scholarly journals UV reflectance as a cue in egg discrimination in twoPriniaspecies exploited differently by brood parasites in Taiwan

Ibis ◽  
2013 ◽  
Vol 155 (3) ◽  
pp. 571-575 ◽  
Author(s):  
Canchao Yang ◽  
Longwu Wang ◽  
Yu-Cheng Hsu ◽  
Anton Antonov ◽  
Arne Moksnes ◽  
...  
Keyword(s):  
Egg Discrimination ◽  
Brood Parasites ◽  
Uv Reflectance

A Test for Conspecific Egg Discrimination in Three Species of Colonial Passerine Birds

The Auk ◽  
1982 ◽  
Vol 99 (3) ◽  
pp. 519-525
Author(s):  
Glen A. Lanier
Keyword(s):  
Brood Parasitism ◽  
Current Theory ◽  
Passerine Birds ◽  
Barn Swallow ◽  
Egg Discrimination ◽  
Intraspecific Brood Parasitism ◽  
Brood Parasites ◽  
Naturally Occurring ◽  
Altricial Birds ◽  
The Cost

Abstract Naturally occurring populations of three species of colonial passerine birds, the Piñon Jay (Gymnorhinus cyanocephalus), Great-tailed Grackle (Quiscalis mexicanus), and Barn Swallow (Hirundo rustica), were tested for conspecific egg discrimination and the presence of intraspecific brood parasitism that such discrimination would imply. Current theory predicts that intraspecific brood parasitism, or cheating, might occur when a brood parasite's fitness is enhanced relative to a nonparasite's. Due to the high cost of parental care in altricial birds, selection for defenses against such cheaters should also be intense. Egg rejection is the most common selection mechanism against interspecific brood parasites, and I tested for the presence or absence of this mechanism. Single eggs were switched between pairs of 19 Piñon Jay nests, 15 Great-tailed Grackle nests, and 14 Barn Swallow nests, and a fifth egg was added to each of 8 Piñon Jay nests. No significant level of rejection of introduced eggs was found, possibly either because the cost of cheating is too great or because egg discrimination and rejection are not the mechanisms of selection against cheaters in the populations tested.

scholarly journals Hosts of avian brood parasites have evolved egg signatures with elevated information content

2015 ◽  
Vol 282 (1810) ◽  
pp. 20150598 ◽  
Author(s):  
Eleanor M. Caves ◽  
Martin Stevens ◽  
Edwin S. Iversen ◽  
Claire N. Spottiswoode
Keyword(s):  
Information Content ◽  
Brood Parasitism ◽  
Colour Pattern ◽  
Egg Discrimination ◽  
Brood Parasites ◽  
Individual Host ◽  
Egg Traits ◽  
The Cost

Hosts of brood-parasitic birds must distinguish their own eggs from parasitic mimics, or pay the cost of mistakenly raising a foreign chick. Egg discrimination is easier when different host females of the same species each lay visually distinctive eggs (egg ‘signatures’), which helps to foil mimicry by parasites. Here, we ask whether brood parasitism is associated with lower levels of correlation between different egg traits in hosts, making individual host signatures more distinctive and informative. We used entropy as an index of the potential information content encoded by nine aspects of colour, pattern and luminance of eggs of different species in two African bird families (Cisticolidae parasitized by cuckoo finches Anomalospiza imberbis , and Ploceidae by diederik cuckoos Chrysococcyx caprius ). Parasitized species showed consistently higher entropy in egg traits than did related, unparasitized species. Decomposing entropy into two variation components revealed that this was mainly driven by parasitized species having lower levels of correlation between different egg traits, rather than higher overall levels of variation in each individual egg trait. This suggests that irrespective of the constraints that might operate on individual egg traits, hosts can further improve their defensive ‘signatures' by arranging suites of egg traits into unpredictable combinations.

scholarly journals Adjustment of egg laying by both hosts and intraspecific brood parasites in a beetle

Ethology ◽  
2021 ◽  
Author(s):  
Jon Richardson ◽  
Sarah Dobson ◽  
Lucy E. Ford ◽  
Per T. Smiseth
Keyword(s):  
Egg Laying ◽  
Brood Parasites

scholarly journals Host density predicts the probability of parasitism by avian brood parasites

2019 ◽  
Vol 374 (1769) ◽  
pp. 20180204 ◽  
Author(s):  
Iliana Medina ◽  
Naomi E. Langmore
Keyword(s):  
Spatial Distribution ◽  
Reproductive Success ◽  
Host Species ◽  
Field Data ◽  
Host Density ◽  
Brood Parasites ◽  
Parasitism Rates ◽  
Analyse Data ◽  
First Time ◽  
Determining Factor

The spatial distribution of hosts can be a determining factor in the reproductive success of parasites. Highly aggregated hosts may offer more opportunities for reproduction but can have better defences than isolated hosts. Here we connect macro- and micro-evolutionary processes to understand the link between host density and parasitism, using avian brood parasites as a model system. We analyse data across more than 200 host species using phylogenetic comparative analyses and quantify parasitism rate and host reproductive success in relation to spatial distribution using field data collected on one host species over 6 years. Our comparative analysis reveals that hosts occurring at intermediate densities are more likely to be parasitized than colonial or widely dispersed hosts. Correspondingly, our intraspecific field data show that individuals living at moderate densities experience higher parasitism rates than individuals at either low or high densities. Moreover, we show for the first time that the effect of host density on host reproductive success varies according to the intensity of parasitism; hosts have greater reproductive success when living at high densities if parasitism rates are high, but fare better at low densities when parasitism rates are low. We provide the first evidence of the trade-off between host density and parasitism at both macro- and micro-evolutionary scales in brood parasites. This article is part of the theme issue ‘The coevolutionary biology of brood parasitism: from mechanism to pattern’.

scholarly journals The role of ultraviolet reflectance and pattern in the pollination system of Hypoxis camerooniana (Hypoxidaceae)

AoB Plants ◽  
2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Yannick Klomberg ◽  
Raissa Dywou Kouede ◽  
Michael Bartoš ◽  
Jan E J Mertens ◽  
Robert Tropek ◽  
...  
Keyword(s):  
Plant Species ◽  
Central Africa ◽  
Complete Removal ◽  
Reproductive Organs ◽  
Specific Pattern ◽  
Flowering Plant ◽  
Pollination System ◽  
Mount Cameroon ◽  
Uv Reflectance ◽  
Montane Grasslands

Abstract Apart from floral morphology and colours perceived by the human eye, ultraviolet (UV) reflectance acts as an important visual advertisement of numerous flowering plant species for pollinators. However, the effect of UV signalling on attracting pollinators of particular plant species is still insufficiently studied, especially in the Afrotropics. Therefore, we studied the pollination system of Hypoxis camerooniana in montane grasslands of Mount Cameroon, West/Central Africa. We focused mainly on the effects of the flowers’ UV reflectance on its visitors. We experimentally removed UV reflection from petals either completely or partially. Thereafter, flower visitors were recorded and pistils were collected post-flowering to quantify germinated pollen tubes per treatments. The most important visitors were bees, followed by flies. Due to their contacts with reproductive organs bees are considered as the primary pollinators. Visitation rates were lower when UV reflectance was completely removed, whereas the decrease of frequency on half-treated flowers did not differ significantly from control treatments. The complete removal of UV also affected bees’ landing behaviour, but not that of flies. We showed that the presence of UV reflectance is more important than UV pattern for bees visiting flowers of H. camerooniana. We hypothesize that exploiting all flowers irrespective of their pattern can be more efficient for pollinators in the open grasslands of high altitudes to spot these relatively scarce flowers by their UV reflectance. Furthermore, we highlight the necessity of both experimental and natural controls in similar studies to control for additional effects of the used UV manipulations. Many plants advertise their flowers with UV reflectance visible to their insect visitors. By manipulating the UV reflectance and pattern of Hypoxis camerooniana in the Afromontane grasslands of Mount Cameroon, we have shown how crucial it is for the predominant visitor, bees. Both bees' preferences for flowers and their behaviour during visits are influenced by changes in UV reflectance. However, the presence of some UV signal is more important than the specific pattern. Especially in montane grasslands with higher UV irradiation, the UV floral colours are important for recognition of flowers by potential pollinators.

Evidence of Conspecific Nest Parasitism and Egg Discrimination in the Sora

The Condor ◽  
1995 ◽  
Vol 97 (3) ◽  
pp. 819-821 ◽  
Author(s):  
Michael D. Sorenson
Keyword(s):  
Nest Parasitism ◽  
Egg Discrimination

Ultraviolet reflectance and female mating preferences in the common kestrel (Falco tinnunculus)

2008 ◽  
Vol 86 (6) ◽  
pp. 479-483 ◽  
Author(s):  
E. Zampiga ◽  
G. Gaibani ◽  
D. Csermely
Keyword(s):  
Female Mate Choice ◽  
Female Preference ◽  
Visible Spectral Range ◽  
Falco Tinnunculus ◽  
Uv Filter ◽  
Skin Reflectance ◽  
Ultraviolet Reflectance ◽  
Uv Reflectance ◽  
Female Mating Preferences ◽  
Uv Reflection

Previous studies revealed the importance of plumage brightness (considering only the visible spectral range) in female mate choice of common kestrels ( Falco tinnunculus L., 1758). Our study focuses on the effect of UV reflectance on female preference; we hypothesize that common kestrel females prefer males with UV-reflecting plumage and refuse, or are not attracted to, males whose plumage UV reflectance is prevented. We tested the preference of 20 captive females who were given a choice between two males, one behind a UV-transmitting (UV+) filter and another one behind a UV-blocking (UV–) filter. Female preference was measured as frequency and duration of visits to either male, specifically by sitting on the perch or hanging on to the partition wall. Females visited the male behind the UV+ filter more often than the male behind the UV– filter, indicating that females prefer males with UV-reflecting plumage than males without UV reflection. UV plumage and skin reflectance could provide females with information regarding current male conditions more so than other colours and other morphological parameters.

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