Another video of a rat attacking a seabird: http://www.arkive.org/henderson-petrel/pterodroma-atrata/video-14.html. There was an unsuccessful attempt to remove rats on Henderson recently. Details can be googled. Those interested in the science might consult: Brooke MdeL, O\'Connell TC, Wingate D, Madeiros J, Hilton GM, Ratcliffe N (2010) Potential for rat predation to cause decline of the globally threatened Henderson petrel *Pterodroma atrata*: evidence from the field, stable isotopes and population modelling. Endang Species Res 11:47-59
On the Samoan rat video commentary "Given the strong, a priori rat indictment, it is also unclear whether any other finding would be acceptable to the investigators." Is this an opinion or *ex cathedra*? Do you have any actual reason to doubt the impartiality/professionalism of the researcher? Attacking grad students is not very impressive, especially if you don't read what they actually said: http://www.petridish.org/projects/saving-an-endangered-bird-the-mao: "To understand the impact of introduced predators we are putting nest cameras on morenests to determine if adult birds are also at risk. (Contrary to Matt's assertion, the proposal says nothing about cameras to document further rat predation on chicks although it is true that such coverage might refine estimates of incidence of such predation)" and "We are also trying to determine if other predators (like feral cats) are affecting young birds after they leave the nest by tracking chicks with transmitters. (Transmitters are different from cameras)" "It would be interesting to know. Knowing either way would not necessarily improve conservation efforts." The recovery plan http://www.sprep.org/att/IRC/eCOPIES/Countries/Samoa/53.pdf makes it clear that the species is disappearing in forest, as well as following forest destruction (p. 9). Rats or cats are suggested as a cause of loss in forest. As the plan suggests, there is now the capability to remove black rats over large areas and populations of Mao could be established on rat free islands. It appears abundantly clear in a real world sense that knowing the effect of rats would "improve conservation efforts" by defining choices. "I wonder if rats could learn to associate human activity with food sources." Rat association with humans seems to have started with the arrival of agriculture (cf http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0026357). Cats as commenseals with humans for rodent control go back almost ten thousand years in Egypt, suggesting rats learned the association a rather long time ago (JA Serpell - The domestic cat: The biology of its behaviour, 2000). There is a rather large literature that answers this question, albeit the question appears irrelevant here. I am sure no one would accuse Matt of bloviating academic logorrhea, but I for one would wish he would read more carefully and reflect more on what he says before he says it. Cheers, David On Wed, Jun 6, 2012 at 8:48 PM, Matt Chew <[email protected]> wrote: > The link I received in the digest included extra characters. Here it is > without them (unless the server is inserting them after the = character) > http://www.youtube.com/watch?v=Y38B8aDfPjQ > > According to the species (Gymnomyza samoensis) recovery plan (see > www.sprep.org/att/IRC/eCOPIES/Countries/Samoa/53.pdf), deforestation, > including that attributed to major cyclones, is thought to have had the > largest effect on these birds. They also have a traditional reputation for > being harbingers of death due to their unusual calls. Traditional risk > management has included the familiar 'kill the messenger' approach. > > The executive summary of the recovery plan mysteriously suggests that the > birds are feeding on the nectar of introduced trees, although I can't find > that claim elsewhere in the document. Also according to the recovery plan > (citing ISSG data), Samoa's three rat species "are considered to have > arrived before 1924." One of them, Rattus exulans, has presumably been > pan-Polynesian for many centuries; the others for perhaps one or two > centuries. I can find no data suggesting their ranges or populations are > still increasing in Samoa, rendering the "invasive" label somehow even less > meaningful than usual. > > In summary: Two years ago, some kind of rat made off with a 'mao' egg. > Maybe it happens all the time, maybe only rarely. It would be interesting > to know. Knowing either way would not necessarily improve conservation > efforts. > > Actually, let's just cut to the chase. At YouTube we learn the video was > posted to raise money for a PhD project on the putative basis that > "introduced rats are having an enormous impact predating chicks and eggs in > the nest." Since the student wants money for (among other things) > additional cameras to document this predation, it remains unclear whether > predation by introduced rats is a major issue. But it already seems to be > more than a hypothesis. Given the strong, a priori rat indictment, it is > also unclear whether any other finding would be acceptable to the > investigators. Skip the extraneous "free video" YouTube step and decide > on the merits whether this proposal inspires you to chip in: > http://www.petridish.org/projects/saving-an-endangered-bird-the-mao > > I wonder if rats could learn to associate human activity with food sources. > > > Matthew K Chew > Assistant Research Professor > Arizona State University School of Life Sciences > > ASU Center for Biology & Society > PO Box 873301 > Tempe, AZ 85287-3301 USA > Tel 480.965.8422 > Fax 480.965.8330 > [email protected] or [email protected] > http://cbs.asu.edu/people/profiles/chew.php > http://asu.academia.edu/MattChew > -- Pacific Cooperative Studies Unit Botany University of Hawaii 3190 Maile Way Honolulu Hawaii 96822 USA 1-808-956-8218
