Tag Archives: conservation

Detection Dogs and DNA on the Trail of Endangered Lizards

Detection dogs trained to sniff out the scat of an endangered lizard in California’s San Joaquin Valley, combined with genetic species identification, could represent a new, noninvasive sampling technique for lizard conservation worldwide. That is according to a study published by the University of California, Davis, in partnership with the nonprofit Working Dogs for Conservation, U.S. Geological Survey and the U.S. Bureau of Land Management.

Scientists have used trained conservation dogs to locate scat and collect DNA samples for everything from bears and foxes to gorillas and whales. But the technique had not been used for reptiles until this study, for which scientists developed a novel approach to identify the presence of the blunt-nosed leopard lizard in the Panoche Hills Recreation Area and Carrizo Plain National Monument, both managed by BLM.

They developed new methods to recover DNA from feces and genetically identify lizard species in the same area. The study, published in the Journal of Wildlife Management, is a proof of concept for a host of reptiles.

Lizard detection dog

Seamus, a trained detection dog, alerts his handler to the presence of scat. (Mike Westphal, Bureau of Land Management)

“So many reptilian species have been hit so hard,” said lead author Mark Statham, an associate researcher with the Mammalian Ecology and Conservation Unit of the UC Davis School of Veterinary Medicine. “A large proportion of them are endangered or threatened. This is a really valuable way for people to be able to survey them.”

No direct contact needed

Current methods for surveying lizard species typically rely on live capture or visual surveys. Scat sampling allows biologists to study elusive, rare or dangerous animals without the need for direct contact. In addition to informing about the presence, habitat and genetics of an animal, scat can also be analyzed to inform researchers about diet, hormones, parasites and other health factors.

Using the new method, the authors genetically identified specific species for 78 percent of the 327 samples collected by dog-handler teams across four years. Most (82 percent) of those identified were confirmed as being from blunt-nosed leopard lizards.

To meet regulatory monitoring requirements, more research is needed to assess the viability of using detection dogs to recover usable DNA at larger scales. But the research highlights the broad potential this method holds for surveying and monitoring reptiles.

Funding was provided by the Bureau of Land Management.

Source:  UC Davis media release

Trained dogs most efficient in monitoring hermit beetle larvae

Hermit beetles (Osmoderma eremita) are considered at risk, but in order to be effectively protected, they first need to be identified and consistently monitored.

However, this turns out to be a tough task, given that the species is only present for a short time as an adult while it is also extremely elusive. On the other hand, although it remains as a larva for up to three years, once again, it is difficult to spot as it hides inside hollow trees living in the wood mould.

The standard method for detecting hermit beetles involves wood mould sampling which is not only arguable in its overall efficiency, but is also unreasonably time-consuming and quite damaging to both the species communities and their habitat.

Searching for an alternative, Italian scientists, led by Dr. Fabio Mosconi of the Italian Agricultural Research Council and Sapienza University of Rome, suggested that trained dogs might be more successful. Such conservation detection dogs are currently being widely deployed when searching for mammals, reptiles and birds and have already been tested for locating a number of invertebrates.

In their paper, published in the open access journal Nature Conservation, the team tested a training programme before comparing it with the traditional method. The study has been conducted as part of the MIPP Project aimed at the development of non-invasive methods for monitoring selected saproxylic beetles.

Starting from the choice of a dog, the scientists carefully made their choice from a number of individuals as well as breeds. They settled on a Golden Retriever – a breed widely used in searches for biological targets. As for the particular dog, they chose Teseo – a six-month pup coming from a line with a strong background in locating illegally imported animals and animal parts.

Conservation dog

The training of Teseo began with the assignment of a trainer/handler and some basic obedience training, involving teaching simple commands, search games and agility activities.

The next step was introducing the dog to various types of odours, since the hermit beetles might give off a different odour dependent on their habitats, such as the presence of fungi, sawdust and other organic materials. Immediately after detecting the target smell, the animal would be given a reward such as food or play, so that its behaviour could be positively reinforced.

Then, the dog was taught to differentiate between different odours. The researchers presented a number of targets to the animal where it needed to select the right one. At this stage, the dog was only rewarded for correct signalling. Should the dog be distant from the trainer, a special clicker was used to ‘announce’ the treat in advance. The researchers noted that it was at this stage when the relationship between the dog and the handler needed to be really strong, so that the training was as efficient as possible.

In conclusion, the scientists reported a significantly higher probability (73%) of Teseo successfully detecting a tree colonised by the larvae, as opposed to two people conducting the traditional wood mould sampling (34-50%). Moreover, the dog would cover a particular area in a very short time when compared to the traditional method – on average it would take it 6 minutes and 50 seconds to examine the whole tree, while the operators using wood mould sampling would need about 80 minutes. Additionally, searching for larvae with dogs poses no risk to either the insects or other organisms that might be living in the trees.

Furthermore, the researchers provided a list of precautions in order to increase the efficiency when searching for beetle larvae with the help of trained dogs. The list included familiarising the dog with the survey site beforehand, opting for the part of the day with the most favourable atmospheric conditions and carefully monitoring the dog for signs of fatigue.

“A conservation detection dog is a powerful tool for locating O. eremita and these results can be useful for other related European species of Osmoderma“, commented the scientists.

“In fact, the use of a trained dog is a fast, accurate and non-invasive method that allows the detection of a target species in an area and to identify the colonised trees; this means that a conservation detection dog can locate new populations, can confirm the presence of the target species and can assist in the mapping of colonised trees in an area, accurately and efficiently.”

Source:  Pensoft Blog