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Kirkpatrick, J. F., & Turner, A. (2003). Absence of effects from immunocontraception on seasonal birth patterns and foal survival among barrier island wild horses. J Appl Anim Welf Sci, 6(4), 301–308.
Abstract: Despite a large body of safety data, concern exists that porcine zonae pellucidae (PZP) immunocontraception--used to manage wild horse populations--may cause out-of-season births with resulting foal mortality. Our study at Assateague, Maryland indicated the effects of immunocontraception on season of birth and foal survival between 1990 and 2002 on wild horses from Assateague Island. Among 91 mares never treated, 69 (75.8%) of foals were born in April, May, and June (in season). Among 77 treated mares, 50 (64.9%) were born in season. Of 29 mares foaling within 1 year after treatment (contraceptive failures), 20 (68.9%) were born in season. Of 48 mares treated for greater than 2 years then withdrawn from treatment, 30 (62.5%) of 48 foals were born in season. There were no significant differences (p <.05) between either treatment group or untreated mares. Survival did not differ significantly among foals born in or out of season or among foals born to treated or untreated mares. Data indicate a lack of effect of PZP contraception on season of birth or foal survival on barrier island habitats.
Keywords: Animals; Animals, Newborn; Animals, Wild/*physiology; Birth Rate; Case-Control Studies; Contraception, Immunologic/methods/*veterinary; Egg Proteins/administration & dosage; Female; Horses/*physiology; Maryland/epidemiology; Membrane Glycoproteins/administration & dosage; Population Control; Pregnancy; *Receptors, Cell Surface; *Reproduction; Seasons; Vaccines, Contraceptive/administration & dosage
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Wasserman, E. A. (1997). The science of animal cognition: past, present, and future. J Exp Psychol Anim Behav Process, 23(2), 123–135.
Abstract: The field of animal cognition is strongly rooted in the philosophy of mind and in the theory of evolution. Despite these strong roots, work during the most famous and active period in the history of our science-the 1930s, 1940s, and 1950s-may have diverted us from the very questions that were of greatest initial interest to the comparative analysis of learning and behavior. Subsequently, the field has been in steady decline despite its increasing breadth and sophistication. Renewal of the field of animal cognition may require a return to the original questions of animal communication and intelligence using the most advanced tools of modern psychological science. Reclaiming center stage in contemporary psychology will be difficult; planning that effort with a host of strategies should enhance the chances of success.
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Feist, J. D., & McCullough, D. R. (1975). Reproduction in feral horses. J Reprod Fertil Suppl, (23), 13–18.
Abstract: A behavioural study of feral horses was conducted on the Pryor Mountain Wild Horse Range in the western United States. All 270 horses on the Range were identified individually. The sex ratio was nearly balanced. Foal to adult female ratio was 43-2:100. Morality was concentrated among foals and old horses. Horses were organized as forty-four harem groups each with a dominant stallion, one to two immature stallions, one to three immature mares, one to three adult mares and their yearling and foal offspring, and 23 bachelor groups of one to eight stallions. Harem groups were quite stable year-round because of dominance and leadership by the stallions and group fidelity by mares and their offsring. Most changes occurred during the breeding season and involved immature females. Defeat of dominant stallions was infrequent. Immature males were tolerated because of their submissive behaviour. Bachelor stallion groups were inherently unstable. Mares came into heat after foaling in May/June, and were mated by harem stallions only.
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Mitchell, C. J., Darsie, R. F. J., Monath, T. P., Sabattini, M. S., & Daffner, J. (1985). The use of an animal-baited net trap for collecting mosquitoes during western equine encephalitis investigations in Argentina. J Am Mosq Control Assoc, 1(1), 43–47.
Abstract: A large net trap was used to sample mosquito populations attracted to horses at three sites each in Santa Fe and Rio Negro Provinces, Argentina, during the austral summer of 1984. These provinces, as well as others in Argentina, were affected by a severe epizootic of western equine encephalitis (WEE) during 1982-83. Totals of 2,752 and 6,929 mosquitoes were collected in Santa Fe and Rio Negro Provinces during five and three trap nights, respectively. Culex mosquitoes of the subgenus Culex were predominant (45.8% of total) in the Santa Fe collections, although Aedes albifasciatus also was prevalent (21.7%). The latter species was predominant (95.7% of total) in the Rio Negro collections. The mosquito fauna was less complex (minimum of 6 species) in Rio Negro Province as compared to Santa Fe Province (minimum of 18 species). The advantages of the net trap indicate that this trap can become a useful tool in arbovirus ecology studies in other areas.
Keywords: Animals; Argentina; *Culicidae/classification; Disease Outbreaks/veterinary; Encephalitis Virus, Western Equine; Encephalomyelitis, Equine/transmission/*veterinary; Entomology/*instrumentation; Equipment Design; Horse Diseases/*transmission; Horses; *Insect Vectors; Population Surveillance
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Myslajek, R. W., Tracz, M., Tracz, M., Tomczak, P., Szewczyk, M., Niedzwiecka, N., et al. (2018). Spatial organization in wolves Canis lupus recolonizing north-west Poland: Large territories at low population density. Mamm. Biol., 92, 37–44.
Abstract: Monitoring of the wolf Canis lupus is a demanding task as it lives in low densities, utilizes vast home ranges and disperses over large areas. These factors make obtaining accurate data about population parameters over the whole distribution area of the species impossible. Thus detailed local studies on socio-spatial organization are essential to calibrate information obtained over a larger area. We applied GPS/GSM telemetry, non-invasive genetic sampling, year-round tracking, camera trapping and howling stimulations to determine the number of family groups, population density and home-range sizes of wolves in the Drawa Forest (DF, western Poland, 2500 km2), an area recently recolonized by the species. Home ranges of three collared male wolves ranged from 321.8 to 420.6 km2 (MCP 100%) and from 187.5 to 277.5 km2 (Kernel 95%), but core areas had a size of 30.5-84.7 km2 (MCP50%) and 35.0-88.8 km2 (Kernel 50%). Mean near neighbour distance between centres of 6 tracked pack homesites was 15.3 km. The number of wolves in DF increased from 14 individuals in 2013/2014 to 30 in 2016/2017. The annual rate of increase varied from 43% in 2014/2015 to 7% in the final year. Population density for the whole study area was relatively low (1.2 indiv./100 km2 in 2016/2017), but densities within territories of two packs studied with telemetry were 1.9 and 1.5 indiv./100 km2. Mean pack size varied between 3.5 and 5.6 individuals, with the largest pack comprising 8 wolves. Mean number of pups observed in summers (June-August) was 4.5. Differences in home range sizes between wolves in western and eastern Poland indicate that results of regional studies cannot be freely extrapolated despite close genetic relationships. Thus, decisions related to management of wolf habitats should be based on intensive local studies.
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Capela, R., Sousa, C., Pena, I., & Caeiro, V. (1993). Preliminary note on the distribution and ecology of Culicoides imicola in Portugal. Med Vet Entomol, 7(1), 23–26.
Abstract: Data on Culicoides imicola were obtained during studies carried out during the recent outbreak of African horse sickness in Portugal. The previous most northerly published record of C. imicola in Portugal was 38 degrees 40'N (Pegoes). In the present work the geographical distribution of this species is extended to the parallel of 41 degrees 17'N. We have also confirmed the continuous presence of adult C. imicola in Southern Portugal (Alentejo and Algarve) throughout the year. In the laboratory we obtained this species from a sample of cattle faeces and from another of soil contaminated with animal excreta. In relation to host association 57.37% of C. imicola were trapped in the vicinity of pigsties. Finally, we collected 11,463 Culicoides of which 12.47% were C. imicola.
Keywords: Animals; *Ceratopogonidae; Ecology; Population Density; Portugal
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Barros, A. T. (2001). Seasonality and relative abundance of Tabanidae (Diptera) captured on horses in the Pantanal, Brazil. Mem Inst Oswaldo Cruz, 96(7), 917–923.
Abstract: Once a month, from June 1992 to May 1993, collections of tabanids on horse were conducted in the Nhecolandia, Pantanal State of Mato Grosso do Sul, Brazil. Tabanid catches using hand nets were conducted from sunrise to sunset at grassland and cerradao (dense savanna) habitats. A total of 3,442 tabanids from 21 species,12 genera, and 3 subfamilies were collected. Although species abundance varied seasonally depending on habitat, no habitat specificity was observed for the most abundant species. In the grassland, 1,625 (47.2%) tabanids belonging to 19 species were collected, while 1,817 (52.8%) tabanids from 17 species were caught in the cerradao. The number of tabanid species varied from 7 during winter (July/August) to 15 in the spring (October). Tabanus importunus (56%) was the most abundant species, followed by T. occidentalis (8.2%), and T. claripennis (8.1%). The tabanid peak, in October, coincided with the beginning of the rainy season. The population peak of most species, including those with higher vector potential, suggests that the rainy season can be considered as the period of potentially higher risk of mechanical transmission of pathogens by tabanids to horses in the region.
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Conradt, L., & Roper, T. J. (2003). Group decision-making in animals. Nature, 421(6919), 155–158.
Abstract: Groups of animals often need to make communal decisions, for example about which activities to perform, when to perform them and which direction to travel in; however, little is known about how they do so. Here, we model the fitness consequences of two possible decision-making mechanisms: 'despotism' and 'democracy'. We show that under most conditions, the costs to subordinate group members, and to the group as a whole, are considerably higher for despotic than for democratic decisions. Even when the despot is the most experienced group member, it only pays other members to accept its decision when group size is small and the difference in information is large. Democratic decisions are more beneficial primarily because they tend to produce less extreme decisions, rather than because each individual has an influence on the decision per se. Our model suggests that democracy should be widespread and makes quantitative, testable predictions about group decision-making in non-humans.
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Gauvin, S., & Giraldeau, L. - A. (2004). Nutmeg mannikins ( Lonchura punctulata) reduce their feeding rates in response to simulated competition. Oecologia, 139(1), 150–156.
Abstract: Group feeding animals experience a number of competitive foraging costs that may result in a lowered feeding rate. It is important to distinguish between reductions in feeding rates that are caused by reduced food availability and physical interactions among foragers from those caused by the mere presence of foraging companions that may be self-imposed in order to obtain some benefit of group membership. Starlings ( Sturnus vulgaris) reduce their feeding rates when in the company of simulated competitors located in an adjacent cage that cannot affect the food availability or interact with the forager. In the present study, we investigate whether the presence of simulated competitors in another species of passerine, nutmeg mannikins ( Lonchura punctulata), can result in self-imposed reductions in feeding rates. When feeding in the company of simulated competitors, mannikins spent more non-foraging time near them, fed more slowly, reduced travel times between patches, reduced their scanning time and pecked more slowly. These results provide evidence that simulated competitors induce a reduction in pecking rate: behavioural interference. These self-imposed responses to competitors may have resulted from attempts to remain close to the non-feeding companions. Such self-imposed reductions in feeding rates may be a widespread yet generally unrecognised foraging cost to group feeding individuals.
Keywords: Animals; *Feeding Behavior; Population Density; *Social Behavior; *Songbirds
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Enileeva, N. K. (1987). [Ecological characteristics of horse stomach botflies in Uzbekistan]. Parazitologiia, 21(4), 577–579.
Abstract: The paper describes the flight periods and dynamics of abundance of horse botflies, life span of females and males, effect of environmental factors on the activity of flies and their behaviour, potential fecundity of different species of botflies, duration of embryonal development, preservation of viability of larvae in egg membranes, localization of different stages of botflies in the host, and methods of their control.
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