I started taking my son in the field to monitor Bald Eagle and Peregrine Falcon nests when he was 3 weeks old, progressing through to his teen years in snotty weather; i.e. rainy/snowy Oregon/U.S. Pacific Northwest. We (he and I only) started using an over the shoulder baby sling (many varieties available), which worked well because you can put your binocs next to the baby to keep the optics warm so they don't fog up, and it is adjustable so you can vary how and where on your body your bioblob can be carried outside or inside of your jacket. The baby sling also allows you to use a lighter backpack to carry your field gear, milk, and extra diapers, and allows you to adjust the twerp as you walk through brush and over slippery downed logs.
Our hikes often were several to multiple miles over mountainous terrain and were amongst the absolute pleasures of my life; as an infant he slept through most of it, but I hope he sensed how important it was for me to share the wonderment of wild habitat. He always was swathed in cloth diapers and wool diaper covers, and later I invested in good wool and synthetic snivel gear (mostly patagonia) for him, which worked incredibly well; easy to change and throw into a bag. As he grew older, I rigged a seat to put him in the upper portion of my gregory backpack, rather than use the larger framed child pack; but he did have that as well. And when he could walk, he walked; we went slower, but it worked out well despite skinned knees, muddy hands, and the attention span of a munchkin. He turned out well-adjusted, and is in forestry school, despite the inherent risks he experienced with me. I am happy that he has taken my affliction and love of outdoors and wild locales and turned it into a well rounded understanding of personal risks and responsibility while in places far from roads and hospitals. I consider myself lucky; my father, who is also in 'our' natural resources profession, let me hang out with him fighting wildland fires and working on controlled burns at a young age; and encouraged my participation in fieldwork with his friends who were game wardens, foresters, wildland firefighters, fisheries biologists, and wildlife ecologists starting when I was 7 years old. I find the discussion and advice to Simone to be amazing, and somewhat disconcerting. As an ecologist, I would hope that we would combine our brains and passions to heartily encourage any and all of us who have well-behaved children to take them in the field.
