{"title":"A parasite reduction conservation intervention does not improve fledging success or most condition metrics for Purple Martins","authors":"Heather M. Williams, K. Dittmar, S. S. Pagano","doi":"10.1093/condor/duaa051","DOIUrl":null,"url":null,"abstract":"ABSTRACT Eastern Purple Martins (Progne subis subis) have an unusually close relationship with humans, as they nest exclusively in man-made nest boxes. Current conservation policy directly promotes further interaction with this species by advocating regular replacement of nest materials during the nestling phase to reduce ectoparasite load and increase nestling fitness. We conducted the first test of the efficacy of this recommendation and found that it was partially effective in reducing parasite abundance, but had no effect on nestling fledging success, body mass, leukocyte count, or triglyceride or uric acid concentration. We found a small but significant increase in nestling hematocrit associated with nest material replacement, implying that parasites may induce nestling anemia. Contrary to our expectations, we also found elevated heterophil/lymphocyte ratios in nestlings with replacements, possibly indicating elevated physiological stress associated with nest replacements. Based on our results, we do not recommend nest material replacements to combat routine parasite infestations. LAY SUMMARY Purple Martins are believed to have a high abundance of blood-feeding parasites (fleas, mites, and blowfly larvae) in their nests. A current conservation policy recommends that nest box managers regularly remove and replace nest materials during the nestling phase to reduce parasite abundance. We tested the efficacy of this policy. Nest replacements reduced flea and blowfly larvae abundance, but mite abundance rebounded quickly. There was no difference in fledging rate, body mass, white blood cell count, or triglyceride or uric acid levels for nestlings with or without nest replacements. Nestlings with nest replacements were less anemic and had a higher ratio of heterophils to lymphocytes.","PeriodicalId":50624,"journal":{"name":"Condor","volume":" ","pages":"1 - 14"},"PeriodicalIF":2.6000,"publicationDate":"2020-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/condor/duaa051","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Condor","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1093/condor/duaa051","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ORNITHOLOGY","Score":null,"Total":0}
引用次数: 2
Abstract
ABSTRACT Eastern Purple Martins (Progne subis subis) have an unusually close relationship with humans, as they nest exclusively in man-made nest boxes. Current conservation policy directly promotes further interaction with this species by advocating regular replacement of nest materials during the nestling phase to reduce ectoparasite load and increase nestling fitness. We conducted the first test of the efficacy of this recommendation and found that it was partially effective in reducing parasite abundance, but had no effect on nestling fledging success, body mass, leukocyte count, or triglyceride or uric acid concentration. We found a small but significant increase in nestling hematocrit associated with nest material replacement, implying that parasites may induce nestling anemia. Contrary to our expectations, we also found elevated heterophil/lymphocyte ratios in nestlings with replacements, possibly indicating elevated physiological stress associated with nest replacements. Based on our results, we do not recommend nest material replacements to combat routine parasite infestations. LAY SUMMARY Purple Martins are believed to have a high abundance of blood-feeding parasites (fleas, mites, and blowfly larvae) in their nests. A current conservation policy recommends that nest box managers regularly remove and replace nest materials during the nestling phase to reduce parasite abundance. We tested the efficacy of this policy. Nest replacements reduced flea and blowfly larvae abundance, but mite abundance rebounded quickly. There was no difference in fledging rate, body mass, white blood cell count, or triglyceride or uric acid levels for nestlings with or without nest replacements. Nestlings with nest replacements were less anemic and had a higher ratio of heterophils to lymphocytes.
期刊介绍:
The Condor is the official publication of the Cooper Ornithological Society, a non-profit organization of over 2,000 professional and amateur ornithologists and one of the largest ornithological societies in the world. A quarterly international journal that publishes original research from all fields of avian biology, The Condor has been a highly respected forum in ornithology for more than 100 years. The journal is one of the top ranked ornithology publications. Types of paper published include feature articles (longer manuscripts) Short Communications (generally shorter papers or papers that deal with one primary finding), Commentaries (brief papers that comment on articles published previously in The Condor), and Book Reviews.