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North American Black Terns (Chlidonias niger) breed primarily in the Prairie Pothole region of southern Canada and the northern United States, winter in Central and South American waters, and often migrate through the northern Gulf of Mexico (nGoM). This species has exhibited long-term population declines and is exposed to a myriad of anthropogenic threats in the nGoM, including oil spills, with an estimated 800-1,000 injured during the Deepwater Horizon oil spill, yet historical studies of Black Terns' use of the nGoM are sparse, with inconsistent spatial and temporal coverage. Using vessel-based observations collected from 2017 to 2019, we characterize Black Tern spatial and temporal occurrence in marine waters of the nGoM. We develop 2 separate habitat models: one describing spatial and temporal aspects of Black Terns occurrence and the other describing the relative density when present. In 10 months of survey effort, January-October, we observed Black Terns in 7 (Mar-May and Jul-Oct), predominantly on the continental shelf at Key words: habitat models, migration, nonbreeding, seasonality, vessel-based observations. (French)--Les guifettes noires d'Amerique du Nord (Chlidonias niger) se reproduisent principalement dans la region des Prairies Pothole du sud du Canada et du nord des Etats-Unis, hivernent dans les eaux d'Amerique centrale et du Sud et migrent souvent a travers le nord du golfe du Mexique (nGoM). Cette espece a montre des declins de population a long terme et est exposee a une myriade de menaces anthropiques dans le nGoM, y compris les marees noires, avec environ 800 a 1 000 individus blesses lors de la maree noire de Deepwater Horizon, mais des etudes historiques sur l'utilisation du nGoM par les guifettes noires sont rares, avec une couverture spatiale et temporelle incoherente. A l'aide d'observations basees sur des navires recueillies de 2017 a 2019, nous caracterisons l'occurrence spatiale et temporelle de la guifette noire dans les eaux marines du nGoM. Nous developpames deux modeles d'habitat distincts: l'un decrivant les aspects spatiaux et temporels de l'occurrence des guifettes noires et l'autre decrivant la densite relative lorsqu'elles sont presentes. Au coure des 10 mois d'enquetes, de janvier a octobre, nous observames des guifettes noires en sept mois (de mars a mai et de juillet a octobre), principalement sur le plateau continental a Mots-cles: migration, modeles d'habitat, non-reproduction, observations basees sur des navires, saisonnalite., The North American Black Terns (Chlidonias niger) are the only obligate wetland-breeding terns in the New World. Black Terns breed primarily in the Prairie Pothole Region with small populations distributed [...]

Shorebird use of horseshoe crab (Limulus polyphemus) eggs as food items has been well documented along the Atlantic coast of the United States at northeastern stopover sites such as the Delaware Bay. However, the relationship between migratory shorebirds and horseshoe crab eggs has not been well studied in the South Atlantic Bight. The objective of our study was to assess the spatial and temporal overlap between the density of horseshoe crab eggs and the relative abundance of foraging shorebirds during spring migration in the Cape Romain-Santee Delta Region (CRSD). South Carolina, USA. The CRSD is a site of international importance for shorebirds that supports -100,000 shorebirds annually. We also sought to determine if horseshoe crab eggs were present in the diets of shorebirds at these sites. We monitored study plots between March and June 2015-2016 at predicted horseshoe crab spawning sites on beaches throughout Cape Romain National Wildlife Refuge. We conducted weekly shorebird surveys and collected core samples of beach substrate twice per month to measure densities of horseshoe crab eggs. We found a positive correlation between number of foraging shorebirds and horseshoe crab eggs for both years. In a molecular analysis of shorebird fecal samples, 95% of the samples tested contained DNA from horseshoe crab eggs. The spatial and temporal overlap between shorebirds and horseshoe crab eggs, and the dietary analysis of fecal samples, suggest that there are areas of localized horseshoe crab spawning that shorebirds can utilize as a food source during spring in Cape Romain National Wildlife Refuge. Received 14 January 2021. Accepted 9 June 2021. Key words: Atlantic flyway, diet, migration. Red Knot, Sanderling, shorebird conservation, South Atlantic Bight. El uso de los huevos del cangrejo cacerola (Limulus plyphemwi) como recurso alimenticio por playeros. ha sido bicn documentado a lo largo de la costa atlantica de los Estados Unidos cn sitios de abastecimiento como Delaware Bay. Sin embargo, la rclacion entre playeros migratorios y hucvos de cangrejo cacerola no ha sido bicn estudiada en la zona South Atlantic Bight. El objetivo de nuestro estudio fue detepninar el traslape espacial y temporal entre la densidad de huevos de cangrejo cacerola y la abundancia relativa de playeros que forrajean durante la migration de primavcra en la region Cape Romain-Santee Delta (CRSD) en South Carolina, EUA. El CRSD es un sitio de importancia international para playeros que da soporte a a -100.000 playeros anualmcntc. Buscamos tambien determinar si los huevos del cangrejo cacerola se encontraban prcscntcs cn la dicta de playeros en esos sitios. Monitoreamos sitios de estudio entre marzo y junio 2015-2016 en sitios previstos de puesta en playas a lo largo del Cape Romain National Wildlife Refuge. Llcvamos a cabo reconocimientos semanalcs y obtuvimos muestras de sustrato de playa dos veces al mes para medir las densidades de huevos de cangrejo cacerola. Encontramos una correlation positiva entre el numero de playeros forrajeando y los huevos de cangrejo cacerola en umbos anos. Por medio del analisis molecular de muestras fecales de playeros, el 96% de estas contenia ADN de los huevos de cangrejo cacerola. El traslape espacial y temporal entre playeros y hucvos de cangrejo cacerola. y el analisis de la dieta a traves de las muestras fecales, sugicren que existen areas localizadas de puesta del cangrejo cacerola que las playeras usan como recurso alimenticio durante la primavera cn el Cape Romain National Wildlife Refuge. Palabras clave: Calidhs alba. Calidris cunutus, conservacion de playeros, dieta. migracion. ruta migratoria del Atlantico. South Atlantic Bight., Shorebirds in North America are declining rapidly, particularly long-distance migrants that nest in the Arctic (Munroe 2017, Rosenberg et al. 2019). Many shorebirds use only a few refueling stops during [...]

Little is known about the reproductive success of Black Skimmers (Rynchops niger) throughout the southeastern USA where availability of undisturbed beaches for nesting is limited. Daily survival rates (DSR) of nests were examined at three nesting sites in Cape Romain National Wildlife Refuge (CRNWR), South Carolina, USA, 2009-2010. The percent of successful nests (n = 346 nests) ranged from 42-69% among colony sites when data were pooled across both years. The DSR of nests was primarily related to colony site, predation risk, height of high tide, and clutch size. Predation and overwash were the principal causes of identifiable nest loss, each accounting for ~33% of nest failures during the two study years. Because of the challenges of resighting skimmer chicks, we were not able to measure chick survival effectively and therefore accurate measures of productivity remain elusive. High variability in nest success among sites within close proximity to each other ( Key words: Black Skimmer, nest predation, nest success, nest survival, Rynchops niger. South Carolina., Black Skimmers (Rynchops niger) in the eastern USA are exclusively coastal and nest in colonies often with or adjacent to other near shore seabirds such as terns and gulls. The [...]

Ectoparasites area common component of seabird colonies and are generally considered to have a negative impact on their hosts. Nest parasites such as the soft tick Carios capensis may pose a distinct threat to altricial nestlings confined to the nest and unable to escape infestation. To assess the potential effects of ticks on growth, we measured linear growth rates of Brown Pelican (Pelecanus occidentalis) nestlings during early development in relation to C. capensis infestation at insecticide treated and untreated nests at two colonies in South Carolina during the 2004 and 2005 breeding seasons. Tick infestation levels differed between colonies but not between years. We found a positive relationship between tick infestation and both growth rates and hatching success at the more infested colony. We did not find a consistent relationship between insecticide treatment and growth rates, although chicks from nests treated with insecticide had fewer ticks compared to chicks from untreated nests. Our study suggests that the cohabitation of ectoparasites and seabirds within colonies may result in behavioral or physiological adaptations of adults of nestlings that inhibit the expected negative effect of ectoparasites on nestling growth at sublethal levels of infestation. Key words: Brown Peliean, Carios capensis, ectoparasite, growth rate, Pelecanus occidentalis, seabird, soft ticks. Los ectoparasitos son un componente comun de las colonias de aves marinas y generalmente se considera que tienen un impacto negativo sobre sus hospederos. Los parasitos de nido como la garrapata Carios capensis pueden resultar una amenaza particular para los pichones nidicolas confinados al nido e incapaces de escapar de la infestacion. Para evaluar los efectos potenciales de las garrapatas sobre el crecimiento, medimos las tasas lineales de crecimiento de los pichones de Peleeanus occidentales durante el desarrollo temprano con relacion a la infestacion de C. capensis en nidos tratados y no tratados con insecticida, en dos colonias en Carolina del Sur durante las estaciones reproductivas del 2004 y 2005. Los niveles de infestacion de garrapatas difirieron entre las colonias pero no entre los anos. Encontramos una relacion positiva entre la infestacion de garrapatas tanto con las tasas de crecimiento como con el exito de eclosion en la colonia mas infestada. No encontramos una relacion consistente entre el tratamiento con insecticida y las tasas de crecimiento, aunque los pichones de los nidos tratados con insecticida tuvieron menos garrapatas que los pichones de los nidos no tratados. Nuestro estudio sugiere que la convivencia de los ectoparasitos con las aves marinas en las colonias puede causar adaptaciones de comportamiento o fisiologicas de los adultos o de los piehones que inhiben el efecto negativo esperado de los ectoparasitos sobre el crecimiento de los pichones a niveles subletales de infestacion.

Maehr (1993) isecorrect that Jodice aaw Humphrey (1992)edid not coaduct a comparative, quaatitative study showiag that urbaa laawscapes are moreevaluable thanenative ones for the threatea Cypressefox squirrel (Sciurus niger avicenaia). However,ethe evidence supportiag ourestatemeat that on golfecourses appear much deaser thanein natural habitat' (p. 691) isesubstantial albeitemossly qualitative. Iasistence on better dataedoes not justifyeinactioa whenethe best available dataeclearl opportunities to realizeewildlife benefits. Useeofeharvest dataeto iafer populatioa status by Maehr alarmig in view ofethe history ofefailure ofethis approach to natural-resource maaagemeat. We propo the comparative study Maehr thinks weeshould haveedone,ebut the fundiag available was insufficieat. reiterateethat the golf-course squirrelsepreseateaneopportunity for coaserviag wildlife, promotiag f laaw use,eaaweengagiag a pro-wildlife coastituency, aaw weeargueefor seizig coaservatioa opportunit wherever they occur, whether in urbaa or native coatext., Despite the criticisms by Maehr, Jodice and Humphrey (1992) are correct in suggesting that golf courses offer a conservation opportunity for Big Cypress fox squirrels (Sciurus niger avicennia). A comparative study of urban and natural habitat fox squirrel populations could not be undertaken for financial reasons. Nevertheless, there is evidence that fox squirrel populations appear denser on golf courses than in native forest. Golf courses appear to help conserve fox squirrels as well as involving golf course users in conservation issues.

The Big Cypress fox squirrel (Sciurus niger avicennia) is listed as threatened by the state of Florida, individuals are secretive, and their biology is poorly known. However, populations in urban areas persist on golf courses, where they are protected, habituated to humans, and readily observed. populations offer opportunities to study and promote the survival of the subspecies. Consequently, w activity and diet of Big Cypress fox squirrels for 1 year on 4 golf courses in Naples, Florida. Perc time spent foraging and inactive varied seasonally. Diets also varied among seasons. Seasonal change foraging and inactivity were not related to changes in diet or weather, and the seasonal dietary shi did occur did not alter the time spent foraging. Mating behavior and young-rearing may have the stro effect on seasonal activity patterns. The diet of fox squirrels on golf courses was unusual in its d seasons and its stability among seasons. Fox squirrels used foods from both native and exotic trees. of golf courses may be maximized by leaving native trees in place and by planting exotic trees with reproductive seasons. Continuing development of urban areas could threaten the viability of fox squi populations on golf courses. Both research and management should be directed at this problem.

We used a supplemental-feeding experiment, the doubly labeled water technique, and a model-selection approach based upon the Akaike Information Criterion to examine effects of food availability on energy expenditure rates of Black-legged Kittiwakes, Rissa tridactyla, raising young in Middleton Island, Alaska. Energy expenditure rates of females were more responsive to fluctuations in food availability than those of males. Our objectives were to determine if the energy expenditure rates of parent kittiwakes provided with supplemental food, differed from those of control parents, and to determine the strength of the relationship between parental energy expenditure rates and a suite of extrinsic and intrinsic covariates and factors. Fed males likely expended more energy while off the nest than fed females, possibly because of nest defense. Energy expenditure rates of fed kittiwakes were similar to values reported for kittiwakes that were either not raising young or not foraging. Fed kittiwakes increased their reproductive output while simultaneously decreasing parental effort and increasing body condition. Parent kittiwakes, therefore, adjusted parental effort in response to variation in breeding conditions due to changes in food availability. Adjustments in reproductive effort in response to variable foraging conditions may have significant effects on the survival and productivity of individuals, and thus provide substantial fitness benefits for long-lived seabirds such as Black-legged Kittiwakes. Differences in survival rates between the sexes may occur if each sex experiences a different survival curve with respect to field metabolic rate or parental effort.

Presents a study which monitored the activity patterns of Marbled Murrels during breeding seasons at different forest stands in the Oregon Coast Range. Methodology; Results; Discussion.