Foraging behaviour and prey size of the painted stork

Nor S. The Breeding Ecology of the Painted Stork Mycteria leucocephala in Central Peninsular Malaysia

The Painted Stork (Mycteria leucocephala) populations in Putrajaya and Shah Alam, Peninsular Malaysia, have increased by almost 10%–13% every year. If this trend continues, it is believed that habitat overlap may occur between this species and the Milky Stork (Mycteria cinerea), which is currently threatened with extinction. Habitat overlap could lead them to compete for food and other necessary resources, and consequently, one species would outcompete another. However, little is known about the breeding ecology of the Painted Stork in Peninsular Malaysia. Therefore, this study aimed to evaluate the breeding ecology of the Painted Stork and examine its nesting characteristics and their effects on breeding success. Direct observations were made of colonies in the Upper Bisa Putrajaya Wetland (UBPW) and Tasik Shah Alam (TSA) during the breeding season from March to September 2016 and 2017. The peak of the breeding season was in June, and no differences were found in nesting colony parameters between study sites, including the nest diameter and nest building period, except for nest height. The average height above the ground level of TSA nests was higher than in UBPW. Human activities near the nesting site in Shah Alam may have led to the birds constructing nests higher to prevent disturbance and predation. Nest diameter and nest building period were influenced by the number of nestlings raised by parents. These findings provide new information that may be used in management programs to control Painted Stork populations and can be useful for conserving threatened species, particularly the Milky Stork.

Mining morphometrics and age from past survey photographs

Background

Researchers often document wildlife surveys using images. These images contain data that can be used to understand alterative research objectives, even years after they were originally captured. We have developed a method to measure age and morphology (body size measurements and tusk size) from survey image databases and future surveys, without the availability of a known subject distance or a scale in each image. African savanna elephants (Loxodonta africana) serve as an ideal model species to develop a non-invasive, image-based morphometric methodology: as handling these animals is particularly invasive and expensive, involving anaesthesia and because of their IUCN ‘vulnerable’ status. We compare in situ measurements, taken during collaring events, to tusk-to-body-size ratios, measured from the images.

Results

We provide evidence that relative morphological measurements, musth timing, and age of male African savanna elephants can accurately be obtained from a survey image database of over 30,000 images, taken over an 18-year period. Of the 11 tusk to body size ratios calculated, we recommend the use of two in particular for future measurement in African elephants to determine size and age: 1) tusk length to tusk diameter and 2) tusk length to body height.

Conclusions

We present a practical, non-invasive measure to estimate morphometrics, including both age and tusk size from photographs, which has conservation applications to the protection of elephants and is relevant to a range of other taxa.

Electronic supplementary material

The online version of this article (10.1186/s12983-019-0309-x) contains supplementary material, which is available to authorized users.

Monitoring Western Snowy Plover Nests with Remote Surveillance Systems in San Francisco Bay, California

The western snowy plover Charadrius nivosus nivosus is listed as threatened under the U.S. Endangered Species Act of 1973 due to long-term population declines related, in part, to nest predation and human disturbance. In San Francisco Bay, California, numbers of predators of western snowy plovers and the potential for recreation-based human disturbances have increased during the past few decades and will likely increase for the foreseeable future. In an attempt to increase the reproductive success of western snowy plovers, managers have dedicated considerable resources to management practices including predator removal and habitat enhancement projects in San Francisco Bay. The unequivocal identification of western snowy plover nest predators and information regarding the behavioral responses of nesting plovers to human disturbance would inform management practices for this species. Therefore, we examined the efficacy of using a digital video surveillance system to identify nest predators of western snowy plovers in former salt evaporation ponds in San Francisco Bay and to assess its potential for use in behavioral studies. This system was designed to minimize disturbance to nesting plovers and limit predator bias at breeding sites that had little or no cover to camouflage or protect the equipment. The system included a small camera with infrared lights placed approximately 20 m from nests and a continuously operating recording unit and power supply that was positioned up to 300 m from nests. The system could be deployed within 20 min, run continuously for up to 5 d, and data could be retrieved without disturbing nesting birds. During a 2-y study period, we recorded six species depredating plover eggs and chicks: red-tailed hawk Buteo jamaicensis, common raven Corvus corax, California gull Larus californicus, northern harrier Circus cyaneus, ruddy turnstone Arenaria interpres, and gray fox Urocyon cinereoargenteus. Our results suggest that this surveillance system was effective for identifying western snowy plover nest predators, and the presence of the camera did not influence nesting success of monitored nests. This system could be integrated into conservation programs intended to improve reproductive success of this species and could be useful for conducting behavioral studies of western snowy plovers and other species.

Morphometric sex determination of Milky and Painted Storks in captivity

Logistic regression was applied to develop a morphometric sexing method of two closely related stork species that were previously sexed through amplification of the CHD gene. Tarsus length (TL) and bill length (BL) measurements were recorded from captive populations of adult Milky Stork (Mycteria cinerea) (n = 60) and Painted Stork (Mycteria leucocephala) (n = 58) at Zoo Negara Malaysia. Despite having monomorphic plumages, both stork species exhibited normal sexual size dimorphism in which males were significantly larger than females in the tested variables. Based on logistic regression analysis, BL correctly classified the sex of sampled individuals from Painted and Milky stork with an overall predicted accuracy of 94.8 and 90.0%, respectively. However, TL measurements generated a lower predicted accuracy level of 86.2% and a same accuracy level of 90% on the sex classification of individuals from Painted and Milky stork, respectively. By comparing the measurements of both species, only the average BL measurements of the Milky storks were significantly lower than that of Painted storks (t-test, P80.001). The logistic regression equation in this study may serve as a simple and more practical option for sexing Milky and Painted storks for their breeding and conservation programmes.

Using heronry birds to monitor urbanization impacts: a case study of painted stork Mycteria leucocephala nesting in the Delhi Zoo, India

Although urbanization is a frequently cited cause of biodiversity loss (Czech and Krausman 1997) our understanding about urban ecology is severely limited (Marzluff et al. 2001). Birds are popular bio-indicators of environmental change because they are ecologically versatile, their populations as well as select fitness parameters can be conveniently monitored, often with the voluntary involvement of local nature enthusiasts across large geographical scales, and their presence/absence in a particular area is consequential (Bibby et al. 1992; Urfi 2004). In India, while several studies have focused on changes in bird populations and distributions in natural habitats (Urfi et al. 2005), very few have actually attempted to study either the impacts of urbanization on birds or how different species have adjusted to environmental change. However, many Indian cities offer foraging and nesting habitat for birds, especially colonial waterbirds such as stork, ibis, spoonbill, heron, egret, cormorant, and spoonbill. Some notable examples in this regard are Piele Gardens in Bhavnagar city (Parasharya and Naik 1990), Karanji Tank in Mysore (Jamgaonkar et al. 1994) and the National Zoological Park (hence forth Delhi Zoo) in India's capital city New Delhi (Urfi 1997). In this article, I focus on the opportunities for meaningful ecological research offered by the wild waterbirds nesting in the Delhi Zoo premises and discuss the significance for initiating novel, long term conservation monitoring programs, involving volunteers and bird watchers, to create data bases that will be useful for understanding urbanization and climate change impacts on biodiversity.