The effects of brush control on bird populations in a mesquite community

TitleThe effects of brush control on bird populations in a mesquite community
Publication TypeThesis
Year of Publication1982
AuthorsReitzel J.A.
Number of Pages55
Date Published1982
UniversityNew Mexico State University
CityLas Cruces, New Mexico
Thesis TypeM.S. Thesispp
Call Number00570
Keywordsbird population, brush control, brush control, herbicide, brush control, Prosopis, community, mesquite, bird populations, dissertation, dissertations, herbicide,"2,4,5-T", mesquite community, also SEE <Prosopis>, Prosopis, bird population, Prosopis, brush control, theses, thesis
AbstractThis study dealt with the effects that brush control, by aerial applications of 2,4,5-T (2,4,5-Trichlorophenoxy acetic acid) had on indigenous bird populations in a mesquite community in southern New Mexico. Vegetation comparisons indicate that the mesquite was killed more completely in the duny areas than in the flat areas. Treatment effects on bird populations were examined via the parameters of species richness, dominance composition, diversity, activity, and total numbers. Species richness was greater in the unsprayed area in the duny subtype, but was approximately equal in sprayed and unsprayed areas in the flats. Dominance composition differed little between treatment areas. In 1979, three species were restricted to the duny subtype, but only one species was restricted to the unsprayed portion of this subtype. In 1980, only one species was restricted to the duny subtype. The evidence for an effect on bird diversity was weak, but may indicate a lower diversity in the sprayed duny mesquite. Activity was lower in the sprayed duny and the sprayed flat mesquite areas as compared to their respective unsprayed areas in 1979, but only in the sprayed duny area in 1980. Based on total numbers observed for each species, the mesquite control had a detrimental effect on eight species; however, five species may have benefited by mesquite control. In conclusion, it appears that mesquite control has a detrimental effect on populations of some bird species. These differences are more pronounced in the first year of study, possibly because of the mesquite regrowth which occurred the following year.