Biscayne National Park colonial nesting birds monitoring protocol—Version 1.1

Breeding colonies of wading birds (orders Ciconiiformes, Pelecaniformes) and seabirds (orders Suliformes, Pelecaniformes) serve as important indicators of aquatic ecosystem health, as they respond to changes in food abundance and quality, contaminants, invasive species, and disturbance. The Comprehensive Everglades Restoration Plan, Restoration Coordination & Verification program (CERP-RECOVER) has identified wading-bird colonies as an important ecosystem restoration indicator. The National Park Service South Florida/Caribbean Inventory & Monitoring Network (SFCN) ranked colonial nesting birds eighth out of 44 vital signs of park natural resource conditions for ecological significance and feasibility. However, while large-scale monitoring efforts are occurring in the rest of the Greater Everglades Ecosystem, only minimal historic data collection and no extensive ongoing monitoring of wading bird and seabird nesting have occurred in Biscayne National Park. Consequently, due to their high importance as biological indicators and because they are a gap occurring in regional monitoring efforts, the network has initiated a monitoring program of colonial nesting birds in Biscayne National Park. This protocol provides the rationale, approach, and detailed Standard Operating Procedures for annual colonial bird monitoring within and close to Biscayne National Park and conforms to the Oakley et al. (2003) guidelines for National Park Service long-term monitoring protocols. The specific objectives of this monitoring program are to determine status and long-term trends in: Numbers and locations of active colonies of colonial nesting birds with a special focus on Double-crested Cormorants, Great Egrets, Great White Herons, Great Blue Herons, White Ibises, and Roseate Spoonbills. Annual peak active nest counts of colonial nesting birds in Biscayne National Park with a special focus on the species mentioned above. An annual nesting index (i.e., sum of monthly nest counts) with a special focus on the species mentioned above. Timing of peak nest counts for the focal species.

Digging into the behaviour of an active hunting predator: arctic fox prey caching events revealed by accelerometry

Background Biologging now allows detailed recording of animal movement, thus informing behavioural ecology in ways unthinkable just a few years ago. In particular, combining GPS and accelerometry allows spatially explicit tracking of various behaviours, including predation events in large terrestrial mammalian predators. Specifically, identification of location clusters resulting from prey handling allows efficient location of killing events. For small predators with short prey handling times, however, identifying predation events through technology remains unresolved. We propose that a promising avenue emerges when specific foraging behaviours generate diagnostic acceleration patterns. One such example is the caching behaviour of the arctic fox (Vulpes lagopus), an active hunting predator strongly relying on food storage when living in proximity to bird colonies. Methods We equipped 16 Arctic foxes from Bylot Island (Nunavut, Canada) with GPS and accelerometers, yielding 23 fox-summers of movement data. Accelerometers recorded tri-axial acceleration at 50 Hz while we obtained a sample of simultaneous video recordings of fox behaviour. Multiple supervised machine learning algorithms were tested to classify accelerometry data into 4 behaviours: motionless, running, walking and digging, the latter being associated with food caching. Finally, we assessed the spatio-temporal concordance of fox digging and greater snow goose (Anser caerulescens antlanticus) nesting, to test the ecological relevance of our behavioural classification in a well-known study system dominated by top-down trophic interactions. Results The random forest model yielded the best behavioural classification, with accuracies for each behaviour over 96%. Overall, arctic foxes spent 49% of the time motionless, 34% running, 9% walking, and 8% digging. The probability of digging increased with goose nest density and this result held during both goose egg incubation and brooding periods. Conclusions Accelerometry combined with GPS allowed us to track across space and time a critical foraging behaviour from a small active hunting predator, informing on spatio-temporal distribution of predation risk in an Arctic vertebrate community. Our study opens new possibilities for assessing the foraging behaviour of terrestrial predators, a key step to disentangle the subtle mechanisms structuring many predator–prey interactions and trophic networks.

Ornithogenic vegetation: how significant has the seabird influence been on the Aleutian Island vegetation during the Holocene?

We have studied the long- and short-term periods of seabird influence on coastal vegetation. In the Aleutian Islands during the Holocene, terrestrial predators were virtually absent; as a result, large seabird colonies thrived along the coasts or across entire islands. Bird guano enriches the soil with nitrogen, which can lead to the formation of highly modified ornithogenic (bird-formed) ecosystems. The vegetation of several Aleutian Islands has been reconstructed; however, only the vegetation on Carlisle Island had noticeable impact from the seabird guano. For more detailed investigation of bird influence, we conducted pollen analysis to reconstruct the 9,300-year-old vegetation dynamics of the coast of Shemya Island. From earlier studies of nitrogen isotopes in peat, we discovered that a large seabird colony existed on Shemya from 4600 to 2400 years ago, and birds also influenced coastal ecosystems between 1470–1160 and 810–360 years ago. In these sequences, the tundra dominated by Ericaceae dwarf shrubs initially spread on the coast. During a period of at least 2200-years nitrogen enrichment led to the development of herb meadows with a high presence of Apiaceae. After a noticeable reduction in seabird colonies due to human hunting, grass-meadows spread. During the late Holocene several hundred years of seabird impact led to an increase in abundance of indicator taxa, ferns and umbelliferous species, as well as in total pollen concentration, but this did not result in a radical change of dominants. In recent decades, due to the extinction of the bird colonies, heather communities have begun to spread on the Shemya coast. Also large ash emissions in the Aleutian Islands can lead to a decrease in pollen concentration even in peat located far from an eruption.

Результаты обследования колоний морских птиц восточной части Тауйской губы (Охотское море)

The results of the sea bird colonies census in the eastern part on the coast of the Tauy Bay, Zavyalov Island, and the Koni Peninsula are presented and discussed. Recent census allows to assess changes in nesting colonies of seabirds that occurred over the past 10-15 years. Total number of nesting seabirds is estimated as more than 92 thousand individuals. Gradual decrease in the number of seabirds colonies was observed on the west coast of the Koni peninsula. The great bulk of seabirds nesting in here is concentrated around Cape Bligan - 11,1 thousand individuals and on Cape Skalisty - 7.5 thousand individuals. Recovery of the colony of murres was recorded. On Cape Skalisty, after almost 30-year absence, and the number of murres quickly grows here. The number of breeding seabirds on Umara Island has remained stable for the last 10 years and is estimated as 60.2 thousand individuals. The total number of breeding seabirds along the surveyed part of the continental coast has decreased from 41.7 thousand individuals to 30.2 thousand in 2009-2019.

Effects of sea birds and soil development on plant and soil nutritional parameters after 50 years of succession on Surtsey

Surtsey, the island that rose from the sea in a submarine eruption during 1963 to 1967, has been the subject of many studies on primary succession. These studies have intensified after the establishment of a seagull colony on the island in 1986. This paper reports on the results of a short sampling expedition in 2013 that intended to characterize the interactive effects of the seagull colony and of soil development on soil nutritional characteristics in the tephra sands that cover the underlying lava, as well as in plants growing inside and outside the seagull colony. Feces and pellets of the gulls were extremely rich in both nitrogen (N) and phosphorus (P) and δ15N analyses showed that N was transferred from pellets and feces to the tephra soils and subsequently taken up by the plants. The tephra soils not affected by the birds showed a high concentration of P compared to N. The concentration of both nutrients was much lower than in the soils of the bird colony. In general, variation in tephra soil depth had little effect on nutritional characteristics, except for the very low N concentration in deep soils. Thus, our results confirm the overriding effect of the seagull colony on Surtsey on nutritional characteristics of the developing soils and vegetation. Due to the very high P availability of the volcanic soils in combination with the high P input by the birds, vegetation productivity is N limited, despite the extremely high N input of 47 kg N ha-1 yr-1 that the birds add to the system. Our findings emphasize the extreme importance of bird colonies on the nutritional ecology of young, N-poor ecosystems.

New approaches to zoology: Plenary 2

Following the second session of the forum, we held a question and answer session facilitated by Paul Willis. The presentations covered by this plenary session were: Back to the future: Aerial surveillance from ‘blimps’ for ecology and conservation (Kye Adams et al. University of Wollongong) Using drones to monitor large and complex breeding bird colonies (Mitchell Lyons, University of NSW) Sniffing solutions to enhance koala conservation (Romane Cristescu et al. University of the Sunshine Coast) Collect, connect, upscale: revolutionising the uptake of citizen science in bird research and conservation (Micha Jackson, University of Queensland).

Seasonal changes of free-living ciliate communities in different biotopes of the Agzibir Lake

The Agzibir Lake is optimal in terms of hydrochemical and hydrobiological factors for formation of higher biodiversity of free-living ciliates. This is facilitated with continuous entering biogenic elements as a result of metabolism of large bird colonies and decaying organic residues of plant and animal origin. The Agzybir Lake having a link with the Caspian Sea in spring and fall is a place of spawning and the subsequent development of larvae of many commercially valuable fishes of the Caspian Sea, for which ciliates are a valuable starting food source in early stages of ontogenesis. During 2014–2019, totally 169 species of free-living ciliates were found by us, and 34 of them were observed for the first time for the Caspian fauna. The minimum species diversity was observed in plankton, where 46 species were recorded. In benthos of the sandy biotope, 58 species were found, whereas in the silty sand one, 80 species. At the silt soil in the biotope of gray silt, we found 72 species, the maximum species diversity (84 species) was observed in the silt biotope with plant residues, while at the black silt with sapropel communities 66 species of free-living ciliates were found. In the periphyton biotope, we observed 71 species, while in coastal thickets of algae (phytociliocenosis) 79 species of free-living ciliates were found. As with the sandy biotope, the black silt biotope, sometimes with small communities of sapropel silt, is much smaller in area than the rest of benthic biotopes of the Agzibir Lake. Yet, free-living ciliate communities of black silt are specific and include several species that are tolerant to low oxygen and hydrogen sulfide in water. The seasonal variations of total quantity of free-living ciliates of benthic biotopes have three maxima (in spring, summer and autumn). As for the rest of biotopes of plankton, periphyton and phytociliocenosis, only two maxima (in spring and autumn) were revealed. The greatest similarity of species diversity was observed within benthic communities. But lowest similarity was observed between sapropel silt and the rest. As was already mentioned, this is due to specific ecological conditions of sapropel silt biotope.

Response of colonial Peruvian guano birds to flying UAVs: effects and feasibility for implementing new population monitoring methods

Background Drones are reliable tools for estimating colonial seabird numbers. Although most research has focused on methods of improving the accuracy of bird counts, few studies have evaluated the impacts of these methods on bird behavior. In this study, we examined the effects of the DJI Phantom 3 drone approach (altitude, horizontal and vertical descent speeds) on changes in the intensity of behavioral response of guano birds: guanay cormorants (Phalacrocorax bougainvilli), Peruvian boobies (Sula variegata) and Peruvian pelicans (Pelecanus thagus). The breeding and non-breeding condition was also evaluated. Methods Eleven locations along the Peruvian coast were visited in 2016–2017. Drone flight tests considered an altitude range from 5 to 80 m from the colony level, a horizontal speed range from 0.5 to 15 m/s, and a vertical descent speed range from 0.5 to 3 m/s. The intensity of the behavioral response of birds was scored and categorized as: 0-no reacting, 1-head pointing to the drone (HP), 2-wing flapping (WF), 3-walking/running (WR) and 4-taking-off/flying (TK). Drone noise at specific altitudes was recorded with a sound meter close to the colony to discriminate visual from auditory effects of the drone. Results In 74% of all test flights (N = 507), guano birds did not react to the presence of the drone, whereas in the remaining flights, birds showed a sign of discomfort: HP (47.7%, N = 130), WF (18.5%), WR (16.9%) and TK (16.9%). For the drone approach tests, only flight altitude had a significant effect in the intensity of the behavioral response of guano birds (intensity behavioral response <2). No birds reacted at drone altitudes above 50 m from the colony. Birds, for all species either in breeding or non-breeding condition, reacted more often at altitudes of 5 and 10 m. Chick-rearing cormorants and pelicans were less sensitive than their non-breeding counterparts in the range of 5–30 m of drone altitude, but boobies reacted similarly irrespective of their condition. At 5 m above the colony, cormorants were more sensitive to the drone presence than the other two species. Horizontal and vertical flights at different speeds had negligible effects (intensity behavioral response <1). At 2 m above the ground, the noise of the cormorant colony was in average 71.34 ± 4.05 dB (N = 420). No significant differences were observed in the drone noise at different flight altitudes because the background noise of the colony was as loud as the drone. Conclusions It is feasible to use the drone DJI Phantom 3 for surveys on the guano islands of Peru. We recommend performing drone flights at altitudes greater than 50 m from guano bird colonies and to select take-off spots far from gulls. Likewise, this study provides a first step to develop guidelines and protocols of drone use for other potential activities on the Peruvian guano islands and headlands such as surveys of other seabirds and pinnipeds, filming and surveillance.

Cormorant pellets as a tool for the knowledge of parasite-intermediate host associations and nematode diversity in the environment

SummaryAnisakids are usually acquired through the diet. Cormorant pellets are useful to detect both parasite larval stages, and prey items which could act as intermediate hosts in the environment. The current study provides information about the feeding habits of both birds and mammals, and the diversity of parasites circulating in the environment. The objective of the study was to identify Anisakidae larvae and prey items in pellets from the Imperial shag Phalacrocorax atriceps and the Red-legged cormorant P. gaimardi, suggesting possible parasite–prey associations. A total of 92 P. atriceps’ and 82 P. gaimardi’s pellets were collected from both Punta León, and Isla Elena bird colonies, respectively, during the period from 2006 to 2010. Pellets were preserved in ethanol and hard prey item remnants, and nematode larvae were studied using standard techniques. Prey item occurrence, nematode prevalence, and mean intensity were calculated. A correspondence analysis was performed to evaluate the larvae-prey association. Contracaecum spp., Pseudoterranova spp,, Anisakis spp., Terranova spp., and Hysterothylacium spp. third-stage larvae (L3) were identifi ed in pellets. Pseudoterranova spp. and Anisakis spp. L3 predominated in the environment of Punta León, whereas Contracaecum spp. and Hysterothylacium spp. L3 predominated in the Puerto Deseado area. The highest larvae-prey association was that of Contracaecum spp. L3 with Engraulis anchoita, followed by with Odontestes sp. in P. atriceps’ pellets. Contracaecum spp. L3 were significantly related to both sprats, Sprattus fueguensis and Ramnogaster arcuatta, in P. gaimardi’s pellets. It was verifi ed that E. anchovy is the main gateway of Contracaecum spp. L3 in P. atriceps. Odonthestes sp. might act as an intermediate/paratenic host of Contracaecum spp. L3 in the area. Both sprats might play a role as intermediate/paratenic hosts of C. australe, being the main gateway into P. gaimardi in the area. Thus, pellet analysis can be postulated as a good tool for indicating parasite-host associations between anisakids, and the prey items which act as intermediate hosts.