Homing Range Research Articles

Age-related variation of homing range in honeybee males (Apis mellifera)

Age-related variation of homing range in honeybee males (Apis mellifera)

Determination of the Homing Range of Cerceris fumipennis (Hymenoptera: Crabonidae)

Cerceris fumipennis (Hymenoptera, Crabronidae) is a ground-dwelling wasp species that provisions its nests with wood-boring jewel beetles (Buprestidae), making it a useful tool for biosurveillance of buprestid forest pests, particularly the Emerald Ash Borer (Agrilus planipennis). The maximum foraging range of C. fumipennis has not yet been determined, but there have been limited studies on how far these wasps may fly when released from measured distances – an indication of their potential homing range. Careless (2008) determined the maximum homing range to be 2 km and hypothesized that the foraging range was limited to this distance. This study was coarsely-grained in that the wasps were released only at 1 km increments up to 3 km. Our study is finer-grained due to the release of wasps at intermediate distances within 3 km from the nesting area. Over 50% of the individuals released from 2.5 km and 3 km returned, indicating that the homing range of C. fumipennis is larger than previously estimated. The implications of this larger homing range and its effects on current predictions of foraging range are discussed.

Temporal variation in homing ability of the neotropical stingless bee Scaptotrigona aff. postica (Hymenoptera: Apidae: Meliponini)

Body size is a known predictor of foraging distance in stingless bees (Apidae: Meliponini). However, effects of seasonality on foraging distances, particularly in tropical regions, are poorly understood. Here, we use translocation (‘homing’) experiments, the release of marked individuals at various distances from the nest, to investigate how homing abilities of the Neotropical stingless bee, Scaptotrigona aff. postica differ across the transition between wet and dry seasons (February–August) in a heterogenous tropical landscape in the eastern Brazilian Amazon. We also determined nectar sugar concentrations of unmanipulated returning foragers to assess temporal changes in collected resource quality. Maximum and typical homing distances (i.e. distances where 90% and 50% of released bees are lost) were estimated to be 860 and 392 m, respectively, confirming that while some individuals travel long distances, most workers must remain close to nests during foraging trips. Homing distances and collected nectar sugar concentrations showed inverse temporal patterns, as homing range declined in later months (May to August), whereas nectar sugar concentrations increased over the same period. Thus, shorter homing distances in later ‘dry season’ months probably reflected an increased availability of floral resources compared with earlier months. Together, our findings highlight the limited spatial extent of foraging activities in S. aff. postica workers, and that bee homing distances vary with environmental conditions. These results provide useful information for both stingless bee colony management and conservation in humid tropical regions.

Homing and home range of the European spiny lobster, Palinurus elephas (Decapoda, Palinuridae) acoustically tracked

Abstract A specific study has been carried out for the first time to investigate the homing capability and daily home range of the spiny lobster Palinurus elephas by means of ultrasonic telemetry. Nine lobsters collected in the Capo Gallo — Isola delle Femmine marine protected area (northwestern Sicily, central Mediterranean) were tagged with miniaturized transmitters and released at a single site inside the protected area. The lobsters were monitored with the purpose of calculating their horizontal and vertical positions, analysing their movement patterns to assess their homing capability, and calculating their daily home range. Five lobsters moved back close to the capture sites within the first 20 hours after release (‘homed’). The remaining four lobsters ‘relocated’ to a different refuge. Homed lobsters had a larger home range than relocated lobsters. This study provides the first description of a homing pattern with high spatial resolution in the wild European spiny lobster as inferred by ultrasonic telemetry.

Concept and testing of an electromagnetic homing guidance system for autonomous underwater vehicles

An effective homing guidance system with precise vehicle dynamic attitude control capability is essential for reliable docking of Autonomous Underwater Vehicles (AUV). The paper describes the bio-inspired concept and electromagnetic finite element analysis-aided design and testing of an electromagnetic homing guidance system (EMHGS) comprising of an underwater dock with 400AT of electromagnetic dipole coil excited with the 20 Hz power supply; a twin-thruster AUV equipped with a differential magnetometer system, and operable in two degrees of freedom (DOF). The vehicle hydrodynamic behavior is characterized in 2 DOFs based on the thruster action and vehicle response method, and used for the control and homing guidance of the AUV. By sensing a magnetic field strength of 190nT, the EMHGS is found to have an effective range of 7 m, and capable of effecting AUV orientation correction by measuring the bearing angle. The FEA is found to comply with the experimental observations with an accuracy of 96% is extended for higher dock magnetic field strengths, and found that an EMHGS utilizing 6000AT dock coil and magnetic field sensors of same sensitivity could have a homing guidance range of 72 m. Based on a priori magnetic map, the system is capable of computing the vehicle range and velocity, serving critical inputs for realizing effective AUV short range homing and docking.

Flight range of the Australian stingless bee Tetragonula carbonaria (Hymenoptera: Apidae)

Bees are key pollinators in both natural and agricultural environments throughout the world. Estimates of the typical distance from their nest that bees will fly to forage are useful when planning their deployment in commercial pollination or ecosystem management. Stingless bees (Meliponini) are social bees that live in colonies comprising a queen and many workers. They pollinate several key tropical crops and can be housed and transported in hives. Thus, there is increasing interest in their use as managed pollinators in regions where they occur naturally, including Australia. Here, we use a mark and release method to estimate the homing range of the most commonly propagated species of Australian stingless bee, Tetragonula carbonaria (Smith), where homing range serves as a proxy for foraging flight range. We find the typical and maximum homing range of T. carbonaria to be 333 and 712 m, respectively. This range is less than that of the most commonly used commercial pollinator, the honey bee Apis mellifera Linnaeus, which we argue confers both advantages and disadvantages on T. carbonaria as an alternative crop pollinator.

Evidence of forage distance limitations for small bees (Hymenoptera: Apidae)

The distribution of ground-nesting bees was investigated using transects of water traps in a mosaic of nesting and forage habitats at Shotover Hill in Oxfordshire, UK. The site includes a large area of ground-nesting bee activity and is adjoined on three sides by floristic hay meadows. This study showed that the females of small bee species (< 1.5 mm intertegular span) that were foraging in the hay meadows demonstrated a functional limitation to their homing range. The abundance of small bees declined rapidly with increasing distance from areas of high density nesting; declining more rapidly than might be expected from uniform dispersal into the surrounding landscape. By modelling the occurrence of bees along each transect it was found that the probability of observing a small bee in the hay meadows was reduced to 10% at a distance of 250-370 m from the nesting habitat. The result emphasises the scale on which habitat fragmentation will begin to impact upon bee diversity, and the relative contribution of managed pollen and nectar strips to areas of nesting habitat.

Evasion Strategies in Decoy Assisted Engagements

Abstract In this paper, the strategies of an evader against a purser in a planar engagement scenario is considered. The evader uses a decoy to lure the hostile pursuer away from its course, together with an evasive maneuver to evade the pursuer. The decisive factors in enhancing the survivability of the evader are the decoy launch time, the decoy launch direction and the evader maneuvers. Limitations on turn rates, fields of views and homing range are used in the mathematical models. Two different evader maneuvers are proposed. Simulation studies are carried out for different decoy launch angles and launch time for each of the strategies. The resulting launch envelope without the evasive maneuver and with the proposed evasive maneuvers are compared.

Mapping the navigational knowledge of individually foraging ants,Myrmecia croslandi

Ants are efficient navigators, guided by path integration and visual landmarks. Path integration is the primary strategy in landmark-poor habitats, but landmarks are readily used when available. The landmark panorama provides reliable information about heading direction, routes and specific location. Visual memories for guidance are often acquired along routes or near to significant places. Over what area can such locally acquired memories provide information for reaching a place? This question is unusually approachable in the solitary foraging Australian jack jumper ant, since individual foragers typically travel to one or two nest-specific foraging trees. We find that within 10 m from the nest, ants both with and without home vector information available from path integration return directly to the nest from all compass directions, after briefly scanning the panorama. By reconstructing panoramic views within the successful homing range, we show that in the open woodland habitat of these ants, snapshot memories acquired close to the nest provide sufficient navigational information to determine nest-directed heading direction over a surprisingly large area, including areas that animals may have not visited previously.

Fine-scale population differentiation and gene flow in a terrestrial salamander (Plethodon cinereus) living in continuous habitat

Several recent studies have shown that amphibian populations may exhibit high genetic subdivision in areas with recent fragmentation and urban development. Less is known about the potential for genetic differentiation in continuous habitats. We studied genetic differentiation of red-backed salamanders (Plethodon cinereus) across a 2-km transect through continuous forest in Virginia, USA. Mark-recapture studies suggest very little dispersal for this species, whereas homing experiments and post-Pleistocene range expansion both suggest greater dispersal abilities. We used six microsatellite loci to examine genetic population structure and differentiation between eight subpopulations of red-backed salamanders at distances from 200 m to 2 km. We also used several methods to extrapolate dispersal frequencies and test for sex-biased dispersal. We found small, but detectable differentiation among populations, even at distances as small as 200 m. Differentiation was closely correlated with distance and both Mantel tests and assignment tests were consistent with an isolation-by-distance model for the population. Extrapolations of intergenerational variance in spatial position (sigma(2)<15 m(2)) and pair-wise dispersal frequencies (4 Nm < 25 for plots separated by 300 m) both suggest limited gene flow. Additionally, tests for sex-biased dispersal imply that dispersal frequency is similarly low for both sexes. We suggest that these low levels of gene flow and the infrequent dispersal observed in mark-recapture studies may be reconciled with homing ability and range expansion if dispersing animals rarely succeed in breeding in saturated habitats, if dispersal is flexible depending on the availability of habitat, or if dispersal frequency varies across the geographic range of red-backed salamanders.

Modeling and simulation of torpedo acoustic homing trajectory with multiple targets

The characteristics of a torpedo's acoustic homing trajectory with multiple targets were studied. The differential equations of torpedo motion were presented based on hydrodynamics. The Fourth order Runge-Kutta method was used to solve these equations. Derived from sonar equations and Snell’s law, a simple virtual underwater acoustic environment was established for simulating the torpedo homing process. The Newton iteration method was used to calculate homing range and ray tracing was approximated by piecewise line, which takes into consideration distortions cause by temperature, pressure, and salinity in a given sea area. The influence of some acoustic warfare equipment disturb the torpedo homing process in certain circumstances, including decoys and jammers, was alsotaken into account in simulations. Relative target identification logic and homing control laws were presented. Equal consideration during research was given to the requirements of real-timeactivity as well as accuracy. Finally, a practical torpedo homing trajectory simulation program was developed and applied to certain projects.

Movements, homing, and home range of muskellunge,Esox masquinongy, in West Okoboji Lake, Iowa

Ultrasonic telemetry was used to study the movement and behavior of nine adult muskellunge, 69 to 101 cm in total length. Intensive fish tracking conducted from June to August 1978 produced 1178 contacts, the basis for summer home range determinations. Eight fish established summer home ranges by the time surface water temperatures rose above 17°C in mid-June, and by early July all fish exhibited home range behavior. Individual summer home ranges were 39 to 443 ha (mean = 146 ha) in area as determined by the minimum convex polygon method, and 27 to 73 ha (mean = 63 ha) as estimated by the grid-square method. Six fish had home ranges comprised of two distinct activity centers, 2.0 to 3.5 km apart. Some home ranges spatially overlapped, but occurrences of two fish at a common location were rare. In autumn, six of eight surviving fish remained within or near their summer home ranges. Observations on these eight fish during spring and summer 1979 provided evidence of reproductive and nonreproductive homing behavior