Interaction between distant taxa in the use of tree cavities in African ecosystems: a study using nest-boxes

Abstract

Abstract:Convergence in the use of resources may occur between distantly related organisms. A major ecological resource in which members of various taxa may be interested is a cavity for nesting. A variety of social hymenopterans and vertebrates may nest within tree cavities in tropical ecosystems. We used 241 nest-boxes placed in seven Kenyan localities to investigate the use of nesting cavities by members of distant taxa and discuss whether interaction between them is a potential factor shaping cavity-nester communities in tropical regions. The nest-boxes were occupied by social insects (ants, bees and wasps) (30.1% of nest-boxes in April–May and 33.1% in September–October) and vertebrates (birds and mammals) (20% and 7.7%, respectively). Hymenopterans were more abundant in forest boxes (36.2% of nest-boxes occupied in April–May and 37% in September–October), whereas savannas had lower figures (21.7% and 31.3%, respectively). Among vertebrates, most occupants of nest-boxes in savanna were birds (17.8% of nest-boxes occupied vs. 8% in mammals), while mammals predominated in forests (4.9% of the nest-boxes occupied vs. 0.3% in birds). Spatial and temporal patterns of occupation highlight the potential that interaction between distant taxa may have on the access to nesting cavities. More nest-boxes remained unoccupied in forested areas than in savanna areas suggesting that a shorter supply of nesting sites in the savanna may be a source of competition. The simultaneous occupation of a nest-box by two different taxa was exceptional, also supporting the hypothesized inter-taxon competition.

A heterogeneous landscape does not guarantee high crop pollination

“…Even though there seems to be plenty of possible nesting opportunities in the landscape, interacting species like aggressive ants may hinder the use of them (cf. [ 49 ]). Studies that compare bee abundances in landscapes at different altitudes as well as examining local limiting factors for bees are necessary in order to come closer to an explanation to the found patterns in our study landscape.…”

Specific nest box designs can improve habitat restoration for cavity‐dependent arboreal mammals

“…Honeybees used less than 10% of all nest boxes, but these observations included abandoned or remnant hives. The loss of approximately 10% of nest boxes to honeybee occupation may be a common occurrence (Harper et al 2005;Durant et al 2009;Grarock et al 2013;Veiga et al 2013;Warakai et al 2013). Lindenmayer et al (2009) argued that maintenance of nest boxes to control honeybee infestations will undermine the economic effectiveness of nest box programs.…”

“…There is also evidence that insectivorous bat populations can be supported by artificial cavities (Stebbings & Walsh ; Flaquer et al ; Baranauskas ; Bender ). In contrast, evidence for cavity‐dependent non‐flying arboreal mammals is equivocal because non‐flying arboreal mammals may show a relatively low frequency of use of nest boxes (5–8% of boxes, Menkhorst ; 8–23%, Rhind & Bradley ; 8–14%, Lindenmayer et al ; 15%, Durant et al ; 20%, Madikiza et al ; 22%, Franco et al ; 8%, Veiga et al ; 2–12%, Warakai et al ; 13%, Williams et al ). The relative lack of success in attracting some mammal species has led some to conclude that attempts to restore habitat value using artificial cavities may not be successful (Lindenmayer et al ).…”

Experimental removal of invasive Africanized honey bees increased breeding population size of the endangered Lear's macaw

“…12,13 Moreover, Africanized honey bees can build hives in cavities used as nesting sites by native species, including vertebrates. [14][15][16] However, because other studies on competition and potential displacement by invasive insects have mostly focused on their impact on native insects, 1 little is known on the impacts of Africanized honey bees on vertebrate populations.…”