Written on 2024-05-15 13:49:14

Bird migration is a natural phenomenon that has captured the imagination of people across cultures for centuries. These annual journeys involve the mass movement of birds across vast distances, often spanning continents, and are driven by a combination of instinct, environmental cues, and survival strategies. Migration is a complex behavior that serves various ecological, evolutionary, and survival purposes. Yet, the very phenomenon of bird migration is under threat, particularly due to declining insect populations, upon which many migratory birds rely for sustenance. Insects provide essential energy for migratory birds, offering a rich source of nutrients critical for their survival. They rely on insects for energy during migration and other stages of their life cycles, especially when feeding their offspring. However, the massive decline in insect populations in many parts of the world is having serious implications for migratory birds. This year’s World Migratory Bird Day will therefore shine a spotlight on the interdependence between insects and birds, urging action to protect insects as a means to safeguard avian populations.


The campaign will explore the intricate relationship between birds and insects, and highlight the challenges faced by both as well as actions people can take to address the threats and halt the decline in insects. Below you will find a set of key messages and recommended actions and conservation measures which will be promoted through this year’s campaign.

We take a look at Migratory Bee eaters notably:

The European bee-eater (Merops apiaster) is a near passerine bird in the bee-eater familyMeropidae. It breeds in southern and central Europe, northern and southern Africa, and western Asia. Except for the resident southern African population, the species is strongly migratory, wintering in tropical Africa. This species occurs as a spring overshoot north of its usual range, with occasional breeding in northern Europe.

The blue-cheeked bee-eater (Merops persicus) is a near passerine bird in the bee-eater family, Meropidae. The genus name Merops is Ancient Greek for "bee-eater", and persicus is Latin for "Persian" It breeds in Northern Africa, and the Middle East from eastern Turkey to Kazakhstan and India. It is generally strongly migratory, wintering in tropical Africa, although some populations breed and live year-round in the Sahel.  This species occurs as a rare vagrant north of its breeding range, with most vagrants occurring in Italy and Greece. This species, like other bee-eaters, is a richly coloured, slender bird. It is predominantly green; its face has blue sides with a black eye stripe, and a yellow and brown throat; the beak is black. It can reach a length of 31 cm (12 in), with the two elongated central tail feathers adding another 7 cm (2.8 in). Sexes are mostly alike but the tail-streamers of the female are shorter.

This is a bird which breeds in sub-tropical semi-desert with a few trees, such as acacia. It winters in open woodland or grassland. As the name suggests, bee-eaters predominantly eat insects, especially beeswasps and hornets, which are caught in the air by sorties from an open perch. However, this species probably takes more dragonflies than any other food item. Its preferred hunting perch is telephone wires if available.

Blue-cheeked bee-eaters may nest solitarily or in loose colonies of up to ten birds. They may also nest in colonies with European bee-eaters. The nests are located in sandy banks, embankments, low cliffs or on the shore of the Caspian Sea. They make a relatively long tunnel of 1 to 3 m (3–10 ft) in length in which the four to eight (usually six or seven), spherical white eggs are laid. Both the male and the female take care of the eggs, although the female alone incubates them at night. Incubation takes 23–26 days. The call sounds 'flatter' and less 'fluty' than the European bee-eater.

These two species are permanent migrants to Cameroon’s Nkambe Plateau between the Months of July and December every season alongside the Blue breasted Bee eater and the little bee eater.

Unfortunately, the population for over three decades precariously hunt the species for consumption as bush meat. The hunters also explains how they use various hunting methods including mimicking of the bird to capture them in numbers. Find in the picture below captured European and Blue-cheeked Bee eaters. It can be estimated that over some 500000 Bee eaters could have been captured between 1980 and 2020. There is a dire need for sensitization of the locals who gave made it a lifestyle to depend on these Bee eaters (Mbii ngoh) for their protein needs each year and some generate even incomes of up to 10000 CFAFrs each yar through the capture and sales of these innocent migrants. The villages of Saah, Njema, Binshua, Mbabi, Tabenken, Manjeng are the major villages in need of sensitization that will benefit these birds species

The decline and disturbance in insect populations across the flyways compounds the threat to birds’ existence and overall welfare.


Challenges Faced By Insects Vis-A Vis Bird Populations


  1. Habitat Loss and Change: Where natural spaces, such as forests or grasslands, are transformed or destroyed by activities such as intensive agriculture or urban development, insect populations decline. This decline has very negative implications for both plants, migratory birds, and the entire food chain in a negative cascading effect that results in severe bird population declines across an entire flyway.
  2. Toxic Trouble: Pesticides and herbicides, which are intended to protect crops, often have unintended negative consequences. They often affect non-target insect species, either directly (by killing them) or indirectly (for example by polluting water bodies and affecting water invertebrates’ development). This collateral effect affects migratory birds, ending up in lower body condition at stop-over sites or lower breeding success.
  3. Decreased Bird Populations: Without an adequate supply of energy-rich insects, birds may struggle to complete their migrations. Insufficient nutrition can lead to weakened immune systems, reduced reproductive success, and increased mortality rates among both adult birds and their offspring.
  4. Ecosystem Imbalance: Birds and insects are a classic example of ecological coevolution. Altering this relationship brings negative impacts to both communities. Maintaining and/or restoring healthy ecosystems means ensuring vital ecosystem services provided by birds and insects, such as pollination, seed dispersal, pest control and human well-being.  
  5. Climate Change; A negative consequence of the current climate is the desynchronization of bird migration: birds arriving at their breeding ground before or after the insect peak, reducing the breeding success, and increasing the damage insect populations can cause to some agricultural or forestry products.





  • The causes of insect decline include land-use change, climate change, agriculture, introduced species, nitrification, pollution, insecticides, herbicides, urbanization and light pollution. (PNAS. 2021)
  • The terrestrial bird population reliant on insects as a food source has dropped by 2.9 billion in the last 50 years (Tallamy & Shriver. 2021)
  • Supporting native plant species that productively sustain insect herbivores could help reverse these declines and benefit birds and other wildlife. (Tallamy & Shriver. 2021)
  • 96% of North American terrestrial birds feed their young exclusively or in part on insects. (Tallamy & Shriver. 2021)
  • Caterpillars are preferred over other insect options due to size, softness and higher nutritional value. Low caterpillar availability has been linked to reduced nestling fitness; for example, smaller clutch sizes, greater mortality from starvation, fewer fledglings, slower growth rates and lower body mass have been reported. (Tallamy & Shriver. 2021)
  • Recent bird population declines in North America, totaling over 3 billion individuals, are concentrated among terrestrial insectivores due to declining insect numbers. (Tallamy & Shriver. 2021)
  • Studies show that insect abundance is declining by 1-2% yearly, leading to potential shifts or losses of ecosystem function. (PNAS. 2021)
  • Not all insects are declining: some species are expanding in range and population size, and those associated with humans may be thriving due to human assistance. (PNAS. 2021)
  • Factors contributing to the decline of honeybees include mites, viral infections, microsporidian parasites, poisoning by pesticides and overuse of artificial foods. (PNAS. 2021)




To preserve the delicate balance between birds and insects, it is crucial to take proactive and effective conservation measures. A range of strategies can safeguard these vital components of our ecosystems.


  1. Habitat restoration and management: Identifying suitable habitats and adequately managing and/or restoring them, through the creation of protected areas when needed that are adequately connected will have immediate and positive impacts for both birds and insects to flourish.
  2. Sustainable Agriculture: Reducing pesticide and chemical fertilizer use, crop rotation, and maintaining natural vegetation corridors within agricultural landscapes benefit both insects and birds.
  3. Pesticide Alternatives: Opt for organic alternatives, targeted application, and integrated pest management systems minimize negative impacts on insect populations and the birds and other species that depend on them.
  4. Public Awareness: Raising public awareness about the importance of birds and insects fosters an understanding and empathy that is the basis for any conservation action. Communities can support conservation efforts, from local clean-up initiatives to creating bird-friendly urban spaces.
  5. International Cooperation: Join forces beyond political boundaries to protect critical stopover points, coordinate conservation measures, and ensure the availability of a chain of habitats required by migratory birds.
  6. Corporate Accountability: Encourage the private sector, companies and industries to adopt sustainable practices that reduce pollution and minimize habitat destruction through both regulations and incentives.

7. Recognizing the Value of Insects: Insects have a critical role in our survival. They contribute to food production, serving as pollinators for numerous fruits and vegetables. Insects enrich the quality of soil for plant growth and contribute to the overall health and balance of our planet. Ensuring the protection of insects enables the sustainability of our ecosystems and the food production industry.



  1. Insect friendly gardens: plant native flowers, shrubs, and trees that provide habitat for insects.  Insects prefer plants that are native to your area and need cover to survive. These plants are accustomed to the local weather and provide a good habitat for bugs.
  2. Support organic farming: choose organic products whenever possible to avoid agricultural practices that use harmful pesticides and prioritize biodiversity.
  3. Minimize habitat destruction: when developing or landscaping your property, minimize habitat destruction, try to compensate for the loss and preserve natural areas.
  4. Don’t rake! Create a thriving ecosystem for insects and birds by leaving leaves in your garden or yard. The leaf litter acts as a natural shelter, food source, and breeding ground for various insect species. The decaying leaves also attract insects that are essential for insectivorous birds’ diets, promoting biodiversity and ecological balance. By refraining from raking leaves, you contribute to a healthier and more sustainable environment for both insects and birds.
  5. Keep water clean by using eco-friendly soaps and cleaners. Some cleaning products and salts can be harmful to insects if they get into the water. 
  6. Teach your friends and family about the significance of insects. Support programs that educate people about insects and speak up for conservation in your community. Make sure rules about lawns and pesticides protect insects and get involved locally to support decisions that protect natural habitats, insects, and other wildlife.
  7. Appreciate insects for the good things they do, like pollinating plants and being part of the food chain. Share positive pictures and stories about insects with your family and neighbors and on social media to help others learn their importance.
  8. Supports pollinator-friendly initiatives: advocate for and support local policies and initiatives that protect insects and their habitats. 


Douglas W Tallamy , W Gregory Shriver, Are declines in insects and insectivorous birds related?, Ornithological Applications, Volume 123, Issue 1, 1 February 2021, duaa059,


PNAS. “A new approach for predicting the evolution of COVID-19.” Proceedings of the National Academy of Sciences of the United States of America, vol. 118, no. 1, 2021, e2023989118.


Both, C., R. G. Bijlsma & M. Visser (2005) : Climatic effects on timing of spring migration and breeding in 351 a long-distance migrant, the pied flycatcher Ficedula hypoleuca. J. Avian Biol. 36 : 368-373. 352


Both, C., S. Bouwhuis, C.M. Lessells, M. Visser (2006) : Climate change and population declines in a 353 long-distance migratory bird. Nature 441, 81-83 354