Seabirds as environmental indicators: foraging behaviour and ecophysiology of common diving petrels (Pelecanoides urinatrix) reflect local-scale differences in prey availability

Dunphy, Brendon; Vickers, Shae; Zhang, J.; Sagar, Rachael; Landers, Todd J.; Bury, Sarah J.; Hickey, Anthony J. R.; Rayner, Matt J.

doi:10.1007/s00227-020-3672-4

Cited by 28 publications

(30 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here foraging behaviour is assumed to occur when birds fly at very low speeds [53]. Modelling methods have also been used to predict diving behaviour taking the sequence of trajectory data into account through hidden Markov models (HMM) typically with 2 or 3 distinct behavioural modes [6,13,32,37], and more occasionally through gaussian mixtures models [18,33], or supervised machine learning approaches such as artificial neural networks, support vector machine, and random forests [19,52]. We may refer the reader to [24] for a more detailed review of these methods.…”

Section: Introductionmentioning

confidence: 99%

Deep inference of seabird dives from GPS-only records: performance and generalization properties

Roy

Fablet

Lanco-Bertrand

2021

Preprint

View full text Add to dashboard Cite

Seabirds are considered as suitable indicators for the study of marine ecosystems, since their foraging strategies provide a real-time response to complex ecosystem dynamics. By deploying GPS sensors on seabirds it is possible to obtain their trajectories, and deep learning have recently shown promising results for the classification of animal behaviour from trajectory data. Yet there is still lot of investigation needed in terms of network architectures, data representation but also to demonstrate the generalization properties of these approaches. From a database of about 250 foraging trajectories derived from GPS data deployed simultaneously with pressure sensors for the identification of dives, this work has consisted in training deep networks in a supervised manner for the prediction of dives from trajectory data. In this study, we confirm that deep learning allows better dive prediction than usual methods such as Hidden Markov Models for two distinct seabirds species. We propose a novel deep learning model for trajectory data. It combines the computational efficiency of convolutional neural networks to distance-matrix-based representations of trajectory data. Our model considerably increases the ability of deep networks to infer behaviour, as well as their stability to different data inputs. The considered trajectory data representation might enable deep networks to better capture spatial information than from longitude and latitude time-series considered in previous works.

show abstract

Section: Introductionmentioning

confidence: 99%

Deep inference of seabird dives from GPS-only records: performance and generalization properties

Roy

Fablet

Lanco-Bertrand

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…in CDP individuals that had to travel further to meet energetic demands (Dunphy et al, 2020), potentially reducing reproductive success (Kitaysky, Piatt and Wingfield, 2007).…”

Section: Consequences For Species Conservationmentioning

confidence: 99%

“…As the carbon isotope results indicate females may also be foraging further from shore than males (Peterson and Fry, 1987), it is possible that their increased energy demands from a longer flight are not being met with energy rich prey (Dean et al, 2013). Previous studies have demonstrated that the stress of travelling further to forage for prey can contribute to higher levels of stress hormones (corticosterone; Crossin et al, 2012;Dunphy et al, 2020), which in turn can have a negative impact on reproductive success (Kitaysky, Piatt and Wingfield, 2007). If female demands of foraging further from the colony than males, this could be a contributing factor to the slow population recovery through compromising reproductive success.…”

Section: Intraspecific Trophic Dynamics For the Whdpsmentioning

confidence: 99%

See 1 more Smart Citation

Characterising the foraging ecology and mercury exposure of the Nationally Critical Whenua Hou diving petrel

Tocker¹

View full text Add to dashboard Cite

<p>With seabird species in decline globally, significant research has gone into characterising their key prey species and foraging areas that need protection. Knowledge on the diet of a species has important implications for the development of conservation programmes. The sand dune system on Whenua Hou is home to the endemic Whenua Hou diving petrel (Pelecanoides whenuahouensis; hereafter WHDP) and a population of common diving petrels (Pelecanoides urinatrix; hereafter CDP). The WHDP is considered ‘Nationally Critical’ due to its small population size (~200 individuals) and restricted breeding range (0.018 km2) on Whenua Hou. The foraging ecology of the WHDP is relatively unknown, as is its exposure to sources of marine pollution. This thesis aimed to characterise the foraging ecology of the WHDP, the potential interspecific competition with the sympatric CDPs, the prey present in the diets of each species, and their resulting exposure to mercury from the environment. In chapter 2, I used stable isotope analysis to infer the trophic dynamics of the WHDP. By sampling and analysing both blood and feathers, I was able to investigate potential differences in WHDP foraging ecology between the breeding and non-breeding seasons. I found a difference between the foraging ecology of male and female WHDPs, with results indicating females forage further out to sea than males and on prey of lower trophic value. I found that WHDPs forage an entire trophic level higher during the breeding season than the non-breeding season. As my sampling effort spanned three consecutive breeding seasons (2017-2019), I was able to detect interannual variation in the foraging ecology of WHDPs. The results revealed that WHDPs foraged at a higher trophic level during the breeding season of 2018 compared to that of 2017 or 2019. By characterising the isotopic niches of both the WHDPs and CDPs over the three years, I was able to demonstrate a degree of trophic segregation between the two species during the breeding season. In chapter 3, I designed and went through the initial development stages for a novel multiplex-PCR assay to identify the prey species present in the diets of WHDPs and CDPs. The obstacles faced in the development of this protocol highlighted the suitability of DNA metabarcoding as an alternative method. In chapter 4, I analysed the mercury concentration in the same blood and feather samples used for stable isotope analysis. I demonstrated that male WHDPs had higher concentrations of mercury in their tissues than females, correlating with their foraging at a higher trophic level. The interannual variation in mercury concentration did not correlate with the trophic variation of WHDPs among years, indicating that the environmental fluctuations in mercury levels had a stronger effect on mercury exposure than diet. WHDP tissues consistently had higher concentrations of mercury than CDPs, correlating with their isotopic niche segregation and highlighting a potential threat to individual survival and reproductive success in WHDPs. Overall, my results describe patterns in the foraging ecology of the WHDP, as well as highlighting the potential threat from mercury exposure. This research can be used as a baseline for future investigations into the key prey species for the endangered WHDP and the impacts mercury exposure may be having on the population growth of this species. </p>

show abstract

“…have been tracked for a portion of their annual cycles (Adams & Takekawa 2008, Navarro et al 2013, Rayner et al 2017, Halpin et al 2018, Hedd et al 2018, Paiva et al 2018, Lago et al 2019, Pollet et al 2019, BirdLife International Seabird Tracking Database 2020, Bolton 2020, Dunphy et al 2020, Rotger et al 2020, Wikelski & Keys 2020. Year-round studies covering > 1 annual cycle are virtually absent for any of these species (Pollet et al 2019).…”

Section: Introductionmentioning

confidence: 99%

Integrated conservation of the Whenua Hou Diving Petrel

Fischer¹

View full text Add to dashboard Cite

<p>Seabirds are one of the most threatened taxa on the planet. These species are also considered ecosystem engineers. Therefore, seabirds are of particular conservation interest. One of the most threatened seabirds is the critically endangered Whenua Hou Diving Petrel (Pelecanoides whenuahouensis; WHDP). The WHDP is restricted to a minute (0.018 km2) breeding colony on a single island — Whenua Hou (Codfish Island), Aotearoa (New Zealand). The WHDP population was estimated at 150 adults in 2005. The WHDP is threatened by storms and storm surges, which erode its breeding habitat (fragile foredunes), and potentially by competition for burrows with congenerics. I aimed to inform suitable conservation strategies for the WHDP. I first quantified the efficacy of past conservation actions (eradications of invasive predators). I compiled burrow counts across four decades to estimate and compare population growth before and after predator eradications. I then investigated offshore threats using tracking data to quantify WHDP offshore distribution, behaviour, and overlap with commercial fishing efforts. Subsequently, I estimated the potential impact and success of WHDP translocations. Specifically, I combined capture-recapture, nest-monitoring, and count data in an integrated population model (IPM) to predict the impact of harvesting chicks for translocations on the source population and to project the establishment of a second population. I then informed future translocation protocols using nest-monitoring data to quantify nest survival and breeding biology. Finally, I tested if WHDP presence had a positive influence on unrelated species groups. I counted two skink species at sites with and without burrows and used occupancy modelling to quantify the influence WHDP burrows had on skink occurrence. Estimates of population growth before and after predator eradications illustrated that WHDP population growth remained comparatively low and unaffected by this conservation strategy. Therefore, additional interventions are required. WHDP tracking revealed that the non-breeding distribution did not overlap with commercial fishing efforts. However, considerable fishing efforts were present within the breeding distribution. Despite these findings, onshore threats remain present and conservation strategies aimed at addressing terrestrial threats may be more feasible. Results from my IPM showed that translocations could successfully establish a second WHDP population without impacting the source excessively, provided translocation cohorts remain small and translocations are repeated over long time periods (5-10 years). Nest survival was not clearly influenced by interannual variation, distance to sea, and intra- or interspecific competition. Furthermore, I informed future translocation protocols by identifying the preferred harvest window, measurements of ideal translocation candidates, and feeding regimes. Occurrence of one skink species was 114% higher at sites with burrows than at sites without, suggesting that WHDP presence benefits unrelated species. The information provided in this thesis facilitates the identification of future management strategies for this critically endangered species. However, future conservation management of the WHDP should be based on structured decision-making frameworks that apply iterative adaptive management loops and must acknowledge the unique position of tangata whenua (people of the land). This approach could address the consequences and trade-offs of each alternative, account for uncertainty, facilitate the decolonisation of conservation biology, and would ultimately result in the best potential outcome of the target species in a truly integrated fashion.</p>

show abstract

Seabirds as environmental indicators: foraging behaviour and ecophysiology of common diving petrels (Pelecanoides urinatrix) reflect local-scale differences in prey availability

Cited by 28 publications

References 53 publications

Deep inference of seabird dives from GPS-only records: performance and generalization properties

Deep inference of seabird dives from GPS-only records: performance and generalization properties

Characterising the foraging ecology and mercury exposure of the Nationally Critical Whenua Hou diving petrel

Integrated conservation of the Whenua Hou Diving Petrel

Contact Info

Product

Resources

About