Offspring Growth ◽  
North American Red Squirrels ◽  
Care Behavior

AbstractParental investment theory predicts that observed levels of parental care afforded to offspring are set by the benefits (to offspring quality and survival) relative to the costs (to parental survival or future reproduction). Although difficult to document in mammals, there is often substantial individual-variation in the amount of parental care within species. We measured the impact of individual variation in maternal care (“attentiveness” towards offspring or maternal motivation) on offspring growth and survival in a wild population of North American red squirrels (Tamiasciurus hudsonicus). We used latency to return to pups following a nest intrusion as a measure of maternal attentiveness to pups. We found this behavior to be repeatable within individuals suggesting this behavior is a personality trait or a “maternal style”. In this population, postnatal growth rate is important for pup overwinter survival. Pups from large litters grew faster if they had a highly attentive mother, indicating that maternal care behavior can mitigate the trade-off between litter size and offspring growth and potentially improve survival of pups. Additionally, more attentive mothers had slightly higher lifetime reproductive success than less attentive mothers. These results highlight important fitness effects of having a highly attentive mother and show that maternal care behavior can alter a fundamental life history trade-off between offspring quantity and quality.Lay SummaryIt pays to be attentive to your pups as a squirrel mom. In a long-term study of a wild population of North American red squirrels, we observed repeatable individual variation in maternal attentiveness towards offspring. Mothers who returned faster to pups following a nest intrusion produced faster growing pups and were able to produce larger fast-growing litters. Over their entire lifetime, attentive mothers also had more offspring recruit into the breeding population.

scholarly journals Neonicotinoid exposure affects foraging, nesting, and reproductive success of ground-nesting solitary bees

2020 ◽  
Author(s):  
D. Susan Willis Chan ◽  
Nigel E. Raine
Keyword(s):  
Reproductive Success ◽  
Food Production ◽  
Pesticide Exposure ◽  
Sublethal Effects ◽  
Environmental Stressors ◽  
Crop Pollination ◽  
Pollination Services ◽  
Risk Of Exposure ◽  
First Time ◽  
Ground Nesting

Despite their indispensable role in food production1,2, insect pollinators are threatened by multiple environmental stressors, including pesticide exposure2-4. Although honeybees are important, most pollinating insect species are wild, solitary, ground-nesting bees1,4-6 that are inadequately represented by honeybee-centric regulatory pesticide risk assessment frameworks7,8. Here, for the first time, we evaluate the effects of realistic exposure to systemic insecticides (imidacloprid, thiamethoxam or chlorantraniliprole) on a ground-nesting bee species in a semi-field experiment. Hoary squash bees (Eucera (Peponapis) pruinosa) provide essential pollination services to North American pumpkin and squash crops9-14 and commonly nest within cropping areas10, placing them at risk of exposure to pesticides in soil8,10, nectar and pollen15,16. Hoary squash bees exposed to an imidacloprid-treated crop initiated 85% fewer nests, left 84% more pollen unharvested, and produced 89% fewer offspring than untreated controls. We found no measurable impact on squash bees from exposure to thiamethoxam- or chlorantraniliprole-treated crops. Our results demonstrate important sublethal effects of field-realistic exposure to a soil-applied neonicotinoid (imidacloprid) on the behaviour and reproductive success of a ground-nesting solitary bee. To prevent potential declines in ground-nesting bee populations and associated impoverishment of crop pollination services, soil must be considered a possible route of pesticide exposure for bees, and restrictions on soil-applied insecticides may be justified.

scholarly journals Selection on Sperm Count, but Not on Sperm Morphology or Velocity, in a Wild Population of Anolis Lizards

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2369
Author(s):  
Ariel F. Kahrl ◽  
Matthew C. Kustra ◽  
Aaron M. Reedy ◽  
Rachana S. Bhave ◽  
Heidi A. Seears ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Sperm Morphology ◽  
Wild Population ◽  
Sperm Count ◽  
Experimental Studies ◽  
Male Reproductive Success ◽  
Brown Anole ◽  
Postcopulatory Selection ◽  
Highly Correlated ◽  
Sperm Traits

Sperm competition is a widespread phenomenon that shapes male reproductive success. Ejaculates present many potential targets for postcopulatory selection (e.g., sperm morphology, count, and velocity), which are often highly correlated and potentially subject to complex multivariate selection. Although multivariate selection on ejaculate traits has been observed in laboratory experiments, it is unclear whether selection is similarly complex in wild populations, where individuals mate frequently over longer periods of time. We measured univariate and multivariate selection on sperm morphology, sperm count, and sperm velocity in a wild population of brown anole lizards (Anolis sagrei). We conducted a mark-recapture study with genetic parentage assignment to estimate individual reproductive success. We found significant negative directional selection and negative quadratic selection on sperm count, but we did not detect directional or quadratic selection on any other sperm traits, nor did we detect correlational selection on any trait combinations. Our results may reflect pressure on males to produce many small ejaculates and mate frequently over a six-month reproductive season. This study is the first to measure multivariate selection on sperm traits in a wild population and provides an interesting contrast to experimental studies of external fertilizers, which have found complex multivariate selection on sperm phenotypes.

scholarly journals Higher sociability leads to lower reproductive success in female kangaroos

2020 ◽  
Vol 7 (8) ◽  
pp. 200950
Author(s):  
C. S. Menz ◽  
A. J. Carter ◽  
E. C. Best ◽  
N. J. Freeman ◽  
R. G. Dwyer ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Social Relationships ◽  
Wild Population ◽  
Social Bonds ◽  
Group Living ◽  
Trade Offs ◽  
Fitness Consequences ◽  
Living Species ◽  
Complex Forms ◽  
First Time

In social mammals, social integration is generally assumed to improve females' reproductive success. Most species demonstrating this relationship exhibit complex forms of social bonds and interactions. However, female eastern grey kangaroos ( Macropus giganteus ) exhibit differentiated social relationships, yet do not appear to cooperate directly. It is unclear what the fitness consequences of such sociability could be in species that do not exhibit obvious forms of cooperation. Using 4 years of life history, spatial and social data from a wild population of approximately 200 individually recognizable female eastern grey kangaroos, we tested whether higher levels of sociability are associated with greater reproductive success. Contrary to expectations, we found that the size of a female's social network, her numbers of preferential associations with other females and her group sizes all negatively influenced her reproductive success. These factors influenced the survival of dependent young that had left the pouch rather than those that were still in the pouch. We also show that primiparous females (first-time breeders) were less likely to have surviving young. Our findings suggest that social bonds are not always beneficial for reproductive success in group-living species, and that female kangaroos may experience trade-offs between successfully rearing young and maintaining affiliative relationships.

Captive Ancestry Upwardly Biases Estimates of Relative Reproductive Success

2017 ◽  
Vol 108 (5) ◽  
pp. 583-587 ◽  
Author(s):  
Janna R Willoughby ◽  
Mark R Christie
Keyword(s):  
Reproductive Success ◽  
Captive Breeding ◽  
Wild Population ◽  
Relative Fitness ◽  
Declining Populations ◽  
In The Wild ◽  
Fitness Measures ◽  
Number Of Individuals ◽  
Mean Population Fitness

Abstract Supplementation programs, which release captive-born individuals into the wild, are commonly used to demographically bolster declining populations. In order to evaluate the effectiveness of these programs, the reproductive success of captive-born individuals released into the wild is often compared to the reproductive success of wild-born individuals in the recipient population (relative reproductive success, RRS). However, if there are heritable reductions in fitness associated with captive breeding, gene flow from captive-born individuals into the wild population can reduce the fitness of the wild population. Here, we show that when captive ancestry in the wild population reduces mean population fitness, estimates of RRS are upwardly biased, meaning that the relative fitness of captive-born individuals is over-estimated. Furthermore, the magnitude of this bias increases with the length of time that a supplementation program has been releasing captive-born individuals. This phenomenon has long-term conservation impacts since management decisions regarding the design of a supplementation program and the number of individuals to release can be based, at least in part, on RRS estimates. Therefore, we urge caution in the interpretation of relative fitness measures when the captive ancestry of the wild population cannot be precisely measured.

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