The Relationship Between Food Supply, Reproductive Effort and Breeding Success in Arctic Terns Sterna paradisaea

10.2307/4999 ◽  
1989 ◽  
Vol 58 (1) ◽  
pp. 261 ◽  
Author(s):  
P. Monaghan ◽  
J. D. Uttley ◽  
M. D. Burns ◽  
C. Thaine ◽  
J. Blackwood
Keyword(s):  
Breeding Success ◽  
Food Supply ◽  
Reproductive Effort ◽  
Sterna Paradisaea ◽  
The Relationship

Effects of nesting location on breeding success of Arctic terns on Machias Seal Island

1994 ◽  
Vol 72 (10) ◽  
pp. 1841-1847 ◽  
Author(s):  
Judah S. Bunin ◽  
J. Sherman Boates
Keyword(s):  
Habitat Quality ◽  
Breeding Success ◽  
Food Supply ◽  
External Factors ◽  
Success Rates ◽  
Opposite Trend ◽  
Single Colony ◽  
Sterna Paradisaea ◽  
Peripheral Area

Over a period of several years (1978 – 1981), Arctic terns (Sterna paradisaea) nesting in the inland grassy area on Machias Seal Island had higher hatching and fledging success than those in the peripheral bare-bedrock area. In 1990, the opposite trend was recorded. In 1991, we attempted to determine the source(s) of this variation in breeding success between locations. An egg-exchange experiment was carried out between inland and peripheral sites that effectively eliminated differential egg and (or) chick quality as a source of variation. Following this exchange, success rates no longer differed between the habitats involved, despite the fact that chicks tended to be heavier in the peripheral area. The relative influences of parental quality and habitat quality on breeding success were examined as well. The results suggest that complex interrelationships exist among a variety of external factors (such as weather, food supply, and predation pressure), habitat quality, and the quality of birds choosing to nest in these areas. Breeding success in a given area is determined by the particular combination of these factors, a combination that may vary from year to year, colony to colony, and even in different breeding locations within a single colony in a given year.

Antecedents of horizontal logistics collaboration in agri-food supply chains

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ismail Badraoui ◽  
Ivo van der Lans ◽  
Youssef Boulaksil ◽  
Jack G.A.J. van der Vorst
Keyword(s):  
Supply Chains ◽  
Food Supply ◽  
Structural Equation ◽  
The Body ◽  
Equation Modeling ◽  
Content Type ◽  
Operational Conditions ◽  
Food Supply Chains ◽  
The Impact ◽  
The Relationship

PurposeThis study investigates the impact of agri-food supply chains (AFSCs) characteristics on the antecedents of horizontal logistics collaboration (HLC). Specifically, the study compares the relationship between collaboration activities and outcomes for companies in and outside AFSCs.Design/methodology/approachFirst, a survey was used to collect data from different industries. Second, confirmatory factor analysis and structural equation modeling were applied to compare the measurement and structural models from different industry categories.FindingsThe results support the premise that collaboration improves trust and commitment in the relationship, which in turn enhance satisfaction. The results also show the existence of a minor influence of AFSCs characteristics on HLC antecedents, in the form of an indirect impact of dedicated investments on commitment.Practical implicationsThe factors having a significant influence on the collaboration outcomes and their respective effects are generally similar across food and nonfood supply chains, providing opportunities for interdisciplinary and collaboration experiences.Originality/valueThis research contributes to the body of knowledge on interfirm collaboration by considering the specificities of HLC. It also highlights the importance of conducting contingency research on collaborative experiences, as firms from different industry contexts operate under distinct operational conditions.

The relationship between protein nutrition, reproductive effort and breakdown in immunity toTeladorsagia circumcinctain periparturient ewes

2001 ◽  
Vol 72 (3) ◽  
pp. 595-606 ◽  
Author(s):  
J.G. M. Houdijk ◽  
I. Kyriazakis ◽  
F. Jackson ◽  
R. L. Coop
Keyword(s):  
Host Resistance ◽  
Dry Matter ◽  
Reproductive Effort ◽  
Late Pregnancy ◽  
Gastrointestinal Nematodes ◽  
Dry Matter Intake ◽  
Teladorsagia Circumcincta ◽  
Nutrient Partitioning ◽  
Ad Libitum ◽  
The Relationship

AbstractA nutritional hypothesis for the occurrence of the periparturient relaxation of immunity (PPRI) to gastrointestinal nematodes was tested within the bounds of a nutrient partitioning framework. It was hypothesized that at times of a scarce supply of metabolizable protein (MP), an increase in MP supply or a reduction in MP demand (having singles instead of twins) should lower the extent of PPRI in sheep. Twenty-one single- and 21 twin-bearing and -rearing Finn-Dorset ewes, 2 to 7 years old, and repeatedly infected withTeladorsagia circumcincta, were given one of three pelleted foods (no. = 7). The foods were formulated to supply 0·8 (L), 1·0 (M) and 1·2 (H) times the MP requirements during lactation, and were offeredad libitumfrom d–21to d35(d0 is day of parturition). Faecal egg counts (FEC) were assessed twice weekly as an indicator for host resistance. Dry-matter intake (DMI) during late pregnancy was higher than expected, and MP supply did not limit performance at this stage. In accordance with the hypothesis, there were no indications of a breakdown of immunity toT. circumcinctaduring late pregnancy. DMI during lactation did not differ between the single- and twin-rearing ewes. Calculated milk production was lower for the L than for the M and H ewes, especially for the twin-rearing ewes. A temporarily elevated FEC was observed during the first few days in lactation, which was probably mainly due to changes in faecal output rather than to PPRI. The FEC returned to low, late pregnancy levels at d12and remained low for the single- but not for the twin-rearing ewes (P< 0·001). Overall, the L ewes had higher FEC than the M and H ewes from d19onwards; this effect was more pronounced for the twin- than for the single-rearing ewes. It was postulated that DMI achieved overcame MP scarcity and thus prevented breakdown in immunity in the single-rearing ewes. The data support the view that, at times of MP scarcity, an increase in MP supply and reduction in MP demand can lower the extent of the breakdown in immunity towardsT. circumcincta.

The relationship between halal traceability system adoption and environmental factors on halal food supply chain integrity in Malaysia

2019 ◽  
Vol 11 (1) ◽  
pp. 117-142 ◽  
Author(s):  
Norasekin Ab Rashid ◽  
Jamil Bojei
Keyword(s):  
Supply Chain ◽  
Environmental Factors ◽  
Food Supply ◽  
Food Industry ◽  
Food Supply Chain ◽  
Content Type ◽  
Traceability System ◽  
Food And Beverages ◽  
Halal Food ◽  
The Relationship

Purpose Muslim consumers have been shocked with the news of cross-contamination issues in the Halal food that they consumed. These issues make them put more effort in ensuring the products that they purchased being monitored throughout the supply chain. In this case, food companies must be prepared to implement systematic traceability system to ensure the authenticity of Halal products and comprehend the importance of Halal industry environmental factors (HIEF) in enhancing integrity of Halal food supply chain and protect from any risk of cross-contaminations. This paper aims to clarify the relationship between the Halal traceability system adoption (HTSA) and HIEFs on Halal food supply chain integrity (HFSCIn). Design/methodology/approach The study opted quantitative research approach by using the self-administrated questionnaires. The questionnaires were distributed during Malaysia International Halal Showcase (MIHAS) 2014 and Halal Fiesta Malaysia (HALFEST) 2014. 127 Malaysian Halal food and beverages companies have been involved in the study. Most of the respondents are the general manager or owner of the company, Halal executives, quality assurance managers, operation managers and sales manager. Findings The study found that there is a significant relationship between HTSA and HIEF on HFSCIn. The study also found that the highest adoptions of Halal traceability system are among the producer and end user, while the highest contributions in influencing the HIEF are the economic and socio-cultural factors. Research limitations/implications This study only focused on Halal food industry particularly the food and beverages category. Thus, future study can explore further on every category in food industry such as raw materials and ingredients; poultry, meat and dairy; fast food and premises and make comparison between pharmaceutical, cosmetics and health care in Halal industry. In addition, the sample size (N = 127) can be considered small; therefore, it is recommended that in future the subject matter be explored with a much larger sample to allow generalization of the result. Originality/value This study provided, perhaps for the first time, an analysis of the relationship between traceability adoptions and HIEF on HFSCIn.

The reproductive effort of Lepeophtheirus pectoralis (Copepoda: Caligidae): insights into the egg production strategy of parasitic copepods

Parasitology ◽  
2015 ◽  
Vol 143 (1) ◽  
pp. 87-96 ◽  
Author(s):  
D. G. FRADE ◽  
M. J. SANTOS ◽  
F. I. CAVALEIRO
Keyword(s):  
Egg Production ◽  
Egg Size ◽  
Reproductive Effort ◽  
Parasitic Copepods ◽  
Egg Number ◽  
Production Strategy ◽  
European Flounder ◽  
Fish Hosts ◽  
First Time ◽  
The Relationship

SUMMARYThe reproductive effort of Lepeophtheirus pectoralis (Müller O. F., 1776), a caligid copepod, which is commonly found infecting the European flounder, Platichthys flesus (Linnaeus, 1758), is studied in detail for the first time. Seasonal variation in body dimensions and reproductive effort are analysed. Data for 120 ovigerous females, 30 from each season of the year, were considered in the analyses. Females were larger and produced a larger number of smaller eggs in winter, than during the summer. The relationship between egg number and egg size is similar to that recorded for other copepods exploiting fish hosts. Much of the recorded variation was also similar to that reported for a copepod parasitic on an invertebrate host, which suggests the possibility of a general trend in copepod reproduction. Overall, our results provide further support for the hypothesis that there is an alternation of summer and winter generations.

Forced Copulation as a Reproductive Strategy of Male Lesser Scaup: a Field Test of Some Predictions

Behaviour ◽  
1985 ◽  
Vol 92 (1-2) ◽  
pp. 146-167 ◽  
Author(s):  
Alan D. Afton
Keyword(s):  
Reproductive Effort ◽  
Strong Support ◽  
Pair Formation ◽  
Exact Nature ◽  
Natural Conditions ◽  
Annual Variations ◽  
Lesser Scaup ◽  
Forced Copulation ◽  
And Performance ◽  
The Relationship

I presented evidence that sperm transfer can occur during forced copulation (FC) under natural conditions, and tested predictions of the fertilization strategy hypothesis, with field data from a marked population of lesser scaup breeding in southwestern Manitoba. As predicted, males directed FC attempts at fertilizable females and seemingly had tactics that increased their effectiveness in inseminating such females. Males selected older females (the more productive) when attempting FCs in 1 year of the study. FC rates were highest in the morning when chances of successful fertilization were probably highest. FC rates were positively correlated with annual variations in female reproductive effort and performance, but the exact nature of the relationship requires further study. Mate-and nonmate-defense by males and other behaviours which probably function as anticuckoldry tactics were observed. Contrary to BARASH'S (1977a) prediction, paired males attempted FCs more frequently than did unpaired males. Although pair formation through mate-switches is probably a more profitable strategy than FC for unpaired males, FC may be an important "last resort" strategy for older, experienced unpaired males late in the season. In general, my results provided strong support for the male fertilization strategy hypothesis.

scholarly journals Population Studies on the Southern Black-Backed Gull

2021 ◽  
Author(s):  
◽  
Robin Alexander Fordham
Keyword(s):  
Breeding Success ◽  
Food Supply ◽  
Population Studies ◽  
Ecological Studies ◽  
Seasonal Fluctuations ◽  
Age Composition ◽  
Feeding Sites ◽  
Larus Dominicanus ◽  
The Social ◽  
Present Distribution

<p>An account is given of ecological studies on the Southern Black-backed Gull Larus dominicanus Licht in which attention is directed to the structure and balance of the Wellington population. This population is large; in the 1963-64 season more than 5,600 pairs were breeding in the study area, and the peak non-breeding season population in 1964 exceeded 12,000 birds. Its growth has been closely associated with the increase of the human population, and the present distribution and dispersal of gulls is strongly influenced by the distribution of " artificial" feeding sites such as refuse tips and meatworks. The population is composed of breeding colonies, night roosting flocks and daily communal flocks which are inter-related by the social activities and dispersal of the birds. Thus the population is more or less integrated, rather than simply comprising discrete geographic units. Seasonal fluctuations in size and age composition of communal flocks are discussed. Breeding success varies between colonies. It is affected by mammalian predation in some, and by drowning in others, while the largest colonies are comparatively safe for breeding birds. The rapid growth of the whole population in the last five to 10 years appears to have some influence on nesting density, clutch size, spread of laying and overall breeding success. In recent years production of young has been twice that required to maintain the population which has grown at the rate of not less than 7.2% annually. Mortality of banded gulls inside and outside the colony is described and the influence of several factors on chick mortality examined. The principal factor limiting the population appears to be the food supply in relation to the number of birds. When numbers increase and the food supply diminishes, major regulation of the population is apparently achieved in the colony by predation (but not cannibalism) of young by adults. Dispersal of banded gulls from the Wellington colonies is very restricted.</p>

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