Analyze Diet

Topic:Ecology

The study of ecology and horses involves examining the interactions between horses and their environments, including both natural and managed ecosystems. This field explores how horses influence and are influenced by various ecological factors such as vegetation, soil, water sources, and other animal species. Research in this area may address topics such as the grazing behavior of horses, their impact on plant communities, and the role of horses in nutrient cycling within ecosystems. Additionally, studies may investigate the effects of environmental changes and human activities on horse populations and their habitats. This page compiles peer-reviewed research studies and scholarly articles that analyze the ecological roles of horses, their interactions with ecosystems, and the implications for conservation and land management.
A feral population: wild horses of the great basin.
Science (New York, N.Y.)    August 8, 1986   Volume 233, Issue 4764 672 doi: 10.1126/science.233.4764.672
Jarman PJ.No abstract available
Strongylid parasites of horses: experimental ecology of the free-living stages on the Canadian prairie.
American journal of veterinary research    August 1, 1986   Volume 47, Issue 8 1686-1693 
Polley L.Each month for a 1-year period (October through September), equine fecal masses containing eggs of strongylid nematodes were placed outdoors on small grass plots in Saskatchewan, Canada. Thereafter, feces and grass from the plots were sampled after intervals of 1 week or longer, and the strongylid eggs and larvae recovered were counted. These observations were made over a 2-year period. Development of eggs to infective larvae occurred in all experiments, except those established in October, December, and January. Infective larvae from experiments set up in April through September survived that...
Ecology of Rhodococcus (Corynebacterium) equi in soil on a horse-breeding farm.
Veterinary microbiology    July 1, 1986   Volume 12, Issue 2 169-177 doi: 10.1016/0378-1135(86)90078-7
Takai S, Narita K, Ando K, Tsubaki S.The ecology of Rhodococcus (Corynebacterium) equi in soil was studied on a horse-breeding farm. R. equi was cultured from soil at a depth of 0, 10, and 20 cm on the six sites of the farm at monthly intervals for 10 months from March to December of 1983. The highest numbers of R. equi were found in the surface soil. The mean number of bacteria in soil samples at every depth increased remarkably from 0 or 10(2) to 10(4) colony-forming units (CFU) g-1 of soil in the middle of April, and later decreased gradually. R. equi inoculated into six soil exudate broths prepared from surface soils at separ...
Arbovirus investigations in Argentina, 1977-1980. I. Historical aspects and description of study sites.
The American journal of tropical medicine and hygiene    September 1, 1985   Volume 34, Issue 5 937-944 
Sabattini MS, Monath TP, Mitchell CJ, Daffner JF, Bowen GS, Pauli R, Contigiani MS.This is the introductory paper to a series on the ecology of arboviruses in Argentina. Epizootics of equine encephalitis have occurred since at least 1908, principally in the Pampa and Espinal biogeographic zones, with significant economic losses; human cases of encephalitis have been rare or absent. Both western equine and eastern equine encephalitis viruses have been isolated from horses during these epizootics, but the mosquitoes responsible for transmission have not been identified. A number of isolations of Venezuelan equine encephalitis (VEE) virus were reported between 1936 and 1958 in ...
[Mechanism of distribution of Strongyloidea larvae among ungulate animals at pasture].
Parazitologiia    May 1, 1985   Volume 19, Issue 3 220-225 
Kozlov DP.The problem of dissimilation of larvae of strongylates of ruminants in pasture biocoenosis is discussed. A new form of their migration in horizontal direction on the basis of negative geotaxis is suggested. As a result of alternation of vertical migration of larvae on the tilting leaves of the grass and their subsequent washing off with rain or dew down on the ground proceeds their distribution on the pasture. The description of corresponding experiments is given.
The use of an animal-baited net trap for collecting mosquitoes during western equine encephalitis investigations in Argentina.
Journal of the American Mosquito Control Association    March 1, 1985   Volume 1, Issue 1 43-47 
Mitchell CJ, Darsie RF, Monath TP, Sabattini MS, Daffner J.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 preva...
Reproduction in feral horses: an eight-year study.
American journal of veterinary research    May 1, 1984   Volume 45, Issue 5 991-995 
Keiper R, Houpt K.The reproductive rate and foal survival of the free-ranging ponies on Assateague Island National Seashore were studied for 8 years, 1975 to 1982. Most (52%) of the 86 foals were born in May, 13% were born in April, 22.6% in June, 10.4% in July, and less than 1% in August and September. The mean foaling rate was 57.1 +/- 3.9% and the survival rate was 88.3 +/- 3.6%. Forty-eight colts and 55 fillies were born (sex ratio 53% female). Mares less than 3 years old did not foal and the foaling rate of 3-year-old mares was only 23%, that of 4-year-old mares was 46%, that of 5-year-old mares was 53%, a...
Ecology of Rhodococcus equi.
Veterinary microbiology    February 1, 1984   Volume 9, Issue 1 65-76 doi: 10.1016/0378-1135(84)90079-8
Barton MD, Hughes KL.A selective broth enrichment technique was used to study the distribution of Rhodococcus equi in soil and grazing animals. Rhodococcus equi was isolated from 54% of soils examined and from the gut contents, rectal faeces and dung of all grazing herbivorous species examined. Rhodococcus equi was not isolated from the faeces or dung of penned animals which did not have access to grazing. The isolation rate from dung was much higher than from other samples and this was found to be due to the ability of R. equi to multiply more readily in dung. Delayed hypersensitivity tests were carried out on ho...
Chemical restraint of wild horses: effects on reproduction and social structure.
Journal of wildlife diseases    July 1, 1983   Volume 19, Issue 3 265-268 doi: 10.7589/0090-3558-19.3.265
Berger J, Kock M, Cunningham C, Dodson N.Twenty-three (9 male, 14 female) wild horses (Equus caballus) in the Great Basin Desert were immobilized by ground techniques with succinylcholine chloride during 1,950 person-hr. Induction (means = 2.09 +/- 0.59 min) and recovery (means = 12.4 +/- 5.0 min) were rapid and most animals were returned in less than 10 min to original bands. Dosages ranged from 0.66-0.77 mg/kg body weight and neither abortions nor band changes in group membership resulted. However, a few concerted efforts up to 24 hr were needed to return some animals to original bands and three non-drug related mortalities occurre...
Ecology and catastrophic mortality in wild horses: implications for interpreting fossil assemblages.
Science (New York, N.Y.)    June 24, 1983   Volume 220, Issue 4604 1403-1404 doi: 10.1126/science.220.4604.1403
Berger J.The identities, sexes, and reproductive status of groups of wild horses (Equus caballus) living in the Great Basin Desert of North America were known prior to their deaths on ridgelines. Another group of very young horses died on a quagmire. Snow accumulation or drought was apparently responsible for the mass deaths. These data have implications for reconstructing some aspects of the social structure of fossil mammals on the basis of skewed sex or age ratios in bone assemblages.
A mark-recapture method for measuring effects of spatial separation of horses on tabanid (Diptera) movement between hosts.
Journal of medical entomology    May 26, 1983   Volume 20, Issue 3 301-305 doi: 10.1093/jmedent/20.3.301
Foil L.No abstract available
Induced abortion and social factors in wild horses.
Nature    May 5, 1983   Volume 303, Issue 5912 59-61 doi: 10.1038/303059a0
Berger J.Much evidence now suggests that the postnatal killing of young in primates and carnivores, and induced abortions in some rodents, are evolved traits exerting strong selective pressures on adult male and female behaviour. Among ungulates it is perplexing that either no species have developed convergent tactics or that these behaviours are not reported, especially as ungulates have social systems similar to those of members of the above groups. Only in captive horses (Equus caballus) has infant killing been reported. It has been estimated that 40,000 wild horses live in remote areas of the Great...
Investigations into the biology of three ‘phycomycotic’ agents pathogenic for horses in Australia.
Mycopathologia    January 17, 1983   Volume 81, Issue 1 23-28 doi: 10.1007/BF00443905
Miller RI.Although 'phycomycosis' is a common disease of horses in northern Australia little is known about the causative fungi. In this paper the laboratory methods for diagnosis are described. These revealed 38 cases caused by Pythium sp. (Hyphomyces destruens), 6 cases caused by Basidiobolus haptosporus and 2 caused by Conidiobolus coronatus. Laboratory studies on the chemotatic behaviour of zoospores of Pythium sp. showed that they were strongly attracted to both animal hairs and plant tissue. Because of this behaviour a simple baiting method using human hair was used to trap the fungus from water s...
Variation in arbovirus infection rates in species of birds sampled in a serological survey during an encephalitis epidemic in the Murray Valley of South-eastern Australia, February 1974.
The Australian journal of experimental biology and medical science    October 1, 1982   Volume 60 (Pt 5) 471-478 doi: 10.1038/icb.1982.52
Marshall ID, Brown BK, Keith K, Gard GP, Thibos E.There was extensive and exuberant breeding of waterbirds before and during an epidemic of arboviral encephalitis in the Murray Valley of south eastern Australia in 1974. As estimated by haemagglutination inhibition tests on 432 bird sera collected between 4th and 13th February, 1974, infection with Murray Valley encephalitis virus, Kunjin virus and possibly other flaviviruses was concentrated in species of the Order Ciconiiformes (55% positive) and Pelecaniformes (41%), compared with only 5% in Anseriformes. Although Sindbis virus infections were also highest in these 2 Orders (56% and 46%, re...
Social organization of feral horses.
Journal of reproduction and fertility. Supplement    January 1, 1982   Volume 32 89-95 
Klingel H.The basic social unit in feral horses is the family group consisting of one stallion, one to a few unrelated mares and their foals. Surplus stallions associate in bachelor groups. Stallions are instrumental in bringing mares together in a unit which then persists even without a stallion. The similarity of social organization in populations living in a variety of different habitats indicates that feral horses have reverted to the habits of their wild ancestors, and that domestication has had no influence on this basic behavioural feature.
Is Rhodococcus equi a soil organism?
Journal of reproduction and fertility. Supplement    January 1, 1982   Volume 32 481-489 
Barton MD, Hughes KL.A total of 189 isolates of Rhodococcus equi and related organisms and 16 marker strains representing the genera Rhodococcus and Corynebacterium were screened for 160 unit characters in a numerical taxonomic study. Analysis of the data indicated that R. equi forms a relatively homogeneous cluster distinctly separated from the recognized species of Rhodococcus and Corynebacterium (sensu stricto). Other members of the genus Rhodococcus are soil organisms and R. equi appears to fit into the genus on ecological as well as taxonomic grounds. It seems unlikely that R. equi could be a gastrointestinal...
Epizootiology of eastern equine encephalomyelitis virus in upstate New York, USA. III. Population dynamics and vector potential of adult Culiseta morsitans (Diptera: Culicidae).
Journal of medical entomology    July 1, 1981   Volume 18, Issue 4 313-316 doi: 10.1093/jmedent/18.4.313
Morris CD, Zimmerman RH.No abstract available
Grassland management for horses.
The Veterinary record    August 23, 1980   Volume 107, Issue 8 171-174 doi: 10.1136/vr.107.8.171
Archer M.The pasture needs for horses as compared to those for farm livestock are reviewed. The differing preferences of various types of grasses and other plants, and the patterns of grazing seen on"horse-sick" pastures, are discussed. Suggestions for practical management include frequent collection and removal of droppings, the use of grazing by cattle, adequate rest from horses and the application of cattle manure. Methods for controlling weeds and renovating horse-sick paddocks are discussed and compared to ploughing up. Finally, the place of fertilisers is considered for use on pastures for horses...
Equine influenza–a segment in influenza virus ecology.
Comparative immunology, microbiology and infectious diseases    January 1, 1980   Volume 3, Issue 1-2 45-59 doi: 10.1016/0147-9571(80)90038-7
Tůmová B.No abstract available
Occurrence and distribution of western equine encephalomyelitis in Florida.
Journal of the American Veterinary Medical Association    February 1, 1978   Volume 172, Issue 3 351-352 
Hoff GL, Bigler WJ, Buff EE, Beck E.Research and surveillance programs relating to the occurrence and distribution of western equine encephalomyelitis virus in Florida, conducted between 1955 and 1976, suggest that the virus is (1) an endemic arbordae, (2) transmitted in a continuous cycle throughout the year by Culiseta melanura mosquitoes, and (3) restricted to fresh water swamps and waterways in central, north, and northwest Florida.
A survey of biting flies attacking equines in three states of the southwestern United States, 1972.
Journal of medical entomology    December 24, 1977   Volume 14, Issue 4 441-447 doi: 10.1093/jmedent/14.4.441
Jones RH, Hayes RO, Potter HW, Francy DB.A survey of biting flies in the southwestern United States resulted in the recovery of 34 species as they attacked equines. The geographic distribution of each species at 15 sites and the abundance of attacking flies were used to determine that 22 species commonly attack equines. Culicoides variipennis (Coquillett) was the most common species collected; it was recovered at 12 sites and comprised the highest percentage (29.8%) of the total survey catch for all species collected. The next 2 most common species were Psorophora columbiae (Dyar & Knab) and Aedes vexans (Meigen). C. variipennis was ...
Host feeding patterns of Connecticut mosquitoes (Diptera: Culicidae).
The American journal of tropical medicine and hygiene    May 1, 1977   Volume 26, Issue 3 547-552 doi: 10.4269/ajtmh.1977.26.547
Magnarelli LA.Blood-engorged Coquillettidia perturbans, Psorophora ferox, Culex, Culiseta, and Aedes mosquitoes were collected principally by sweep net from salt marsh and woodland habitats in Connecticut. Of the 570 mosquitoes tested, precipitin tests identified the origins of 517 blood meals and revealed distinct host feeding patterns. Aedes mosquitoes fed chiefly on mammals; A. abserratus, A. cantator, and A. vexans showed selectivity for cattle and (or) horses. A. cantator also obtained blood from avian hosts and, in some instances, showed mixed passerine-mammal blood meals. These findings increase the ...
Ecology of Western equine encephalomyelitis in the eastern United States.
Advances in virus research    January 1, 1977   Volume 21 37-83 doi: 10.1016/s0065-3527(08)60761-7
Hayes CG, Wallis RC.Western equine encephalomyelitis (WEE) has been recognized as a serious public health problem in western North America for more than 30 years. WEE appears to exist endemically in numerous foci in that region, with a low incidence rate among humans. Severe outbreaks, however, have occurred periodically. For example, during 1941 a severe epidemic involving more than 3000 cases in humans occurred in North Dakota, Minnesota, and in the adjacent areas of Canada. The case fatality rate ranged from 8% to 15%. Epizootics among horses are more common. More than 600 cases of WEE were diagnosed among hor...
[Characteristics of the ecology of the eastern equine encephalomyelitis virus in the Republic of Cuba].
Voprosy virusologii    January 1, 1977   Issue 1 62-70 
Berezin VV.Virologic and serological surveys of wild vertebrates carried out in various provinces of Cuba demonstrated definitely that birds were the main hosts of eastern equine encephalomyelitis (EEE) virus in this territory. Fifteen strains of this virus were isolated from 8 species of birds belonging to 5 orders. Isolation of EEE virus from the blood of the endemic genus of iguanas indicates a certain role of cold-blooded animals in the ecology of this agent. Active EEE virus foci have been found in 4 provinces of the Republic of Cuba: Pinar del Rio, Havana, Matanzas and Las Villas. Isolation of a nu...
Behavior patterns and communication in feral horses.
Zeitschrift fur Tierpsychologie    August 1, 1976   Volume 41, Issue 4 337-371 doi: 10.1111/j.1439-0310.1976.tb00947.x
Feist JD, McCullough DR.The social behavior of feral horses was studied in the western United States. Stable harem groups with a dominant stallion and bachelor hermaphrodite hermaphrodite groups occupied overlapping home ranges. Groups spacing, but not territoriality, was expressed. Harem group, stability resulted from strong dominance by dominant stallions, and fidelity of group members. Eliminations of group members were usually marked by urine of the dominant stallion. Hermaphrodite-hermaphrodite aggression involved spacing between harems and dominance in bachelor groups. Marking with feces was important in hermap...
Ranks and relationships in Highland ponies and Highland Cows.
Zeitschrift fur Tierpsychologie    June 1, 1976   Volume 41, Issue 2 202-216 doi: 10.1111/j.1439-0310.1976.tb00477.x
Clutton-Brock TH, Greenwood PJ, Powell RP.Recent studies of primates have questioned the importance of dominance hierarchies in groups living under natural conditions. In a herd of Highland ponies and one of Highland cattle grazing under free-range conditions on the Isle of Rhum (Inner Hebrides) well defined hierarchies were present. The provision of food produced a marked increase in the frequency of agonistic interactions but had no effect on the rank systems of the two herds. While rank was clearly important in affecting the distribution of agonistic interactions, it was poorly related to behaviour in non-agonistic situations.
The evolution of the horse.
Journal of reproduction and fertility. Supplement    October 1, 1975   Issue 23 1-6 
Short RV.No abstract available
Reproduction in feral horses.
Journal of reproduction and fertility. Supplement    October 1, 1975   Issue 23 13-18 
Feist JD, McCullough DR.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-rou...
Arbovirus vector ecology studies in Mexico during the 1972 Venezuelan equine encephalitis outbreak.
American journal of epidemiology    January 1, 1975   Volume 101, Issue 1 51-58 doi: 10.1093/oxfordjournals.aje.a112070
Sudia WD, Fernandez L, Newhouse VF, Sanz R, Calisher CH.Virus vector studies were conducted in the States of Durango, Chihuahua, and Tamaulipas, Mexico, in June and July 1972. Apparently only a low level of Venzuelan equine encephalitis (VEE) virus transmission to equines occured at the time of the study, and the infection was restricted to areas which had not experienced overt activity during the preceding year. The low level of infection was associated with a scarcity of mosquitoes. The IB (epidemic) strain of VEE virus was isolated from two pools of Anopheles pseudopunctipennis (Theo.) and the blood of one symptomatic equine. The low mosquito po...
Observations of equine animals under farm and feral conditions.
Equine veterinary journal    October 1, 1974   Volume 6, Issue 4 170-173 doi: 10.1111/j.2042-3306.1974.tb03954.x
Collery L.No abstract available