I had a rather different take on what "science" is in this context. I was thinking of things like:
* Did someone survey the species so they know what they have? If not, go do that.
* Are they then counting the species regularly to determine which if any can be harvested, and if so, in what numbers? If not, go do that.
* You don't actually have to have a conservation goal. You can just decide to set off some land not to be developed. "Never go there" is a great standard of conservation management, and science not only bothers the wildlife but tempts people to meddle. If you have a goal, however, you should write it down and periodically check to see if you are achieving it. If not, you need to change something, which means also having a plan on how to do that.
* There are lots of different goals. A conservation goal may be to make the environment more like it was before humans messed with it. A production goal is very different. That means you want to go in and get something out of it. For instance, you might manage deer for bigger bucks, or just as many deer as possible. It depends whether you want to hang the head on a wall or eat the meat. (Big bucks = nice rack but tough as jerky right off the hoof. Lots of yearlings = no rack but many small packets of tender delicious meat.) Both of of those goals are in play at different locations. Now to do it right, you have to start by estimating what actions will move toward that goal; then track results; and if it's not working, take new observations to figure out what went wrong and fix it. Lather, rinse, repeat. Scientific method lends itself quite well to things like "I think doing X will put more wild turkeys in this habitat."
* Is anyone out there doing experiments, observations, or other scientific projects? Some places are really into tagging and tracking critters to see how they behave, which can give really good ideas on how to manage them.
Thinking about the stuff the article cited as science:
* Clear objectives. These are really optional. Your management can consist of, well, NOT managing it. We need to do more of that. But if you choose to set objectives, they should indeed be clear, written out, and easily accessible. I recommend making a thumbnail that will fit on one page, so you can post it on walls, then support with as much detail as desired in a manual.
* Use of evidence. They skipped the very important step of gathering information. You have to do that before you can use it. If you are doing it, you should use proper scientific methods. You can actually gather it and do nothing with it. There have been a number of studies, now crucial, where people did nothing more than record everything in sight and then cache it for later reference, so now we know what the baseline was 50 or 100 years ago. Once you have information, you can use it to make good plans. What you should NOT do is pretend to be using evidence when you are not, or Newton forfend, crop the data. Those are definitely not science.
* Transparency. Not actually required. Plenty of conservationists have done very important work without mentioning it to anyone, or actively hiding it because conservation was unfashionable at the time. Some of the best fragments of redwood forest and prairie that we have left exist because someone stashed them -- and some of those folks were citizen scientists who helpfully recorded their observations for years but kept their yap shut, and it only came out after they died. Not all management projects are public; many a landed hunter has quietly managed his territory for what pleases him, and maybe shared with a few friends, but these guys can be as tight-lipped about how they maximize game as they are about their fishing holes. In a public organization, transparency is desirable to discourage misbehavior and encourage information exchanges that may lead to improvement.
* External review. As above, not required, for the same reasons. Now if you want to use the scientific techniques of peer review and replication, you will need this; but there are other things that can be done with science than just that. If you are handling large sums of other people's money, or public resources, then external review is highly advisable to discourage misbehavior.
I suspect that production and honesty would be more effective if we did more of most of these things. Conservation? Not so much. The more human activity -- and that includes scientists hiking around bothering the wildlife and hanging equipment on them and scaring some of them to death and scaring a lot more of them away -- the less wildlife. If you want conservation, you are better off NOT doing science to it. Leave it the fuck alone.
It would be nice if state agencies were more meticulous about their science. But that requires money, and preferably, money not coming from hunter lobbies who may be interested in slipping a thumb onto the scales. That doesn't seem likely any time soon. So think about what your standards are for science in wildlife management, then look at the groups around you and see who measures up or not.
One of my favorite groups is Pheasants Forever. Leaving aside that ringnecks are an invasive species, PF also promotes habitat for many other game species such as quail, wild turkey, and deer. For instance, they have biologists developing mixes for native seed and food plot seed. They've done a lot of figuring out how to make more birds. While the main angle is hunting (birds are delicious) they also support conservation in general. It's a popular resource who guys who are tired of that hard-to-reach, low-yield patch of mostly weeds on their farm. Throw down some native seed and ignore it, or plant a food plot and hunt it. You want to do homemade science, try planting a different mix on different plots and tally the traffic in each. Sometimes their fair booth has handouts on the results people have gotten from various mixes or methods, which is fun to read.