Since the mid-1980s, there has been a steady rise in the numbers of great cormorants in all Eurasia, and in the number over-wintering annually in Israel. Winter counts in recent years show about 15,000 - 20,000 great cormorants in Israel; they arrive in October and stay until March. Over the years, colonies of over-wintering great cormorants, which can have over 5,000 individuals each, come into conflict at commercial fish farms in Israel, which are in the form of local concentrations of open earthen ponds, in which are grown very high concentrations of food fish, mainly carp, tilapia, grass carp, and mullet. Over the years, many attempts have been made to reduce the negative impact of over-wintering great cormorants on the commercial fish farms in Israel, utilizing lethal and non-lethal methods. Over 50 banding returns from the last 2 decades showed that the great cormorants over-wintering in Israel originated in the area around the northern Black Sea and Sea of Azov, around the Crimean Peninsula in southern Ukraine (about 1400 km or 850 miles due north). This overabundant species causes considerable damage around its nesting sites in Ukraine by interfering with endangered waterbirds, and by conflicting with fishermen. Israel has recently been exploring ways to utilize international cooperation for management of the nesting population in Ukraine, in order to reduce the size of the wintering population in Israel and also to prevent damage to endangered waterbirds in Ukraine. The major instruments are the European Union’s project INTERCAFE (Interdisciplinary Initiative to Reduce Pan-European Cormorant-Fisheries Conflicts: www.intercafeproject.net), and the African-Eurasian Waterbird Agreement (AEWA) under UNEP’s Convention on Migratory Species (CMS): www.unep-aewa.org, as well as other International Environmental Agreements. An experimental program is proposed for reducing the nesting success of the Ukrainian population. A smaller great cormorant population should impact less upon nesting waterbirds in Ukraine and also decrease the intensity of the conflict with both Ukrainian and Israeli fishermen, thereby lessening the extent of lethal control used against great cormorants in both countries. The proposed experimental program includes egg-oiling of ground-nesting birds and hazing tree-nesting birds with green lasers.

Although Israel is a small country, it sits at the junction of three continents, and has an especially rich diversity of ecotones and wildlife. In addition, Israel serves as a narrow land-bridge on the major migratory route for millions of birds between Eurasia and Africa. Competing with all this wildlife for living space is a relatively dense human population. Israel is quite conservation-minded with strict wildlife protection laws and very little hunting. All these factors contribute to a situation in which there is much human influence over whatever available habitat is left for wildlife. Consequently, wildlife-human conflicts are common and diverse, but are dealt with mainly with non-lethal methods. Millions of migratory birds cross through Israel and share Israel’s small airspace with the Israeli Air Force (IAF). Israel is especially active in Bird Aircraft Strike Hazard (BASH) issues, which are controlled by a variety of means, including real-time radar information of migratory birds, habitat management, and use of border collies at airfields. Wildlife in Israel are vectors for human diseases (e.g., leishmaniasis, rabies, and West Nile fever). To prevent rabies epidemics, Israel has recently begun successful use of oral rabies vaccination (ORV) for jackals (Canis aureus) and foxes (Vulpes vulpes).

The use of scarecrows to prevent bird damage to crops probably dates back thousands of years to the beginning of agriculture. Because many of the birds that can cause damage to field crops are protected species, farmers need effective non-lethal protection methods. Despite their perception as “low-tech” and thus ineffective, scarecrows are being used in Israel in a new way, as a cost-effective part of modern bird-damage prevention programs for field crops. Farmers in the Hula Valley in northern Israel placed seated life-size human effigies dressed in yellow hooded rain-suits, each holding a large black pipe (to simulate a shotgun) in fields of winter field crops, as part of a program to prevent damage by Eurasian cranes. Each effigy was also equipped with a life-like facial mask. Experience has shown that approximately one seated scarecrow is needed per 5 ha (about 12 acres) of field crop. To make these scarecrows more effective, and to prevent habituation, the farmers occasionally dressed in yellow rain-suits like the scarecrows, and seated themselves in the field, opening fire with pyrotechnics when birds approached. In addition, the farmers donned the yellow rain-suits whenever conducting any bird harassment activity, such as shooting pyrotechnics from vehicles while patrolling their fields. The birds apparently learned to associate the yellow-suited figures with danger and to keep away from them (and the crops). Farmers who used the new scarecrows in this way found them to be cost-effective because crop damage was almost nil, while damage prevention expenses were also kept low, since the scarecrows are cheap to build and maintain, and less pyrotechnic ammunition was needed for crop protection.

This study examined the effects of emotion on the long-term acquisition of a procedural skill over a five-day period. Two tasks were employed: a word association task (WAT) and a visual discrimination task (VDT). Over the initial four days of the study participants went through a mood induction procedure (MIP) then subsequently completed both tasks. Both tasks showed a reduction in reaction time consistent with the power law of learning. No significant change in reaction time between day four and day five (one week later) was noted suggesting the change in reaction time was robust. These data further suggest that emotion modifies the rate at which the VDT is acquired.

How do chemically defended animals resist their own toxins? This intriguing question on the concept of autotoxicity is at the heart of how species interactions evolve. In this issue of Molecular Ecology (Molecular Ecology, 2024, 33), Bodawatta and colleagues report on how Papua New Guinean birds coopted deadly neurotoxins to create lethal mantles that protect against predators and parasites. Combining chemical screening of the plumage of a diverse collection of passerine birds with genome sequencing, the researchers unlocked a deeper understanding of how some birds sequester deadly batrachotoxin (BTX) from their food without poisoning themselves. They identified that birds impervious to BTX bear amino acid substitutions in the toxin-binding site of the voltage-gated sodium channel Nav1.4, whose function is essential for proper contraction and relaxation of vertebrate muscles. Comparative genetic and molecular docking analyses show that several of the substitutions associated with insensitivity to BTX may have become prevalent among toxic birds through positive selection. Intriguingly, poison dart frogs that also co-opted BTX in their lethal mantles were found to harbour similar toxin insensitivity substitutions in their Nav1.4 channels. Taken together, this sets up a powerful model system for studying the mechanisms behind convergent molecular evolution and how it may drive biological diversity.

The community of plant-feeding insects (herbivores) that specialize on milkweeds (Apocynaceae) form a remarkable example of convergent evolution across levels of biological organization¹. In response to toxic cardiac glycosides produced by these plants, the monarch butterfly (Danaus plexippus) and other specialist herbivores have evolved parallel substitutions in the alpha subunit (ATPA) of the Na⁺/K⁺-ATPase. These substitutions render the pump insensitive to cardiac glycosides^2,3, allowing the monarch and other specialists, from aphids to beetles, to sequester cardiac glycosides, which in turn provide defense against attacks by enemies from the third trophic level⁴. The evolution of 'target-site-insensitivity' substitutions in these herbivores poses a fundamental biological question: have predators and parasitoids that feed on cardiac-glycoside-sequestering insects also evolved Na⁺/K⁺-ATPases that are similarly insensitive to cardiac glycosides (as predicted by Whiteman and Mooney)⁵? In other words, can plant toxins cause evolutionary cascades that reach the third trophic level? Here we show that at least four enemies of the monarch and other milkweed herbivores have indeed evolved amino-acid substitutions associated with target-site insensitivity to cardiac glycosides. These attackers represent four major animal clades, implicating cardiac glycosides as keystone molecules⁶ and establishing ATPalpha, which encodes ATPA, as a keystone gene with effects that reverberate within ecological communities⁷.