Digital records of Brown-headed Cowbirds removing eggs and nestlings from nests of grassland passerine birds in southwest Wisconsin

We present digital recordings from video surveillance systems at nests of grassland birds. Video surveillance systems were used as part of grassland bird studies done in southwestern Wisconsin. Study sites were clustered near Mt. Horeb (43.0167°N, 89.7500°W). Four grassy field types were studied: continuously-grazed pasture, prairie, and cool- and warm-season grass fields. The digital recordings archived here were used to document egg and nestling destruction by the Brown-headed Cowbird (Molothrus ater)., We used video surveillance systems at nests to identify the nest predators in all the studies. We prioritized putting video surveillance systems on nests of obligate grassland birds, followed by facultative grassland birds, and finally generalist birds that occurred in the grasslands. In general, we used cameras with infrared light-emitting diodes (LEDs) that facilitated recording quality images under low-light conditions. We distributed cameras among fields to avoid clustering and we set up cameras at nests during or soon after the egg-laying stage ended to lower the chance for abandonment. Recording systems were attached to cameras with 25-m cables (following the protocol established by Renfrew and Ribic 2003). Each camera was mounted on a wooden dowel 3 – 38 cm above the ground. Cameras were 64 cm3 and placed 12 –25 cm from the nest, depending on the nest structure and surrounding vegetation. The field of view at these distances ranged from 414 to 1,320 cm3. Cameras were typically pl..., , # Digital records of Brown-headed Cowbirds removing eggs and nestlings from nests of grassland passerine birds in southwest Wisconsin

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We present digital recordings from video surveillance systems at nests of grassland birds. Video surveillance systems were used as part of grassland bird studies done in southwestern Wisconsin. The digital recordings archived here were used to document egg and nestling destruction by the Brown-headed Cowbird (Molothrus ater). Study sites were clustered near Mt. Horeb (43.0167°N, 89.7500°W). Four grassy field types were studied: continuously-grazed pasture, prairie, and cool- and warm-season grass fields.

We used video surveillance systems at nests to identify the nest predators in all the studies. We prioritized putting video surveillance systems on nests of obligate grassland birds, followed by facultative grassland birds, and finally generalist birds that occurred in the grasslands. In general, we used cameras with infrared light-emitting diodes ...