Guarding Effort Research Articles

Parental self-feeding effects on parental care levels and time allocation in Palestine sunbirds.

The trade-off between parents feeding themselves and their young is an important life history problem that can be considered in terms of optimal behavioral strategies. Recent studies on birds have tested how parents allocate the food between themselves and their young. Until now the effect of food consumption by parent birds on their food delivery to their young as well as other parental activities has rarely been studied. I have previously shown that parent Palestine sunbirds (Nectarinia osea) will consume nectar and liquidized arthropods from artificial feeders. However, they will only feed their young with whole arthropods. This provided a unique opportunity to experimentally manipulate the food eaten by parents independent of that fed to their offspring. Here, I hypothesized that parents invest in their current young according to the quality of food that they themselves consume. Breeding pairs with two or three nestlings were provided with feeders containing water (control), sucrose solution (0.75 mol) or liquidized mealworms mixed with sucrose solution (0.75 mol). As food quality in feeders increased (from water up to liquidized mealworms mixed with sucrose solution): 1) Parents (especially females) increased their food delivery of whole arthropod prey to their young. 2) Only males increased their nest guarding effort. Nestling food intake and growth rate increased with increasing food quality of parents and decreasing brood size. These results imply that increasing the nutrient content of foods consumed by parent sunbirds allow them to increase the rate at which other foods are delivered to their young and to increase the time spent on other parental care activities.

Beehive fences as effective deterrents for crop-raiding elephants: field trials in northern Kenya

Increasing elephant populations in Kenya since 1989 have been widely praised as a conservation success story. However, where elephants and agricultural land overlap, incidents of human‐elephant conflict are on the increase. Wildlife managers and farmers are now trying different farm-based deterrents to keep elephants out of crops. Here, we present data on the effectiveness of a novel beehive fence deployed in a Turkana community of 62 communally run farms in Kenya. Specifically, 1700 m of beehive fences semi-surrounded the outer boundaries of seventeen farms, and we compared elephant farm invasion events with these and to seventeen neighbouring farms whose boundaries were ‘protected’ only by thorn bush barriers. We present data from 45 farm invasions, or attempted invasions, recorded over 2 years. Thirteen groups of elephants approached the beehive fences and turned away. Of the 32 successful farm invasions, only one bull elephant broke through the beehive fences. These results demonstrate that beehive fences are more effective than thorn bush barriers at deterring elephants and may have a role to play in alleviating farmer‐elephant conflict. Additionally, the harvesting of 106 kg of honey during the trial period suggests that beehive fences may also improve crop production and enhance rural livelihoods through honey sales.

Mary Versus Eve: Paternal Uncertainty and the Christian View of Women

The Virgin Mary and Eve constitute two opposite sexual poles in the way Christian discourse has approached women since the time of the church fathers. This stems from a predicament faced by the human male throughout hominid evolution, namely, paternal uncertainty. Because the male is potentially always at risk of unwittingly raising the offspring of another male, two (often complementary) male sexual strategies have evolved to counter this genetic threat: mate guarding and promiscuity. The Virgin Mary is the mythological expression of the mate guarding strategy. Mary is an eternal virgin, symbolically allaying all fear of paternal uncertainty. Mary makes it possible for the male psyche to have its reproductive cake and eat it too: she gives birth (so reproduction takes place) and yet requires no mate guarding effort or jealousy. Eve, the inventor of female sexuality, is repeatedly viewed by the church fathers, e.g., Augustine and Origen, as Mary’s opposite. Thus, Eve becomes the embodiment of the whore: both attractive in the context of the promiscuity strategy and repulsive in terms of paternal uncertainty: “Death by Eve, life by Mary” (St. Jerome). The Mary-Eve dichotomy has given a conceptual basis to what is known in psychology as the Madonna-Whore Dichotomy: the tendency to categorize women in terms of two polar opposites. This paper will explore the way mythology reflects biology, i.e., human psychological traits that have evolved over millennia.

Perceptions of partner femininity predict individual differences in men's sensitivity to facial cues of male dominance

Recent research suggests that men may possess adaptations that evolved to counter strategic variation in women's preferences for masculine men. For example, women's preferences for masculine, dominant men are stronger during the fertile phase of the menstrual cycle than at other times and men demonstrate increased sensitivity to facial cues of male dominance when their partners are ovulating. Such variation in men's dominance perceptions may promote effi- cient allocation of men's mate guarding effort (i.e., allocate more mate guarding effort in response to masculine, dominant men in situations where women show particularly strong preferences for such men). Here, we tested for further evidence of adaptations that may have evolved to counter strategic variation in women's masculinity preferences. Men who reported having particularly feminine romantic partners demonstrated a greater tendency to attribute dominance to masculin- ized male faces than did men who reported having relatively masculine romantic partners. This relationship between partner femininity and men's sensitivity to facial cues of male dominance remained significant when we controlled for potential confounds (men's age, self-rated masculin- ity, reported commitment to their relationship, and the length of the relationship) and may be adaptive given that feminine women demonstrate particularly strong preferences for masculine, dominant men. While previous research has emphasized variation in women's masculinity prefer- ences, our findings add to a growing body of research suggesting that sexual selection may also have shaped adaptations that evolved to counter such systematic variation in women's preferences for masculine, dominant men.

Is female promiscuity constrained by the presence of her social mate? An experiment with bluethroats Luscinia svecica

Extra-pair paternity is common in birds and much research has focussed on the selective advantage of extra-pair matings for both sexes. In contrast, little attention has been given to the fact that in most species the majority of offspring are sired by the social male. We investigated whether extra-pair matings of female bluethroats (Luscinia svecica) are constrained by the presence of the pair male, by detaining males in cages on their territories for one morning during the peak of female fertility. The proportion of offspring sired by extra-pair males was higher in broods where males had been detained (35%) than in control broods (16%), while the proportion of broods that had at least one extra-pair offspring did not differ significantly between experimental (65%) and control broods (44%). Within the experimental group, levels of extra-pair paternity were not related to the day of experiment in relation to start of egg laying, but males caught early in the morning lost more paternity than males caught later on. Our results show that pair males exert constraints on the frequency of extra-pair paternity by being present during the period of peak fertility, which could be a direct effect of their mate guarding effort and/or due to an advantage in sperm competition for pair males.

Factors affecting susceptibility of farms to crop raiding by African elephants: using a predictive model to mitigate conflict

Summary Crop raiding by African elephants Loxodonta africana erodes local tolerance for elephants and thereby impedes conservation efforts, so solutions are urgently required. Within conflict zones, crop raiding is not distributed equally amongst farms, which may be a result of variation in local physical or geographical factors, or in farmers’ efforts to defend their fields. Understanding the efficacy of local conflict mitigation methods is important, but few quantitative evaluations exist. Using a comparative survey of raided and non‐raided farms in Transmara District, Kenya, and multivariate logistic and linear regression analyses, we explored a range of factors affecting (i) the susceptibility of farms to elephant crop raiding and (ii) the amount of crop damage once elephants had entered a field. The results revealed that farms that had been habitually raided in the past were more likely to be raided during the study period, as were those that were larger and bordered by hedges or fences. Greater guarding effort increased the likelihood that elephants were detected prior to entry and decreased the likelihood of successful crop raiding, as did the use of fire and noise. However, there was an interaction between physical and human factors; larger farms used more advanced barrier methods at the expense of guarding effort. Farmers’ efforts did not appear to diminish the damage inflicted once elephants had entered a field. A subsequent experimental test confirmed these results; the application of enhanced early warning and guarding effort on previously raided farms reduced incidents of crop raiding by 89·6% over 2 years in comparison with a control group of farms. Synthesis and applications. These results suggest that early detection of elephants approaching fields, increased guarding effort, and the use of active deterrents could form the basis of an effective mitigation strategy regardless of location and the physical attributes of a farm. Validating the results of predictive models through participatory mitigation trials serves to demonstrate effective solutions to farmers themselves. Researchers and practitioners should be encouraged to replicate such field trials over broader spatial and temporal scales and to find means to encourage farmers to take up appropriate solutions.

AIS and Long Range Identification & Tracking

This paper describes the United States Coast Guard's efforts regarding Long Range Identification & Tracking (LRIT) of ships. Among those elements included in the LRIT plan, automatic identification systems (AIS), typically envisioned as a short-range system, may also play a long-range role. AIS vessel tracking may be accomplished through high elevation shore sites allowing reception of AIS signals to nominally 24 nm that loosely puts it in the category of a short-range sensor. Additionally, the US Coast Guard is conducting research and development efforts to determine the feasibility of using AIS receive capability on low earth orbit (LEO) satellites and high altitude, long endurance (HALE) airships or balloons. In parallel with the developing technical capabilities, the US approach with the International Maritime Organization (IMO), and domestic legislation and regulations are also addressed. Finally, a vision for the implementation of LRIT is offered. The paper was presented on 9 November 2004 at Church House, London during the Institute's NAV 04 Conference.

Part‐Time Mate Guarding Affects Paternity in Male Reed Buntings (Emberiza schoeniclus)

AbstractMale mate guarding by close following has been reported in many socially monogamous bird species and is generally believed to function as a paternity guard. Many aspects of the dynamics and effectiveness of this behavior are still however poorly understood. Here, we describe the temporal variation in mate guarding behavior in male reed buntings (Emberiza schoeniclus) with a particular focus on how males allocate their mating effort between mate guarding and extrapair mating in a context of intense sperm competition. In our highly synchronous study population most males have to balance the simultaneous and mutually exclusive demands of mate guarding and seeking extrapair copulations (EPCs). We found that males frequently switched between guarding their mates and performing intrusions to neighboring territories. Both activities seemed to have significant fitness payoffs, as male mate guarding effort had a positive effect on paternity, and a large fraction of extrapair fertilizations occurred during the days when the sire guarded its own female. The reed bunting is thus an example of how discontinuous or part‐time mate guarding can still be effective in securing paternity. Female reed buntings were not particularly active in initiating EPCs as they never were observed performing extraterritorial forays. We argue that the absence of female‐initiated EPCs is a prerequisite for males to trade mate guarding against seeking EPCs. Otherwise, if females circumvent male mate guarding by timing their EPCs to periods of male absence, males should guard their mates almost continuously or rely on alternative paternity guards.

A Network-Centric Approach to Maritime Domain Awareness

The Integrated Deepwater System's C4ISR (command, control, communications, computers, intelligence, reconnaissance, and surveillance) system is a critical element in the U.S. Coast Guard's efforts to modernize its aging force structure and implement its maritime strategy for homeland security. >> Conceived during the 1990s, the fully implemented Deepwater program will consist of three classes of new cutters and their associated small boats, a new and upgraded fixed-wing manned aircraft fleet, a combination of new and upgraded helicopters, both cutter-based and land-based unmanned aerial vehicles (UAVs), and highly improved systems for C4ISR and advanced logistics capabilities. Integrated Coast Guard Systems (ICGS, a joint venture between Lockheed Martin and Northrop Grumman) is Deepwater's partner in industry and systems integrator. >> Deepwater's C4ISR capability improvements will contribute to higher levels of maritime domain awareness (comprehensive information, intelligence, and knowledge of all relevant entities within the U.S. maritime domain, and their respective activities, that could affect U.S. security, safety, economy, or environment). The Integrated Deepwater System (IDS) will play an important role in transforming the Coast Guard to meet the nation's 21st-century maritime-security requirements

Development of risk-based ranking measures of effectiveness for the United States Coast Guard's vessel inspection program

This paper describes the results of an analysis of the effectiveness of the U.S. Coast Guard's efforts to promote the safety of life and property at sea through its program to inspect large, ocean-going vessels. The effectiveness of specific U.S. Coast Guard vessel inspection activities was evaluated using risk-based metrics that linked categories of root causes of accidents to the particular inspection activities designed to reduce the risk of each root cause category. The results demonstrate a risk-based ranking of USCG inspection activities. These metrics, describes as measures of effectiveness (MOEs), yield insights regarding the most beneficial areas in which to concentrate inspection resources. Insights regarding quality of vessel casualty investigation data and database design as related to risk-based importance analysis are also discussed. The MOEs constructed in this study are specific to the USCG's Marine Inspection and Boarding Program, but the methodology of the study is based on sound theoretical principles that are probably applicable to a range of maritime safety activities. Hence the methodology applies equally to other important governmental regulatory programs and can be similarly used to measure their effectiveness and as an aid to decision-making.

Development of Risk‐Based Ranking Measures of Effectiveness for the United States Coast Guard's Vessel Inspection Program

This paper describes the results of an analysis of the effectiveness of the U.S. Coast Guard's efforts to promote the safety of life and property at sea through its program to inspect large, ocean‐going vessels. The effectiveness of specific U.S. Coast Guard vessel inspection activities was evaluated using risk‐based metrics that linked categories of root causes of accidents to the particular inspection activities designed to reduce the risk of each root cause category. The results demonstrate a risk‐based ranking of USCG inspection activities. These metrics, describes as measures of effectiveness (MOEs), yield insights regarding the most beneficial areas in which to concentrate inspection resources. Insights regarding quality of vessel casualty investigation data and database design as related to risk‐based importance analysis are also discussed. The MOEs constructed in this study are specific to the USCG's Marine Inspection and Boarding Program, but the methodology of the study is based on sound theoretical principles that are probably applicable to a range of maritime safety activities. Hence the methodology applies equally to other important governmental regulatory programs and can be similarly used to measure their effectiveness and as an aid to decision‐making.

Male parental care in the orange-tufted sunbird: behavioural adjustments in provisioning and nest guarding effort

Monogamy is thought to be prevalent in bird species because of the role of male parental care. Evolutionarily stable strategies for biparental cooperation provide a behavioural mechanism for the maintenance of monogamous relationships, under which any shortfall in one parent's work rate is predicted to be partially compensated for by its partner. Both parents should invest more effort when there are more young. These predictions were tested simultaneously using tail-weights to reduce the visit rates of female members of pairs of orange-tufted sunbirds, Nectarinia osea, feeding broods of two or three chicks. Prior to the manipulation and in unmanipulated control pairs, females provisioned at a greater rate, removed proportionally more faecal sacs and spent longer at the nest, whilst males showed greater nest guarding effort. As predicted by game theory, males with tail-weighted females compensated incompletely for their partners' lower provisioning rate. Males failed to nest guard when provisioning at high rates, implying an important trade-off for biparental cooperation. Larger broods were fed at a greater rate by both parents. Visit rates per chick decreased in experimental nests and in larger broods, and this was reflected in lower chick growth rates. Greater chick growth rates per visit in control nests and larger broods suggest that they received superior load sizes and/or quality of prey. These results concur with previous studies of parental responses to partner effort, and further reveal the behavioural flexibility in provisioning and nest guarding strategies in a species with predominantly female care.

The Conflict between Nest Guarding and Mate Guarding in Penduline Tits (Remiz pendulinus)

AbstractIn penduline tits (Remiz pendulinus), polygynous males build several very elaborate nests successively during one breeding season to attract females. The time and effort invested in nest building is positively related to their mating success. Intraspecific competition for nest material resulting in nest material theft, delays males' nest building progress which in turn decreases their mating success. Therefore, a nest guarding strategy was predicted. In many bird species, males develop some kind of paternity strategy during the female fertile phase. However, as nest building and the female fertile phase frequently coincide, one would expect a trade‐off between these strategies. In this study we determined in particular how nest guarding in males conflicts with their mate guarding behaviour in penduline tits.Our results show that nest building is costly in terms of a male's time budget. Thieves benefit by increasing their rate of acquiring nest material which reduces the effort invested in nest building. Nest guarding is an efficient strategy to avoid thieves, as indicated by the negative relation between the presence of the male near the nest and the frequency of nest material theft. Nest guarding is required for the whole building period but males, however, increased their mate guarding effort during the peak fertile phase to ensure their paternity. The data suggest that, for the trade‐off “mate guarding versus nest guarding”, paternity insurance seems to be more important.

Coast Guard Requirements for Marine Vapor Control Systems

The paper describes the U.S. Coast Guard's efforts to establish regulations for marine vapor control systems that will maintain the safe operation of tankships, tank barges, and waterfront facilities when the more stringent air-quality standards are implemented by the Environmental Protection Agency. The reasons for the new standards are given. Marine vapor control systems are described, along with their attendant hazards. The development and nature of the Coast Guard's regulations are described and, finally, international efforts in the area are briefly reviewed.