Beginning with Emlen (1966) and MacArthur and Pianka (1966) and extending through the last ten years, several authors have sought to predict the foraging behavior of animals by means of mathematical models. These models are very similar,in that they all assume that the fitness of a foraging animal is a function of the efficiency of foraging measured in terms of some "currency" (Schoener, 1971) -usually energy- and that natural selection has resulted in animals that forage so as to maximize this fitness. As a result of these similarities, the models have become known as "optimal foraging models"; and the theory that embodies them, "optimal foraging theory." The situations to which optimal foraging theory has been applied, with the exception of a few recent studies, can be divided into the following four categories: (1) choice by an animal of which food types to eat (i.e., optimal diet); (2) choice of which patch type to feed in (i.e., optimal patch choice); (3) optimal allocation of time to different patches; and (4) optimal patterns and speed of movements. In this review we discuss each of these categories separately, dealing with both the theoretical developments and the data that permit tests of the predictions. The review is selective in the sense that we emphasize studies that either develop testable predictions or that attempt to test predictions in a precise quantitative manner. We also discuss what we see to be some of the future developments in the area of optimal foraging theory and how this theory can be related to other areas of biology. Our general conclusion is that the simple models so far formulated are supported are supported reasonably well by available data and that we are optimistic about the value both now and in the future of optimal foraging theory. We argue, however, that these simple models will requre much modification, espicially to deal with situations that either cannot easily be put into one or another of the above four categories or entail currencies more complicated that just energy.

Citation classic - optimal foraging - a selective review of theory and tests

The World's Largest Wetlands: Ecology and Conservation

The current study was intended to investigate the breeding habitats and ecology of the Eurasian coot Fulica atra in Fez region Morocco. To achieve our goals, nests were monitored in three wetlands Oued Al Jawahir river, Mahraz and El Gaada dams. In addition, nesting vegetation and nest’s dimensions were analysed to characterise the Eurasian coot nests. As results, 46 nests (74%) were found in Oued al Jawahir, compared with 15 nests (24%) in Mahraz dam. In El Gaada dam only 2 nests were built by the Eurasian coots. On the other hand, all nests were built on the riparian vegetation of the river and dams. Besides, nests were located in the periphery of the river stream. Many plants were used entirely or special parts, such as stems and roots in nesting activity. Typha angustifolia is used in 45.3% of nests and J. acutus in 38.6% of nests. Other plants are found with a minor presentation in nests, including P. stratiotes (9.6 %) of nests, Phragmites australis (5.6%), and Tamaris sp. (0.9%). These plants form the structure of nests and support. Besides nesting in river’s periphery, the nests were constructed at an average height of 14.5 ± 0.05 away from the stream of water. Concerning nest success, nest predation ranged from 57% (2018) to 60% (2019). Nests were lost due to water stream and human disturbance. Finally, Eurasian coots build its nests in the periphery of water ecosystems and in an important high to avoid flooding periods and human disturbances.

/pdf/nesting-habitat-and-breeding-success-of-fulica-atra-in-tree-3lbdooqcz9.pdf

Nesting habitat and breeding success of Fulica atra in tree wetlands in Fez’s region, central Morocco

Ecology of wetlands

With their species diversity, their population abundance and their integrator characters, higher plants represent useful tools to solve problems concerning the environment analysis and management. As they are good bioindicators, plants integrate many environmental parameters and can help to reveal the misworking of the ecosystems. Within this framework, a recent and complete survey of the phanerogamic flora of the Brussels area was carried out by the method of the floristic grid-map based on 1 km - squares. A comparison with earlier data has allowed us to appreciate the consequences of half a century of human activities on plant diversity in the urban ecosystem. The basic aim is to present a method of diagnosis and mapping that has been used, so as to turn the descriptive information about the biological environment of the area into a series of guidelines for land-use regulation and management within the city. Ellenberg's indicator values were used to express the relationship of flora to soil nitrogen, moisture content, reaction, light and temperature. Considering the biological characteristics of new floristic components and plants which have become rare or disappeared, it was possible to draw conclusions about the alterations in environmental conditions in Brussels. Our results show that the number of species did not differ significantly from 1940 until now. However, considerable changes have appeared during this period: there is a clear increase in the number of alien species; the flora of the Brussels area is becoming more nitrophilous and tolerant to shade, while it does not differ with respect to soil moisture, reaction and temperature. Human activities have disturbed the distribution and abundance of many species, inducing a decline or disappearance Of some of them, principally those which are associated with cropland, with marshland and woodland. On the other hand, numerous species have recently appeared in the city, many of which are aliens. The comparison between indigenous and alien species has revealed that their occurrence depends upon their ecological requirements: alien species are more tolerant of nitrogen, light, drought, heat and alkaline soils. The response of the flora to human impact is clearly demonstrated. Such sensitivity has obvious implications for both conservation and management. Circumstances, where Brussels plant monitoring is carried out permitting the avoidance of potential disaster and the saving of valuable biological resources, are developed. Arguments for the conservation of wild plants in cities also lead to some remarks concerning nature conservation practices in Brussels. © 2001 Elsevier Science B.V.

Temporal analysis of the Brussels flora as indicator for changing environmental quality

Population structure, behavior, and distribution pattern of the river lapwing Vanellus duvaucelii (Lesson, 1826)

Foraging behavior in river lapwing, Vanellus duvaucelii (Lesson, 1826) (Charadriiformes: Charadriidae): Differences in technique, prey, and habitat

Understanding the diversity and structure of bird communities is indispensable to delineate the importance of regional or local landscapes for avian conservation. The aim of the present study was to appraise community composition and threat status of avifauna of Bakhira Bird Sanctuary. The various species of birds were identified by using key references. During the study period 84 species of birds were identified. Maximum 15 species of birds were found to be belonging to order Anseriformes followed by minimum 2 species in Bucerotiformes and Gruiformes. We have enlisted 22 species of wetland birds in family Anatidae. However, only 1 species has been recognized in 11 different families. The documentation of the residential status of avifauna showed that 47 resident species (R), 28 migrant species (M) and 9 as resident migrant species (RM). According to the IUCN based categorization, maximum 86.90% species were recorded as least concerned (LC), followed by 1.19% endangered (EN), 4.76% near threatened (NT) and 7.14% vulnerable (VU). Guild based classification uncovered that maximum (44) birds were carnivorous and minimum (1) piscivorous. The result of our study concluded that Bakhira Bird Sanctuary is facing huge anthropogenic threats which include trapping and hunting of birds, habitat destruction by soil erosion, sedimentation and extension of crop fields, water pollution and eutrophication.

/pdf/community-composition-and-threats-status-of-ornithofauna-of-4c5gjc18kj.pdf

Community Composition and Threats Status of Ornithofauna of Bakhira Bird Sanctuary: A Wetland Ecosystem

Nesting success is defined as the percentage of nests that have at least one chick that successfully fledges from them. In this regard, this study was conducted in the Gangetic plain of district Ra...

Factors influencing nesting success of the river lapwing, Vanellus duvaucelii (Lesson, 1826):

There is little information about habitat use pattern of river lapwing in India as well as in Southeast Asia. In this regard, we employed the line transect method to quantify the density of river lapwing concerning vegetation height, water depth and soil penetrability. Scan and focal sampling methodology was adapted to investigate the activities (foraging and roosting) and breeding events. The results showed that invertebrates were abundant at 4 cm of soil penetrability, particularly in open unvegetated river bank (OURB) and open unvegetated river island (OURI) habitat types. River lapwings were significant in short vegetation. They occurred in high density in the vicinity of river water at 5 cm of water depth and 4 cm of soil penetrability in OURB and OURI habitat types. Human activities also influenced the density of river lapwing in different habitat types. Results of GLM analysis revealed that all interactions strongly influenced the density of river lapwings except two interactions, e.g. vegetation height*water depth and vegetation height*soil penetrability. Moreover, we found that river lapwing foraged more frequently in OURB and OURI habitat types while less in vegetated river bank (VRB) and crop fields (CF). Roosting activities were more frequently observed in VRB and CF habitat types. Different breeding events (nest seen, chick seen, alarm calling and territory defence) were primarily seen in OURB and OURI habitat types. Finally, developing greater understanding of the river lapwing could help us to design effective conservation measures for this species.

Dynamics of habitat use by the river lapwing Vanellus duvaucelii (Lesson, 1826)

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