Storms and heat limit the nest success of Bank Cormorants: implications of future climate change for a surface-nesting seabird in southern Africa

Sherley, Richard B.; Ludynia, Katrin; Underhill, Les G.; Jones, R.; Kemper, Jessica

doi:10.1007/s10336-011-0760-8

Cited by 30 publications

(29 citation statements)

References 43 publications

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“…Elevated environmental temperatures in other colonies of seabirds nesting in artificial nests have caused harmful water loss in eggs and decreases in hatching success (Lei et al , Ropert‐Coudert et al ). In addition, extreme heat events later in the nesting season can cause heat stress for chicks in artificial nests (Sherley et al , Chowdhury et al ).…”

Section: Discussionmentioning

confidence: 99%

Environmental temperatures, artificial nests, and incubation of Cassin's auklet

et al. 2015

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Hatching success in birds is influenced by the temperature and turning rate of the egg, but our understanding of the environmental factors that effect incubation temperatures and egg turning rates in birds is limited. Especially little is known of these effects for species that nest in burrows or crevices, such as the Cassin's auklet (Ptychoramphus aleuticus). On Southeast Farallon Island, California, USA, a subset of the Cassin's auklet (hereafter auklet) population nest in artificial nest boxes. The nest boxes are above ground and made out of a single layer of plywood. Temperatures in unshaded nest boxes can increase significantly with high ambient temperatures (to >35° C). Shaded structures put on top of occupied nest boxes help mediate nest box temperatures, but the effects of elevated temperatures on auklet incubation behaviors and egg viability remain equivocal. We used egg data loggers to measure the temperatures and turning rates of auklet eggs in natural burrows, shaded nest boxes, and unshaded nest boxes on Southeast Farallon Island. Nest box (13.93 ± 1.26° C) and egg (37.43 ± 1.92° C) temperatures were highest and most variable in unshaded nest boxes. Mean hourly egg turning rate was 2.11 ± 2.02 turns/hour and turning rates were greater at night. Egg turning rates also varied with fluctuating nest and egg temperatures, being positively correlated with nest temperatures during the day and negatively correlated with egg temperatures during the night. Our results suggest that nest box design can influence incubation behaviors of breeding birds. As seasonal temperatures and the number of extreme heat events rise, understanding the impacts of temperature on auklets nesting in artificial nests can have positive implications for conservation and management of the species, such as implementing improved artificial nest box designs to prevent overheating of burrow nesting seabirds. © 2015 The Wildlife Society.

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Section: Discussionmentioning

confidence: 99%

Environmental temperatures, artificial nests, and incubation of Cassin's auklet

et al. 2015

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“…The temporal scale also defines the difference between weather and climate: the former consists of short-term (minutes to months) changes in the atmosphere, whereas the later is the average of weather over time and space. Some weather events (such as strong storms and tsunamis, Viera et al, 2006;Sherley et al, 2012) are not necessarily correlated with climate indexes and can introduce some noise when analysing their potential association with some ecological parameters, particularly short-term processes such as reproduction and hence breeding success (Schreiber, 2002).…”

Section: The Importance Of Suitable Temporal and Spatial Scalesmentioning

confidence: 99%

“…Even though population change in seabirds is in theory less sensitive to changes in breeding success, this parameter, which influence recruitment rates, is often the vital rate that exhibits the most variation and it certainly constitutes an important factor that can affect population fluctuations. Sometimes the association between climate and breeding success is either direct in the form of heat strokes and catastrophic events such as volcanic eruptions, gales or tsunamis (Viera et al, 2006;Finkelstein et al, 2010;Sherley et al, 2012), or indirect, i.e., mediated by parasitism or diseases (Gaston et al, 2002;Cooper et al, 2009;Rolland et al, 2009a). That association should be strong in seabirds, because they are long-lived organisms and selection pressures have shaped conservatism in the energy devoted to reproduction: when environment is harsh, individuals invest less or may refrain from breeding and very low breeding success or even failures are commonly recorded for a number of species (La Cock, 1986;Frederiksen et al, 2006).…”

Section: The Mechanisms Linking Climate Variation To Seabird Populatimentioning

confidence: 99%

Seabirds and climate: knowledge, pitfalls, and opportunities

Oró

2014

Front. Ecol. Evol.

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As a physical driver of ecosystem functioning, it is not surprising that climate influences seabird demography and population dynamics, generally by affecting food availability. However, if we zoom in ecologically, seabirds are in fact very heterogeneous, ranging in size from very small to very large species (with a difference of more than two orders of magnitude in body weight), from planktivorous forms to predators of large fish and squid, from benthic to pelagic, from species with small foraging ranges to species feeding throughout the whole circumpolar region, and from resident species (at a spatial mesoscale) to trans-equatorial migrating seabirds that travel large distances across several oceanographic systems. Due to this high variability and the difficulty in obtaining direct reliable estimates of long-term food availability, global climatic indices have been extensively used in studying seabird demography and population dynamics. However, the use made by researchers of these indices has certain conceptual and methodological pitfalls, which I shall address in this review. Other factors, such as anthropogenic impacts (including oil-spills and interaction with fisheries), may further alter or confound the association between climate and seabird demography. These pitfalls and environmental noise, together with the inability to incorporate resilience, may bias our predictions regarding the future impact of global warming on seabirds, many of which have vulnerable populations.Keywords: predictive models, resilience, methodological bias, evolution, global change, climate, seabirds HISTORICAL BACKGROUNDA search performed in June 2014 using the words "climate & seabird" in the ISI Web of Science resulted in 946 items. Even though some of those items dealt with other marine organisms or were focused on some related issues (such as oceanographic processes), that result represents a large number of scientific contributions on the topic of how climate may influence seabird ecology. The influence of climate on marine organisms has been extensively studied in seabirds because, compared to most other species (except some marine mammals such as seals and sealions), their demography and population dynamics can be easily monitored in breeding colonies.Up to the 90s, the changes in demographic parameters and population size in seabirds were explored mostly in relation to intrinsic features of the colonies such as their size or the presence of predators (Hunt et al., 1986). The effects of climate (mostly in the form of oceanographic indices) on seabird ecology were seldom analyzed in those years (Myres, 1979), and research efforts were addressed mostly to determining the distribution of seabirds at sea (Abrams, 1985). The influence of oceanographic features was outlined especially when extreme and anomalous events occurred (such as cyclones or El Niño-Southern Oscillation (ENSO) years (e.g., Blomqvist and Peterz, 1984;Graybill and Hodder, 1985), whereas some pioneering studies dealt with the relationship between climatic ev...

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“…Although rock lobsters have not shifted their distribution to the same extent as anchovy and sardine, their reduced populations off northwest South Africa appear to have been insufficient to support formerly large colonies of bank cormorants in this region (Crawford et al, 2008a). Recent nest failures for bank cormorants at Robben Island were related to wave heights and air temperature, with chick survival being reduced in years when major storm events occurred during breeding and destroyed nests (Sherley et al, 2012b).…”

Section: Frontiers In Ecology Andmentioning

confidence: 99%

A changing distribution of seabirds in South Africaâ€”the possible impact of climate and its consequences

et al. 2015

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In the southern Benguela ecosystem off South Africa, there were recent shifts to the south and east in the distributions of three forage resources (anchovy, sardine, rock lobster), which probably were influenced by environmental change although fishing too may have played a part. In this study, we review information on trends in distributions and numbers of eight seabirds breeding in South Africa. For five species that feed predominantly on anchovy, sardine or rock lobster, their populations off northwest South Africa decreased markedly. For three of these species, which exhibit behavioral inertia and have restricted foraging ranges when breeding (African penguin, Cape cormorant, bank cormorant), there were large decreases in their overall populations in South Africa. Conversely, for two showing more plasticity and able to range over wide areas or move between breeding localities (Cape gannet, swift tern) there were increases. It is thought that movement of forage resources away from the northern islands led to a mismatch in the distributions of breeding localities and prey of dependent seabirds off western South Africa and to attempts by several species to establish colonies on the southern mainland closer to food resources. There also were shifts to the south and east in the distributions of three seabirds that do not compete with fisheries for prey (crowned cormorant, white-breasted cormorant, kelp gull), suggesting some environmental forcing, but decreases of these species off northwest South Africa were less severe and populations in South Africa remained stable or increased in the long term. It is likely, because many fishing plants are located in the northwest, that there was increased competition between seabirds and fisheries for prey as forage resources moved south and east. Potential interventions to mitigate the adverse impacts of distributional changes for seabirds include allocations of allowable catches of shared forage resources at regional levels, closures to fishing around impacted seabird colonies and establishment of new colonies nearer to the present location of food.

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Storms and heat limit the nest success of Bank Cormorants: implications of future climate change for a surface-nesting seabird in southern Africa

Cited by 30 publications

References 43 publications

Environmental temperatures, artificial nests, and incubation of Cassin's auklet

Environmental temperatures, artificial nests, and incubation of Cassin's auklet

Seabirds and climate: knowledge, pitfalls, and opportunities

A changing distribution of seabirds in South Africaâ€”the possible impact of climate and its consequences

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