Jennifer M. Arnold

Albatross populations in peril: a population trajectory for black-browed albatrosses at south Georgia.

Simulation modeling was used to reconstruct Black-browed Albatross (Diomedea melanophris) population trends. Close approximations to observed data were accomplished by annually varying survival rates, reproductive success, and probabilities of returning to breed given success in previous years. The temporal shift in annual values coincided with the start of longline fishing at South Georgia and potential changes in krill abundance. We used 23 years of demographic data from long-term studies of a breeding colony of this species at Bird Island, South Georgia, to validate our model. When we used annual parameter estimates for survival, reproductive success, and probabilities of returning to breed given success in previous years, our model trajectory closely followed the observed changes in breeding population size over time. Population growth rate was below replacement (lambda < 1) in most years and was most sensitive to changes in adult survival. This supports the recent IUCN uplisting of this species from Vulnerable to Endangered. Comparison of pre-1988 and post-1988 demography (before and after the inception of a longline fishery in the breeding area) reveals a decrease in lambda from 0.963 to 0.910. A life table response experiment (LTRE) showed that this decline in lambda was caused mostly by declines in survival of adults. If 1988-1998 demographic rates are maintained, the model predicts a 98% chance of a population of fewer than 25 pairs within 78 years. For this population to recover to a status under which it could be delisted, a 10% increase in survival of all age classes would be needed.

Responses of Known-aged Common Terns to Experimental Shortening of the Wings

Abstract Fourteen male Common Terns (Sterna hirundo) of known age (3-21 yr) were handicapped by shortening their wings early in the incubation period, and were then followed through chick-raising. The study was conducted at Bird Island, Massachusetts, USA, in 1996, a year when chick growth and survival appeared to be limited by food availability. Chick growth and survival were used as indirect measures of allocation of resources to current reproduction. Rates of change of body-mass and feather re-growth (ptilochronology) were used as indirect measures of allocation of resources to self-maintenance. The birds’ mates were studied similarly, but were not handicapped. Experimental birds and pairs were compared to controls matched for laying date and clutch-size. Handicapped males re-grew tail-feathers pulled for ptilochronology significantly more slowly than controls. They and their mates raised significantly more young than controls. Older handicapped males lost more body-mass during chick-raising than their matched controls, whereas younger males lost less. These results conflict with the prediction of life-history theory that long-lived birds faced with increased costs of reproduction should allocate these costs to their offspring rather than to themselves. However, we point out several problems in using handicapping to test such predictions. The assumed effects of handicapping on the cost of flight and on foraging ability have not been verified or measured. Changes in reproductive effort are not measured directly, and the end points that have been investigated are often ambiguous. The assumption that older individuals consistently have lower residual reproductive value than younger individuals may be incorrect if there is selective survival of high-quality individuals within the study population.

Effect of intraspecific interactions on seasonal decline in productivity of Common Terns Sterna hirundo

Capsule Kleptoparasitic activities of older chicks from earlier nests did not contribute to late reproductive declines. Aims To determine whether intraspecific interactions, such as kleptoparasitism and aggression, were experienced more frequently by birds breeding late in the season as a result of exposure to breeders at a more advanced stage. If so, to investigate whether this was the cause of the observed seasonal decline in reproductive parameters observed at Bird Island, where nesting density is high and interactions are more probable. Methods Plots were fenced within the colony, exploiting natural variability in distribution of early and peak breeders to create two treatments: plots with only late-laying terns and those with a mixture of early-, peak- and late-layers. Hatching success, productivity and the growth and survival of chicks were measured for all late-laying pairs. Intraspecific interactions, adult attendance and provisioning of chicks were recorded during 9600 minutes of nest observations made within two periods: a few days after hatching and one week later. Results The frequency of intraspecific interactions was maintained by the kleptoparasitic activities of older chicks within the mixed-laying-date treatment and was significantly lower in plots containing only late breeders with chicks of similar ages (mean 11.0 days). The overall rate was rarely greater than two interactions per nest per hour and there was no corresponding reduction in the growth or survival of chicks from late nests or any change in the provisioning activities of late-breeding adults. Conclusion Increased frequency of intraspecific interactions experienced by late breeders in the presence of early-breeding conspecifics resulted from the kleptoparasitic activities of older chicks but was not sufficient to contribute to the observed seasonal reproductive decline at this dense breeding colony.

Abundance and Trends of Colonial Waterbirds on the Large Lakes of Southern Manitoba

Abstract. n Regular surveys of waterbird colonies are needed to identify changes in abundance and distribution. Consistent surveys have been maintained in some regions, but one area where updated surveys were needed was southern Manitoba, where Lakes Winnipeg, Winnipegosis and Manitoba had not been jointly surveyed since 1979. In mid-June, 2012, an aerial survey of the region was conducted using digital photography to estimate abundance of six colonial waterbird species that are regular breeders on these lakes. Breeding by at least one of the six species was confirmed at 131 locations. Double-crested Cormorant (Phalacrocorax auritus) was the most abundant breeder (43,388 pairs, 47 colonies), followed by Ring-billed Gull (Larus delawarensis, 41,819 pairs, 67 colonies), American White Pelican (Pelecanus erythrorhynchos, 12,680 pairs, 20 colonies), Common Tern (Sterna hirundo, 7,950 pairs, 31 colonies), Herring Gull (L. argentatus, 4,013 pairs, 90 colonies) and Caspian Tern (Hydroprogne caspia, 3,207 pairs, 14 colonies). Comparisons with earlier surveys in this region suggest that all six species have increased in abundance from the 1970s when populations were still recovering from earlier threats. However, Double-crested Cormorants, Caspian Terns and Common Terns show evidence of declines since the early 1990s. Standardized surveys of colonial waterbirds on these lakes should be maintained at 10-year intervals similar to the Great Lakes Monitoring Program.

Piracy at the nest: factors driving kleptoparasitic behaviour of Common Tern Sterna hirundo chicks

Abstract. n Stealing of provisioned food items by adult conspecifics (intraspecific kleptoparasitism or piracy) is common among birds, can reduce breeding success and may be one disadvantage of colonial breeding. Theft by chicks from neighbouring broods has rarely been quantified but may have similar reproductive consequences and the factors that influence it require further study. We took advantage of unusually diverse weather during the critical early stages of growth to elucidate the factors driving kleptoparasitic behavior of Common Tern Sterna hirundo chicks. Kleptoparasitism was restricted to misty days when large chicks were fed much smaller fish than on other days, inducing them to steal from neighbouring broods with young chicks. Our study indicates that kleptoparasitism by chicks could be a way to overcome shortfalls in parental provisioning, and may be a net cost of colonial breeding. Our results both provide evidence of a potential mechanism behind food-stealing by chicks and suggest hypotheses for future testing.

Jeremy J. Hatch, 1937–2015

Jeremy Hatch died on December 2, 2015, in his home in South Tawton, Devon, UK, after a struggle with melanoma that ultimately led to brain cancer. He will be fondly remembered for his excellent mentorship, attention to detail, enthusiasm for fieldwork, contributions to ornithology, caring heart, and dry sense of humor. Think back to your graduate school days. Do you remember that late-afternoon lecture with that Britishsounding professor? The one who looked benign, as you settled back in your seat, but before your eyes could close, would jolt you back to reality with an unexpected action or question. Perhaps you had a thesis advisor who set extremely high standards for thorough, well-planned experiments, although he was probably harder on himself than on you. Perhaps you were lucky enough to be on a field excursion with your research advisor and watch as, with the enthusiasm of the proverbial kid in the candy shop, he would undertake some elaborate experiment, visit new islands, or just band a few chicks. Well, if you attended UMass Boston, that professor would have been Jeremy Hatch. Jeremy John Hatch was born in London on October 7, 1937. He was instilled with his family’s natural curiosity and with his mother’s deep love for the Devonshire countryside. His father was in the British Colonial Service in Nigeria, so Jeremy boarded at Bryanston School in Dorset. It was there that he became interested in birds, inspired by his zoology teacher, Mr. Harthan (known to his students as ‘‘GDH’’), and by extensive birding outings with his brother and other members of the school’s natural history society. Following in the footsteps of Charles Darwin, he went on to study at Christ’s College, Cambridge, for his undergraduate degree, graduating in 1961. He enrolled in a Ph.D. program at Duke University, studying the song of mockingbirds under the mentorship of Peter Klopfer. During this time, he studied endemic mockingbird species as part of an expedition to the Galápagos Islands, working alongside Jack Hailman and Robert Risebrough. He completed his dissertation in 1967 and accepted a National Institutes of Health postdoctoral fellowship under Donald Griffin at Rockefeller University. Jeremy was appointed Assistant Professor of Biology at the newly founded University of Massachusetts (UMass) Boston in 1969. There he continued to pursue his careerlong interest in seabirds, which had begun in the late 1960s, using experimental and observational approaches to study the life history and behavior of terns, gulls, and shearwaters. His academic partnership with Ian Nisbet cemented his research focus on seabirds, and terns in particular. Jeremy’s legacy includes more than 50 papers in scientific journals, a plethora of inventions for fieldwork that are still in use today, and the detail-oriented approach to science that he so carefully fostered in his students. A major hallmark of Jeremy’s contributions to ornithology is the breadth of his research inquiries in seabird ecology, especially human impacts on seabirds. These included studies on band wear and loss in terns, applied studies in seabird biology (particularly the effect of Jeremy Hatch doing fieldwork on the Abrolhos Islands, Western Australia, in 1997. Photo credit: Chris Surman

Caspian Terns (Hydroprogne caspia) Fledge a Ring-billed Gull (Larus delawarensis) Chick: Successful Waterbird Adoption Across Taxonomic Families

Abstract. n This paper describes the interspecific fostering of two Ring-billed Gull chicks (Larus delawarensis) following natural adoption by a pair of Caspian Terns (Hydroprogne caspia) at Gull Island, Presquile Provincial Park, Ontario, Canada, in 2011. Naturally-occurring, interspecific adoptions among waterbirds are rare and those between distantly-related species have not been confirmed to produce fledglings. The observation of one Ring-billed Gull chick being raised by Caspian Terns beyond fledging (approximately 46 days of age) appears to be the first record of successful adoption between different taxonomic families of waterbirds. Behavior, provisioning rate, and growth of chicks were recorded to document this adoption. During linear growth, the mass of the adopted Ring-billed Gull chicks were close to, or even exceeding, maximum mass of Ring-billed Gull chicks raised by their natural parents. After this period, however, the adoptive Caspian Tern parents reduced provisioning rates below those recorded for conspecifics and the adopted Ring-billed Gull chicks lost mass, one of which left the territory prematurely and died. Although initial circumstances leading to the adoption were unclear, that one Ring-billed Gull chick was ultimately fledged by Caspian Terns is remarkable given the different provisioning methods and diet of these species.