2026-10-14T05:13:17Z https://api.figshare.com/v2/oai

oai:figshare.com:article/29695685 2026-09-21T01:06:09Z category_24400 item_type_3 month_year_09_2026

<b>Repeated parasitism of individual female Dark-eyed Juncos (</b><b><i>Junco hyemalis)</i></b><b><i> </i></b><b>by Brown-headed Cowbirds (</b><b><i>Molothrus ater)</i></b><b><i> </i></b><b>over two decades</b> Abbigail Turner (11520397) Dustin G. Reichard (5011310) Mark. E. Hauber (12012356) Animal behaviour brown headed cowbird dark eyed junco brood parasitism repeated parasitism <p dir="ltr">Repeated interactions between individual brood parasites and their hosts within and between breeding seasons are an understudied dynamic of most host-parasite systems due to a lack of longitudinal data. Dark-eyed Juncos (<i>Junco hyemalis</i>) are a common host that accepts and raises offspring of obligate brood parasitic Brown-headed Cowbirds (<i>Molothrus ater</i>). The Ketterson-Nolan lab at Indiana University has collected long-term, publicly available data on this host-parasite system in Virginia, USA, which allowed us to examine the occurrence and effect of repeated cowbird parasitism on color-banded individuals of a host species across twenty-two years. Based on previous data collected elsewhere on this and other cowbird hosts, we hypothesized that some individual juncos in this system would experience repeated parasitism within and between breeding years and that the likelihood of repeated parasitism would be negatively related to the reproductive success of the host. We did not detect a statistical pattern of repeated parasitism of female juncos within the same breeding year. In contrast, we found that juncos that were parasitized in their first year were statistically more likely to be parasitized in subsequent breeding years relative to females that had not been parasitized at the onset of their breeding. Current reproductive success was not related to the likelihood of future parasitism. However, the number of breeding years was a significantly positive predictor of whether a female junco was ever parasitized in her lifetime. Our findings align with other studies on Brown-headed Cowbird hosts; however, the factors that affect the patterns of repeated brood parasitism of the same individual hosts remain unknown in this system.</p> 2026-09-21T01:06:09Z Dataset Dataset 10.6084/m9.figshare.29695685.v1 https://figshare.com/articles/dataset/_b_Repeated_parasitism_of_individual_female_Dark-eyed_Juncos_b_b_i_Junco_hyemalis_i_b_b_i_i_b_b_by_Brown-headed_Cowbirds_b_b_i_Molothrus_ater_i_b_b_i_i_b_b_over_two_decades_b_/29695685 CC BY 4.0