Sage-grouse survey uses innovative approach to find endangered birds in Saskatchewan
The dramatic decline in greater sage-grouse numbers in Canada has given it the unenviable status as one of the most endangered bird species in the country and various conservation efforts are taking place to identify and protect critical habitat areas.
A 2012 survey indicated 93 to 138 individual birds are still in Canada, which is an all-time low.
Their distribution in Canada is limited to the sagebrush and native prairie areas in southeastern Alberta and southwestern Saskatchewan.
A presentation at the Best Western Inn in Swift Current on March 27 highlighted the results of a project that used microphones and field cameras during the 2013 spring survey in Saskatchewan to identify the presence of sage grouse at historic breeding sites.
The event was hosted by the Saskatchewan Prairie Conservation Action Plan as part of its Native Prairie Speaker Series and the presenter was Beatriz Prieto, a terrestrial ecologist in the Science and Assessment Unit of the Fish and Wildlife Branch of the Saskatchewan Ministry of Environment.
“This is just a method that will detect the presence of the birds in areas where the birds used to be,” she said. “So we’re talking about inactive or historical lek sites or breeding sites and we just want to make sure we know if the birds are coming back to those sites that were abandoned at some point.”
A lek is a dancing area where male birds will gather in early spring to compete for space and to impress the females with their boisterous behaviour.
“They have air sacks that they move up and down,” she explained. “They produce these strutting sounds to try to attract females and that’s what we’re looking after when we set up those microphones, trying to record those strutting sounds that they make.”
The number of active leks in Saskatchewan has declined rapidly, especially in the past 10 years. During the 2012 survey only 18 males were counted at leks in Saskatchewan, which indicated a population of 54 to 80 adults in the province. The same survey counted 13 males at leks in Alberta that suggested a population of 39 to 58 adults.
The Saskatchewan Ministry of Environment conducted an extensive aerial and ground survey of sage-grouse habitat in 2012 with limited success.
“We visited more than 30 different sites that were historical records for sage grouse and all we got was beautiful sunrises and beautiful sunsets,” she said.
The ministry’s limited resources resulted in a decision to follow a different approach during the 2013 spring survey in an attempt to monitor the return of sage grouse to inactive lek sites.
“The chances of finding the bird are low and we don’t have enough people,” she said. “We thought we need to design an appropriate and effective long-term monitoring program for greater sage grouse using non-intrusive and passive surveillance methods.”
Eight sites where sage grouse might potentially occur were used for the project. Three trail cameras and two microphones were installed at each site during the period April 11 to May 7, 2013. The equipment remained on a site for six to seven consecutive days.
Important benefits of this approach are little disturbance to birds and it is an effective way to survey multiple sites at the same time. The project provided the survey team with 852.5 hours of sound recordings and 2,000 photographs.
“The trail cameras did not provide any positive results,” she said. “We went through all those 2,000 pictures, no birds.”
Two recognizer models were created to analyse the sound recordings, but there were some accuracy problems with the identification of actual sage-grouse sounds. According to Prieto one of the reasons for these difficulties was the use of recorded sage-grouse sounds from Wyoming to create the recognizer models.
“So we’re thinking they might be a little different to what our birds sound like,” she said. “That’s one of the actions we have for this year — trying to get some better quality recordings from our own birds so we can build a model based on that and maybe the model will be improved if we are able to do that.”
There were some positive results from the sound recordings. They were able to identify sage grouse at three of the sites. The one site is inside the Grasslands National Park and the other two sites are located near the Alberta border on the western side of the distribution area for sage grouse in Saskatchewan.
The results from this survey method will be used to prioritize conservation efforts in the areas where birds were found. The project will continue this year, but they will only use microphones because the trail cameras were not really effective.
Their goal this spring is to locate active lek sites in the areas where sage-grouse sounds were positively identified last year.
“We’re going to go out with direction microphones and try to see if we can follow the sound and actually get to the lek and figure out where they are,” she said. “So that’s going to be a lot of work. It’s a difficult task but hopefully we can find those birds.”
Another objective for 2014 is to obtain higher-quality recordings of Saskatchewan sage grouse to improve the recognizer model.
“So we’re going to try to get closer to a lek that we know the birds are there and try to record their strutting sound,” she said.
The ministry’s broader objective for the project is to develop a systematic sage-grouse monitoring program in Saskatchewan that can be used in areas where the birds have not been active for some time.
“The idea is to develop a national methodology by which we could go out and survey a certain number of historical sites per year and still make sure that we know if the birds are coming back to those sites,” she said.
via SW Sask News – Prairie Post – Prairie Post http://ift.tt/1pWbHDY