The most important cue to observe when nest-searching is bird behavior. Cape Sable seaside sparrows nest in grass cups in the marl prairies of the Everglades, so finding their nest without watching them can be nearly impossible. Nest-finding has been my favorite aspect of all of my positions as a field technician, so I want to share what I believe is one of the most rewarding days in the field: finding a nest.

A marl prairie in the Everglades: there are Cape Sable seaside sparrow nests somewhere out there.

When we know where there is a breeding pair, we go to the territory area first thing in the morning and watch the pair. It is not unusual to spend a whole day’s work trying to find one nest, especially if the female is on eggs. It’s the easiest to find a nest when there are nestlings because the adults are making constant trips to the nest with food as long as no one is too close to the nest. If they aren’t going to a nest and are constantly chipping, we back away. They generally will calm down and go feed their young once we are about 30 meters from the nest area. Once we see the adults go into the grasses a few times, we can get a good idea of where the nest is. Flagging areas around where they disappeared into the grasses can help as a reference point.

Finding a nest with eggs tends to be more difficult. The female only gets off the nest every 40 minutes to eat, so you have to be watching the right area to know when she is off. She will come back after ten to twenty minutes, which is when it is very important to watch where she goes. Once we see her disappear, we walk to the area to see if we can flush her off the nest and have an easy find. Often that doesn’t happen, so we flag the area and wait for her next feeding trip where we can observe how close she is to our reference point and at what angle. This makes it much easier to find the nest the second (or third…or fourth) go around. Once we are pretty confident about the area where the nest is, we search the grass clumps for a grass cup containing eggs or nestlings.