Browsing by Author "Quigley, Howard B."

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    Long term monitoring of jaguars in the Cockscomb Basin Wildlife Sanctuary, Belize; Implications for camera trap studies of carnivores
    Harmsen, Bart J.; Foster, Rebecca J.; Sanchez, Emma E.; Gutierrez-Gonzalez, Carmina E.; Silver, Scott C.; Ostro, Linde E. T.; Kelly, Marcella J.; Kay, Elma; Quigley, Howard B. (PLOS, 2017-06-28)
    In this study, we estimate life history parameters and abundance for a protected jaguar population using camera-trap data from a 14-year monitoring program (2002–2015) in Belize, Central America. We investigated the dynamics of this jaguar population using 3,075 detection events of 105 individual adult jaguars. Using robust design open population models, we estimated apparent survival and temporary emigration and investigated individual heterogeneity in detection rates across years. Survival probability was high and constant among the years for both sexes (φ = 0.78), and the maximum (conservative) age recorded was 14 years. Temporary emigration rate for the population was random, but constant through time at 0.20 per year. Detection probability varied between sexes, and among years and individuals. Heterogeneity in detection took the form of a dichotomy for males: those with consistently high detection rates, and those with low, sporadic detection rates, suggesting a relatively stable population of ‘residents’ consistently present and a fluctuating layer of ‘transients’. Female detection was always low and sporadic. On average, twice as many males than females were detected per survey, and individual detection rates were significantly higher for males. We attribute sex-based differences in detection to biases resulting from social variation in trail-walking behaviour. The number of individual females detected increased when the survey period was extended from 3 months to a full year. Due to the low detection rates of females and the variable ‘transient’ male subpopulation, annual abundance estimates based on 3-month surveys had low precision. To estimate survival and monitor population changes in elusive, wide-ranging, low-density species, we recommend repeated surveys over multiple years; and suggest that continuous monitoring over multiple years yields even further insight into population dynamics of elusive predator populations.
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    Right on track? Performance of satellite telemetry in terrestrial wildlife research
    Hofman, M. P. G.; Hayward, M. W.; Heim, M.; Marchand, P.; Rolandsen, C. M.; Mattisson, J.; Urbano, F.; Heurich, M.; Mysterud, A.; Melzheimer, J.; Morellet, N.; Voigt, U.; Allen, B. L.; Gehr, B.; Rouco, C.; Ullmann, W.; Holand, O.; Jorgensen, n H.; Steinheim, G.; Cagnacci, F.; Kroeschel, M.; Kaczensky, P.; Buuveibaatar, B.; Payne, J. C.; Palmegiani, I.; Jerina, K.; Kjellander, P.; Johansson, O.; LaPoint, S.; Bayrakcismith, R.; Linnell, J. D. C.; Zaccaroni, M.; Jorge, M. L. S.; Oshima, J. E. F.; Songhurst, A.; Fischer, C.; McBride, R. T. Jr.; Thompson, J. J.; Streif, S.; Sandfort, R.; Bonenfant, C.; Drouilly, M.; Klapproth, M.; Zinner, D.; Yarnell, R.; Stronza, A.; Wilmott, L.; Meisingset, E.; Thaker, M.; Vanak, A. T.; Nicoloso, S.; Graeber, R.; Said, S.; Boudreau, M. R.; Devlin, A.; Hoogesteijn, R.; May-Junior, J. A.; Nifong, J. C.; Odden, J.; Quigley, Howard B.; Tortato, F.; Parker, D. M.; Caso, A.; Perrine, J.; Tellaeche, C.; Zieba, F.; Zwijacz-Kozica, T.; Appel, C. L.; Axsom, I.; Bean, W. T.; Cristescu, B.; Periquet, S.; Teichman, K. J.; Karpanty, Sarah M.; Licoppe, A.; Menges, V.; Black, K.; Scheppers, T. L.; Schai-Braun, S. C.; Azevedo, F. C.; Lemos, F. G.; Payne, A.; Swanepoel, L. H.; Weckworth, B., V.; Berger, A.; Bertassoni, A.; McCulloch, G.; Sustr, P.; Athreya, V.; Bockmuhl, D.; Casaer, J.; Ekori, A.; Melovski, D.; Richard-Hansen, C.; van de Vyver, D.; Reyna-Hurtado, R.; Robardet, E.; Selva, N.; Sergiel, A.; Farhadinia, Mohammad S.; Sunde, P.; Portas, R.; Ambarli, H.; Berzins, R.; Kappeler, P. M.; Mann, G. K.; Pyritz, L.; Bissett, C.; Grant, T.; Steinmetz, R.; Swedell, L.; Welch, R. J.; Armenteras, D.; Bidder, O. R.; Gonzalez, T. M.; Rosenblatt, A.; Kachel, S.; Balkenhol, N. (PLOS, 2019-05-09)
    Satellite telemetry is an increasingly utilized technology in wildlife research, and current devices can track individual animal movements at unprecedented spatial and temporal resolutions. However, as we enter the golden age of satellite telemetry, we need an in-depth understanding of the main technological, species-specific and environmental factors that determine the success and failure of satellite tracking devices across species and habitats. Here, we assess the relative influence of such factors on the ability of satellite telemetry units to provide the expected amount and quality of data by analyzing data from over 3,000 devices deployed on 62 terrestrial species in 167 projects worldwide. We evaluate the success rate in obtaining GPS fixes as well as in transferring these fixes to the user and we evaluate failure rates. Average fix success and data transfer rates were high and were generally better predicted by species and unit characteristics, while environmental characteristics influenced the variability of performance. However, 48% of the unit deployments ended prematurely, half of them due to technical failure. Nonetheless, this study shows that the performance of satellite telemetry applications has shown improvements over time, and based on our findings, we provide further recommendations for both users and manufacturers.