Search results for "Body Condition"
showing 10 items of 20 documents
Stopover strategies in birds: a review of methods for estimating stopover length
1999
This study categorizes and reviews methods used to estimate stopover length in migratory birds. Stopover length is an important variable in analysing migration strategies. The analysis of the stopover pattern of migratory birds typically attempts to investigate variability in the number of stopovers and in the length of time spent at stopover sites in relation to species, age, sex and body condition. Although the number of capture-recapture studies analysing stopover length has increased substantially, most are analysed using the simple last-first capture method which gives biased estimates. The use of mathematical models to calculate stopover length is uncommon. Most researchers assume hom…
Body weight provides insights into the feeding strategy of swarming bats.
2010
Temperate bat species that hibernate in underground sites are known to visit hibernacula in late summer where they perform an activity known as "swarming". We analysed trends in body mass-to-forearm ratio - the body condition index (BCI) - to investigate whether bats arrive at swarming sites following intensive nocturnal feeding. In a two-year study, Myotis daubentonii, M. brandtii and M. dasycneme were captured by mist-net at one swarming site from late July until early October. In late summer, the BCIs of captured males, females and subadult bats were positively correlated to the time of their capture during the night. In September, adult bats had higher BCIs than in late summer and the B…
FOOD MAKES YOU A TARGET: DISENTANGLING GENETIC, PHYSIOLOGICAL, AND BEHAVIORAL EFFECTS DETERMINING SUSCEPTIBILITY TO INFECTION
2010
Genetics, physiology, and behavior are all expected to influence the susceptibility of hosts to parasites. Furthermore, interactions between genetic and other factors are suggested to contribute to the maintenance of genetic polymorphism in resistance when the relative susceptibility of host genotypes is context dependent. We used a maternal sibship design and long- and short-term food deprivation treatments to test the role of family-level genetic variation, body condition, physiological state, and foraging behavior on the susceptibility of Lymnaea stagnalis snails to infection by a trematode parasite that uses chemical cues to locate its hosts. In experimental exposures, we found that sna…
Physiological stress does not increase with urbanization in European blackbirds: Evidence from hormonal, immunological and cellular indicators
2020
Urbanization changes the landscape structure and ecological processes of natural habitats. While urban areas expose animal communities to novel challenges, they may also provide more stable environments in which environmental fluctuations are buffered. Species´ ecology and physiology may determine their capacity to cope with the city life. However, the physiological mechanisms underlying organismal responses to urbanization, and whether different physiological systems are equally affected by urban environments remain poorly understood. This severely limits our capacity to predict the impact of anthropogenic habitats on wild populations. In this study, we measured indicators of physiological…
Body condition score and related productive responces in rabbit does.
2008
A simplified 3-point scale method for in vivo scoring body condition is proposed as an useful and rapid tool to support experimental and on-farm management of nutrition and reproduction of rabbit does. The productive responses of lactating rabbit does scored and inseminated at 11 days post partum (pp) are verified, as well as performance of non-pregnant does scored and re-inseminated at 32 days pp when non-lactating. After their first parturition, 96 New Zealand White rabbit does were checked for 126 days over three successive 42-day reproductive cycles. The body condition scoring was based on feel by hand the loin and the rump for bone protrusions and muscle fullness. The loin was evaluate…
Personality and body condition have additive effects on motivation to feed in Zebra Finches Taeniopygia guttata
2012
Several hypotheses have been proposed to account for the adaptive evolution of person-ality, defined as inter-individual differences in behaviour that are consistent over timeand across situations. For instance, the ‘pace-of-life syndrome’ hypothesis suggests thatpersonality evolved as a behavioural correlate of life-history trajectories that vary withinpopulations. Thus, proactivity, corresponding to higher exploratory tendencies or higherboldness levels, has been linked to higher productivity or mortality rates. However, theextent to which proactivity is associated with a higher motivation to forage remainspoorly understood. Moreover, although personality and its effects on foraging behavi…
Impact of trace metals from past mining on the aquatic ecosystem: a multi-proxy approach in the Morvan (France).
2014
10 pages; International audience; This study seeks to determine to what extent trace metals resulting from past mining activities are transferred to the aquatic ecosystem, and whether such trace metals still exert deleterious effects on biota. Concentrations of Cd, Cu, Pb and Zn were measured in streambed sediments, transplanted bryophytes and wild brown trout. This study was conducted at two scales: (i) the entire Morvan Regional Nature Park and (ii) three small watersheds selected for their degree of contamination, based on the presence or absence of past mining sites. The overall quality of streambed sediments was assessed using Sediment Quality Indices (SQIs). According to these standar…
Changes in ewe milk fatty acids following turning out to pasture
2008
Abstract Ten Comisana dairy ewes were selected to observe time of changing in milk fatty acids as a result of switching from stall to pasture feeding. At first, ewes were subjected to a stall-feeding period of 30 days (pre-experimental phase). After which, ewes were abruptly turned out to a vetch and oats pasture as their sole feed (experimental phase). Individual milk samples were collected on experimental days 0 (the last day of stall feeding), 1–4, 8, 11, 17 and 23. Milk and feeds fatty acid composition was determined by gas chromatography. The sudden passage from a stall to a pasture diet significantly modified the fatty acid profile of ewe milk. Medium- and long-chain fatty acids were …
Experimental evidence for a cost of resistance to the fungal pathogen, Batrachochytrium dendrobatidis, for the palmate newt, Lissotriton helveticus
2013
Background Batrachochytrium dendrobatidis (Bd), the causative agent of chytridiomycosis, is decimating amphibians worldwide. Unsurprisingly, the majority of studies have therefore concentrated on documenting morbidity and mortality of susceptible species and projecting population consequences as a consequence of this emerging infectious disease. Currently, there is a paucity of studies investigating the sub-lethal costs of Bd in apparently asymptomatic species, particularly in controlled experimental conditions. Here we report the consequences of a single dose of B. dendrobatidis zoospores on captive adult palmate newts (Lissotriton helveticus) for morphological and behavioural traits that …
Heterozygosity-fitness correlations in adult and juvenile Zenaida Dove, Zenaida aurita.
2013
10 pages; International audience; Understanding how fitness is related to genetic variation is of crucial importance in both evolutionary ecology and conservation biology. We report a study of heterozygosity-fitness correlations in a wild, noninbred population of Zenaida Doves, Zenaida aurita, based on a sample comprising 489 individuals (382 adults and 107 juveniles) typed at 13 microsatellite loci, resulting in a data set comprising 5793 genotypes. In both adults and juveniles, and irrespective of sex, no evidence was found for an effect of either multilocus or single-locus heterozygosity on traits potentially related to fitness such as foraging tactic, competitive ability, and fluctuatin…