Risk and Benefits of Early Migration
Here on my nature blog here you will constantly see me noting my first of the year sightings! Normally those are the birds trying to be the first on their breeding grounds. These early birds are the experienced adults taking advantage of the many benefits of arriving early. Those males who arrive first will have their first choice in the most suitable nesting habitat and provide a better chance for the males to be pair up with a female. These earlier nesting pairs will then have a longer nesting period with a better fledgling success rate. Those individuals that show up later will then result in a less suitable habitat where they could have less available food for their young. Obviously this will reduce their chances of producing successful fledglings and open up the opportunity for predators finding their nest.
These long-distance migrants have many hazardous obstacles that the birds will need to avoid during their migration. My Ornithology text book by Frank Gill states “More than half the small land birds of the Northern Hemisphere never return from their southbound migration”. This is so hard to believe but there are so many physical risk that they encounter like: exhaustion, predators or even the weather. It was my post yesterdays where I discussed temperatures being in the ~70sF (Tuesday’s 1/2 day off). There were a few species including a dragonfly which I had listed as my first for the year find. Could they be risking their lives for the possible benefits of arriving early? (more…)
Mon@rch's Nature Blog 