Wolf scat and seabird bracelets: finding better methods to monitor wildlife

So what do wolf scat and seabird bracelets have in common? They've both been subjects of recent studies exploring better methods for collecting data on wildlife movement. When researchers develop methods to study ecology, they have to think about a variety of theoretical issues. However, the practical issues are usually the most daunting. How much does it cost? Does it negatively impact the species? Can research assistants and volunteers realistically do it? Each of the studies below addresses these issues.

Testing the effect of data loggers on diving sea birds...Great cormorant. Image credit, J.M. Garg.
In a study published in the Journal of Zoology, researchers looked at the effect of data logging devices on birds. Scientists frequently attach data loggers to birds to determine their location at sea. However, in the past, scientists have found that these devices may negatively affect birds - for example by throwing off their balance or affecting their diving ability - particularly when the device exceeds 3% of the mass of the animal. This obviously has ethical implications - the first rule of thumb of conservation science should be 'do no harm.' It can also throw off (literally) the data you're trying to collect.

A lightweight type of data logger called a Global Location Sensor holds promise and is increasingly being used but its impacts on birds have yet to be studied extensively. In a recent study published in the Journal of Zoology, scientists looked at how global location sensors attached to the legs of birds, affect swimming and diving behavior. The researchers looked at male cormorants (Phalacrocorax carbo) raising chicks on Qeqertaq Island in the Diskofjord Area of West-Greenland during June and July 2004. The study found that global location sensors did not have any short-term effects on swimming and diving behavior of the cormorants. This is good news for scientists looking for non-invasive methods for studying seabirds.

Wolf scat collection as a non-invasive alternative to physical capture...
Gray wolf (canis lupus).Monitoring populations of rare, wide-ranging, elusive mammals can be challenging. Wolf monitoring programs have often relied on physical captures, collaring and radiotelemetry, a method that is logistically difficult and expensive to implement. One can imagine that physical captures are not entirely pleasant for the animal either.

In a study published in the Journal of Applied Ecology, scientists tested a non-invasive and cost-effective method for studying wolves, Canis lupus, in the Western Alps. Rather than physically capturing individuals, the method involves the ongoing collection and genetic testing of wolf scat otherwise known as "genetic capture-recapture."

The research team comprised of scientists from Montana, Italy and France, used the genetic capture-recapture approach to monitor wolf population size over seven years (1999–2006) and estimate survival rates. Wolves are a fully protected species in Western Europe having recently recolonized the Western Alps of Italy after 70years. The researchers found that the wolf population increased over the duration of the study, as did the number of packs. This study marked the first systematic, precise estimate of wolf population and survival in the Western Alps.

Source:	Journal of Applied Ecology
Title:	Wolf survival and population trend using non-invasive capture-recapture techniques in the Western Alps
Authors:	Francesca Marucco, Daniel Pletscher, Luigi Boitani, Michael Schwartz, Kristy Pilgrim and Jean-Dominique Lebreton

Source:	Journal of Zoology
Title:	Leg-attached data loggers do not modify the diving performances of a foot-propelled seabird
Authors:	Y. Ropert-Coudert , A. Kato, N. Poulin & D. Grémillet