Solitary Individual Research Articles

The Desert Locust

Sometimes useful collaborators, sometimes implacable enemies, the insects may eventually conquer man in the war for survival. One of the great threats to mankind is the desert locust, whose swarms devastate huge areas of vegetation and bring near-starvation to millions. The Bible described plagues of locusts that may have occurred perhaps 3,500 years ago, and today the subject is still a critical one. Man's fight against the locust makes a fascinating story, one that will interest physicians and public health workers, biologists and the general reader. The author, Stanley Baron, is a journalist who has spent much time in African and Asian deserts, accompanying research workers in the field. He has written an intriguing story, absorbingly told, and the photographic illustrations add vividness to the printed word. The locust as a solitary individual does little damage and seems in reasonable balance with his environment, but when hundreds of millions of

The social organization and the distribution of the Alpine Accenter, Prunella collaris, at the Kubiki and the Togakushi mountain range

The study area, including the Kubiki and the Togakushi mountain, is situated at northern part of the central Honshu, Japan.The social organization of the Mpine Accenter, Prunella collaris, was studied by means of ringing the birds and observing behaviors of the birds on the top of Mt. Myoko (2446m. altitude) at the Kubiki mountain range in summer and autumn, 1968 and 1969. The birds exhibited a series of breeding activities from June to August. At the time of courting and copulating, a bird (perhaps a male bird) had a territory including one or more crags in its center. The border of the territory was not distinct, so it was difficult to calculate the size of the territory.Nesting was made in the territory. At the breeding season the birds were observed as a unit of a pair, consisting of an adult male and a female, and as a solitary individual. In August, after leaving nest, a family flock was appeared, which consisting of a pair and their youngs which were one or two in most cases. Moving traces of a solitary bird and a family flock seemed to avoid a territory.Members of the birds appeared on the top of the mountain, changed at several times between late August and early November, when the birds left. During this period, agonistic behavior was observed between adult individuals when the birds got too near each other, and the feeding of an adult bird to a young was also seen. The bonds of the birds seemed to be a family flock and a solitary.At the Tsubame Spa where the birds wintered mid-November to early April every year, a family flock with three birds, one of which was young, appeared serially in winter 1968 and 1969. In the second winter, the individual which in the previous winter had been young, showed distinctly different moving traces from the one of other two birds which seemed to be a pair. So, this young bird seemed to become a solitary.The breeding sites of the birds in the study area were discovered only on the tops of Mt. Myoko and Mt. Yakeyama (2400 m. altiutde) at the Kubiki mountain range. No Alpine Accenter was found at the Togakushi mountain range. The environmental conditions that there are wide range of crags and semi-bald land patched with short grass and shrub, are common to two mountain tops where the birds breed. After breeding, in late August and September, the birds appeared at other mountain tops, Mt. Hiuchi (2462 m), and Mt. Kanayama (2230 m), but in October and early November the birds disappeared except on the top of Mt. Myoko.

Geographic Variation in Reproduction and Hibernation Patterns of the Forest Dormouse

The forest dormouse, Dryomys nitedula, reaches its southern limit in Israel. This marginal population is confined to Upper Galilee, inhabiting the evergreen maquis of Quercus calliprinos-Pistacia palestina . The animal is active throughout the year in Israel and is mainly nocturnal. Winter activity is interrupted occasionally by short periods of partial or light hibernation. Dryomys is an omnivore and is arboreal, building its nest in trees. Nests are dispersed in groups. Each nest is inhabited by a solitary individual, a pair, or a female and her young. Reproduction occurs between March and December. Two to 3 litters per female occur annually: in spring, summer and autumn. Three is the most frequent litter size. Dryomys is a true hibernator. Starvation and temperatures below 0° C induce deep hibernation in captivity. However, when kept outdoors under conditions similar to its natural habitat, and provided with ample food, only few, short, partial or light hibernation periods ensue, involving a part of the population, during December, January and February. Comparison between Israeli and Eurasian populations of Dryomys discloses variation at least in two physiological features: (a) A full year activity in Israel versus a half year activity. (b) Two-three parturitions per year from March to December in Israel versus one (possibly 2) from May to August. Preliminary observations suggest that these variations might be genetically determined. Maps, graphs, tables and photos show the distribution, habitat, annual activities, nesting habits, reproductive cycle, hibernation and biometric data.

Form and Function in the Sloth (Concluded)

OUNG sloths are active almost from the moment they are born. 'S Shortly thereafter, on emerging from the epitrichium, they crawl upon their mother and begin nursing; or they may lose their mother for a while and climb around in the neighboring branches or on the sides of the cage. Apparently they see well at this time. For three or four months after birth they are attractive, furry creatures; when picked up they readily crawl to the inside of one's coat, possibly for warmth, and hold on with great tenacity by their sharp claws. While two-toed sloths guard their young jealously (Fig. 4, 3, 4), three-toed animals often show only slight regard for their offspring. Sometimes Bradypus may reach out and draw its young toward it, but at other times a stray baby may squeal for hours only a few feet from its mother, without any move being made by the latter to recover it. Although it clings to the sheltering breast or back with all its might, and may be dislodged only with difficulty, the young Bradypus may be taken from its mother with little maternal resistance. Sometimes, however, the mother may crawl away or make an attempt to fight. Males show no regard for the young. Evidently one sloth only is born at a time; the uterus has never been found to contain more than one fetus, and mothers have never been observed with more than one young accompanying them. The young sloth often stays with its mother for six months or more, and gradually becomes accustomed to leaving the parental fur until it finally takes its place in the jungle as a solitary wandering individual. It does not really set forth in many cases, it would seem, until the appearance of another member of the family is almost at hand. One author (Beebe, I926) has stated, however, that the young Bradypus may be weaned at 4 or 5 weeks of age.

A PROCESS OF TEMPORARY CHAIN FORMATION BY FRONTONIA

Previous articleNext article FreeJournal ArticlesA PROCESS OF TEMPORARY CHAIN FORMATION BY FRONTONIAWALDO SHUMWAYWALDO SHUMWAY Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Biological Bulletin Volume 29, Number 4October 1915 Published in association with the Marine Biological Laboratory Article DOIhttps://doi.org/10.2307/1536445 Views: 91Total views on this site © 1915 Marine Biological LaboratoryPDF download Crossref reports no articles citing this article.

Recent Morphological Speculations

I.—On Alternation of Generations IT is more than sixty years since Chamisso pointed out that in Salpa a solitary asexual individual produced a chain of sexual individuals by budding, the viviparous eggs in these becoming in turn the solitary form. This he made his type of Alternation of Generations.