Search

Human harvests can unwittingly drive evolution on morphology and life history, and these selective effects may be detrimental to the management of natural resources. Although theory suggests that harvest refuges, as sources of unselected animals, could buffer the effects of human exploitation on wild populations, few studies have assessed their efficiency. We analyzed records from >7000 trophy bighorn rams (Ovis canadensis) harvested in Alberta, Canada, between 1974 and 2011 to investigate if the movement of rams from refuges toward harvested areas reduced the effects of selective harvesting on horn size through phenotypic rescue. Rams taken near refuges had horns on average about 3% longer than rams shot far from refuges and were slightly older, suggesting migration from refuges into hunted areas. Rams from areas adjacent to and far from harvest refuges, however, showed similar declines in horn length and increases in age at harvest over time, indicating a decreasing rate of horn growth. Our study suggests that the influx of rams from refuges is not sufficient to mitigate the selective effects of sheep trophy harvest. Instead, we suggest that selective hunting of highly mobile animals may affect the genetic structure of populations that spend part of the year inside protected areas.

European settlement led to extirpation of native Audubon's bighorn sheep (formerly Ovis canadensis auduboni) from North Dakota during the early 20th century. The North Dakota Game and Fish Department subsequently introduced California bighorn sheep (formerly O. c. californiana) that were indigenous to the Williams Lake region of British Columbia, Canada, and Rocky Mountain bighorn sheep (O. c. canadensis) that were indigenous to the Sun River region of Montana. Although California bighorn sheep are no longer recognized as a distinct subspecies, they are smaller and adapted to a milder climate than either the native bighorn sheep of North Dakota or introduced bighorn sheep from Montana. Because reintroductions still play a key role in the management of bighorn sheep and because local adaptation may have substantial demographic consequences, we evaluated causes of variation in recruitment of bighorn sheep reintroduced in North Dakota. During 2006–2011, Montana stock recruited 0.54 juveniles/adult female (n = 113), whereas British Columbia stock recruited 0.24 juveniles/adult female (n = 562). Our most plausible mixed-effects logistic regression model (53% of model weight) attributed variation in recruitment to differences between source populations (odds ratio = 4.5; 90% CI = 1.5, 15.3). Greater recruitment of Montana stock (fitted mean = 0.56 juveniles/adult female; 90% CI = 0.41, 0.70) contributed to a net gain in abundance (r = 0.15), whereas abundance of British Columbia stock declined (fitted mean = 0.24 juveniles/adult female; 90% CI = 0.09, 0.41; r = − 0.04). Translocations have been the primary tool used to augment and restore populations of wild sheep but often have failed to achieve objectives. Our results show that ecotypic differences among source stocks may have long-term implications for recruitment and demographic performance of reintroduced populations. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Wild sheep in North America are highly prized by hunters and most harvest regulations restrict legal harvest to males with a specified minimum horn curl. Because reproductive success is skewed toward larger males that are socially dominant, these regulations may select against high-quality, fast-growing males. To evaluate potential selective effects of alternative management strategies, we analyzed horn increment measures of males harvested over 28 yr (1975-2003) in 2 bighorn sheep (Ovis canadensis) ecotypes in British Columbia, Canada. Using mixed- effect models we examined variation in hunter selection for horn size, early horn growth, and male age under different harvest regulations (Full Curl, Three Quarter Curl, Any Ram). Under all regulations, males with the greatest early horn growth were harvested at the youngest ages, before the age at which large horns influence reproductive success. Early growth decreased with harvest age and until � 7 yr of age it was greatest in males harvested under Full Curl regulation. Permit type (General vs. Limited Entry Hunt) and hunter origin (British Columbia Resident vs. Non- Resident) had little effect on horn size of harvested males. Full Curl regulations increased the average age of harvested males by

Argali sheep (Ovis ammon) are the world's largest wild sheep and are threatened throughout their range in Mongolia. Little is known about the ecology of this highly cursorial species. This project was initiated to develop safe capture techniques in order to learn more about the ecology of argali in the Ikh Nartiin Chuluun Nature Reserve in southeastern Mongolia by using radiotelemetry. To our knowledge no one had ever successfully live-caught a free-ranging argali. We developed three techniques for capturing argali. From 2003 to 2007 we hand captured 65 argali lambs, losing one (our first capture) to maternal neglect because we stayed too long in the area and a second that was euthanized after being accidentally injured by a horse. Between 2000 and 2003 we captured six argali by darting, losing one ewe to an abdominal infection after a misplaced dart. Finally, between 2002 and 2007 we captured 32 argali by drive-netting. We lost one ewe to over-exertion after a long drive. The remaining 31 animals captured by drive-netting did not appear to suffer any immediate effects (still alive in 30 days). This report will discuss the strengths and weaknesses for each of these capture techniques. Zoo Biol 27:137-144, 2008. (c) 2008 Wiley-Liss, Inc.

Paphos forest, Cyprus. Unpublished PhD thesis, University of Edinburgh. McPHe, H. C., RUSSEL, E. Z. & ZELLER, J. (1931): An inbreeding experiment with Poland China swine. J. Hered. 2 2 393403. OBRIEN, S. J., WILDT, D. E. & BUSH, M. (1986): The cheetah in genetic peril. Sci. Am. 252(3): 84-92. PEVET, P. (1987): Environmental control of the annual reproductive cycle in mammals. In Comparaitve physiology of environmental adaptations: adaptations to climatic changes: 92-100. Pevet, P. (Ed.). Basel, Miinchen: Karger. F’FEFFER, P. (1967): Le mouflon de corse (Ovis ammon musimon Schreber, 1762): position systematique ecologie et ethologie comparbes. Mammalia 31 Suppl.: 1-262. SCHALLER, G. B. (1977): Mountain monarchs: wild sheep and goats of the Himalaya. Chicago, London University of Chicago Press. SCHALLER, B. G. & MIRZA, Z. B. (1974): On the behaviour of Punjab urial (Ovis orientalis ouniabiensis). IUCN Pubis (N.S.) No. 24: 306323. . . . . Morges: IUCN. Sou~k. M. E. (1980): Threshold for survival: ~I

At the beginning of the 19th century, the Barbary sheep Ammotragus lervia was still present throughout the whole of Egypt except for the Sinai region. However, by the beginning of the 20th century it had disappeared from the Nile Delta region and from the Faiyum Oasis. In 1950 it was still present in the extreme south-east and in a small stretch of land in the Eastern Desert, and in half of the Western Desert. Today it is found only in the extreme south-east (Gebel Elba) and the extreme south-west (Gebel Uweinat and/or Gilf El Kebir) of the country. This sharp decrease in the distribution area of Ammotragus lervia is the result of intensive hunting by humans. The Barbary sheep of Gebel Elba now live in a region that has been designated a national park, which offers some protection. The Barbary sheep populations in the Uweinat/Gilf El Kebir area is in rapid decline, and it is now urgent that the Egyptian government enforce effective conservation measures to safeguard the last wild populations of Barbary sheep still present in its territory.

Data used in recreation demand modeling are characterized by the facts that trip frequencies are non-negative integers and that consumers are often faced with alternative destinations. This paper considers these features by estimating a multivariate recreation demand model that accounts for trip frequency and choice among alternative recreation sites using a mixed multinomial-Poisson hurdle distribution. The specification of the Poisson hurdle distribution at the aggregate level accounts for participation and trip frequency, and avoids the restrictive mean-variance property of the basic Poisson model. The model is estimated using data from Bighorn sheep hunters in Alberta, Canada. Simulation results suggest that changing price and quality variables cause substitution among sites. The welfare implications of changes in these variables are also examined. Les donnees utilisees dans la modelisation de la demande de loisirs sont caracterisees par le fait que les frequences des voyages sont des entiers non negatifs et que les consommateurs sont souvent confrontes a plusieurs possibilites de destinations. Cet article considere ces caracteristiques en estimant un modele de demande de loisirs a plusieurs variables qui rend compte de la frequence des voyages et du choix des lieux de loisirs en utilisant une combinaison de la distribution multinomiale et de la distribution de Poisson avec barriere. La specification de la distribution de Poisson avec barriere au niveau agrege rend compte de la participation et de la frequence des voyages, et contourne la propriete restrictive de la moyenne-variance du modele de Poisson de base. Le modele a ete estime en utilisant des donnees collectees a Alberta, Canada, aupres de chasseurs de mouflons. Les resultats de la simulation suggerent que des variations des variables de prix et de qualite entrainent des substitutions parmi les destinations. Sont aussi examinees les implications que des variations de ces variables ont sur le bien-etre.

The seasonal variations in grouping patterns of the forest-dwelling Cyprus mouflon were examined over the annual cycle. Most of the trends observed in the size and composition of groupings agree with previous work on open-country living sheep. The main difference between Cyprus mouflon, which live in forest, and wild sheep living in open country, was in the overall group size, which is smaller in Cyprus mouflon. In fact, in their overall group size, Cyprus mouflon seem to follow the pattern of other forest-dwelling ungulates.

Female bighorn sheep were studied over a 27-month period to quantify linearity and stability of social rank; expression of behaviour as a function of rank; development of rank relationships; and reproductive correlates of rank. Females exhibited a stable, non-linear hierarchy that correlated strongly with age. Dominant females used proportionally more threats, whereas subordinates used more subordinance patterns. Females integrated into the hierarchy at1–2 years of age and then fought their way to high social status. Dominant and subordinate females did not differ in pre-natal maternal investment, but dominant females nursed lambs at higher rates, and were more likely than subordinates to nurse alien lambs after their own lamb died.

Reindeer and caribou are best known as migratory, seasonally nomadic animals; many continental populations, for example, travel between distinct summer and winter ranges which may lie hundreds of km apart. Much less is known about the movements of animals belonging to island populations. This paper describes seasonal and annual movements of wild reindeer Rangifer tarandus platyrhynchus on the high arctic archipelago of Svalbard, based on observations of nine animals captured and individually marked in Adventdalen, Spitsbergen, between 1977 and 1982. Four ear-tagged reindeer (one male and three females) were followed extensively for between four and seven years. Five radio-collared females were followed intensively for seven months in 1982. Svalbard reindeer seem neither to undertake long migrations nor to be nomadic within seasons like mountain reindeer or barren-ground caribou. They appear instead to use small, traditional, seasonal home ranges more, for example, like red deer or wild sheep. This atypical behaviour is discussed in relation to the dispersion of reindeers' resources in Svalbard.

SUMMARY 1 Life tables and survival curves were constructed for eight species of mammal from data in the records of the Zoological Society of London. 2 Upon arithmetic coordinates, all the survival curves were approximately straight lines over the period of adult life. 3 The survival curves of two species of sheep, and of hybrid wolves, were nearly identical. That of wild goats was similar in form but significantly longer in duration. 4 The data are compared with figures for wild and domestic populations of similar animals. The survival curve of wolves was approximately similar to that of wolfhounds. The maximum longevities of domestic, wild, and zoological garden sheep were similar, but the median age reached by zoological garden sheep was lower, and the early adult mortality higher, than in wild sheep subject to predation. There was no significantly greater loss of lambs in zoological garden sheep compared with agricultural flocks. 5 The relationship between survival curves obtained under these conditions and curves for wild and for fully domestic animals is discussed.

In proportion to body size, North American wild sheep (Ovis canadensis and Ovis dalli) carry the largest horns among ruminants. Their horns have been recorded as exceeding 51 inches (130 cm.) in length, and 16 inches (40.6 cm.) in circumference at the base (Anonymous, 1964). Old males may bear eight to twelve per cent of their body weight as horns. The horns of rams grow substantially in length and mass each year. This increase is greatest in the early years of life and smallest in later years. The horns of females remain quite small throughout life and rarely exceed nine inches (23 cm.) in length. The huge horns of rams invite enquiry as to what selection processes brought about and retain such disproportionate organs. Several functions can be proposed for ram horns. Horns act as weapons.-This implies that horns can inflict damage on opponents when used in fighting. This I have found. The tiny horns of mountain goat (Oreamnos), however, also serve as weapons (Geist, 1964). Hence this proposed function alone explains little about the evolution of sheep horns. Horns act as a shield.-During fighting rams attempt to catch the opponents' head blows with their horns (Fig. 1). There is little doubt that sheep horns function in this manner. Other bovids, however, also attempt to catch an opponent's attack with their horns, i.e., Bos and Bison. These cattle carry only small, curved horns. Again, this function explains by itself little about the evolution of mountain sheep horns. Horns act as shock absorbers.-During their frequent social interactions, rams collide head on. They may run on their hindlegs at each other and then jump into the clash. Since the rams may weigh about 220--250 pounds each, the collisions must be frightful. It appears quite reasonable hence, that the heavy horns function in absorbing the heavy impact. This appearance is deceptive. A number of Artiodactyla clash head on during fighting, or deal out blows with their heads. None carry horns to match those of sheep males. Though female sheep fight very similar to rams, they carry only tiny horns. The wart hogs (Phacochoerus) and giant forest hogs (Hylockoerus) in fighting clash head on after a run at each other (Mohr, 1960; Fradrich, 1965). They possess no horns at all. Bison bulls may clash head on with considerable force (McHugh, 1958). They have only tiny horns. Giraffes (Giraffa) deal out severe blows with their heads, but carry only little ossicones on the skull. All these species (including sheep of both sexes) possess however one feature in common. They have a pneumated skull with a double roof of bone over the brain. Since there is no correlation between horn size and the mode of fighting: I reject the "shock-absorption" function. Horns act as display organs.-This is an old, but unverified concept of obscure origin. Beninde (1937) stated it clearly. He proposed that large-antlered deer could intimidate small-antlered opponents with their horn size, and hence gain social advantages without fighting. This hypothesis was never carried through to its various logical conclusions and hence never verified or rejected. If the horns of mountain sheep have been selected for as display or intimidation organs, then the following predictions must be inherent

Changes in the coat and skin of a mouflon sheep were followed from the age of three months to the age of twenty-one months. The birth coat was shed between four and six months of age and there was a marked moult the following spring. During both these moults the coat was lost as a single mat. The wool of the under-coat was shed only once during the spring moult, whereas the hairs of the outer coat were shed a second time in summer, but this was less obvious than the spring moult. Details of the histology of the skin and of fibre shedding are given in addition to incidental observations on growth and the horns.