: The US Fish and Wildlife Service and the Alaska Department of Fish and Game have cooperated since 1984 to develop and evaluate satellite telemetry as a means of overcoming the high costs and logistical problems of conventional VHF (very high frequency) radio-telemetry systems Detailed locational and behavioral data on caribou (Rangifer tarandus), polar bears (Ursus maritimus), and other large mammals in Alaska have been obtained using the Argos Data Collection and Location System (DCLS) The Argos system, a cooperative project of the Centre National d'Etudes Spatiales of France, the National Oceanic and Atmospheric Administration, and the National Aeronautics and Space Administration, is designed to acquire environmental data on a routine basis from anywhere on earth Transmitters weighing 16-20 kg and functioning approximately 12-18 months operated on a frequency of 401650 MHz Signals from the transmitters were received by Argos DCLS instruments aboard two Tiros-N weather satellites in sun-synchronous, near-polar orbits Data from the satellites were received at tracking stations, transferred to processing centers in Maryland and France, and made available to users via computer tape, printouts, or telephone links During 1985 and 1986, more than 25,000 locations and an additional 28,000 sets of sensor data (transmitter temperature and short-term and long-term indices of animal activity) were acquired for caribou and polar bears Locations were calculated from the Doppler shift in the transmitted signal as the satellite approached and then moved away from the transmitter The mean locational error for transmitters at known locations (n = 1,265) was 829 m; 90% of the calculated locations were within 1,700 m of the true location

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Satellite Telemetry: A New Tool for Wildlife Research and Management,

Philopatry in migratory species can apply to any location used during the annual cycle. The degree of philopatry influences the genetic structure of populations, but only at the stage of the annual cycle when pair formation and gene exchange occur. Because pair formation in birds typically occurs during the breeding season, most studies have fo- cused on breeding-site philopatry. Waterfowl (Anseriformes) are an important exception to this pattern because pair formation often occurs during the winter months. Yet, surprisingly few studies have examined winter philopatry in waterfowl. To serve as an impetus for future research, we summarize published information on winter philopatry in waterfowl and ex- amine these patterns in light of current hypotheses proposed to explain philopatric behavior. Our analyses indicate that geese, swans, and sea ducks show high levels of winter philopatry, with homing rates varying between 49 and 98% to small study areas. In contrast, return rates (0 to 20%) and homing rates (35 to 85%) to large study areas probably are comparatively lower for dabbling ducks and pochards. Unfortunately, detailed comparisons among groups are hindered by variation in the scale at which philopatric behavior is evaluated (ranging from <1 km2 to 105 kM2), and by confounding of return rates with homing rates. Future studies of winter philopatry would benefit by the adoption of a more standardized meth- odology. Many of the hypotheses proposed to explain breeding philopatry apply equally well to winter philopatry. In particular, both genetic and ecological mechanisms may play a role in the evolution of philopatry to the wintering ground. Additional field studies are needed to test these hypotheses, and we suggest future directions for a more detailed ex- amination of this neglected area of research. Received 9 September 1996, accepted 28 April 1998.

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Winter philopatry in migratory waterfowl

/pdf/pesticide-use-and-toxicology-in-relation-to-wildlife-1mxa3qv8pa.pdf

Pesticide Use and Toxicology in Relation to Wildlife: Organophosphorus and Carbamate , Compounds

Analyse de la taille des populations de canards pilet et de leur succes reproducteur en relation avec les conditions de l'habitat au printemps (mares temporaires dans les prairies de nidification), en hiver (precipitations en Californie) et la chasse

Relationships of Population Size and Recruitment of Pintails to Habitat Conditions and Harvest

If we consider a multi-year tagging study where tag returns are obtained from a recreational or commercial fishery it is possible to estimate total annual survival rate. The methodology has been described in detail by Brownie et al. (1985). Fishery biologists would also like to be able to estimate natural and fishing mortality rates from these data but this is not possible without the additional assumption that all tags are reported. Sometimes high reward tags are used in the hope of satisfying this assumption. In this paper we review the theory of the tagging models and then show how to estimate the reporting rate of tags by conducting a creel surveyor port sample in conjunction with the tagging study. It is then possible to partition total mortality into fishing and natural mortality. The question of additive versus compensatory mortality processes can then be addressed. 3 In recent years there has been a lot of work on the analysis of multi-year banding studies for migratory birds. The methodology has been described in detail by Brownie et al. (1985). Although this methodology has been developed in a wildlife context it is just as applicable to fisheries tagging studies. In fact, it was partly a study on lake trout (see Youngs and Robson 1975) that led to much of the recent work. Pollock and O'Connell (1989) apply the Brownie models to Pacific Halibut (Hippoglossus stenolepis) tagging studies. In this paper we first review the Brownie models emphasizing model structure and assumptions. We then discuss the use of reward tags as a method of estimating reporting rate of regular tags; this allows conversion of recovery rates to fishing mortality rates. Following this, we consider the most important work in our paper which is how to use a creel surveyor port sample to estimate reporting rate as an alternative to use of reward tags. Finally we discuss the important implications of this approach which allows separate estimation of fishing and natural mortality rates. REVIEW OF TAGGING MODELS Concepts To begin our review of the tagging models described by Brownie et al. (1985) let us consider the possible fates of a fish tagged at the start of the year based on the diagrams in Brownie et al. (1985, p. 14) (Figure 1). Our notation for mortality rates follows Ricker (1975). We have: S = the finite survival rate or the probability of surviving the year, u = the finite exploitation rate or the probability of being harvested, and A = the tag reporting rate, or the probability that a tag will be found and reported to the fisheries biologist given that the fish has been harvested.

Don Rees

Papers

Population Ecology of the Mallard, VIII, Winter Distribution Patterns and Survival Rates of Winter Banded Mallards