We monitored a population of American Kestrels (Falco sparverius) nesting in boxes at the northern extent of the kestrel range (between 66° and 68°N) in the Alaskan Arctic, 2002–2021. There was no significant trend in occupancy during the study period but yearly variation in occupancy was high (range = 17–70%). Occupancy rate was positively related to the lowest temperature recorded in May (7–20°C). The mean estimated clutch initiation date was 16 May ± 6 d; we observed a slight but significant trend for later clutch initiation (4 d) during the study period. Kestrel clutch size averaged 4.7 ± 1.0 (range = 1–7), brood size averaged 4.6 ± 0.8, and the mean minimum number of young fledged/successful pair was 4.9 ± 0.4. Clutch and brood sizes remained stable from 2002–2021, with no significant trend. Nest failure was low (16%). We report a late nesting and possible double brooding attempt in 2018, suggesting a possible response to the warming trend (2002–2021) in average temperatures at the end of the normal nesting season.
{"title":"AMERICAN KESTREL NESTING BIOLOGY AND LONG-TERM TRENDS IN THE ALASKAN ARCTIC: 2002–2021","authors":"E. Craig, T. Craig, Jenny McMillan","doi":"10.3356/jrr-22-12","DOIUrl":"https://doi.org/10.3356/jrr-22-12","url":null,"abstract":"\u0000 We monitored a population of American Kestrels (Falco sparverius) nesting in boxes at the northern extent of the kestrel range (between 66° and 68°N) in the Alaskan Arctic, 2002–2021. There was no significant trend in occupancy during the study period but yearly variation in occupancy was high (range = 17–70%). Occupancy rate was positively related to the lowest temperature recorded in May (7–20°C). The mean estimated clutch initiation date was 16 May ± 6 d; we observed a slight but significant trend for later clutch initiation (4 d) during the study period. Kestrel clutch size averaged 4.7 ± 1.0 (range = 1–7), brood size averaged 4.6 ± 0.8, and the mean minimum number of young fledged/successful pair was 4.9 ± 0.4. Clutch and brood sizes remained stable from 2002–2021, with no significant trend. Nest failure was low (16%). We report a late nesting and possible double brooding attempt in 2018, suggesting a possible response to the warming trend (2002–2021) in average temperatures at the end of the normal nesting season.","PeriodicalId":16927,"journal":{"name":"Journal of Raptor Research","volume":"142 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77340334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nest boxes are often used to monitor animals, and it is common practice to relocate nest boxes from unproductive sites into presumably better habitat. This relocation of nest boxes means that a given nest box program progressively monitors better sites over time. Ecological theory holds that occupancy and reproduction should generally increase with habitat quality. Thus, relocating nest boxes from poor quality sites might positively bias trends in occupancy and reproduction. These biased trends might cause researchers to be overly optimistic about the status of their focal populations. To demonstrate this potential pitfall, I built a stochastic model to simulate a nest box program that relocates the least productive 25% of nest boxes every 5 yr over a 25-yr study. The model assumed occupancy and reproduction levels for the entire population were stable throughout the study, so changes in occupancy and reproduction observed in nest boxes could only be due to relocation. I implemented this model under three settings: (1) Stable, where the same sites are monitored over the entire study; (2) Random, where the unproductive nest boxes are relocated to random sites; and (3) Learning, where the unproductive nest boxes are relocated to sites of better quality. For each of the 1000 simulations per setting, I performed logistic and Poisson regressions to determine whether there were statistically identifiable (P < 0.05) temporal trends in occupancy and number of young fledged from nest boxes. As expected, occupancy and number of offspring fledged from nest boxes were stable during the Stable simulations, and increased over the 25 yr during the Random and Learning simulations. Trends in occupancy were rarely identifiable during Stable simulations, were identifiable in 46% of simulations under Random settings, and in 97% of simulations under Learning settings. Trends in number of young fledged were identifiable in 18% of simulations under Stable settings, 91% of simulations under Random settings, and 100% of simulations under Learning settings. Such statistically significant trends, induced solely by relocating poorly performing nest boxes, represent a potential pitfall when interpreting vital rates measured using nest boxes. Potential solutions might include calculating occupancy using a subset of boxes that are never considered for relocation, or statistical models that account for preferential sampling.
{"title":"RELOCATING NEST BOXES FROM POOR QUALITY SITES CAN BIAS INFERENCE INTO POPULATION DYNAMICS","authors":"C. Mcclure","doi":"10.3356/jrr-22-50","DOIUrl":"https://doi.org/10.3356/jrr-22-50","url":null,"abstract":"\u0000 Nest boxes are often used to monitor animals, and it is common practice to relocate nest boxes from unproductive sites into presumably better habitat. This relocation of nest boxes means that a given nest box program progressively monitors better sites over time. Ecological theory holds that occupancy and reproduction should generally increase with habitat quality. Thus, relocating nest boxes from poor quality sites might positively bias trends in occupancy and reproduction. These biased trends might cause researchers to be overly optimistic about the status of their focal populations. To demonstrate this potential pitfall, I built a stochastic model to simulate a nest box program that relocates the least productive 25% of nest boxes every 5 yr over a 25-yr study. The model assumed occupancy and reproduction levels for the entire population were stable throughout the study, so changes in occupancy and reproduction observed in nest boxes could only be due to relocation. I implemented this model under three settings: (1) Stable, where the same sites are monitored over the entire study; (2) Random, where the unproductive nest boxes are relocated to random sites; and (3) Learning, where the unproductive nest boxes are relocated to sites of better quality. For each of the 1000 simulations per setting, I performed logistic and Poisson regressions to determine whether there were statistically identifiable (P < 0.05) temporal trends in occupancy and number of young fledged from nest boxes. As expected, occupancy and number of offspring fledged from nest boxes were stable during the Stable simulations, and increased over the 25 yr during the Random and Learning simulations. Trends in occupancy were rarely identifiable during Stable simulations, were identifiable in 46% of simulations under Random settings, and in 97% of simulations under Learning settings. Trends in number of young fledged were identifiable in 18% of simulations under Stable settings, 91% of simulations under Random settings, and 100% of simulations under Learning settings. Such statistically significant trends, induced solely by relocating poorly performing nest boxes, represent a potential pitfall when interpreting vital rates measured using nest boxes. Potential solutions might include calculating occupancy using a subset of boxes that are never considered for relocation, or statistical models that account for preferential sampling.","PeriodicalId":16927,"journal":{"name":"Journal of Raptor Research","volume":"52 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73733413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Winter, migration, and breeding surveys indicate widespread declines of American Kestrels (Falco sparverius; Farmer and Smith 2009, McClure et al. 2017). Suspected drivers of declines include degradation of habitat, direct mortality, and impaired reproduction due to contaminants, including insecticides and anticoagulant rodenticides in the environment, and the loss of natural nest cavities (McClure et al. 2017, Rattner et al. 2020). Documented causes of nestling mortality include the loss of a parent, predation, cannibalism (Bortolotti et al. 1991), and high loads of ectoparasites (Lesko and Smallwood 2012). We report on the frequency of ‘‘spraddle-leg,’’ a mortality source that is well known in the poultry and birdfancier sectors but minimally documented in wild nestling American Kestrels. Spraddle-leg is a condition that results in malformed legs, which impairs movement and fledging of affected individuals, and is often associated with inadequate nest-site substrate. Given that kestrel declines have catalyzed the creation and expansion of many nest box monitoring networks that are operated by various groups, including private citizens, research labs in academia, and other conservation groups, we feel it important to spotlight this phenomenon and ensure those working toward the recovery and conservation of kestrels and other cavity-nesting species via management of nest box networks take steps to provide sites that enhance success of these species. We also call for a collaborative approach among kestrel researchers to better document this issue. Since 2014, HawkWatch International and its team of community scientists have monitored an average of 100 nesting kestrel pairs per year within a network of 500þnest boxes and non-box nesting locations in Utah as part of an ongoing demographic study. During this time, we identified six separate broods in which at least one nestling presented with a condition causing both legs to splay laterally from the body, resulting in the nestlings being unable to stand, perch, or jump (Fig. 1A). Between 2017 and 2021, we observed seven spraddle-legged nestlings (four males, two females, and one unknown sex) from six nest boxes (occurring in ,0.35% of 2241 nestlings and in ,1% of 767 nesting attempts from 2014–2021). Siblings of spraddle-legged nestlings fledged from five of the six nest boxes, and one brood included two siblings with spraddleleg. A spraddle-legged nestling was the only individual in a brood in only one case. Unfortunately, we know the breeding history for only one pair of adults that produced spraddle-legged young. This pair successfully raised a healthy brood of three nestlings in 2018 before having a brood in 2019, in which one of two nestlings was spraddlelegged. None of the seven spraddle-legged nestlings fledged, and all presumably died from starvation or other causes 15–30 d after hatch. Our observations fit the description of conditions called ‘‘splay-leg’’ or spraddle leg; as well as angular
冬季、迁徙和繁殖调查表明，美洲红隼(Falco sparverius;Farmer and Smith 2009, McClure et al. 2017)。可能的下降驱动因素包括栖息地退化、直接死亡和环境中杀虫剂和抗凝血灭鼠剂等污染物造成的繁殖受损，以及自然巢腔的丧失(McClure et al. 2017, Rattner et al. 2020)。记录在案的雏鸟死亡原因包括失去父母、被捕食、同类相食(Bortolotti等人，1991年)和大量体外寄生虫(Lesko和Smallwood, 2012年)。我们报告了“跨腿”的频率，这是一种在家禽和鸟类爱好者中众所周知的死亡来源，但在野生美国红隼中鲜有记录。跨腿是一种导致腿部畸形的疾病，它损害了受影响个体的运动和羽翼发育，并且通常与巢址基质不足有关。考虑到红隼数量的减少促进了许多巢箱监测网络的创建和扩展，这些网络由各种团体运营，包括私人公民，学术界的研究实验室和其他保护团体，我们认为关注这一现象并确保那些通过管理巢箱网络来恢复和保护红隼和其他洞穴筑巢物种的工作人员采取措施提供提高这些物种成功的场所是很重要的。我们还呼吁在红隼研究人员之间开展合作，以更好地记录这一问题。自2014年以来，作为正在进行的人口研究的一部分，国际鹰观察组织及其社区科学家团队在犹他州的一个500英尺筑巢箱和非箱筑巢地点的网络中，平均每年监测100对筑巢的红隼。在此期间，我们确定了六个单独的巢，其中至少有一个雏鸟表现出双腿从身体两侧张开的状况，导致雏鸟无法站立，栖息或跳跃(图1A)。在2017年至2021年间，我们从6个巢箱中观察到7只跨腿雏鸟(4只雄性，2只雌性，1只性别未知)(在2241只雏鸟中占0.35%，在2014年至2021年的767次筑巢尝试中占1%)。跨腿雏鸟的兄弟姐妹从6个巢箱中的5个羽化，其中一窝包括两个跨腿的兄弟姐妹。只有一种情况下，两腿分开的雏鸟是一窝鸟中唯一的个体。不幸的是，我们所知道的繁殖历史中，只有一对成年恐龙产生了双腿叉开的后代。这对夫妇在2018年成功地养育了一窝健康的三只雏鸟，然后在2019年生了一窝，其中两只雏鸟中的一只是伸腿的。七只四肢叉开的雏鸟都没有羽翼丰满，它们在孵化后15-30天可能都死于饥饿或其他原因。我们的观察结果符合所谓的“八字腿”或跨腿的描述;以及角状或旋转肢体畸形(Worell 2012)。圈养鸟类双腿病的疑似病因多种多样，从雏鸟时期地板光滑到缺乏钙和维生素D (Harcourt-Brown 2002)。雏鸟的腿部畸形也可能是由于母亲饮食不足造成的，并且经常出现在一窝蛋中最后孵化的雏鸟身上(Harcourt-Brown 2002)。此类腿部畸形通常与胫跗骨相关，但也可能发生在股骨或跗跖骨(Worell 2012)。跨腿最常见于雏禽、鹦鹉形目、岩鸽(Columba livia)和鸽子(Pierson and Hester 1982, Worell 2012, Mangus et al. 2021)，但也可以在田鼠、鹳和鹤等群体中发现(Reece et al. 1992)。我们在野生猛禽中只发现了两种关于跨腿的轶事报道(游隼和哈里斯鹰)。如果不经常去巢，这种异常可能会被忽视，因为死去的雏鸟可能被成年鸟吃掉，被它们的同窝同伴践踏，或被驱逐出巢。另外，尸检可能不会1电子邮件地址:jwatson@hawkwatch.org
{"title":"Documenting Occurrence and Rates of Spraddle-leg in American Kestrel Nestlings within a Nest Box Monitoring Network","authors":"Jesse L. Watson, D. Oleyar","doi":"10.3356/jrr-22-19","DOIUrl":"https://doi.org/10.3356/jrr-22-19","url":null,"abstract":"Winter, migration, and breeding surveys indicate widespread declines of American Kestrels (Falco sparverius; Farmer and Smith 2009, McClure et al. 2017). Suspected drivers of declines include degradation of habitat, direct mortality, and impaired reproduction due to contaminants, including insecticides and anticoagulant rodenticides in the environment, and the loss of natural nest cavities (McClure et al. 2017, Rattner et al. 2020). Documented causes of nestling mortality include the loss of a parent, predation, cannibalism (Bortolotti et al. 1991), and high loads of ectoparasites (Lesko and Smallwood 2012). We report on the frequency of ‘‘spraddle-leg,’’ a mortality source that is well known in the poultry and birdfancier sectors but minimally documented in wild nestling American Kestrels. Spraddle-leg is a condition that results in malformed legs, which impairs movement and fledging of affected individuals, and is often associated with inadequate nest-site substrate. Given that kestrel declines have catalyzed the creation and expansion of many nest box monitoring networks that are operated by various groups, including private citizens, research labs in academia, and other conservation groups, we feel it important to spotlight this phenomenon and ensure those working toward the recovery and conservation of kestrels and other cavity-nesting species via management of nest box networks take steps to provide sites that enhance success of these species. We also call for a collaborative approach among kestrel researchers to better document this issue. Since 2014, HawkWatch International and its team of community scientists have monitored an average of 100 nesting kestrel pairs per year within a network of 500þnest boxes and non-box nesting locations in Utah as part of an ongoing demographic study. During this time, we identified six separate broods in which at least one nestling presented with a condition causing both legs to splay laterally from the body, resulting in the nestlings being unable to stand, perch, or jump (Fig. 1A). Between 2017 and 2021, we observed seven spraddle-legged nestlings (four males, two females, and one unknown sex) from six nest boxes (occurring in ,0.35% of 2241 nestlings and in ,1% of 767 nesting attempts from 2014–2021). Siblings of spraddle-legged nestlings fledged from five of the six nest boxes, and one brood included two siblings with spraddleleg. A spraddle-legged nestling was the only individual in a brood in only one case. Unfortunately, we know the breeding history for only one pair of adults that produced spraddle-legged young. This pair successfully raised a healthy brood of three nestlings in 2018 before having a brood in 2019, in which one of two nestlings was spraddlelegged. None of the seven spraddle-legged nestlings fledged, and all presumably died from starvation or other causes 15–30 d after hatch. Our observations fit the description of conditions called ‘‘splay-leg’’ or spraddle leg; as well as angular","PeriodicalId":16927,"journal":{"name":"Journal of Raptor Research","volume":"138 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86825011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Melissa B. Hannay, Megan E Shave, Olivia J. Utley, Sarah A. Groendyk, C. Lindell
Abstract. Landscape enhancements such as nest boxes can attract birds to agricultural areas, where they can provide ecosystem services such as pest reduction through their consumption of crop pests. However, there are large gaps in knowledge about how birds respond to enhancements. From 2014 to 2018 we installed American Kestrel (Falco sparverius; hereafter kestrel) nest boxes in a blueberry production region in western Michigan. From 2015 to 2018 we conducted surveys to monitor kestrel presence along 1.6-km transect segments (hereafter, sites) to estimate kestrel occupancy in areas with and without boxes. We also monitored box occupancy and reproductive success. Kestrel presence increased over time in the study area although there was some uncertainty in this trend. The presence of a box at a site did not increase kestrel presence there, but boxes in neighboring sites did increase presence. This indicated that enriching an area with boxes increases kestrel presence. Box occupancy rates were positively influenced by occupancy of the same box the previous year. Percent successful nests ranged from 75 to 100 percent, and mean number of fledglings produced was approximately 4 per nest box. Our results showed that nest boxes can serve as effective landscape enhancements to attract kestrels to agricultural landscapes, but the degree to which kestrels occupy boxes can vary geographically. Local-scale studies can provide information about the potential benefits and challenges of using nest boxes as a pest management tool. Resumen. Las mejoras del paisaje, tales como la colocación de cajas nido, pueden atraer aves a las áreas agrícolas, donde pueden prestar servicios ecosistémicos como la reducción de plagas en cultivos. Sin embargo, existen grandes lagunas en el conocimiento sobre cómo responden las aves a estas mejoras. De 2014 a 2018 instalamos cajas nido para Falco sparverius en una región de producción de arándanos en el oeste de Michigan. De 2015 a 2018 realizamos censos para determinar la presencia de la especie a lo largo de transectos de 1.6 km (en adelante, sitios) y estimar la ocupación de F. sparverius en áreas con y sin cajas nido. También monitoreamos la ocupación de las cajas nido y el éxito reproductivo. La presencia de F. sparverius aumentó con el tiempo en el área de estudio, aunque hubo cierta incertidumbre en esta tendencia. La presencia de una caja nido en un sitio no aumentó la presencia de la especie allí, pero las cajas en lugares vecinos sí aumentaron la presencia. Esto indicó que enriquecer un área con cajas nido aumenta la presencia de F. sparverius. Las tasas de ocupación de cajas nido se vieron influidas positivamente por la ocupación de la misma caja el año anterior. El porcentaje de nidos exitosos varió del 75 al 100 por ciento, y el número medio de volantones producidos fue de aproximadamente 4 por caja nido. Nuestros resultados mostraron que las cajas nido pueden servir como mejoras efectivas del paisaje para atraer a F.
摘要诸如巢箱之类的景观改善措施可以吸引鸟类到农业区，在那里它们可以提供生态系统服务，例如通过消耗作物害虫来减少害虫。然而，关于鸟类如何对增强反应的知识有很大的差距。2014年至2018年，我们安装了美国红隼(Falco sparverius;密歇根西部蓝莓产区的巢箱(以下简称红隼)。从2015年到2018年，我们在1.6公里的样带段(以下简称站点)进行了调查，以监测红隼的存在情况，以估计有和没有盒子的地区红隼的占用情况。我们还监测了箱子占用率和繁殖成功率。随着时间的推移，红隼在研究区域的存在有所增加，尽管这一趋势存在一些不确定性。在一个地点放置盒子并没有增加红隼的数量，但在邻近地点放置盒子却增加了红隼的数量。这表明，在一个区域增加盒子会增加红隼的数量。包厢入住率受到前一年同一包厢入住率的积极影响。成功筑巢的百分比从75%到100%不等，平均每个巢箱产出的雏鸟数量约为4只。研究结果表明，巢箱可以有效地吸引红隼进入农业景观，但红隼占据巢箱的程度因地域而异。地方规模的研究可以提供关于使用巢箱作为虫害管理工具的潜在好处和挑战的信息。Resumen。Las mejoras del paisaje, tales como la colocación de cajas nido, pueden traer aves a Las áreas agrícolas, donde pueden prestar servicios ecosistos como la reducción de plagas en culvos。在禁运期间，现有的大lagunas和conconimiiento sobre cómo响应了一个新记录。2014年，2018年安装的cajas nido para Falco sparverius在región De producción De arándanos和el oeste De Michigan。2015年，2018年实现了一项关于确定区域的调查，特别是1.6公里的大横断面，估计为ocupación De F. sparverius en áreas con y in cajas nido。tamamicasten monitoreoas la ocupación de las cajas nido y . tamamicasten monitoreo . ocupaciónLa presencia de F. sparverius aumentó con el tiempo en el área de estudio, unque hubo cierta incertidumbre en esta tendency。La presencia de una caja nido en un sitesno aumentó La presencia de La especie allí， pero las cajas en lugares vecinos sí aentarcia La presencia。estestindicó que enriquecer和área con cajas nidumenta la prescia de F. sparverius。Las tasas de ocupación de cajas nido de vieron influidpositivamente pla ocupación de la misma caja el año前部。El porcentaje de nidos exitosos varió del 75 al 100 pciento, El número medio de volantones producidos fues近4 pcaja nido。Nuestros resulttados mostraron que las cajas nido puedin servir como mejoras effectivas del paisaje para atraer a F. sparverius a los paisajes agrícolas, perel grado en que los个人占用las cajas puede var geográficamente。这些工作室和当地居民的比例为información，他们可能会受益于desafíos del uso de cajas nido como herramienta para el control de plagas。[Traducción del equipo社论]
{"title":"Nest Boxes Increased Presence of American Kestrels in a Blueberry Production Region Despite Low Box Occupancy","authors":"Melissa B. Hannay, Megan E Shave, Olivia J. Utley, Sarah A. Groendyk, C. Lindell","doi":"10.3356/JRR-21-80","DOIUrl":"https://doi.org/10.3356/JRR-21-80","url":null,"abstract":"Abstract. Landscape enhancements such as nest boxes can attract birds to agricultural areas, where they can provide ecosystem services such as pest reduction through their consumption of crop pests. However, there are large gaps in knowledge about how birds respond to enhancements. From 2014 to 2018 we installed American Kestrel (Falco sparverius; hereafter kestrel) nest boxes in a blueberry production region in western Michigan. From 2015 to 2018 we conducted surveys to monitor kestrel presence along 1.6-km transect segments (hereafter, sites) to estimate kestrel occupancy in areas with and without boxes. We also monitored box occupancy and reproductive success. Kestrel presence increased over time in the study area although there was some uncertainty in this trend. The presence of a box at a site did not increase kestrel presence there, but boxes in neighboring sites did increase presence. This indicated that enriching an area with boxes increases kestrel presence. Box occupancy rates were positively influenced by occupancy of the same box the previous year. Percent successful nests ranged from 75 to 100 percent, and mean number of fledglings produced was approximately 4 per nest box. Our results showed that nest boxes can serve as effective landscape enhancements to attract kestrels to agricultural landscapes, but the degree to which kestrels occupy boxes can vary geographically. Local-scale studies can provide information about the potential benefits and challenges of using nest boxes as a pest management tool. Resumen. Las mejoras del paisaje, tales como la colocación de cajas nido, pueden atraer aves a las áreas agrícolas, donde pueden prestar servicios ecosistémicos como la reducción de plagas en cultivos. Sin embargo, existen grandes lagunas en el conocimiento sobre cómo responden las aves a estas mejoras. De 2014 a 2018 instalamos cajas nido para Falco sparverius en una región de producción de arándanos en el oeste de Michigan. De 2015 a 2018 realizamos censos para determinar la presencia de la especie a lo largo de transectos de 1.6 km (en adelante, sitios) y estimar la ocupación de F. sparverius en áreas con y sin cajas nido. También monitoreamos la ocupación de las cajas nido y el éxito reproductivo. La presencia de F. sparverius aumentó con el tiempo en el área de estudio, aunque hubo cierta incertidumbre en esta tendencia. La presencia de una caja nido en un sitio no aumentó la presencia de la especie allí, pero las cajas en lugares vecinos sí aumentaron la presencia. Esto indicó que enriquecer un área con cajas nido aumenta la presencia de F. sparverius. Las tasas de ocupación de cajas nido se vieron influidas positivamente por la ocupación de la misma caja el año anterior. El porcentaje de nidos exitosos varió del 75 al 100 por ciento, y el número medio de volantones producidos fue de aproximadamente 4 por caja nido. Nuestros resultados mostraron que las cajas nido pueden servir como mejoras efectivas del paisaje para atraer a F. ","PeriodicalId":16927,"journal":{"name":"Journal of Raptor Research","volume":"62 1","pages":"12 - 21"},"PeriodicalIF":1.7,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91160465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Mcclure, Hana C. Weaver, Melissa Murillo, J. Gallardo, R. Thorstrom
Abstract. Conservationists often face tradeoffs. We present a tradeoff that we recently faced involving nest management of the endangered Puerto Rican Sharp-shinned Hawk (Accipiter striatus venator). Given our logistical constraints, we determined we were able to either continue our ongoing efforts to induce laying of a second clutch (hereafter, double clutching) of four nests per year, or we could stop double clutching and apply insecticide for parasitic nest flies (Philornis spp.) to as many nests as possible. Observed fledging rates justified our assumptions that the fledging rate of unmanaged nests was approximately one young per nest per year, whereas nests sprayed with insecticide for flies fledged two young, and double-clutched nests fledged three young. These three young from double-clutched nests were a combination of the young from both the parent-raised and hand-raised clutches. Although double clutching is more effective than spraying nests, it is also more labor intensive. We developed a model to determine how many nests we would need to spray to produce the same number of fledglings as if we continued the ongoing double clutching regime. Modeling revealed that if we could find and spray at least eight nests, then cessation of double clutching was justified. We also performed sensitivity analysis and determined that our management conclusion was robust to uncertainty in the assumed values of fledging rates. Our modeling exercise presents an example of informed decision making in the face of uncertainty. Resumen. Los conservacionistas a menudo se enfrentan a soluciones de compromiso. Presentamos una solución de compromiso que tomamos recientemente asociada al manejo de nidos de Accipiter striatus venator, una especie en peligro de extinción. Dadas nuestras limitaciones logísticas, determinamos que podíamos o bien continuar con nuestros esfuerzos en curso para inducir la puesta de una segunda nidada (en adelante, nidada doble) de cuatro nidos por año o, alternativamente, podíamos detener la nidada doble y aplicar insecticida para las moscas parásitas del género Philornis a tantos nidos como fuera posible. Las tasas de emplumamiento observadas justificaron nuestras suposiciones de que la tasa de emplumamiento de los nidos no manejados fue de aproximadamente una cría por nido por año, mientras que los nidos rociados con insecticida para moscas produjeron dos crías y los nidos con nidada doble produjeron tres crías. Estas tres crías de nidos de nidada doble eran una combinación de las crías de las nidadas alimentadas por los progenitores y alimentadas a mano. Aunque la nidada doble es más efectiva que rociar los nidos, también requiere más trabajo. Desarrollamos un modelo para determinar cuántos nidos necesitaríamos rociar para producir la misma cantidad de polluelos que si continuáramos con el régimen de nidada doble en curso. La modelización reveló que, si podíamos encontrar y rociar al menos ocho nidos, entonces se justificaba el cese
摘要环保主义者经常面临权衡。我们提出了一个权衡，我们最近面临涉及濒临灭绝的波多黎各锐光鹰(纹状鹰)的巢管理。考虑到我们的后勤限制，我们决定要么继续我们正在进行的努力，每年诱导产下4个巢的第二窝(以下简称双抓)，要么我们可以停止双抓，并在尽可能多的巢上施用杀虫剂，以消灭寄生巢蝇(Philornis spp.)。观察到的羽化率证实了我们的假设，即未经管理的巢每年羽化率约为1只，而喷洒杀虫剂的巢每年羽化2只，双窝每年羽化3只。这三只来自双窝的幼崽是父母抚养和人工抚养的幼崽的结合。虽然双抓比喷巢更有效，但也更劳动密集。我们开发了一个模型来确定我们需要喷洒多少巢穴才能产生相同数量的雏鸟，如果我们继续进行正在进行的双重抓握制度。模型显示，如果我们能找到并喷洒至少8个巢穴，那么停止双重抓紧是合理的。我们还进行了敏感性分析，并确定我们的管理结论对羽化率假设值的不确定性是稳健的。我们的建模练习展示了一个在面对不确定性时做出明智决策的例子。Resumen。保守主义者们有一份菜单，可以找到一种妥协的解决方案。提出了一种新的解决方案，即如何解决问题，特别是如何解决问题，特别是如何解决问题。限制数据收集logísticas，确定数据收集podíamos在连续的数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中，数据收集过程中。拉斯维加斯tasas de emplumamiento observadas justificaron nuestras suposiciones de公式emplumamiento tasa de los nido没有manejados fue de aproximadamente una cria nido运动,可以另mientras,洛杉矶nido rociados con insecticida para莫斯卡produjeron dos cria y洛杉矶nido con nidada快produjeron非常cria。Estas treres crías de nidos de nidada double eran una combinación de las crías de nidadas alimentadas穷人的祖先是alimentadas和mano。unque la nidada double es más effective que rociar los nidos, tamamaciman required más trabajo。研究发现，在确定的模型中，不确定的模型cuántos不确定的模型necesitaríamos不确定的模型，不确定的模型，不确定的模型，不确定的模型，不确定的模型，不确定的模型，不确定的模型，不确定的模型。La modelización reveló que, si podíamos encontrar al menos ocho nidos, entonces se idicaba el cese de las nidadas dobles。tamamicassan实现了对análisis敏感性的确定conclusión de gestión的确定和对其他因素的确定和对其他因素的确定和对其他因素的确定。新法律法规与法律法规与法律法规的关系:法律法规与法律法规的关系。[Traducción del equipo社论]
{"title":"Breakeven Points in Nest Management of an Endangered Island Endemic Raptor","authors":"C. Mcclure, Hana C. Weaver, Melissa Murillo, J. Gallardo, R. Thorstrom","doi":"10.3356/JRR-22-39","DOIUrl":"https://doi.org/10.3356/JRR-22-39","url":null,"abstract":"Abstract. Conservationists often face tradeoffs. We present a tradeoff that we recently faced involving nest management of the endangered Puerto Rican Sharp-shinned Hawk (Accipiter striatus venator). Given our logistical constraints, we determined we were able to either continue our ongoing efforts to induce laying of a second clutch (hereafter, double clutching) of four nests per year, or we could stop double clutching and apply insecticide for parasitic nest flies (Philornis spp.) to as many nests as possible. Observed fledging rates justified our assumptions that the fledging rate of unmanaged nests was approximately one young per nest per year, whereas nests sprayed with insecticide for flies fledged two young, and double-clutched nests fledged three young. These three young from double-clutched nests were a combination of the young from both the parent-raised and hand-raised clutches. Although double clutching is more effective than spraying nests, it is also more labor intensive. We developed a model to determine how many nests we would need to spray to produce the same number of fledglings as if we continued the ongoing double clutching regime. Modeling revealed that if we could find and spray at least eight nests, then cessation of double clutching was justified. We also performed sensitivity analysis and determined that our management conclusion was robust to uncertainty in the assumed values of fledging rates. Our modeling exercise presents an example of informed decision making in the face of uncertainty. Resumen. Los conservacionistas a menudo se enfrentan a soluciones de compromiso. Presentamos una solución de compromiso que tomamos recientemente asociada al manejo de nidos de Accipiter striatus venator, una especie en peligro de extinción. Dadas nuestras limitaciones logísticas, determinamos que podíamos o bien continuar con nuestros esfuerzos en curso para inducir la puesta de una segunda nidada (en adelante, nidada doble) de cuatro nidos por año o, alternativamente, podíamos detener la nidada doble y aplicar insecticida para las moscas parásitas del género Philornis a tantos nidos como fuera posible. Las tasas de emplumamiento observadas justificaron nuestras suposiciones de que la tasa de emplumamiento de los nidos no manejados fue de aproximadamente una cría por nido por año, mientras que los nidos rociados con insecticida para moscas produjeron dos crías y los nidos con nidada doble produjeron tres crías. Estas tres crías de nidos de nidada doble eran una combinación de las crías de las nidadas alimentadas por los progenitores y alimentadas a mano. Aunque la nidada doble es más efectiva que rociar los nidos, también requiere más trabajo. Desarrollamos un modelo para determinar cuántos nidos necesitaríamos rociar para producir la misma cantidad de polluelos que si continuáramos con el régimen de nidada doble en curso. La modelización reveló que, si podíamos encontrar y rociar al menos ocho nidos, entonces se justificaba el cese ","PeriodicalId":16927,"journal":{"name":"Journal of Raptor Research","volume":"58 1","pages":"44 - 51"},"PeriodicalIF":1.7,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85619122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Same-sex copulations by raptors, and birds in general, have been rarely reported. In American Kestrels (Falco sparverius), there have been no previous reports of a female copulating with a female. Here, we summarize our observations of a pair of female kestrels that were documented to copulate repeatedly with each other over a 5-wk period in north Texas. Two females were first observed together on 17 March 2020, when they copulated 23 times. That same day, we trapped and marked both females with coded anodized color bands. Between 17 March and 20 April 2020, we observed the pair copulate an average of 9.2 times/hr (7 d of observation, 7.9 hr), with both kestrels being present during 74.9% of our observations. The kestrels alternated which bird was in the top position during copulations, with the female with band code E/17 on top during 55.8% of copulations (n = 45) and female E/20 on top during 44.2%. One or both kestrels vocalized during 75.6% of copulations. We recorded other behaviors typical of breeding kestrels, including nest-site inspection, territorial defense, and an apparent aerial courtship display. Contrary to published speculations on same-sex pairs in birds, our observations do not support the hypothesis that the females typically adopt separate sex-specific behavioral roles. We propose probable benefits of a female-female pairing may include (1) stimulating ovulation, (2) sharing incubation and provisioning duties that could result in a greater number of young fledged, and (3) the ability to more easily defend and hold territory by two females, which typically hold higher-quality territories than males in American Kestrels.
{"title":"Female-Female Spring Fling in American Kestrels: An Observation of a Female–Female Pair and Copulation Behavior","authors":"H. Bullock, K. Biles, J. Bednarz","doi":"10.3356/jrr-22-14","DOIUrl":"https://doi.org/10.3356/jrr-22-14","url":null,"abstract":"\u0000 Same-sex copulations by raptors, and birds in general, have been rarely reported. In American Kestrels (Falco sparverius), there have been no previous reports of a female copulating with a female. Here, we summarize our observations of a pair of female kestrels that were documented to copulate repeatedly with each other over a 5-wk period in north Texas. Two females were first observed together on 17 March 2020, when they copulated 23 times. That same day, we trapped and marked both females with coded anodized color bands. Between 17 March and 20 April 2020, we observed the pair copulate an average of 9.2 times/hr (7 d of observation, 7.9 hr), with both kestrels being present during 74.9% of our observations. The kestrels alternated which bird was in the top position during copulations, with the female with band code E/17 on top during 55.8% of copulations (n = 45) and female E/20 on top during 44.2%. One or both kestrels vocalized during 75.6% of copulations. We recorded other behaviors typical of breeding kestrels, including nest-site inspection, territorial defense, and an apparent aerial courtship display. Contrary to published speculations on same-sex pairs in birds, our observations do not support the hypothesis that the females typically adopt separate sex-specific behavioral roles. We propose probable benefits of a female-female pairing may include (1) stimulating ovulation, (2) sharing incubation and provisioning duties that could result in a greater number of young fledged, and (3) the ability to more easily defend and hold territory by two females, which typically hold higher-quality territories than males in American Kestrels.","PeriodicalId":16927,"journal":{"name":"Journal of Raptor Research","volume":"21 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89962167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sandesh Gurung, T. Subedi, R. Baral, J. Pérez-García, M. Ghimire, H. S. Baral, Munir Virani, R. Buij
Abstract. The Egyptian Vulture (Neophron percnopterus) is a resident species in Nepal, and breeds in the lower mountains in the southern plains of Nepal. Nest-site availability is an important factor that determines the population growth of vultures; however, such information is lacking in South Asia. We here describe the characteristics and spatial distribution patterns of Egyptian Vultures' nest sites in the foothills of the Himalayan Mountains in central-west Nepal, and the factors that influence their nest-site selection. From 2012 through 2018, we surveyed all the known and potential nesting cliffs of the Egyptian Vulture located in the Pokhara Valley and its periphery during the nest building and nestling-rearing periods. In addition, we used generalized linear models to analyze the influence of landscape configuration, topography, and human disturbance factors on nest-site selection. We found a total of 21 occupied nests in a sampled area of 346 km2. Nests were not uniformly distributed, and the nearest neighbor distance between nests averaged 8.8 ± 6.1 km. Nests were located at an elevation of 523–1644 masl on cliffs with a mean height of 20.1 ± 12.2 m; 76% were in caves and 24% were on open ledges. Our models suggested that cliff height, anthropogenic trophic resources, and altitudinal variation around the cliff were the main determinants of the nesting cliff selection. Selection of small cliffs closer to food sources could minimize energy expenditure during food delivery and interspecific competition for nesting sites. The high altitudinal variation around the nest sites suggest that Egyptian Vultures preferred heterogeneous habitat, which might also be relatively difficult for humans to access and use easily. Resumen. Neophron percnopterus es una especie residente en Nepal, que se reproduce en las montañas más bajas de las llanuras del sur de Nepal. La disponibilidad de sitios de nidificación es un factor importante que determina el crecimiento de la población de buitres; sin embargo, dicha información falta en el sur de Asia. Aquí describimos las características y los patrones de distribución espacial de los sitios de nidificación de N. percnopterus en las estribaciones de las montañas del Himalaya en el centro-oeste de Nepal, y los factores que influyen en la selección de sus sitios de nidificación. Desde 2012 hasta 2018 inspeccionamos todos los roquedos de cría conocidos y potenciales de N. percnopterus ubicados en el valle de Pokhara y áreas periféricas durante los períodos de construcción de nidos y cría de polluelos. Además, usamos modelos lineales generalizados para analizar la influencia de la configuración del paisaje, la topografía y los factores relacionados con los disturbios humanos en la selección del lugar de cría. Encontramos un total de 21 nidos ocupados en un área muestreada de 346 km2. Los nidos no se distribuyeron uniformemente y la distancia entre nidos vecinos más cercanos promedió 8.8 ± 6.1 km. Los nidos se ubica
摘要埃及秃鹫(Neophron percnopterus)是尼泊尔的常住物种，在尼泊尔南部平原的低山上繁殖。筑巢地点的可用性是决定秃鹫种群增长的重要因素;然而，南亚缺乏这方面的资料。本文描述了尼泊尔中西部喜马拉雅山麓埃及秃鹫筑巢地的特征和空间分布规律，以及影响埃及秃鹫筑巢地选择的因素。从2012年到2018年，我们调查了位于博卡拉山谷及其周边的埃及秃鹫在筑巢和育雏期间的所有已知和潜在筑巢悬崖。此外，我们还利用广义线性模型分析了景观配置、地形和人为干扰因素对巢址选择的影响。我们在346平方公里的采样区域内发现了21个被占领的巢穴。巢间分布不均匀，巢间最近邻距离平均为8.8±6.1 km。巢位于海拔523 ~ 1644米的悬崖上，平均高度为20.1±12.2米;76%在洞穴里，24%在露天的岩壁上。我们的模型表明，悬崖高度、人为营养资源和悬崖周围的海拔变化是筑巢悬崖选择的主要决定因素。选择靠近食物来源的小悬崖可以最大限度地减少食物传递过程中的能量消耗和种间筑巢地点的竞争。筑巢地点周围的高海拔变化表明埃及秃鹫更喜欢异质性的栖息地，这些栖息地对人类来说也相对难以进入和使用。Resumen。Neophron percnopterus是尼泊尔的一种特别的居民，它们的繁殖方式为montañas más bajas de las llanuras del sur de Nepal。1 .关于nidificación的情况的责任，不确定因素的重要性，确定población的情况;在禁运中，dicha información falta在亚洲南部。Aquí描述了以下网址:características y ' s patrones de distribución e ' s spatiial de los sites de nidificación N. percnoterus和e . stribaciones de las montañas d . Himalaya和e . centro-oeste de Nepal, y ' s factores que influyen and selección e . sus sitos de nidificación。自2012年起至2018年，在波卡拉山谷和áreas周围的 ()和 (construcción)和(cría)的污染山谷中，对 ()和 ()的污染山谷进行检查。Además, usamos modelos lineales generizados para analiar la influencia configuración del paisaje, la topografía通过los factors relations ados los dis扰动humanos en la selección del lugar de cría。共有21个被占领区，面积为346平方公里，面积为área。在距离中心nidos vecinos más cercanos promedió 8.8±6.1 km处，Los nidos无均匀分布。在海拔523-1644米的地区，在海拔20.1±12.2米的地区，在海拔523-1644米的地区，在海拔20.1±12.2米的地区;76%的人认为自己是在做运动，24%的人认为自己是在做运动。我们都莫德罗sugieren la altura del roquedo,洛杉矶recurso项目troficos antropogenicos y la variacion高度的alrededor del roquedo fueron洛杉矶螯行列式de la seleccion del roquedo de cria。La selección de pequeños roquedos, más cercanos和las fuentes de alimentos, podría minimizar tanto el gasto de energía durante La entrega de alimentos como La competencia interespecífica穷人的处境de cría。La gran variación海拔高度已经改变了de los lugares cría sugiere que N. percnopterus prefirió un hábitat heterogsamen, que tamamsamen podría ser relativamente difícil de acceder y de fácil utilización por partite de los seres humanos。[Traducción del equipo社论]
{"title":"Breeding Habitat and Factors Affecting the Cliff Selection by Egyptian Vultures in Central-West Nepal","authors":"Sandesh Gurung, T. Subedi, R. Baral, J. Pérez-García, M. Ghimire, H. S. Baral, Munir Virani, R. Buij","doi":"10.3356/JRR-21-59","DOIUrl":"https://doi.org/10.3356/JRR-21-59","url":null,"abstract":"Abstract. The Egyptian Vulture (Neophron percnopterus) is a resident species in Nepal, and breeds in the lower mountains in the southern plains of Nepal. Nest-site availability is an important factor that determines the population growth of vultures; however, such information is lacking in South Asia. We here describe the characteristics and spatial distribution patterns of Egyptian Vultures' nest sites in the foothills of the Himalayan Mountains in central-west Nepal, and the factors that influence their nest-site selection. From 2012 through 2018, we surveyed all the known and potential nesting cliffs of the Egyptian Vulture located in the Pokhara Valley and its periphery during the nest building and nestling-rearing periods. In addition, we used generalized linear models to analyze the influence of landscape configuration, topography, and human disturbance factors on nest-site selection. We found a total of 21 occupied nests in a sampled area of 346 km2. Nests were not uniformly distributed, and the nearest neighbor distance between nests averaged 8.8 ± 6.1 km. Nests were located at an elevation of 523–1644 masl on cliffs with a mean height of 20.1 ± 12.2 m; 76% were in caves and 24% were on open ledges. Our models suggested that cliff height, anthropogenic trophic resources, and altitudinal variation around the cliff were the main determinants of the nesting cliff selection. Selection of small cliffs closer to food sources could minimize energy expenditure during food delivery and interspecific competition for nesting sites. The high altitudinal variation around the nest sites suggest that Egyptian Vultures preferred heterogeneous habitat, which might also be relatively difficult for humans to access and use easily. Resumen. Neophron percnopterus es una especie residente en Nepal, que se reproduce en las montañas más bajas de las llanuras del sur de Nepal. La disponibilidad de sitios de nidificación es un factor importante que determina el crecimiento de la población de buitres; sin embargo, dicha información falta en el sur de Asia. Aquí describimos las características y los patrones de distribución espacial de los sitios de nidificación de N. percnopterus en las estribaciones de las montañas del Himalaya en el centro-oeste de Nepal, y los factores que influyen en la selección de sus sitios de nidificación. Desde 2012 hasta 2018 inspeccionamos todos los roquedos de cría conocidos y potenciales de N. percnopterus ubicados en el valle de Pokhara y áreas periféricas durante los períodos de construcción de nidos y cría de polluelos. Además, usamos modelos lineales generalizados para analizar la influencia de la configuración del paisaje, la topografía y los factores relacionados con los disturbios humanos en la selección del lugar de cría. Encontramos un total de 21 nidos ocupados en un área muestreada de 346 km2. Los nidos no se distribuyeron uniformemente y la distancia entre nidos vecinos más cercanos promedió 8.8 ± 6.1 km. Los nidos se ubica","PeriodicalId":16927,"journal":{"name":"Journal of Raptor Research","volume":"40 1","pages":"81 - 91"},"PeriodicalIF":1.7,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76214007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michael T. Stewart, W. S. Clark, B. Millsap, B. Bibles, Timothy Brush
Abstract. We studied the natural history of Gray Hawks (Buteo plagiatus) in the Lower Rio Grande Valley of Texas. We used GPS-GSM telemetry to quantify dispersal time and distance, winter home range size of juveniles, and home range size of adults. Home ranges were calculated using the kernel Brownian bridge home range estimator. The median dispersal date for 14 juvenile Gray Hawks was 11 August and they traveled a median straight-line distance of 453 km. Mean winter home range sizes for 11 juveniles was 707 ha. For juveniles, female winter home ranges were larger than those of males, and juvenile winter home ranges were larger in natural than in urban areas. Mean 95% home range sizes for 20 adult Gray Hawks was 530 ha. Mean adult male home range size was larger in natural than in urban areas. Adult Gray Hawks remained in their home ranges year-round. Resumen. Estudiamos la historia natural de Buteo plagiatus en el Valle Inferior del Río Grande de Texas. Utilizamos telemetría GPS-GSM para cuantificar el tiempo y la distancia de dispersión, el tamaño del área de campeo de los juveniles en invierno y el tamaño del área de campeo de los adultos. Las áreas de campeo se calcularon utilizando el estimador de puentes brownianos del método kernel. La fecha mediana de dispersión de 14 juveniles de B. plagiatus fue el 11 de agosto y recorrieron una distancia mediana en línea recta de 453 km. El tamaño medio del área de campeo de invierno para 11 juveniles fue de 707 ha. Considerando los juveniles, las áreas de campeo de invierno de las hembras fueron más grandes que las de los machos, y las áreas de campeo de invierno de los juveniles fueron más grandes en las áreas naturales que en las urbanas. El tamaño medio del 95% del área de campeo para 22 adultos de B. plagiatus fue de 526 ha. El tamaño promedio del área de campeo de los machos adultos fue mayor en las áreas naturales que en las urbanas. Los adultos de B. plagiatus permanecieron en sus áreas de campeo durante todo el año. [Traducción del equipo editorial]
摘要我们研究了德克萨斯州下里奥格兰德河谷的灰鹰(Buteo plagiatus)的自然历史。利用GPS-GSM遥测技术，定量测定了幼鱼和成鱼的迁徙时间和距离、冬季活动范围和活动范围。用核布朗桥估计器计算了家乡距离。14只灰鹰幼鸟的分散时间中位数为8月11日，直线距离中位数为453公里。11只幼鱼的平均冬季栖息地面积为707公顷。雌鱼的冬栖范围大于雄鱼，自然地区的冬栖范围大于城市地区。20只成年灰鹰95%的家庭面积平均为530公顷。自然地区成年男性的平均家庭范围比城市地区大。成年灰鹰全年都呆在它们的栖息地。Resumen。德州大河谷(Río Grande de Texas)。利用telemetría GPS-GSM的准量化的时间，从距离到dispersión，从tamaño到área，从青少年到因特网，从tamaño到área到成人。最后áreas de campeo se calcularon utility和el estimador de puentes brownianos del m todo内核。La fecha mediana de dispersión de 14幼兽de B. platiatus fue de 11 agosto y recorierer1距离mediana en línea范围453公里。tamaño medio del área de campeo de invierno，第11段，未成年人，第707页。考虑到青少年，las áreas青少年教育活动más大男孩教育活动，las áreas青少年教育活动más大男孩教育活动áreas自然学生教育活动，las las urbanas。El tamaño medio del 95% del área de campeo para 22 adultos de B. plagiatus fue de 526 ha。El tamaño promedio del área de campeo de los machos adultos futes mayor en las áreas naturales que en las urbanas。成年白齿贝虫的永久经验是:áreas de campeo durante todo el año。[Traducción del equipo社论]
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C. Mcclure, F. H. Vargas, A. Amar, Camille B. Concepcion, Christopher MacColl, P. Sumasgutner
A minimum of 159 bird species, including eight raptor species, have gone extinct since the year 1500 (BirdLife International 2021). Monitoring programs can help prevent extinction if they alert conservationists to population losses in time to take action (Martin et al. 2012, Lindenmayer et al. 2013, Woinarski et al. 2017). Indeed, monitoring, which is defined as ‘‘collecting and analyzing repeated observations or measurements to identify changes and evaluate progress of management towards stated aims’’ (Robinson et al. 2018) is essential for conservation (Wiens 1984, Nichols and Williams 2006, Lovett et al. 2007) and provides for the prioritization of taxa and places for conservation effort. Raptors tend to be long-lived and to reproduce slowly, making their populations susceptible to changes in adult survival (Newton 1979). Decreases in survival of adult raptors can therefore cause precipitous population declines (Pain et al. 2008, Ogada et al. 2016) that must be detected quickly to avert catastrophe. Importantly, these species tend to be wide-ranging and occur at relatively low densities (Newton 1979). Thus, a single scientist or program might not be able to cover sufficient area or attain the sample sizes necessary for inference of population dynamics, whereas a consortium of researchers could monitor raptors more effectively. Collaboration is therefore needed for global populations of most raptors to be properly monitored. This Conservation Letter provides the results of a survey of raptor researchers across the globe to identify current spatial, taxonomic, and topical gaps in raptor monitoring. The intent of the Raptor Research Foundation (RRF) is to provide readers with evidencebased recommendations for more impactful global raptor monitoring and greater collaboration among raptor researchers, and to provide readers with a better understanding of where and for which species gaps in raptor monitoring persist.
自1500年以来，至少有159种鸟类，包括8种猛禽，已经灭绝(国际鸟盟2021年)。监测程序可以帮助防止物种灭绝，如果它们提醒保护主义者及时采取行动(Martin et al. 2012, Lindenmayer et al. 2013, Woinarski et al. 2017)。事实上，监测，被定义为“收集和分析重复的观察或测量，以确定变化和评估实现既定目标的管理进展”(Robinson et al. 2018)，对保护至关重要(Wiens 1984, Nichols和Williams 2006, Lovett et al. 2007)，并为保护工作提供分类群和地点的优先级。猛禽往往寿命长，繁殖缓慢，使其种群易受成年生存变化的影响(Newton 1979)。因此，成年猛禽的存活率下降可能导致种群急剧下降(Pain et al. 2008, Ogada et al. 2016)，必须迅速发现以避免灾难。重要的是，这些物种往往分布广泛，密度相对较低(Newton 1979)。因此，一个科学家或一个项目可能无法覆盖足够的区域或获得推断种群动态所需的样本量，而一个研究人员联盟可以更有效地监测猛禽。因此，要对全球大多数猛禽种群进行适当监控，就需要合作。这封保护信提供了对全球猛禽研究人员的调查结果，以确定目前猛禽监测的空间、分类和局部差距。猛禽研究基金会(RRF)的目的是为读者提供基于证据的建议，以便更有效地进行全球猛禽监测，加强猛禽研究人员之间的合作，并使读者更好地了解猛禽监测中存在的物种差距。
{"title":"Conservation Letter: Monitoring Raptor Populations – A Call for Increased Global Collaboration and Survey Standardization","authors":"C. Mcclure, F. H. Vargas, A. Amar, Camille B. Concepcion, Christopher MacColl, P. Sumasgutner","doi":"10.3356/JRR-22-68","DOIUrl":"https://doi.org/10.3356/JRR-22-68","url":null,"abstract":"A minimum of 159 bird species, including eight raptor species, have gone extinct since the year 1500 (BirdLife International 2021). Monitoring programs can help prevent extinction if they alert conservationists to population losses in time to take action (Martin et al. 2012, Lindenmayer et al. 2013, Woinarski et al. 2017). Indeed, monitoring, which is defined as ‘‘collecting and analyzing repeated observations or measurements to identify changes and evaluate progress of management towards stated aims’’ (Robinson et al. 2018) is essential for conservation (Wiens 1984, Nichols and Williams 2006, Lovett et al. 2007) and provides for the prioritization of taxa and places for conservation effort. Raptors tend to be long-lived and to reproduce slowly, making their populations susceptible to changes in adult survival (Newton 1979). Decreases in survival of adult raptors can therefore cause precipitous population declines (Pain et al. 2008, Ogada et al. 2016) that must be detected quickly to avert catastrophe. Importantly, these species tend to be wide-ranging and occur at relatively low densities (Newton 1979). Thus, a single scientist or program might not be able to cover sufficient area or attain the sample sizes necessary for inference of population dynamics, whereas a consortium of researchers could monitor raptors more effectively. Collaboration is therefore needed for global populations of most raptors to be properly monitored. This Conservation Letter provides the results of a survey of raptor researchers across the globe to identify current spatial, taxonomic, and topical gaps in raptor monitoring. The intent of the Raptor Research Foundation (RRF) is to provide readers with evidencebased recommendations for more impactful global raptor monitoring and greater collaboration among raptor researchers, and to provide readers with a better understanding of where and for which species gaps in raptor monitoring persist.","PeriodicalId":16927,"journal":{"name":"Journal of Raptor Research","volume":"91 1","pages":"106 - 113"},"PeriodicalIF":1.7,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78593301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Artificial nest boxes have played an important role in American Kestrel (Falco sparverius) conservation worldwide, facilitating nesting and research efforts. However, these conservation efforts frequently unintentionally facilitate other cavity-nesting species including the European Starling (Sturnus vulgaris), a widespread invasive species in North America. Understanding how to deter European Starlings from occupying nest boxes is an essential responsibility of project design when deploying nest boxes. We examined the efficacy of five different abatement methods to mitigate the use of our nest boxes by European Starlings: nest removal, nest and egg removal, egg shaking, egg cracking, and egg oiling. We found spraying European Starling eggs with 100% food-grade corn oil and cracking eggs to be the most effective abatement methods. We recommend future American Kestrel nest box programs in this region use egg oiling or egg cracking on European Starling eggs.
{"title":"MANAGEMENT OF EUROPEAN STARLINGS IN AN AMERICAN KESTREL NEST BOX PROGRAM","authors":"Jessica N. Schlarbaum, J. Hull, Sara M. Kross","doi":"10.3356/jrr-22-08","DOIUrl":"https://doi.org/10.3356/jrr-22-08","url":null,"abstract":"\u0000 Artificial nest boxes have played an important role in American Kestrel (Falco sparverius) conservation worldwide, facilitating nesting and research efforts. However, these conservation efforts frequently unintentionally facilitate other cavity-nesting species including the European Starling (Sturnus vulgaris), a widespread invasive species in North America. Understanding how to deter European Starlings from occupying nest boxes is an essential responsibility of project design when deploying nest boxes. We examined the efficacy of five different abatement methods to mitigate the use of our nest boxes by European Starlings: nest removal, nest and egg removal, egg shaking, egg cracking, and egg oiling. We found spraying European Starling eggs with 100% food-grade corn oil and cracking eggs to be the most effective abatement methods. We recommend future American Kestrel nest box programs in this region use egg oiling or egg cracking on European Starling eggs.","PeriodicalId":16927,"journal":{"name":"Journal of Raptor Research","volume":"80 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80363728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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