Search results for "Bird"
showing 10 items of 420 documents
Maternal effects in quail and zebra finches: behavior and hormones.
2013
8 pages; International audience; Maternal effects are influences of parents on offspring phenotype occurring through pathways other than inherited DNA. In birds, two important routes for such transmission are parental behavior and non-DNA egg constituents such as yolk hormones. Offspring traits subject to parental effects include behavior and endocrine function. Research from the Adkins-Regan lab has used three avian species to investigate maternal effects related to hormones and behavior. Experiments with chickens and Japanese quail have shown that maternal sex steroids can influence sex determination to produce biased offspring sex ratios. Because all birds have a ZZ/ZW chromosomal sex de…
Susceptibility of eye fluke-infected fish to predation by bird hosts.
2005
Host manipulation by trophically transmitted parasites may predispose infected hosts to predation and in this way enhance parasite transmission. In most study systems, however, the evidence comes from laboratory studies, and therefore knowledge of the effect of manipulation on parasite transmission efficiency in the wild is still limited. Here we examined the effect ofDiplostomum spathaceum(Trematoda) eye flukes on the susceptibility of fish intermediate hosts to predation by bird definitive hosts. Our earlier studies have shown that the parasite alters fish phenotype and increases their susceptibility to artificial predation under laboratory conditions. In the present field study, we allow…
An optimised multi-host trematode life cycle: fishery discards enhance trophic parasite transmission to scavenging birds
2016
Overlapping distributions of hosts and parasites are critical for successful completion of multi-host parasite life cycles and even small environmental changes can impact on the parasite's presence in a host or habitat. The generalist Cardiocephaloides longicollis was used as a model for multi-host trematode life cycles in marine habitats. This parasite was studied to quantify parasite dispersion and transmission dynamics, effects of biological changes and anthropogenic impacts on life cycle completion. We compiled the largest host dataset to date, by analysing 3351 molluscs (24 species), 2108 fish (25 species) and 154 birds (17 species) and analysed the resultant data based on a number of …
Who's better at spotting? A comparison between aerial photography and observer-based methods to monitor floating marine litter and marine mega-fauna.
2020
Pollution by marine litter is raising major concerns due to its potential impact on marine biodiversity and, above all, on endangered mega-fauna species, such as cetaceans and sea turtles. The density and distribution of marine litter and mega-fauna have been traditionally monitored through observer-based methods, yet the advent of new technologies has introduced aerial photography as an alternative monitoring method. However, to integrate results produced by different monitoring techniques and consider the photographic method a viable alternative, this ‘new’ methodology must be validated. This study aims to compare observations obtained from the concurrent application of observer-based and…
The importance of pattern similarity between Müllerian mimics in predator avoidance learning
2004
Müllerian mimicry, where unpalatable prey share common warning patterns, has long fascinated evolutionary biologists. It is commonly assumed that Müllerian mimics benefit by sharing the costs of predator education, thus reducing per capita mortality, although there has been no direct test of this assumption. Here, we specifically measure the selection pressure exerted by avian predators on unpalatable prey with different degrees of visual similarity in their warning patterns. Using wild-caught birds foraging on novel patterned prey in the laboratory, we unexpectedly found that pattern similarity did not increase the speed of avoidance learning, and even dissimilar mimics shared the educatio…
Helminth communities of herons (Aves: Ardeidae) in southern Italy
2016
The helminth communities of nine species of herons from southern Italy were studied and compared. Of 24 taxa found including seven digeneans, seven nematodes, six cestodes and four acanthocephalans, only five taxa were found in more than one heron species, and five of the 21 taxa that could be identified to species level were classified as 'heron specialists'. The total number of helminth species per heron species ranged from 1 in Botaurus stellaris to 9 in Ixobrychus minutus with infection levels generally low. A statistical comparison was carried out for herons with a sample size >. 5. At the infracommunity level, only I. minutus clearly differed from other heron species. Diversity parame…
Manipulating Individual Decisions and Environmental Conditions Reveal Individual Quality in Decision-Making and Non-Lethal Costs of Predation Risk
2012
Received: July 6, 2012; Accepted: November 13, 2012; Published: December 13, 2012
Climate driven life histories: the case of the Mediterranean Storm petrel
2014
Seabirds are affected by changes in the marine ecosystem. The influence of climatic factors on marine food webs can be reflected in long-term seabird population changes. We modelled the survival and recruitment of the Mediterranean storm petrel (Hydrobates pelagicus melitensis) using a 21-year mark-recapture dataset involving almost 5000 birds. We demonstrated a strong influence of prebreeding climatic conditions on recruitment age and of rainfall and breeding period conditions on juvenile survival. The results suggest that the juvenile survival rate of the Mediterranean subspecies may not be negatively affected by the predicted features of climate change, i.e., warmer summers and lower rai…
The migratory birds: novel ecological niche of fungal diversity?
2015
Francesca et al (2010) studied the ecology of wine yeasts associated to birds caught in vineyards. The same authors were able to prove that migratory birds might carry living pro-technological yeasts for about 12 hours from the ingestion of inoculated feed (Francesca et al 2012). In subsequent studies, they tried to demonstrate that microorganisms are not only transported for a short period by birds, but microorganisms might be adapted to the specific conditions (body temperature about 42 °C and low pH) of the intestinal tract of birds. Hence, it was demonstrated that the majority of isolates carried by birds are thermotolerant. The most interesting results were the isolation of two new spe…
Winter movement patterns of a globally endangered avian scavenger in south-western Europe
2020
AbstractPartial migration, whereby some individuals migrate and some do not, is relatively common and widespread among animals. Switching between migration tactics (from migratory to resident or vice versa) occurs at individual and population levels. Here, we describe for the first time the movement ecology of the largest wintering population of Egyptian Vultures (Neophron percnopterus) in south-west Europe. We combined field surveys and GPS tracking data from December to February during four wintering seasons (2014–2018). The wintering population consisted on average of 85 individuals (range 58–121; 76% adults and 24% subadults). Individuals were counted at five different roosting sites lo…