Yellow-eyed Penguin (Megadyptes antipodes) as a case study to assess the reliability of nest counts

Hegg, Danilo; Giroir, Thibaut; Ellenberg, Ursula; Seddon, Philip J.

doi:10.1007/s10336-011-0761-7

Cited by 6 publications

(2 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We are confident that we have full records of birds due to the intensive monitoring at the study site and annual monitoring at adjacent sites along the coast, and the high level of natal (∼81%) and breeding philopatry (∼98%), and monogamy exhibited by this species ( Richdale, 1957 ; Ratz et al, 2004 ). Birds that skip breeding remain largely undetectable during the breeding season, with only ∼8% of skipped birds in our sample being re-sighted as a non-breeder, however detection of breeders is close to 100% ( Hegg et al, 2012 ). In our sample, 53 yellow-eyed penguins that survived to breed skipped at least one breeding season once they had established breeding, which is not uncommon, particularly in the year following a poor season, death of a mate or a divorce ( Moore, 1994 ; Ratz et al, 2004 ; Setiawan et al, 2005 ).…”

Section: Methodsmentioning

confidence: 77%

Evidence for high inter-generational individual quality in yellow-eyed penguins

Stein

Young

Darby

et al. 2017

PeerJ

Self Cite

View full text Add to dashboard Cite

Longitudinal studies focusing on lifetime reproductive success (LRS) have been used to measure individual breeding performance and identify commonalities among successful breeders. By extending the focus to subsequent generations we identify a proportion of high-quality individuals that contribute disproportionately to the population over multiple generations. We used 23 years of yellow-eyed penguin (Megadyptes antipodes) breeding data from one breeding area to identify the proportion of individual birds that raised successful breeders, which in turn raised offspring. We explored which life-history components influenced LRS, as this knowledge would enable conservation resources to be focused on high-performing individuals in this endangered population. From 2,147 birds marked as chicks, 370 (17.2%) survived to adulthood and recruited to their natal location, of which 219 (10.2%) fledged offspring: 124 (56.6%) of the 219 birds produced offspring that recruited as breeders. Only 102 birds (4.8% of 2,147) fledged first-generation offspring that in turn fledged offspring (second-generation offspring, or grand-offspring). We found that ∼25% of the birds that survived to breed had above-average LRS as well as above-average numbers of grand-offspring, and were more likely to have produced first-generation chicks that recruited and also produced above-average numbers of second-generation chicks. Our findings suggest that there is a core of “super-breeders” that contribute disproportionately to the population over successive generations. Lifespan and age-at-first-breeding were correlated with LRS. We suggest that traits of birds relating to longevity, health (e.g., immunocompetence) and fitness could be examined to identify potential links with high LRS and inter-generational fecundity. “Super-breeders” appear to consistently achieve high LRS and long lifespans in a stochastic environment, demonstrating greater resilience in the face of extreme events.

show abstract

Section: Methodsmentioning

confidence: 77%

Evidence for high inter-generational individual quality in yellow-eyed penguins

Stein

Young

Darby

et al. 2017

PeerJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…We address the former possibility first. The counting population trend detection method involved only counting once, which will almost always yield an underestimate of the true number of nests and provides no means of expressing uncertainty (Hegg et al 2012). However, provided there are not systematic biases in the single nest counts over time, a single count will provide adequate trend estimates, and if there are multiple monitoring sites (as in this study), the uncertainty can be reflected in the error estimate of the modelled rate of change.…”

Section: Population Trajectorymentioning

confidence: 99%

Assessing the population trend and threats to New Zealand’s Fiordland crested penguin using counting and demographic modelling approaches

Otley¹,

Edmonds²,

Hiscock³

et al. 2018

NZ J Ecol

View full text Add to dashboard Cite

The Fiordland crested penguin Eudyptes pachyrhynchus is one of the least studied crested penguin species, with indications the species has a declining population, which would be in line with the historic and contemporary trends for most crested penguins. To determine the current population trend of the Fiordland crested penguin, a number of monitoring programmes using both abundance counts and demographic modelling approaches were carried out between 1990 and 2010 in the northern half of the species' range. A 2.6% ± 0.8% annual decline rate of active nests was detected at 14 monitoring plots, and the number of nests along two coastlines declined annually by 1.2% and 2.6%. Population matrix models using site-specific demographic rates for the species at two South Westland sites indicated contrasting population trends, with one site increasing by 1.6% annually and a second site decreasing at 0.3% annually. Due to concerns about the reproductive parameters used in the model, the trajectory indicated by the nest-chick data was deemed more robust and should be used to inform management. Six potential threats to Fiordland crested penguin were reviewed against the detected population trend and specifically adult survival, but it was determined that there is insufficient understanding about the species, particularly its foraging ecology and effects of fishing and terrestrial predation, to confidently identify the key threats. Therefore, the recommended management action is to address these knowledge gaps.

show abstract

Weather variability permitted within amphibian monitoring protocol and affects on calling Hylidae

Milne

Bennett

Hoyle

2013

Environ Monit Assess

View full text Add to dashboard Cite

Anuran populations are sensitive to changing environmental conditions and act as useful indicators. Presently, much information collected concerning frog populations comes from volunteers following the North American Amphibian Monitoring Protocol. Does weather variability allowed within protocol affect the abundance of calling frogs? For 10 years, Credit Valley Conservation (Ontario, Canada) has been collecting anuran data concerning nine frog species employing three frog monitoring runs. Records include frog abundance by protocol code and five weather variables. Antecedent precipitation and temperature were determined from the nearest weather station. Locations with large source populations of two Hylidae species were selected (spring peeper calling in April and gray tree frog in May). Spearman correlations suggested there were no significant relationships between calling abundance of Hylidae species and ambient wind speed or humidity. However, gray tree frogs were temperature sensitive and calling was significantly related to increased water and air temperatures as well as day time high temperatures over the previous 2 weeks. Both species of calling Hylidae were affected by the volume and timing of precipitation (though, in different ways). Gray tree frogs seem to prefer drier conditions (when temperatures are significantly warmer) while spring peepers prefer to call during, or closely following, precipitation. Monitors targeting gray tree frog should track local weather conditions and focus on evenings when it is (a) warmer than the minimum temperatures and (b) drier than suggested by the protocol. It is recommended that an additional monitoring run could be added to reduce detection variability of this species.

show abstract

Yellow-eyed Penguin (Megadyptes antipodes) as a case study to assess the reliability of nest counts

Cited by 6 publications

References 21 publications

Evidence for high inter-generational individual quality in yellow-eyed penguins

Evidence for high inter-generational individual quality in yellow-eyed penguins

Assessing the population trend and threats to New Zealand’s Fiordland crested penguin using counting and demographic modelling approaches

Weather variability permitted within amphibian monitoring protocol and affects on calling Hylidae

Contact Info

Product

Resources

About