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Detectability of penguins in aerial surveys over the pack-ice off Antarctica


, : Detectability of penguins in aerial surveys over the pack-ice off Antarctica. Wildlife Research 35(4): 349-357

Knowledge of penguin abundance at regional and circumpolar scales across the Southern Ocean is important for the development of ecosystem models and to estimate prey consumption by penguins to assess potential competition with fisheries' operations. One means of estimating penguin abundance is to undertake aerial surveys across the pack-ice surrounding Antarctica where penguins forage. However, it has long been recognised that aerial counts and resultant abundance estimates are likely to be negatively biased unless detectability is estimated and taken into account. Mark-recapture line-transect methods were used to estimate the detectability of penguin groups resting on ice floes during helicopter surveys over the pack-ice off Antarctica. Group size had the greatest effect of several measured covariates on detectability. Despite a concerted effort to meet the central assumption of conventional line-transect sampling (all objects on the transect line are detected), this was close to being achieved by single observers only in the case of the occasional very large group of > 20 penguins. Emperor penguins were more detectable than Adelie penguins. Although observers undertook an extensive simulation training program before the survey, overall they improved in their ability to detect penguin groups throughout the survey. Mark-recapture line-transect methods can provide less biased estimation than conventional line-transect methods in aerial survey applications. This improvement comes with some costs, including the need for more demanding data-recording procedures and the need to use larger, more expensive aircraft. These additional costs will often be small compared with the basic cost, but the gain in terms of improved estimation may be substantial.

US$19.90

DOI: 10.1071/WR07093


Other references

Gaylord, C.; Hodge, H.C., 1944: Duration of sleep produced by pento-barbital sodium in normal and castrate female rats. Normal and castrate [female] rats were given 30 mg. of pentobarbital/kg. of body wt. subcut. The normal rats slept significantly longer than did the castrate rats. Both groups of rats were exposed to various environmental temps., specifically 13[d...

Winfield, G.F., 1937: Studies on the control of fecal-borne diseases in North China. I. Problems and methods. "This paper is the first of a series reporting the results of studies on composting as a farm process in North China to control faecal-borne diseases and to increase fertilizers." Winfield surveys the problem and discusses the methods of...

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Dilanyan, Z.K.; Alagezyan, R.G., 1973: Demonstration of bactericidal effects of disinfectants. In the USSR 2 microorganisms (Escherichia coli and Staphylococcus aureus) have been so far used to establish the bactericidal effect of dairy disinfectants. It is concluded from studies using highly phenol- and heat-resistant cultures of E. coli,...

Lu, S-shan.; Zou, R.; Xu, J-wei., 2005: Relationship between prognosis of nasal inverted papilloma and human papillomavirus types. To detected HPV human papillomavirus DNA and HPV types in NIP nasal inverted papilloma, to inquire into the infection of HPV in the pathogenesis of NIP, and the relationship of HPV with the prognosis of NIP. Twenty-eight cases of NIP were divided...

Spivey, K.A.; Banyard, J., 2010: A prognostic gene signature in advanced ovarian cancer reveals a microfibril-associated protein (MAGP2) as a promoter of tumor cell survival and angiogenesis. Ovarian cancer is the most lethal gynecologic cancer, and this is largely related to its late diagnosis. High grade serous cancers often initially respond to chemotherapy, resulting in a better survival rate, compared to other ovarian carcinoma su...

Nance Richard, 1970: Positions of lunar features from Apollo 8. Journal of Geophysical Research 75(11): 2029-2034

Estraneo, A.; Pascarella, A.; Moretta, P.; Masotta, O.; Fiorenza, S.; Chirico, G.; Crispino, E.; Loreto, V.; Trojano, L., 2017: Repeated transcranial direct current stimulation in prolonged disorders of consciousness: A double-blind cross-over study. To evaluate effects of 5 sessions of transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex in patients with prolonged disorders of consciousness (DOC). Seven patients in vegetative state (VS) and 6 in minimall...

Rabiratna Dash; Varma, S.C., 2003: Management of weeds, nitrogen and tillage operations in wheat (Triticum aestivum) sown after puddled rice (Oryza sativa). A field experiment was conducted on wheat cv. HUW 234 in a rice-wheat cropping system during the 1999-2000 winter season in Varanasi, Uttar Pradesh, India, to evaluate 3 tillage systems (no-tillage, no-tillage with mulching and conventional tillag...

Dillon T.F., 1982: Use of prostaglandins in menstrual induction in 1st trimester pregnancy. Contraceptive Delivery Systems 3(3-4): 263