![]() After 21 years of birding in Glacier and about three years of blood, sweat, and swearing. Glacier is for the Birds; a Trail Guide to the Birds of Glacier National Park is finally here. It is a trail guide covering 48 trails, roads, or other locations with details on what you will find along the way. It focuses on birds first and foremost with descriptions of where to find over 170 species. It also covers plants, geology, mammals, basic ecology, and recommendations for what to do, where to do it, and when. It's written conversationally because it's meant to be a substitute for when you can't just have me walk along the trails with you. It's meant for people who like (or think they might like) birds, but it can also take the place of a more universal trail guide because of all the other good, non-avian information, not to mention the 55 maps, it contains. ![]() Within the trail descriptions are 42 informational boxes giving facts and ideas about such topics as the importance of a fungus to cavity nesting birds, historic fire regimes and how GNP deals with fire, Darwin's ideas on species, beaver as restoration ecologists, giardia, moose, and several covering geology. An appendix gives suggestions for what to do if you only have one day, if you need to stay near your car, or if you love to hike. In the intro I talk about how humans are actually more similar to birds than to other mammals in some important ways and I give tips for birdwatching in Glacier, especially given there are big, furry mammals with sharp teeth traipsing about. It's already on Amazon, but if you are going to buy it, I'd prefer you purchase it here: https://www.createspace.com/6249233.
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Picture in your mind a farmer’s field that was left fallow for a year. What would you expect to see growing? Weeds, mostly. Right? How about after 5 years? Maybe some shrubs and small trees? 50 years? A young forest, perhaps? In one hundred years you’ll likely see a mature forest and in 500 years, probably a different forest type altogether – the “climax” forest. This process is called succession and all landscapes go through it. The pattern and speed of the succession may differ among locations, and there may not truly be any set endpoint or “climax” for any particular area. But, you get the idea.
What natural disturbances like fire, flood, avalanche, and tornadoes do is knock succession back a few “seral stages,” a few years, tens of years, or even hundreds of years. Take fire, for instance. Some fires are hot enough that they can take a mature forest and bring it back to, basically, bare dirt. Here in Glacier, avalanches tend to take mature forest and convert it to shrubs. Even bear digs are a natural disturbance. These are areas that look like a rototiller has gone through. It’s just bears digging up roots and bulbs. They take a meadow and return it to dirt. Dirt that has been nicely seeded with the plants they turned over. You call them “natural disasters” back home, but these natural disturbances are the reason you go to a place like Glacier National Park! You could have just gone to the zoo in your home town or an arboretum or botanical garden. That would have been much easier than coming all the way out here! But you didn’t. Why? Because something is happening here. There are processes. It is a system. There are interactions. Ecology. Natural disturbances are part of that process and a part that creates the diversity of habitats that we birders love. The reason why Glacier has an amazingly high number of breeding bird species is, in part, those disturbances. We have been taught by Disney to cherish the “balance of nature.” There is no true balance, there is constant change and chaos. And life has evolved to deal with and take advantage of this lack of balance. Below are drafts of two of the over 50 maps contained in Glacier is for the Birds. They were designed following the KISS principle in an attempt to make them useful, but uncluttered.
Black-headed Grosbeak are big, robin-sized birds that are a gorgeous combination of Black, yellow and orange. They are so striking that people often confuse them with Orioles. They also have a long and loud song, like a whistling Robin, that they will sing over and over. So, how is it that they can hide so well? You can hear the bird and know it is “just right there!” But, then you can look for ages, initially intrigued, then more and more annoyed as they continue to evade detection.
This relatively common phenomenon brings up a couple of interesting topics. Natural selection has caused these brightly colored birds to evolve adaptations to avoid detection by predators. Only the males that successfully avoid being eaten end up passing their genes on to the next generation. So, they tend to sit still while singing, making sighting them more difficult. Their songs also are difficult to localize. They often sound much closer and higher up then they actually are – they throw their voices. This then brings up the question of how can evolution cause these birds to avoid detection on the one hand and yet be brightly colored and loud on the other. The simple answer is that natural selection is not the only mechanism of evolution. Survival doesn’t automatically cause your genes to make it into the next generation. You also have to reproduce. So, behaviors and characteristics that help females find you and recognize you as a particularly studly male (e.g. bright coloration and long, loud song) will be passed on in greater abundance to the next generation. Just because they are brightly colored doesn’t mean they are easy to see. |
Top of page photo by Randy Patrick
David Benson Ph.D.White-tailed Ptarmigan researcher and National Park Service Ranger Naturalist in GNP since 1995. "The Bird Ranger" Archives
June 2019
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