scholarly journals Juvenile plumage whiteness is associated with the evolution of clutch size in passerines

2019 ◽  
Vol 30 (4) ◽  
pp. 1106-1112 ◽  
Author(s):  
Judith Morales ◽  
José Javier Cuervo ◽  
Juan Moreno ◽  
Juan José Soler
Keyword(s):  
Predation Risk ◽  
Clutch Size ◽  
Bird Species ◽  
Passerine Bird ◽  
Sibling Conflict ◽  
Plumage Color ◽  
Structural Trait ◽  
Strong Resemblance ◽  
High Predation ◽  
White Plumage

Abstract The offspring of many animals are conspicuous during parental dependence, despite juveniles generally suffering from high predation risk. However, to date, it is unclear whether offspring structural ornaments play a role in intrafamily communication. This is the case of conspicuous plumage in young birds, which is worn unchanged during a long period after fledging, when they still depend on their parents. If plumage color facilitates intrafamily interactions, its role should be more important in large-brooded species, where the strength of intrafamily conflict is potentially stronger. We therefore performed a comparative study in 210 passerine bird species to test whether an offspring structural trait, white plumage, evolves more frequently in lineages with larger clutches. We also explored the number of broods raised per year as another source of intrafamily conflict. First, we found that juvenile whiteness was more frequent in open-nesting species. Moreover, in agreement with our prediction, the presence of juvenile white tail/wing patches was strongly and positively associated with clutch size. This relationship was not due to the strong resemblance between offspring and adult plumage, which was controlled for in the statistical analyses. Moreover, the association remained significant after taking into account predation risk, for which there was information for a subset of species. In contrast, juvenile whiteness was not associated with the number of broods raised per year. These results may suggest that the evolution of juvenile conspicuousness is favored in species with potentially stronger intrabrood sibling conflict.

Elevated nest predation risk promotes offspring size variation in birds with prolonged parental care.

2019 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Emeline Mourocq ◽  
Michael Griesser
Keyword(s):  
Predation Risk ◽  
Reproductive Cycle ◽  
Perceived Risk ◽  
Nest Predation ◽  
Bird Species ◽  
Size Variation ◽  
Egg Laying ◽  
Offspring Size ◽  
Natural Predation ◽  
Risk Spreading

Predation of offspring is the main cause of reproductive failure in many species, and the mere fear of offspring predation shapes reproductive strategies. Yet, natural predation risk is ubiquitously variable and can be unpredictable. Consequently, the perceived prospect of predation early in a reproductive cycle may not reflect the actual risk to ensuing offspring. An increased variance in investment across offspring has been linked to breeding in unpredictable environments in several taxa, but has so far been overlooked as a maternal response to temporal variation in predation risk. Here, we experimentally increased the perceived risk of nest predation prior to egg-laying in seven bird species. Species with prolonged parent-offspring associations increased their intra-brood variation in egg, and subsequently offspring, size. High risk to offspring early in a reproductive cycle can favour a risk-spreading strategy particularly in species with the greatest opportunity to even out offspring quality after fledging.

scholarly journals Glucocorticoids, state-dependent reproductive investment and success in the face of danger in a long-lived bird

2020 ◽  
Author(s):  
Kristina Noreikienė ◽  
Kim Jaatinen ◽  
Benjamin B. Steele ◽  
Markus Öst
Keyword(s):  
Predation Risk ◽  
Telomere Length ◽  
Clutch Size ◽  
Body Condition ◽  
Nest Predation ◽  
Hatching Success ◽  
Reproductive Investment ◽  
Trade Off ◽  
Relative Telomere Length ◽  
Future Reproduction

AbstractGlucocorticoid hormones may mediate trade-offs between current and future reproduction. However, understanding their role is complicated by predation risk, which simultaneously affects the value of the current reproductive investment and elevates glucocorticoid levels. Here, we shed light on these issues in long-lived female Eiders (Somateria mollissima) by investigating how current reproductive investment (clutch size) and hatching success relate to faecal glucocorticoid metabolite [fGCM] level and residual reproductive value (minimum years of breeding experience, body condition, relative telomere length) under spatially variable predation risk. Our results showed a positive relationship between colony-specific predation risk and mean colony-specific fGCM levels. Clutch size and female fGCM were negatively correlated only under high nest predation and in females in good body condition, previously shown to have a longer life expectancy. We also found that younger females with longer telomeres had smaller clutches. The drop in hatching success with increasing fGCM levels was least pronounced under high nest predation risk, suggesting that elevated fGCM levels may allow females to ensure some reproductive success under such conditions. Hatching success was positively associated with female body condition, with relative telomere length, particularly in younger females, and with female minimum age, particularly under low predation risk, showing the utility of these metrics as indicators of individual quality. In line with a trade-off between current and future reproduction, our results show that high potential for future breeding prospects and increased predation risk shift the balance toward investment in future reproduction, with glucocorticoids playing a role in the resolution of this trade-off.

Geographical differences in seasonal clutch size variation in multi-brooded bird species

Ibis ◽  
2002 ◽  
Vol 144 (4) ◽  
pp. 646-651 ◽  
Author(s):  
André A. Dhondt ◽  
Tracey L. Kast ◽  
Paul E. Allen
Keyword(s):  
Clutch Size ◽  
Bird Species ◽  
Size Variation ◽  
Geographical Differences

High predation risk for a small mammal: the eastern pygmy-possum (Cercartetus nanus)

2013 ◽  
Vol 35 (2) ◽  
pp. 149 ◽  
Author(s):  
Bradley Law ◽  
Mark Chidel ◽  
Alf Britton
Keyword(s):  
Predation Risk ◽  
Small Mammal ◽  
High Predation ◽  
Cercartetus Nanus

We report high rates of predation within a population of eastern pygmy-possum (Cercartetus nanus) near Sydney, observed during a study of the impacts of logging on the species. Predation by reptiles was observed on six of 61 radio-tracked pygmy-possums, while two were suspected of being taken by raptors. We further investigated predation by sooty owls (Tyto tenebricosa) by identifying remains in pellets. Pygmy-possums comprised 15% of the 126 dietary items identified. Predation occurred at both logged and unlogged sites in our study. We suggest that documented high rates of predation in our study could make the species vulnerable to altered predation regimes, such as influxes of feral predators, and highlight the need for a better understanding of any influence of logging on predator activity.

scholarly journals Limited reproductive impairment in a passerine bird species exposed along a perfluoroalkyl acid (PFAA) pollution gradient

2019 ◽  
Vol 652 ◽  
pp. 718-728 ◽  
Author(s):  
Thimo Groffen ◽  
Robin Lasters ◽  
Ana Lopez-Antia ◽  
Els Prinsen ◽  
Lieven Bervoets ◽  
...  
Keyword(s):  
Bird Species ◽  
Passerine Bird ◽  
Pollution Gradient ◽  
Reproductive Impairment ◽  
Perfluoroalkyl Acid

scholarly journals Interspecific information on predation risk affects nest site choice in a passerine bird

2018 ◽  
Vol 18 (1) ◽  
Author(s):  
Jere Tolvanen ◽  
Janne-Tuomas Seppänen ◽  
Mikko Mönkkönen ◽  
Robert L. Thomson ◽  
Hannu Ylönen ◽  
...  
Keyword(s):  
Predation Risk ◽  
Nest Site ◽  
Passerine Bird ◽  
Nest Site Choice

scholarly journals Is it safe to nest near bold neighbours? Spatial patterns in predation risk associated with the density of American Golden-Plover nest

2016 ◽  
Author(s):  
Marie-Andrée Giroux ◽  
Myriam Trottier-Paquet ◽  
Joël Bêty ◽  
Vincent Lamarre ◽  
Nicolas Lecomte
Keyword(s):  
Predation Risk ◽  
Spatial Patterns ◽  
Bird Species ◽  
Artificial Nests ◽  
Species Of Conservation Concern ◽  
Composition And Structure ◽  
Negative Effect ◽  
Conservation Concern ◽  
Golden Plover ◽  
Mobbing Behaviour

Predation is one of the main factors explaining nesting mortality in most bird species. Birds can avoid nest predation or reduce predation pressure by breeding at higher latitude, showing anti-predator behaviour, and nesting in association with protective species. Plovers actively defend their territory by displaying early warning and aggressive/mobbing behaviour, potentially benefiting the neighbouring nests by decreasing their predation risk. To test for the existence of such a protective effect, we studied the influence of proximity to plover nests on predation risk of artificial nests on Igloolik Island (Nunavut, Canada) in July 2014. We predicted that the predation risk of artificial nests increases and decreases with the distance to and the density of plover nests, respectively. We monitored 18 plover nests and set 35 artificial nests at 30, 50, 100, 200 and 500 m from seven of those plover nests. Surprisingly, we showed that predation risk of artificial nests increases with the density of active plover nests. We also found a significant negative effect of the distance to the nearest active protector nest on predation risk of artificial nests. Understanding how the composition and structure of shorebird communities generate spatial patterns in predation risks represent a key step to better understand the importance of these species of conservation concern in tundra food webs.

scholarly journals High-throughput sequencing is revealing genetic associations with avian plumage color

The Auk ◽  
2019 ◽  
Vol 136 (4) ◽  
Author(s):  
Erik R Funk ◽  
Scott A Taylor
Keyword(s):  
High Throughput Sequencing ◽  
Large Body ◽  
Bird Species ◽  
Genetic Associations ◽  
Plumage Color ◽  
Protein Coding ◽  
Avian Evolution ◽  
Color Changes ◽  
Coding Regions ◽  
Color Differences

Abstract Avian evolution has generated an impressive array of patterns and colors in the ~10,000 bird species that exist on Earth. Recently, a number of exciting studies have utilized whole-genome sequencing to reveal new details on the genetics of avian plumage color. These findings provide compelling evidence for genes that underlie plumage variation across a wide variety of bird species (e.g., juncos, warblers, seedeaters, and estrildid finches). While much is known about large, body-wide color changes, these species exhibit discrete color differences across small plumage patches. Many genetic differences appear to be located in regulatory regions of genes rather than in protein-coding regions, suggesting gene expression is playing a large role in the control of these color patches. Taken together, these studies have the potential to broadly facilitate further research of sexual selection and evolution in these charismatic taxa.

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