scholarly journals Adult insect personality in the wild— Calopteryx splendens as a model for field studies

2021 ◽  
Author(s):  
Maria J. Golab ◽  
Szymon Sniegula ◽  
Andrzej Antoł ◽  
Tomas Brodin
Keyword(s):  
Field Studies ◽  
Adult Insect ◽  
In The Wild ◽  
Calopteryx Splendens

scholarly journals Adult insect personality in the wild -- Calopteryx splendens as a model for field studies

2021 ◽  
Author(s):  
Maria Gołąb ◽  
Szymon Sniegula ◽  
Andrzej Antoł ◽  
Tomas Brodin
Keyword(s):  
Field Studies ◽  
Ecological Research ◽  
Model Species ◽  
Personality Differences ◽  
The Past ◽  
Adult Insect ◽  
In The Wild ◽  
First Time ◽  
Calopteryx Splendens ◽  
Trait Correlation

Animal personality has received increasing interest and acknowledgement within ecological research over the past two decades. However, some areas are still poorly studied and need to be developed. For instance, field studies focused on invertebrates are currently highly underrepresented in the literature. More studies including a wider variety of traits measured and species tested is needed to improve our understanding of trait-correlation patterns and generalities. We studied nine behavioural traits, in the damselfly Calopteryx splendens, from an array of three experiments: (i) courtship, (ii) aggressiveness and (iii) boldness, and calculated their repeatability. The behaviours were measured twice, in two different contexts: (i) undisturbed territory and (ii) partially deteriorated territory. All behavioural traits measured, except for two, were repeatable across the two contexts. This work demonstrates, for the first time, the presence of within population personality differences in an adult damselfly in the wild. We further propose Calopteryx splendens as a promising model species for testing personality in the wild under highly controlled environmental conditions.

Into the wild: developing field tests to examine the link between elasmobranch personality and laterality

Behaviour ◽  
2016 ◽  
Vol 153 (13-14) ◽  
pp. 1777-1793 ◽  
Author(s):  
Evan E. Byrnes ◽  
Catarina Vila Pouca ◽  
Sherrie L. Chambers ◽  
Culum Brown
Keyword(s):  
Personality Traits ◽  
Field Tests ◽  
Animal Personality ◽  
Field Studies ◽  
Individual Level ◽  
In The Wild ◽  
Port Jackson ◽  
The Relationship

The field of animal personality has received considerable attention in past decades, yet few studies have examined personality in the wild. This study investigated docility, a measure of boldness, in two Port Jackson shark (Heterodontus portusjacksoni) populations using field tests, and if laterality differences explained docility levels. We developed a struggle test as an assay for docility, which is particularly amenable to field studies. The struggle test was effective, and repeatable inter-individual docility differences were observed. Sex, but not population, influenced docility scores, with male sharks being less docile than females. This difference is likely due to the contrasting role each sex plays during mating. We also found individualized lateralization. However, no individual-level relationship between lateralization and docility was detected. Despite reported links between laterality and some personality traits, the relationship between laterality and boldness remains inconclusive in sharks. Further studies will prove essential to clarify the mechanisms behind personality traits in vertebrates.

scholarly journals The effect of male-male competition and ornament size on mean and variance of courtship intensity towards heterospecific and conspecific females

2015 ◽  
Vol 65 (2) ◽  
pp. 113-131
Author(s):  
Inka Keränen ◽  
Aapo Kahilainen ◽  
Janne S. Kotiaho ◽  
Katja Kuitunen
Keyword(s):  
Reproductive Investment ◽  
Search Costs ◽  
Competitive Environment ◽  
Species Discrimination ◽  
Sexual Ornaments ◽  
Courtship Intensity ◽  
In The Wild ◽  
Mean And Variance ◽  
Calopteryx Splendens

Discrimination between hetero- and conspecifics is the elementary choice an individual performs when searching for potential mates. The level of selectivity and strength of species discrimination is modified by variance in the quality of females, level of the male’s reproductive investment, mate search costs, and the competitive environment. The effect of the competitive environment on both species discrimination and conspecific mate choice has seldom been studied simultaneously. We experimentally manipulated territorial competition ofCalopteryx splendensdamselfly males in the wild, and asked two questions. First, does increased competition influence the territorial males’ responses towards introduced heterospecificC. virgofemales. The effect of the size of the territorial males’ sexual ornaments (wing spot) on their responses towards females was also investigated. Second, does increased competition influence the territorial males’ response towards conspecific females? The effect of the size of the territorial males ornament was again investigated. The mean level of response towards heterospecific females did not change between the control (i.e., no competitors presented) and the competition (i.e., two competitors presented) treatments, but the variance of responses towards heterospecifics was greater in the competition treatment. The territorial males’ responses towards conspecific females did not change between control and competition treatments. These results indicate individual differences in the behavior of males towards heterospecifics when territorial competition was experienced. The observed pattern of discrimination might be adaptive when overall reproductive success is considered.

scholarly journals How tall is an elephant? Two methods for estimating elephant height

Web Ecology ◽  
2007 ◽  
Vol 7 (1) ◽  
pp. 1-10 ◽  
Author(s):  
F. Della Rocca
Keyword(s):  
Field Studies ◽  
Height Distribution ◽  
African Elephants ◽  
Linear Distance ◽  
Elephant Population ◽  
Photo Camera ◽  
In The Wild ◽  
Absolute Height ◽  
Free Ranging ◽  
Geometric Formula

Abstract. Shoulder height is a reliable indicator of age for African elephants (Loxodonta africana), and is therefore an important parameter to be recorded in field studies of population ecology of these pachyderms. However, it can be somewhat difficult to estimate with precision the shoulder height of free-ranging elephants because of several reasons, including the presence of drops and vegetation cover and the potential dangerousness of approaching them in the wild. Here I test two alternative models for estimating shoulder height of elephants. In both models, the equipment needed to generate the height estimates is minimal, and include a telemeter and a digital photo-camera furnished with an ×16 zoom. The models are based respectively on a linear regression approach and on a geometric formula approach, and put into a relationship the linear distance between the observer and the animal, the number of pixels of an elephant silhouette as taken from digital photos, and the absolute height of the animal. Both methods proved to have a very small measurement error, and were thus reliable for field estimates of elephant shoulder heights. The model based on a geometric formula was used to estimate the shoulder height distribution of an elephant population in a savannah region of West Africa (Zakouma National Park, Chad). I demonstrated that Zakouma elephants were among the tallest populations in Africa, with growth rates being highest throughout the first five years of life.

A songbird adjusts its heart rate and body temperature in response to season and fluctuating daily conditions

2021 ◽  
Vol 376 (1830) ◽  
pp. 20200213 ◽  
Author(s):  
Nils Linek ◽  
Tamara Volkmer ◽  
J. Ryan Shipley ◽  
Cornelia W. Twining ◽  
Daniel Zúñiga ◽  
...  
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Environmental Conditions ◽  
Field Studies ◽  
Weather Extremes ◽  
Ambient Temperatures ◽  
In The Wild ◽  
Radio Transmitters ◽  
Save Energy ◽  
Free Ranging

In a seasonal world, organisms are continuously adjusting physiological processes relative to local environmental conditions. Owing to their limited heat and fat storage capacities, small animals, such as songbirds, must rapidly modulate their metabolism in response to weather extremes and changing seasons to ensure survival. As a consequence of previous technical limitations, most of our existing knowledge about how animals respond to changing environmental conditions comes from laboratory studies or field studies over short temporal scales. Here, we expanded beyond previous studies by outfitting 71 free-ranging Eurasian blackbirds ( Turdus merula ) with novel heart rate and body temperature loggers coupled with radio transmitters, and followed individuals in the wild from autumn to spring. Across seasons, blackbirds thermoconformed at night, i.e. their body temperature decreased with decreasing ambient temperature, but not so during daytime. By contrast, during all seasons blackbirds increased their heart rate when ambient temperatures became colder. However, the temperature setpoint at which heart rate was increased differed between seasons and between day and night. In our study, blackbirds showed an overall seasonal reduction in mean heart rate of 108 beats min −1 (21%) as well as a 1.2°C decrease in nighttime body temperature. Episodes of hypometabolism during cold periods likely allow the birds to save energy and, thus, help offset the increased energetic costs during the winter when also confronted with lower resource availability. Our data highlight that, similar to larger non-hibernating mammals and birds, small passerine birds such as Eurasian blackbirds not only adjust their heart rate and body temperature on daily timescales, but also exhibit pronounced seasonal changes in both that are modulated by local environmental conditions such as temperature. This article is part of the theme issue ‘Measuring physiology in free-living animals (Part I)’.

The effect of feeding levels on the fecundity of plaice (Pleuronectes platessa)

1989 ◽  
Vol 69 (1) ◽  
pp. 81-92 ◽  
Author(s):  
J. W. Horwood ◽  
M. Greer Walker ◽  
P. Witthames
Keyword(s):  
Body Weight ◽  
Gonad Development ◽  
Field Studies ◽  
Practical Significance ◽  
Food Level ◽  
In The Wild ◽  
Early Decision ◽  
Mature Fish ◽  
Different Levels ◽  
Effect Of Feeding

Previous field studies have recorded yearly variations in fecundity of 40–60% in similar sized plaice, and an experiment was conducted to investigate whether these changes could be generated, in the laboratory, by feeding plaice different levels of ration. One group of plaice was fed at a rate of about 2–2.3% of wet body weight per day, and a second group was fed initially 0.5% and later 1.8% per day. The experiment lasted for a period of 406 days.Of those fed on the lower ration, 39% produced no granular oocytes, whereas all fish on the higher ration produced granular oocytes. A comparison between the two groups, of those which did produce granular oocytes, found that the better-fed fish had 59% more granular oocytes, but the differences were less pronounced for the smaller, mature fish. Numbers of resting oocytes are also recorded.The results suggest that food level can significantly affect fecundity, and also revealed a new mechanism for regulation of fecundity in the plaice. The lack of granular oocytes was not due to atresia, but to an early decision not to proceed with gonad development; whether this is of practical significance for the population of plaice in the wild is not yet established.

Demographic and life cycle characteristics of montane deer mice

1983 ◽  
Vol 61 (3) ◽  
pp. 574-585 ◽  
Author(s):  
John S. Millar ◽  
Duncan G. L. Innes
Keyword(s):  
Life Cycle ◽  
Food Consumption ◽  
Field Studies ◽  
Demographic Characteristics ◽  
Deer Mice ◽  
Adult Size ◽  
Laboratory Studies ◽  
Nestling Growth ◽  
In The Wild ◽  
Nestling Survival

Demographic and life cycle characteristics of Peromyscus maniculatus borealis were documented in the wild and in the laboratory. Field studies in the Kananaskis Valley, Alberta, indicated that no mice matured in the summer of their birth, overwintered females produced a maximum of 3 litters each season (average, 1.9), nestling survival was variable (0 to 100%), summer survival of weaned young (average, 0.81/2 weeks) was similar to that of summer adults (average, 0.80/2 weeks), dispersal rates were low, and winter survival (average, 0.98/semimonthly period) was relatively high. These demographic characteristics are similar to those of other populations in which opportunities for reproduction are limited. Laboratory studies indicated that basic life cycle characteristics such as adult size (20.3 g), litter size (5.2), neonate weights (1.70 g), nestling growth rates (0.34 g/day), age at weaning (24.9 days), weight at weaning (9.9 g), and food consumption during lactation (220% of nonbreeding consumption) were not all the same as previously reported for northern P. m. borealis or other Peromyscus. These differences may be related to specific aspects of the annual cycle.

scholarly journals Survey of some plants utilized as feed by the Grasscutter (Thryonomys swinderianus Temminck) at Akpaka Forest Reserve, Onitsha, Nigeria.

2021 ◽  
Vol 34 (2) ◽  
pp. 258-264
Author(s):  
C.I. Ebenebe
Keyword(s):  
Field Studies ◽  
Plant Materials ◽  
Forest Reserve ◽  
Anambra State ◽  
Nitrogen Free Extract ◽  
The Family ◽  
North Eastern ◽  
In The Wild ◽  
High Level ◽  
Proximate And Mineral Composition

Field studies were conducted for 10 months (September 2001 to June 2002) to identify plans consumed by grasscutters in the wild ar the Akpaka Forest reserve located at Latitude 6o 09'N and longitude 69o 47'E North eastern of Onitsha, in Onitsha North Local Government Area of Anambra State. Twenty-two plant species were observed to be utilized as feed by the grasscutter at Akpaka forest reserve. Of these Twenty-two plants, fourteen were grasses of the family gramineae, Three were tuber crops, four were fruits and only one - Chromoleana odorata was a shrub (weed). Nine of these plants were not documented by earlier authors. Ten of these plants were chosen and analyzed for both proximate and mineral composition based on their food value, high level of utilization by grasscutters and their abundance. The results showed that these plant materials were low in crude protein, high in fibre, moisture and nitrogen free extract and also low in all the minerals and therefore may not satisfy the nutritional requirements of the animals for improved productivity This paper therefore recommend inclusion of concentrate, vitamins and minerals in the diet of grasscutters.

scholarly journals A stable pollination environment limits current but not potential evolution of floral traits

2019 ◽  
Author(s):  
Maria Clara Castellanos ◽  
Javier Montero-Pau ◽  
Peio Ziarsolo ◽  
Jose Miguel Blanca ◽  
Joaquin Cañizares ◽  
...  
Keyword(s):  
Field Studies ◽  
Floral Traits ◽  
Stabilizing Selection ◽  
Heritable Variation ◽  
Genome Wide ◽  
Stable Conditions ◽  
In The Wild ◽  
High Heritability ◽  
Vast Variation ◽  
Pollination Environment

AbstractPlants’ vast variation in floral traits at a macroevolutionary level is often interpreted as the result of adaptation to pollinators. However, field studies often find no evidence of pollinator-mediated selection on flowers. This could be explained by periods of stasis, when selection is relaxed under stable conditions, followed by pollinator changes that provide innovative selection. We asked if periods of stasis are caused by stabilizing or absence of other forms of selection on floral traits, or by low trait heritability even if selection is present. We studied Ulex parviflorus, a plant predominantly pollinated by one bee species across its range. We measured heritability and evolvability of floral traits, using genome-wide molecular relatedness in a wild population, and combined this with estimates of selection. We found evidence for both stabilizing selection and low trait heritability as explanations for stasis in flowers. The area of the standard petal is under stabilizing selection, but the variability observed in the wild is not heritable. A separate trait, floral size, in turn presents high heritability, but is not currently under selection. We show how a stable pollination environment can lead to a lack of evolutionary change, yet maintain heritable variation to respond to future selection pressures.

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