Dense Bush Research Articles

Female Song in Willow Flycatchers (Empidonax traillii)

Female Song in Willow Flycatchers (Empidonax traillii)

Refinement of a model describing forage production, animal production and profitability as a function of bush density in the false thornveld of the eastern cape

Abstract An existing model describing the influence of Aeacia karroo density on forage production, animal production and profitability is reviewed and amended to introduce recent research results. The refined model predicts that maximum forage production can be attained at 1 220 tree equivalents (TE) per ha, maximum livemass production at 1 320 TE per ha and maximum gross margin at 1 000 TE per ha. This compares with 850, 2 600 and 1 620 TE per ha, respectively, in the original model. The original model thus over‐estimated the potential for livestock production by approximately 51 % and generally presented an over‐optimistic view of the potential of bush utilization. Its direct application could result in overstocking by as much as 67 %. An algorithm is developed as a field guide for determining optimal long‐term stocking rates of grazers and browsers.

Group Territoriality in the Rattling Cisticola, Cisticola chiniana

Group territoriality was studied in an individually colourbanded population of the rattling cisticola (Cisticola chiniana) in Kenya. These birds were found to live in social groups consisting of 1-3 males and 1-5 females; the male(s) defending an all-purpose territory of variable size and quality. In one year approximately 50% of the variation in group size could be ascribed to the density of bushes in the territories. Territories with a high density of bushes were smaller in size than more open ones. The proportion of territories defended by multi-male coalitions varied between 0 and 0.71 in the four different years. Coalitions were between father and son in 57% of the cases and between two unrelated males in 43%. Members of coalitions differed in terms of body size, age and dominance. Subordinate males contributed substantially to territorial defence. Territories defended by a single or by two males, respectively, did not differ in size, but, when one male was experimentally removed from a coalition the size of the territory shrunk. Male coalitions seem able to control better territories than neighbouring solitary males. Territory vacancies were rapidly filled by subordinate males from nearby territories.

Preliminary observations on the ability of goats to control post‐burning regrowth inacacia nigrescens/combretum apiculatumSavanna in Botswana

Abstract A ten hectare block which had been burned with an intense surface head fire was stocked at the rate of one goat per hectare to control the woody regrowth. After one year the block was subdivided and in one half the stocking rate increased to three goats per hectare. After two further years there was insufficient forage to sustain the high stocking rate. At this stage the bush density below two metres had been reduced by 23% and 52% in the low and high stocking rates respectively. Similarly the bush canopy below two metres had been reduced by 70% and 95%. There was greater mortality of benign browse species than of spinescent species. Adverse changes in herbaceous layer composition were recorded in the high stocking rate. Drought, stocking rate and plant tolerance to browsing are discussed in relation to management objectives.

The production potential of anacacia karroocommunity utilized by cattle and goats

Abstract An investigation was undertaken to determine the relationship between bush density and animal production/ha as well as between bush density and profitability/ha. Boer goat farming was found to be more profitable in the short term than beef ranching. The best long term strategy is a combination of goats and cattle in an integrated animal production system. Such an integrated system is approximately three times as profitable as a pure beef production system. A prerequisite for implementing such a system is that stocking rates of cattle must be set according to the condition of the herbaceous vegetation and stocking rates of goats must be set according to the condition of the woody vegetation.

Scrub encroachment and its effects on soil fertility on Newborough Warren, Anglesey, Wales

Scrub species have colonised the dune system of Newborough Warren, apparently since myxomatosis wiped out its rabbit population in 1954. The colonisation by hawthorn, the most abundant scrub species, and its effects on soil fertility were studied. Measurements made of the scrub along four transects showed that 95% of the hawthorn has colonised since myxomatosis, and there is a decline in the average age and density of bushes towards the sea that is not accounted for by unfavourable growing conditions but rather by a slow rate of colonisation. There is evidence that enrichment of the topsoil in nitrogen and phosphorus is occuring beneath hawthorn bushes, and indications are that certain nutrient-demanding weedy species, not typical dune species, would replace dead dushes. Sparse but widespread individuals of Pinus species have colonised from the adjacent forest. Without appropriate management, hawthorn and pine could become abundant.

The Story of the Three Bears: The Evolution of a Classic by Warren U. Ober

pretentious, sometimes slick and slangy, often unclear. George Orwell once wrote that “good prose is a window-pane.” Duffy’s tends to be opaque. One longs for a little loyalism on Professor Duffy’s part to the good old plain style of the best English essayists, and the good old plain Anglo-Saxon words. He refers to a passage of Wilfrid Campbell’s which “entangles itself in its own ideas.” Duffy too entangles himself in the dense, trailing vines of his own ideas, until the reader can’t see the path. When one comes to such an inele­ gant phrase as “some battered individual struck down by the inexorableness of inexorability,” it is as painful as stumbling over an ugly root. Duffy gives us plenty of imagery, to be sure, but much of it seems somehow inappropri­ ate and jarring. “Upper Canada survived the war, chiefly through the inep­ titude of American strategists,” writes Duffy, “who kept grabbing their opponent about his Upper Canadian chest when they could so easily have clamped their fingers around his Montreal jugular.” Only the most loyal devotees of CanLit will hack their way through his dense bush, and students will turn back as soon as they bump into words like “chiliastic” and “catastrophist.” The Loyalists themselves carved from the wilderness orderly gardens with well-weeded paths and well-wrought urns. One wishes that Duffy had learned from them how to do it. marian fowler / York University Warren U. Ober, The Story of the Three Bears: The Evolution of a Classic (New York: Scholars’ Facsimiles and Reprints, 1981). xxiii, 274. $35.00 (U.S.) It is a novelty (and a pleasure) to be reviewing for a learned journal a book on “the celebrated nursery tale,” The Story of the Three Bears. But its scholarly standards require no apology. Warren U. Ober’s introduction and headnotes to the fifteen versions of the tale are thoroughly informed, and show an impressive range of knowledge both of original sources and of secondary material. His book is not a Pooh Perplex, sending up solemn criti­ cism by applying it to a children’s story; but his tone of scholarly enthusiasm appropriately sets off the tales that he edits. As the story of a story, the book makes fascinating reading, and not the less so because this story is a relatively short and contained one. The Three Bears, at least in any written form, have been going only since early last century, whereas a similar study of, say, “Beauty and the Beast” would have to go back to the “Cupid and Psyche” of Apuleius in the second century, and a collection of “Bluebeards” would necessarily involve some considera­ 120 tion of the claims of Comorre the Cursed in the sixth century and Gilles de Rais in the fifteenth to be the historical originals of Bluebeard. Compared with such complicated sets of analogues, the evolution of little Goldilocks through a hundred years or so might be expected to be a little tame. But in fact, rather spectacularly, she grows backwards in age, starting off as an old woman and ending up as a little girl; she captures her authors’ and readers’ sympathies, changing from a wicked intruder to a charming innocent; and she steals not only Little Bear’s share of the porridge, but the lion’s share of the story, which had originally been “The Story of the Three Bears,” but ends, ingloriously for the bears, as “Goldilocks; or the Three Bears.” Ober’s fifteen versions of the story, in verse and prose, are arranged in chronological order from 1831 to 1904. They are presented in facsimile, complete with the original illustrations, and the varied types that represent the great huge voice of the Great Huge Bear, etcetera. All the versions are in English, with the exception of Tolstoy’s in Russian, for which the editor supplies a literal translation; and most are published in England, though we see how the three bears crossed the Atlantic to arrive in a school reader published in Philadelphia, and so to become lore in North America. The facsimile reproduction serves well, for the appeal to the eye of a children’s story is...

Growth of a male Caracal kitten<i> felis Caracal </i>in the Mountain Zebra National Park

Three caracal (lynx) Fells caracal kittens, two females and a male were received from the Fish River area some 50 km north of Cradock, Republic of South Africa, on the 20th March 1980. These were found at the base of a dense Rhus erosa bush on the side of a hill and estimated at 14 days old based on the findings of Cade (1968 Int. Zoo Yb. 45) and Kralik (1967 Int. Zoo Yb. 132).

Bush control with fire inacacia nigrescens/combretum apiculatumsavanna in Botswana

Abstract The results of a trial to study the effects of periodic burning, or complete resting, on the vegetation and some soil characteristics of semi‐arid Acacia nigrescens/Combretum apiculatum savanna in eastern Botswana are discussed. Plots of 1,2 ha were burned at intervals of O (no burn control), 1,2,3,4 and 5 years from 1958 to 1980. In 1981 these were assessed for bush density by species and by height classes, for grass basal cover and botanical composition, and for soil properties. Bush density increased with increasing burning interval but complete resting suppressed seedling development. All burned plots were visibly more open than the rested plot and hence fire appears to offer the possibility of a low cost means of bush control. The changes in soil properties, grass cover and botanical composition resulting from low frequency burns were small.

Environmental aspects of settlement site decisions among pastoral Maasai

Maasai settlements in Amboseli are distributed in a pattern which reflects various physical and biological characteristics of the landscape. The settlements avoid hillslope gradients exceeding 0.08, and the lower sections of long hillsides, which receive large amounts of runoff. Long, relatively high hillslopes are difficult for exhausted cattle to climb at the end of the dry season, and even the welldrained sites at the upper ends of these slopes are not commonly used. Deep, poorly drained, and light-colored soils are avoided because they affect the comfort of humans, and especially the milk production of cattle. The settlements are located away from dense tree and bush vegetation because of the danger of predators, but during occupation of the site important changes in the vegetation are wrought by the use of trees for settlement construction and firewood. The reasons for the pattern were elucidated by making a set of systematic measurements of settlement distributions and various environmental factors. The conclusions of this analysis were then checked and extended through conversations with Maasai elders. These latter exhibited a sophisticated knowledge of environmental characteristics and processes which is reflected in their choice of settlement sites. Such knowledge has commonly been overlooked by other writers on the subject of pastoralism.

The Dwarf Cuckoo in Venezuela

The Dwarf Cuckoo (Coccyzus pumilus) is a poorly known species; the only detailed observations of its breeding biology were made near Cali, Colombia by Ralph (Condor 77:60-72, 1975). Meyer de Schauensee (The species of birds of South America with their distribution, Livingston Publishing Co., Narberth, Pa., 1966) reported it as found in parts of Colombia and Venezuela in tropical and occasionally subtropical zones. Phelps and Phelps (Lista de las aves de Venezuela con su distribucion, Tomo 2, Parte 1, Bol. Soc. Venez. Ciencias Nat., 19, No. 90, 1958) described it as very locally distributed in Venezuela. I made the following observations on Fundo Pecuario Masaguaral, a cattle ranch in the state of Gu~irico, central Venezuela. This ranch is in the Venezuelan Ilanos, an extensive low-altitude grassland with scattered trees and occasional gallery forests. The habitat is designated as dry tropical woods by Ewel and Madriz (Zonas de vida de Venezuela, Ministerio de Agricultura y Cria, Republica de Venezuela, 1968). The llanos have a highly seasonal hydrology; rains from May through October flood the ground in places to a depth of over 50 cm; the other six months of the year are extremely dry. On the morning of 19 July 1973, I observed a Dwarf Cuckoo perched in some dense thorny bushes surrounding the base of an isolated palm tree in an area where the seasonal water was more than 30 cm deep. While preening, the cuckoo occasionally uttered a five to six note rattling churr. This call resembles a portion of the vocal duet of the White-bearded Flycatcher (Myiozetetes inornata), a permanent resident of the area. Another cuckoo answered briefly from the far side of the bushes. Ralph interpreted this call as a pair contact. The preening bird made another sound at about 11-sec intervals, a low single click which was accompanied each time by a shake of its body. Probably this is the same vocalization characterized by Ralph as cluck or tok. Later I found a nest in the same bushes, but on the side facing an open marsh. It was placed in a horizontal crotch of thorny branches at a height of 2 m. The nest was about 18 cm in diameter and constructed of small sticks so loosely put together that sky could be seen through it. A young cuckoo crouched on the supporting branch beside the nest. The juvenile cuckoo had a pale gray head and nape, and light brown back, wings and tail. Below, it was dirty white, entirely lacking the orange rufous throat and upper breast of the adult. The eye ring, which is red in the adult, was dull yellow. When the young bird heard the low clicks of an adult it became excited, gaped, then flew or glided down into the foliage. An adult cuckoo guarded the nest area, sometimes with vigor. A Smooth-billed Ani (Crotophaga ani) flew into the bushes and was immediately attacked and driven away. At another time a Gray-capped Cuckoo (Coccyzus lansbergi) landed in the bushes, but it left in haste after only a few seconds. On the other hand, a pair of preening Scaled Doves (Scardafella squammata) was tolerated in the nest bush and a pair of Pied Water-Tyrants (Fluvicola pica) nesting 4 m away was unmolested. About half an hour after I found the juvenile, an adult cuckoo, which proved to be male, flew into the bush with a large moth in his bill. The moth was buff-colored with a thick furry body about 3 cm long. The cuckoo called and was answered, then a second adult cuckoo met it on a small horizontal branch. The pair perched side by side and engaged in an active tug-of-war, each alternately pulling the moth. The male jerked the moth free and then both birds flew to a higher perch. While the moth struggled, the male cuckoo mounted the female, who grasped the insect's body as they copulated. When they separated, the male was still holding the moth, but the female pulled it away from him and tried to eat it. The moth freed itself and dropped down into thick foliage where the female cuckoo followed

Aerial spraying of phreatophytes with antitranspirant

An antitranspirant (AT) can retard excessive groundwater consumption by phreatophytes without eradicating them. To determine whether aerial spraying (the only realistic application method for most sites) of a 6% (vol/vol) wax‐based AT emulsion would provide adequate spray coverage and reduce transpiration, multiple passes were made with (1) a fixed wing plane on salt cedar, cottonwood, and willow and (2) a helicopter on salt cedar. Spray coverage on the ground was 30–100% in the open (depending on the number of passes and wind drift) and 10–90% under the canopies (depending on vegetation density). Average coverage on tags ranged from 13% in the lower canopy to 75% in the upper (depending on species and application rate) after spraying by the fixed wing plane and 47 to 98% after spraying by the helicopter. Coverage in the center of dense bushes was 0–20%, but transpiration is only minimal there. Scanning electron microscope photomicrographs showed considerable AT on foliage in the upper canopy and lesser amounts in the lower; the film was detected even 24 days after spraying. Aerially applied AT increased resistance to leaf water vapor diffusion by 150% during the first few days and by 80% thereafter. Transpiration of outer foliage of salt cedar was reduced 50% initially and 20% after two weeks without phytotoxicity.

Coping behaviour: correlates of survival on a raft.

The seven survivors of a shipwreck, involving ten men, were interviewed within a few days of rescue. They had been floating in a rubber raft for 9 days and had thereafter been on an isolated rocky beach for four days. Three of the men walked through dense bush to obtain help. Rescue came on the thirteenth day. The purpose of the authors' examination was to identify those behaviours which the survivors reported as helping them to cope during their ordeal. The most prominent of these were attachment ideation, drive to survive, modelling, prayer and hope. Attachment behaviour is described in some detail as a most potent, but inadequately recognised coping behaviour.

Studies on the Ecology of Haemaphysalis silacea Robinson 1912 (Acarina: Ixodidae)

Haemaphysalis silacea Robinson is known to be established only in the Eastern Cape Province of South Africa, in localized areas of Fish River Bush in the river valleys and in the coastal bush complex. In the Kowie River valley, it was shown that the distribution of larvae is limited by microclimatic conditions. The humid leaf litter zone in the dense vegetation on the river banks and along minor tributaries is the focus of the larval population. Nymphs are most numerous in drier microhabitats on the wooded, river floodplain. Larvae are active during the humid conditions of autumn and early winter, nymphs during late winter and spring, and adults during the hot, dry summer months. The main hosts of H. silacea are artiodactyls, which are numerous in the dense Fish River Bush. The host/tick interaction occurs as a result of the daily movements and feeding habits of the hosts.

A comparative study on the wintering ecology of four species of Emberiza in the basin of Chikuma River

1. The ecology of four species of Emberiza wintering along the basin of Chikuma River in Nagano, was studied comparatively with road-side census method during February to April, 1969 (four times) and November, 1969 to April, 1970 (seven times), taking a fixed route of 6km.2. Analyses of census data were made by dividing the winter season into 4 periods, dividing census route by 500m sections and classifying the habitat into 15 environments.3. The numerical dominance among four species were: E. rustica 65.1%, E. cioides 31.1% E. schoeniclus 3.4% and E. spodocephala 0.4%4, E. cioides was widely distributed with no particular concentration with the occurrence rate 83.3-100% (Av. 97.4%) and dominance 5-14%; E. rustica had local concentrations, with occurrence rate 41.7-91.6% (Av. 71.2%) and dominance 0.7-46%; E. schoeniclus was restricted in particular habitat and E. spodocephala was very few in number and was found extremely localized.5. The flock size of E. cioides ranged 1-20 birds and that of E. rustica 1-300 birds, and the latter was unstable (reflecting its migratory habit) in relation to the grassy area of the habitat, while E. cioides was well dispersed and stable (reflecting its sedentary nature), 6. E. cioides gathered at less grassy elevated spots, while E. rustica formed large flock at lower wet grassy places. E. schoeniclus occurred singly or in small parties selecting the reeds or long grass areas. E. spodocephala was also found by singles or in small groups in reeds or bank sides.7. In summary, each species requires a set of habitat. E. cioides seeks a patch of dry ground with fallen grass seeds, with some nearby bushes to escape in; E. rustica prefers wetter part with plenty of grass seeds and some dense bushes or trees to escape on; E. schoeniclus restricts itself to reeds, and other tall water vegetations and E. spodocephala is partial to grassy bushes with nearby feeding ground where grass seeds are to be found.

Preliminary Notes on the Suni, Nesotragus Moschatus and Red Duiker, Cephalophus Natalensis

AbstractVery few studies have been done on the Suni. These tiny antelopes are threatened by extinction and for this reason an investigation seemed extremely necessary. It was convenient to study the Red Duiker at the same time, since both species inhabit the same bush country.The Suni live in pairs occupying a very small territory. They are very shy animals and only come out of the bush into the open when weather conditions are very favourable. Investigations in the dense bush, where they occur, were therefore extremely difficult. The Suni feed mainly on small shrubs, leaves and fruits.It was observed that the Red Duiker, living in the same habitat, reacts much more quickly, occupies a larger territory, but was seen more often, because of its bright reddish-brown colour and since it also occurs in greater numbers.

Home range structure of a population of Aegithalos caudatus

1. The structure and distribution of pair territories of Aegithalos caudatus in breeding season was studied. Then, the winter flock territory was discussed in comparison with them. The field studies were made at foot zone in 5 breeding seasons during 1964 and 1968. The habitat was mixed woods of middle Honshu, Japan, consisting of Quercus serrata, Castanea creata, Larix leptolepis and Pinus densifrora.2. Breeding territorialism was discussed with analyses on pair behaviors, distribution of activity loci, movements, fighting behavior and helpers.3. The pair formation behavior was not observed in spring but was confirmed in summer and autumn of the previous year. Pairs split from winter flock, and at interval stage of pair formation, one or several pair flocks existed. These flocks were involved within their common range of winter flock. The range of pair flock was communally defended by members of the same flock against adjacent such flocks. Pairs occur in the winter flock and gradually become isolated with each other, but never go out of the winter flock range.4. At night, all the pairs assemble to one winter roost, but during the day each of them is engaged in nest-building at separate place. In early spring, nesting is done only in the morning, returning to flock life in the afternoon, especially when the weather is bad.As breeding season advances, pairs remain more of the time in their own territories.5. Pair ranges established by dividing a winter flock range are considerably overlapped, especially at their previous center of the flock. The pair of dominant male first become independent against the group of pairs of subordinate males, which settle at or near the flock center.6. During early stage, all the pairs splitted from a common winter flock make a group and communally fight against the members of other such groups. At the stage of completion of outerwall of the nest, pairs roost in it and completely isolate themselves from the flock.7. The highest frequency of fighting is seen in nesting period when copulation occurs, and thus the territoriality in this species becomes the most evident and its territorialism is perfectly established. After that, the fighting frequency and territory size markedly decrease.Under such condition, the social structure settles and production of the next generation is under way. But, in reality, this stable condition is greatly disturbed by predation on their nests and various behaviors of renesting are resumed.8. A pair has a few central areas with highest activity density which never overlap with those of adjacent pairs. The patrolling course for maintaining the pair range starts from the central area and return to it. On patrolling along the periphery of the pair range, the pair would fly against the adjacent pair when they meet.9. The male show many available nest sites to the female who determines one of them as their nest. The male after this event performs several nest-invitation displays which remind behavior patterns of courtship and mating. The nest is not necessarily located at the central area, though in most cases it is found in or near it. Although the nest is made often in a branch of pine, typically it is concealed in a dense bush.10. Pairs renest when the first nest is destroyed, often beyond a few adjacent pair ranges. However, the site of renesting is never selected outside of the winter flock range and tend to be correlated with the previous activity range.11. In nestling and fledgling periods, the helpers are observed, but never before that. The helpers consist of unmated birds and unsuccessful breeding pairs. As soon as young birds become independent from the parents, the helpers and young birds make a family flock with the parent birds.

A System for Radio-Tracking Monkeys in Dense Bush and Forest

A study aimed at establishing the role played by vervet menlkeys (Cercopithecus aethiops) in the transmission cycle of an insect-borne virus made use of a radio-tracking system to determine the territorial behavior of these animals. Most of the study area was covered by dense bush and tall7 caxlopied riverine forest. The radio-tracking system was designed to utilize horizontally polarized radio waves because, in passing through dense vegetation, these suffer less attenuation than vertically polarized waves. Consequently, a tracking system was evolved that differed in several respects from the more com- monly used systems based on vertical polarization. The transmitters were attached to the animals by means of collars that also served as antennas. The signals were received on a horizontal Yagi antenna in contrast to the often-used loop antenna. A short operating wavelength of 3.5 m was selected because it facilitated the de,sign of the receiving antenna and improved the range. The performance of the sys- tem proved adequate for the requirements, and the results showed that the monkeys are strictly territorial; the sizes of their territories varied with the nature of the habitats. Abstract: A study aimed at establishing the role played by vervet menlkeys (Cercopithecus aethiops) in the transmission cycle of an insect-borne virus made use of a radio-tracking system to determine the territorial behavior of these animals. Most of the study area was covered by dense bush and tall7 caxlopied riverine forest. The radio-tracking system was designed to utilize horizontally polarized radio waves because, in passing through dense vegetation, these suffer less attenuation than vertically polarized waves. Consequently, a tracking system was evolved that differed in several respects from the more com- monly used systems based on vertical polarization. The transmitters were attached to the animals by means of collars that also served as antennas. The signals were received on a horizontal Yagi antenna in contrast to the often-used loop antenna. A short operating wavelength of 3.5 m was selected because it facilitated the de,sign of the receiving antenna and improved the range. The performance of the sys- tem proved adequate for the requirements, and the results showed that the monkeys are strictly territorial;

SOME PRELIMINARY OBSERVATIONS ON THE FOOD OF ELEPHANT IN THE TSAVO ROYAL NATIONAL PARK (EAST) OF KENYA

SummaryThe background to this study is discussed. In the last five years elephant have caused a change in vegetation from dense bush to open country over large regions near the permanent water supplies in the Tsavo Royal National Park (East) of Kenya. Much destruction has also been caused, or aggravated, by fire. (See Map 1).In the 1961 drought, rhinoceros appeared to have suffered from competition with elephant for food, to the point of starvation, but there did not seem to be serious competition in normal dry seasons, such as 1962. In the drought the destruction of trees and bushes by elephant occurred to a far greater extent than during the dry season of 1962.The records of plants eaten apply specifically only to the areas where the data were collected (see Map 2), but probably in a more general manner to the Park as a whole. These plants, with their observed relative importance, are listed in Appendix I. It is emphasised that this study is as yet only in a preliminary stage, and should continue for several years, before final conclusions can be drawn.Elephant were found to eat a few plants in bulk at a particular time, such as grasses, creepers and herbs, along with smaller quantities of other materiai such as bark and leaves. Grasses were always of varying importance. Bark and leaves formed a larger proportion of the food in the dry season than in the rains, but were always eaten to some degree. The plant species of which the feeds were composed varied seasonally and annually. Certain apparently suitable plants were not eaten.Many food plants were analysed, and a few of these results are briefly mentioned. It appears possible that the eating of bark is a search for calcium, as the barks consumed are very rich in this mineral. Feeding behaviour is briefly described.

Seasonal fluctuations of the Kestrel and other birds, near Jusangai-chiff, Nagano

During October, 1953 and January, 1956, bird observations were made at Jusangai-cliff along Yomase River, Nagano; weekly in the breeding season of 1954 and fortnight in 1955 through the year. Bird counts were made one hour before sunset along the cliff, about 70m. long, at a walking speed, average 0.9km./h. The Kestrel, Falco tinnunculus, was the dominant species. It came for breeding in late February and the maximum numbers of adult birds were 32 (March 14) in 1954 and 36 (June 19) in 1955. The nests were 12 in 1954 and 11 in 1955. The fledglings were seen at the entrance of nest-holes from late May. Their maximum numbers were 27 and 26 in 1954 (June 20) and 1955 (May 28) respectively. These numbers are conservative because not all young birds appear at the entrance, and fledged ones sat in dense bushes, which made exact counts difficult. They began to leave the area in late August and all have disappeared by the beginning of October, followed by the adult birds in early November. Only a few birds remained during the winter, and their number was subject to a certain depth of snow cover (20 cm.), which would have hindered their food search. The fluctuations of other birds, very few in number compared with the Kestrel, are also given in Table II.