Invasive species can lead to dramatic native species loss and ecosystem change. In Australia the invasive cane toad has been shown to have adversely affected populations of native Australian predators such as snakes and quolls, which die after consuming toads. In contrast, anecdotal reports suggest than many native birds prey upon cane toads with no adverse effects, and that some birds have learned how to handle toads such that they do not come in contact with the poison glands. The questions of whether cane toads seriously affect populations of native birds, or if birds have the potential to control toad populations, have not been studied.
The main objectives of my research are:
Identify bird species potentially at risk from eating toxic toads.
Determine if birds with cosmopolitan distribution show greater tolerance to toad toxins than endemic species.
Expand our knowledge of the impacts of cane toads on bird populations.
Identify the potential role of native birds in population control of cane toads.
My Masters research focused on the behavioural response to predation risk during reproduction in passerines. In response to perceived risk of predation, many animals reduce their level of activity presumably so that they are less likely to be detected, and therefore killed, by a predator. Such behavioural flexibility has been reported for a variety of species but has primarily been studied in the context of foraging decisions during non-reproductive life stages. My general objective was to examine activity patterns by two species of passerine birds during both the incubation and brood-rearing stages of breeding to determine if perceived predation risk elicited a reduction in activity levels as it does with other animals during non-reproductive periods. I found that behavioural changes exhibited by both species were dependent on food availability, the study species, predator type, and stage of breeding.
Beckmann, C., P.A. Biro, and J.R. Post. 2006. Asymmetrical impact of pisciverous birds on size-structured fish populations. Canadian Journal of Zoology 48:1584-1593.
Pearman, M. and C. Beckmann. 2006. Influence of nest box design on box choice by mountain bluebirds and tree swallows. Blue Jay 64(4):186-190.
Beckmann, C. 2008. An intraspecific killing in Reef Egrets (Egreta scara). Wilson Journal of Ornithology 120:422-424.
Biro, P., C. Beckmann, and M.S. Ridgway. 2008. Early microhabitat use by young-of-the-year brook charr (Salvelinus fontinalis) in lakes. Journal of Fish Biology 73:226-240.
Beckmann, C., and R. Shine. 2009. Are Australia's birds at risk due to the invasive cane toad? Conservation Biology 23:1544-1549.
Biro, P.A., C. Beckmann, and J.A. Stamps. 2010. Small within-day increases in temperature affects boldness and alters personality in coral reef fish. Proceedings of the Royal Society of London B 277:71-77
Beckmann, C., and R. Shine. 2010. The power of myth: the (non) impact of invasive cane toads (Bufo marinus) on domestic chickens (Gallus gallus). Animal Production Science 50:847-851.
Beckmann, C., and R. Shine. 2011. Toad's tongue for breakfast: exploitation of a novel prey type, the invasive cane toad, by scavenging raptors in tropical Australia. Biological Invasions 13:1447-1455.
Beckmann, C., M. R. Crossland, and R. Shine. 2011. Responses of Australian wading birds to a novel toxic prey type, the invasive cane toad Rhinella marina. Biological Invasions: in press.
Beckmann, C., P.A. Biro, and J.R. Post. 2001. The impact of piscivorous birds on rainbow trout populations in lakes. Canadian Conference for Fisheries Research, Toronto, Canada. Oral presentation
Beckmann, C. and R.M. Brigham. 2004. Predation risk reduces chick provisioning in tree swallows (Tachycineta bicolor). University of Regina Graduate Day of Seminars, University of Regina, Canada. Oral presentation
Beckmann, C. and R.M. Brigham. 2004. The effects of perceived predation risk on incubation behaviour in two species of passerines. Prairie Universities Biological Symposium, University of Alberta, Canada. Oral presentation
Beckmann, C. and R.M. Brigham. 2004. The effects of perceived predation risk on incubation behaviour in two species of passerines. American Ornithologists' Union and Society of Canadian Ornithologists Joint Meeting, University Laval, Quebec City, Canada. Oral presentation
Beckmann, C. and R. Shine. 2007. The invasive cane toad and Australia's native birds: who is at risk? American Ornithologist's Union, University of Wyoming, Laramie WY, USA. Poster presentation
Beckmann, C. and R. Shine. 2007. The invasive cane toad and Australia's native birds: who is at risk? Australasian Ornithological Conference, University of Western Australia, Perth WA. Oral presentation